THE MAGAZINE OF THE GLOBAL BBR NETWORK OF EXPERTS

Edition 10 | 2016

DURABILITY AS
A DELIVERABLE
BBR technology & expertise
delivers durable infrastructure

ELECTRICALLY
ISOLATED
PT TENDONS
Launch of new BBR technology

GATEWAY TO SOUTH
EASTERN EUROPE
New passenger terminal at Zagreb Airport

OPTIMIZED
BRIDGE
CONSTRUCTION
New guidelines encourage innovation in Norway

VOYAGE OF DISCOVERY
Excellence in BBR stay cable technology
for Polands Rzeszw Bridge

www.bbrnetwork.com

The BBR Network is recognized as the leading group of specialized

engineering contractors in the field of post-tensioning, stay cable and
related construction engineering. The innovation and technical excellence,
brought together in 1944 by its three Swiss founders Antonio Brandestini,
Max Birkenmaier and Mirko Robin Ros continues, more than 70 years
later, in that same ethos and enterprising style.
From its Technical Headquarters and Business Development Centre in
Switzerland, the BBR Network reaches out around the globe and has at its
disposal some of the most talented engineers and technicians, as well as
the very latest internationally approved technology.
THE GLOBAL BBR NETWORK
Within the Global BBR Network, established traditions and strong local
roots are combined with the latest thinking and leading edge technology.
BBR grants each local BBR Network Member access to the latest technical
knowledge and resources and facilitates the exchange of information on
a broad scale and within international partnering alliances. Such global
alliances and co-operations create local competitive advantages in dealing
with, for example, efficient tendering, availability of specialists and
specialized equipment or transfer of technical know-how.
ACTIVITIES OF THE NETWORK
All BBR Network Members are well-respected within their local business
communities and have built strong connections in their respective regions.
They are all structured differently to suit the local market and offer a
variety of construction services, in addition to the traditional core business
of post-tensioning.
BBR TECHNOLOGIES & BRANDS
BBR technologies have been applied to a vast array of different structures
such as bridges, buildings, cryogenic LNG tanks, dams, marine structures,
nuclear power stations, retaining walls, tanks, silos, towers, tunnels,
wastewater treatment plants, water reservoirs and wind farms. The BBRTM
brands and trademarks CONA, BBRV, HiAm, HiEx, DINA, SWIF,
BBR E-Trace and CONNCT are recognized worldwide.
The BBR Network has a track record of excellence and innovative
approaches with thousands of structures built using BBR technologies.
While BBRs history goes back over 70 years, the BBR Network is focused
on constructing the future with professionalism, innovation and the very
latest technology.

BBR VT International Ltd is the Technical Headquarters and Business Development Centre of the BBR
Network located in Switzerland. The shareholders of BBR VT International Ltd are: BBR Holding Ltd
(Switzerland), a subsidiary of the Tectus Group (Switzerland); KB Spennteknikk AS (Norway), BBR Polska
z o.o. (Poland) and KB Vorspann-Technik GmbH (Germany) all three are members of KB Group (Norway);
BBR Pretensados y Tecnicas Especiales PTE, S.L. (Spain), a member of the FCC Group (Spain).

02 CONNCT | EDITION 10

DELIVERING
CERTAINTY
OF OUTCOME
When embarking on any project, the thing that customers most want is certainty of outcome they want to be
sure of getting what they need. The BBR Network is always ready with the latest technology and techniques
and to work closely with the wider professional team on shaping the best and most durable construction solution.
We see more-and-more customers, such as the Norwegian roads authority
in relation to the Gulli Bridge, adopting new procurement methods which
call for value engineered construction. Meanwhile, in Australia the
construction of new post-tensioned water tanks in an extreme climate and
THE MAGAZINE OF THE GLOBAL BBR NETWORK OF EXPERTS

Edition 10 | 2016

with sandy ground conditions brought out the best of the BBR Networks
ability to innovate. It is clear that Members of the BBR Network welcome

DURABILITY AS
A DELIVERABLE
BBR technology & expertise
delivers durable infrastructure

these challenges and are ready to participate with a flexible approach

and the highest level of specialist construction advice.
The Portfolio section contains numerous further examples like the
Tamina and Almonte arch bridges and two massive bridges in Malaysia
where technical excellence and teamwork have combined to deliver great
outcomes for customers. Then there are achievements resulting from
long-term customer relationships based on mutual trust such as the
work in New Zealand for Ports of Auckland Limited. Still other successful
projects arise from the BBR Networks ability to contribute two examples

ELECTRICALLY
ISOLATED
PT TENDONS
Launch of new BBR technology

GATEWAY TO SOUTH
EASTERN EUROPE
New passenger terminal at Zagreb Airport

among many fine projects featured are the Q22 tower in Poland and the
rock anchoring work underway in Croatia. We congratulate BBR Network

OPTIMIZED
BRIDGE
CONSTRUCTION
New guidelines encourage innovation in Norway

VOYAGE OF DISCOVERY
Excellence in BBR stay cable technology
for Polands Rzeszw Bridge

Members teams all over the world for their dedication and skill.
For us, of course, one of the most exciting recent developments is the
securing of a European Technical Assessment (ETA) for the BBR VT CONA
CMI Electrically Isolated Tendon (EIT). While we have launched many new
technologies over the years, CONA CMI EIT represents a major step forward
in providing the industry with a highly advanced and durable system which

www.bbrnetwork.com

can also be monitored you can read about this in the Technology section.
Perhaps the best evidence, certainly over the last ten years, that BBR
technologies and the BBR Network bring the latest and most enduring
solutions can be found in the pages of CONNCT. Like our business, in the
last decade our magazine has grown and evolved while demonstrating the
best technology and techniques on the international market.

Marcel Poser
Chairman, BBR VT International Ltd

Jos Manuel Illescas

Vice Chairman, BBR VT International Ltd

www.bbrnetwork.com 03

CONTENTS
05

TALKING BBR
06 BUSINESS REVIEW
09 SPECIAL FEATURE:
A DECADE OF HIGHLIGHTS
12 CONFERENCE NOTES
14 NEWS HIGHLIGHTS
16 PERSPECTIVE
17

PORTFOLIO
18 IN THE SPOTLIGHT
20 BRIDGES
37 BUILDINGS
54 STAY CABLES
62 SPECIAL APPLICATIONS
70 MRR
79

TECHNOLOGY
80 RESEARCH & DEVELOPMENT
83 TECHNICAL UPDATE
86 TECHNIQUES
88 INSIGHT
91

BBR DIRECTORY

EDITORIAL, SOURCES
AND REFERENCES

EDITORIAL OFFICE
BBR VT International Ltd
Technical Headquarters and Business Development Centre
Switzerland
www.bbrnetwork.com
info@bbrnetwork.com
EDITOR
Jane Sandy
CONTRIBUTING EDITOR
Juan Maier
DESIGNER
Jenny Chillingworth
CONTRIBUTORS
Tie King Bang, Richard Blair, elimir Bodiroga, Norbert Bogensperger, Mark
Bond, Andrew Bray, Antonio Caballero, Aaron Callegari, Yeo Swee Choo, Chang
Chee Cheong, Chok Moi Chun, Yan Mung Chun, Jrg Dniker, Andrew Garton,
Martin Grob, Radwan Hamoshi, George Jacob, Kate Janikowska, Tomasz
Jendernal, Mark Kurtovich, Juan Manuel Linero, Tomislav Lopandic, Bartosz
ukijaniuk, Behzad Manshadi, Valentina Mihajlovic, John Mo, Terry Palmer,
Jan Piekarski, Thomas Richli, Chris Roost, Stig Solbjr, Roger Stables, Cezary
Sternicki, Bong Su-Fah, Vedran Tomac, Goran Tomiic, Sascha Weder, Lee
Chong Whey, Paul Wymer, Janelle Yeo.
PUBLISHER
BBR VT International Ltd
Every effort is made to ensure that the content of this edition is accurate
but the publisher accepts no responsibility for effects arising there from.
p-ISSN 1664-6606
e-ISSN 1664-6614
BBR VT International Ltd 2016
ACKNOWLEDGEMENTS, SOURCES AND REFERENCES
Front cover image: The Gulli Bridge in Norway was built to endure using
technology and expertise from the BBR Network. Photograph by Byggenytt.
Portfolio section
Optimized bridge construction: en.wikipedia.org
Gateway to South Eastern Europe: en.wikipedia.org, www.routesonline.com
New gateway for Mersey: Wikipedia.en, www.merseygateway.co.uk
UKs largest & most complex project: tfl.gov.uk, www.bbc.co.uk
Anchoring for agriculture: www.voda.hr
Technology section
Bernhard Elsener & Markus Bchler, Quality Control and Monitoring of
electrically isolated post-tensioning tendons in bridges, Eidgenssisches
Departement fr Umwelt, Verkehr, Energie und Kommunikation UVEK,
Bundesamt fr Strassen, 2011.
Bernhard Elsener, Monitoring of electrical isolated post-tensioning tendons,
Tailor Made Concrete Structures-Walraven & Stoelhorst (Eds), Taylor & Francis
Group, London, ISBN 978-0-415-47535-8, 2008.
Tarun R. Naik, F. ASCE, Sustainability of concrete construction, Practice
Periodical on Structural Design and Construction, pp:99-103, ASCE 2008.
Dane Miller, Jeung-Hwan Doh & Tim Peters, Environmental Impact
Assessment of Post Tensioned and Conventional Reinforced Concrete Slab
Design, New Developments in Structural Engineering and Construction,
Yazdani, S and Singh A. (Eds), ISEC-7, Honolulu, 2013.
This paper is manufactured with 15% recycled fibre, FSC certified.
All pulps used are Elemental Chlorine Free (EFC) and the manufacturing mill
is accredited with the ISO14001 standard for environmental management.
Vegetable based inks have been used and 85% of all waste associated with
this product has been recycled.

04 CONNCT | EDITION 10

TALKING BBR
06 DURABILITY AS A DELIVERABLE
BBR VT International CEO Antonio
Caballero presents thoughts on
durability as a deliverable while
reviewing the business
09 A DECADE OF HIGHLIGHTS
on the 10th Anniversary of
CONNCT, Editor Jane Sandy
talks about its history and
some highlights
12 CONFERENCE NOTES
observations on a particularly
lively conference in Bangkok,
by Cesary Sternicki
14 OUT-AND-ABOUT WITH THE
BBR NETWORK
selection of international events,
happenings and news over the
last 12 months
16 PERSPECTIVE
leading specialist construction
engineering consultant, Dr Hermann
Weiher, shares his vision on the
future of construction technology

www.bbrnetwork.com 05

TALKING BBR

BUSINESS REVIEW
Reflections & outlook from BBR VT Internationals CEO

DURABILITY AS
A DELIVERABLE
Durability is a topic which occupies the minds of many people the world over. Dictionary definitions include the
words able to resist wear or decay well and lasting or enduring. In this context, the period of time during which
the expected performance must be delivered is also a critical factor. BBR VT International Ltds CEO Antonio
Caballero explores these and further aspects of durability with particular relevance to the construction industry.

Some ancient structures for example

Right technology

Fit-for-purpose

from the early Greek, Roman or Egyptian

Durability is key for sustainability a

Although BBRs three founders were

civilizations have shown extraordinary

durable structure will deliver the expected

certainly far-sighted, could it be possible

durability over the centuries. While we

performance over its entire service life

that they foresaw some of todays

may admire and wonder at these

with minimal or no maintenance.

infrastructure challenges as they developed

achievements, nowadays structures are

Monitoring is however required to preserve

their technology back in the 1940s? Right

designed and built under extreme cost

the predictability and, thus, minimize time

from the start, it has been part of our culture

pressure and subjected to strict

taken to react to any maintenance issues

to invest heavily in Research & Development

environmental regulations. Most recently

both of which influence the minimum

to ensure that we can offer the right

and due to environmental challenges

safety standards for users.

construction technology for the application.

new structures must also be more eco-

Although there are no objective ways to

Our R&D process includes thorough

friendly and sustainable.

measure sustainability, it is possible to

independent testing of our technology, not

In the modern era, approaches to

measure and monitor durability. The recently

only to meet current standards but also to

construction have also changed. The

introduced BBR VT CONA CMI Electrically

satisfy our own internal benchmarks which

amount of data to which we all now have

Isolated Tendon system (CONA CMI EIT)

are very often more stringent and have

access has grown exponentially with the

permits the indirect measurement of

been specially developed to ensure that it

continuous development of new

durability of post-tensioning tendons

is fit-for-purpose.

information technologies. We can record,

through the evaluation of electrical

BBR post-tensioning and stay cable

analyze and exploit detailed information

resistivity, allowing verification of the

technologies have a proven track record for

in ways that people just a couple of

integrity of the plastic duct, also whether

durability. For example, both De Molenbrug

generations ago would never have

there has been ingress of water and/or

bridge in the Netherlands and the now iconic

believed possible. Today, infrastructure is

aggressive chlorides all elements which

Sydney Tower in Australia have recently

planned thoroughly it is specified and

contribute to the shortening of the life

had thorough health checks and, even

built to be easily maintained or adapted to

expectancy of the structure. Measurements

after more than 40 years service, the BBR

changed usage. This is where BBR comes

can be made during construction and during

stay cable systems are still delivering the

into the picture.

the service life of the structure which will

expected performance and serviceability.

facilitate early detection of any aggressive

element which may be compromising the
durability of the tendon. You can read more
about CONA CMI EIT from page 80 onwards.

06 CONNCT | EDITION 10

TALKING BBR

www.bbrnetwork.com 07

TALKING BBR

Quality performance

made impressively detailed presentations

It is a well known fact that a whole chain

on major projects in their countries to their

is only as strong as the weakest link.

spellbound international BBR colleagues.

Therefore ensuring quality in all the

Quality of manufacture is also fundamental

processes involved from design,

to durability and performance this is

production, transport, storage, installation

where our well-established network of

and so on is crucial. Every single process

component manufacturers comes in.

involved in the project and every single

They all have specialized and plentiful

element is important and deserves the

know-how and are regularly audited by

appropriate level of attention to achieve

independent certification bodies.

the right level of quality.

The system of attestation of conformity,

Quality has a direct impact on durability

having been established in our post-

and sustainability of systems and products.

tensioning systems as a part of the CE

Therefore, having a solid, proven and

requirements, is currently in place for all

adaptable quality management system

systems and components not only PT

(QMS) in place is a must. The QMS must

and has become a standard for supply

cover all aspects from factory production

to any part of the world. Basically, we

control right up to installation on site.

commoditized and globalized the

As well as our development and testing

state-of-the-art European standards.

processes, the BBR Factory Control

Naturally, much credit must also go to the

Process (FPC) enables full bi-directional

owners, architects and designers of

traceability of each single component from

structures for their foresight in actively

raw material to project execution. On page

choosing to build using the latest

83, you can read about the latest upgrades

construction technology. By doing so, they

to our well-established internet trading and

are creating more durable structures and

QA platform, BBR E-Trace, which supports

investing not only in strength and durability,

our FPC process.

but also low maintenance, flexibility and

protecting the environment. Of course, in

People & technology

the long term they are saving money too.

Today, the construction industry like

1 De Molenbrug on the River Ijssel in the

Netherlands and the iconic Sydney Tower
in Australia respectively feature BBR HiAm
parallel wire and BBR DINA stay cables
and the BBR technology has been proven
to be functioning well, even after over 40
years service.

08 CONNCT | EDITION 10

most other industries has developed

Asset management

to a high level of specialization among all

Just as we humans seek medical check-ups

stakeholders and therefore a high level

and preventative medicines from our health

of atomization. Thus, another important

professionals, a structure also needs some

factor is continuous training and fluent

monitoring, control and occasionally some

communication between all the

treatment or repairs to achieve its

stakeholders the producers who

planned service life. Of course, the owners

manufacture the systems, the designers

are the main party in this and must work

who need to specify the right system,

together with specialists from our Network

PT specialist who must have the right

who will provide the right technical

knowledge and so forth.

assistance and deliver the most optimal

Correct installation including appropriate

solution for the continued healthy and safe

grouting procedures is crucial to the

operation of their structural assets.

long-term reliable performance of BBR

Durability is part of the value judgment that

technology and this is why we also invest

people make when they purchase something

heavily in education, training and

the value lies in the characteristics of the

knowledge exchange. Engineers and

item and its purpose. At BBR, our business

managers within the BBR Network are

has always been about listening to what

great networkers and theres nothing that

customers want and delivering the best

they enjoy more than sharing experiences

technical support and solutions for

visiting each others sites, over the

structural resilience our approach is as

telephone or a quiet drink. The pride with

sustainable as the structures created with

which they view their work is always evident

our technology.

for example, at our recent training session

Dr. Antonio Caballero

in Amsterdam, BBR Network Members

TALKING BBR

TENTH ANNIVERSARY OF CONNCT MAGAZINE

Charting ten years of BBR Network achievements

A DECADE OF
HIGHLIGHTS
The BBR Networks annual magazine CONNCT is celebrating its tenth birthday this
year. BBR HQ has invited Jane Sandy, the magazines editor, to share the background to
how this now long-running magazine came about and some reflections about the culture
and achievements of the BBR Network, as shown through the pages of CONNCT
containing reports about over 600 projects over the past ten years.

www.bbrnetwork.com 09

TALKING BBR

STAY
CABLES
BRIDGES

LEGENDARY BBR STAY CABLE TECHNOLOGY

Staying power

ince the early days of post-tensioning, BBR Stay

Cable Technology has been recognised as the
most advanced and most reliable system on the
market. BBR is not only the godfather and inventor
of high fatigue resistant wire stay cables, but has also
pioneered, invented and constructed the worlds first
project using modern parallel strand stay cables and has
invented and successfully applied the worlds first
carbon stay cables.

CONNCT has been a ten year-long

adventure which has metaphorically taken
me around the world to explore some of the

Today, BBR Stay Cable Technology can

be used for the following applications:

most exciting construction engineering

achievements anyone could imagine.

Not only this, I have enjoyed some excellent
company along the way there is nothing
I

finer than working with people at the top of

their game in this case the PT Specialists

    have been

built in rapidly increasing numbers
since 1950 and have been found to
be especially economical for medium
to long-span bridges from 100 to
1000m, where technical and
economic arguments dictate this
solution. For smaller bridges, other
parameters may be decisive for the
choice of a cable stayed solution
such as reduced depth of deck,
construction methodology and
aesthetics. BBR Stay Cable Technology
is the ideal choice for the cables.
    have been used
since ancient times and nowadays
suspension bridges with spans close

to 2000m have been built. BBR

Technology can be used for the main
suspension cables as well as for the
hangers.
 of grandstands, stadiums,
aircraft hangars and other lightweight
wide-span structures are an ideal
application for BBR Stay Cable
Technology.

 for communication facilities,
chimneys and antennas, as well as
wind power stations can be
stabilised using BBR Stay Cable
Technology.

R&D & QUALITY ASSURANCE

Extensive research, testing and
development efforts place BBR at the
forefront in the field of post-tensioning
and stay cable applications. BBR also

In 1971, the Olympic Stadium in Munich, Germany with its cable supported membrane
roof structure hosted the Games in 1972. Until 2005, the stadium was home to
Bayern Munich FC, one of the world's premier soccer clubs and record title holder in
Germany. The 488 stay cables are comprised of parallel strands, with which BBR
pioneered the usage of High Amplitude fatigue resistant strand stay cables. Photos: Kevin
Lazarz

within the BBR Network. Over the past

decade, I have also found myself sharing
their passion for a challenge and the small

In 1961, the first bridge to be built using parallel wire cables was the pedestrian Schillersteg Bridge across the Schillerstrasse in Stuttgart, Germany.

offers a variety of solutions to counter cable

vibration such as the BBR Square Damper and
cable surface treatments. To assure the highest
quality product, all of the system components are
subjected to the most stringent testing and
Quality Assurance procedures, based on
internationally recognised codes and
recommendations.

SUPERIOR FATIGUE & STATIC

RESISTANCE
For many years, the minimum fatigue test strength
for stay cable systems has been 160N/mm2 (PTI).
More recently, a stress range of 200N/mm2 for
2x106 load cycles in combination with angular
rotations at the anchorages has been adopted
and is now specified by most codes and
recommendations. BBR Stay Cable Technology
had already fulfilled requirements for such fatigue
testing decades before these provisions were
considered to be state-of-the-art!


   
    
Standard BBR Wire Cables are composed of 7mm diameter wires of low
relaxation grade, with a minimum guaranteed ultimate tensile stress of 1670 or
1770N/mm2. Typically, the wire bundle is galvanized and covered with a thick-walled
UV-resistant HDPE pipe, and the voids in the pipe are filled with a flexible
corrosion protection compound.

    

Today, standard BBR Strand Cables are composed of galvanized, waxed and PEcoated 0.62" (15.7mm) strands of low relaxation grade, with a minimum
guaranteed ultimate tensile stress of 1770N/mm2 or 1860N/mm2 inside a UVResistant HDPE Stay Pipe.


   

The BBR Carbon Stay Cables consist of CFRP (Carbon Fibre Reinforced Polymer)
wires of 5mm diameter covered with thick-walled UV-resistant HDPE pipe.

DECADES AHEAD
Whereas many cable suppliers built their first
major cable supported structure in the late 1970s
and early 1980s, BBR Stay Cable Technology was
used for the first time in the late 1950s and, since
those days, BBR Stay Cable Technology has been
applied to over 300 major structures around the
world including the breathtaking Tatara Bridge in
Japan, which has the longest main span to have
been constructed in the 20th Century.
G

The Strchenbrcke in Wintherthur, Switzerland

crossing the major east-west axis of the Swiss
Federal Railway Network was the world's first
bridge to be constructed using carbon stay cable
technology.

selection of highlights shown here have

34 CONNCT

CONNCT 35

been particularly inspiring.

2007
The first edition of CONNCT, back in 2007, carried a memorable article reflecting on BBRs achievement in the
development of stay cable technology. They were the first to use wire stay cables in 1958, the first to use strand stay
cables 10 years later and the first to use carbon stay cables in 1994. This article is memorable because, through
subsequent editions of the magazine, we can see this same pioneering approach being applied to the development
of still further technology and many projects.

SPORTS ARENA, DZ, POLAND

BUILDINGS

roof ring, there is a huge gutter

made of prefabricated concrete
elements permanently fixed to
the ring structure. The box is
strengthened with cross-walls every
eight meters, where steel roof
girders are supported on the ring.

Ring of confidence
The City of dz Office had
decided to build a new 10,000-seat
sporting and entertainment venue
within the complex of one of the
citys sports clubs dzki Klub
Sportowy. The arena is adjacent to
the existing football stadium which
is home to the former Polish
football league champions.

8*:;8:767The box-shaped concrete structure

of the ring is post tensioned with
28 BBR CONA 1906 internal
tendons (72 t of strands) and 88
BBR CONA 706 external tendons
(12 t of strands).
The internal tendons spaced
equally on the cross-section of the
ring, with seven tendons in one
section take horizontal forces
from main loads (dead loads), while
external tendons placed in
appropriate numbers wherever
needed, as dictated by the bending
moments diagram take bending
moments from excess loads.
Because the ring is so very long, it
is divided into four quarters
resulting in an internal tendon
length of around 120 m. The
internal tendons are anchored in
four specially designed anchor
blocks inside the ring. The external
tendons are anchored in cross-walls
the longest tendon was some
25 m long.

8*:;20(07!
The round sports hall has a
concrete structure with a steel roof
and steel cover wall. The arena level
is approximately six meters below
the surrounding ground level. The
hall is surrounded with a type of
moat, over which there are bridges
leading to the entrances. Inside, will
be the main arena plus all the usual
facilities and a full size basketball
court.
The roof of this huge arena is
supported by a post-tensioned
concrete ring an icon of modern
engineering techniques, constructed
by BBR Polska.

8*:;2:3907!;--8:'
The bearing system involved the installation of 64
elastomeric bearings and 16 specially designed
steel directional slide bearings. The system has a
set of five bearings on each column four
elastomeric slide bearings and one steel guided
slide bearing. The elastomeric bearings transfer
vertical load from the ring to the column, allowing
movement in all directions. Meanwhile, the steel
guided bearings take horizontal forces and allow
radial movement blocking forces from any other
direction to prevent unequal deformation of the
ring.
The ring structure was concreted in stages first
the bottom slab, then side walls, next cross-walls
and lastly, the top slab. Strands were pushed into
ducts after the concreting process was finished.

BBR POLSKA COMPLETED THE

WORK WITH A HIGH STANDARD
OF PROFESSIONALISM AND TO A
HIGH TECHNICAL STANDARD ....
.08;6$;;6$$0.:

8*:;8;-:
:7.:

to stress all internal tendons from both ends. This

all resulted in much time and effort being spent
on moving and preparing the stressing sets and
operations.
The stressing sequence of the external tendons
was also developed so that equal stressing force
was applied to the structure.
All the work inside the ring box was carried out
by hand it was not possible to use a crane as
there were no openings in the top of the ring
structure and cross-walls precluded the use of a
small crane to operate inside the ring box.

The post-tensioning sequence assumed that first

all internal tendons were tensioned. Then, we
started tensioning all external tendons. The round
shape of the structure meant that it was
extremely important to apply stressing force
equally around the perimeter, as well as on the
cross-section of the ring. Therefore, we used two
stressing sets which operated on opposite sides
of the ring.
Due to high values of loss of stressing force
because of friction on curves it was necessary

The 25 m span post tensioned beam supports a

floor slab. The development of a basketball court
meant that a few columns were replaced with
hangers attached to the beam originally these
were support only to the girders for the arena
seating. The high loads and low acceptable
deflection indicated that a PT beam was the only
solution. The beam was post tensioned with six
BBR VT CONA CMI 1206 tendons (3 t of strands).

8*:;2:3'

This extremely demanding posttensioning task was finished in May

2008 two weeks ahead of
schedule. This superb result is due
largely to the excellent working
relationships which developed
between the BBR Polska team and
the main contractor.
Investor satisfaction is a priority for
us and the reference letter
received from our client, the City
of dz Office, was a great reward
for our efforts. This was the first
time that BBR Polska had executed
such a challenging and unusual
stressing operation we are
looking forward to post-tensioning
another stadium soon!
G

BUILDINGS

229;1", the BBR Network member in Poland has

completed an extraordinary post-tensioning task. Site Engineer,
M. Sc. Bartosz ukijaniuk explains how a massive post-tensioned
roof ring needed to support the dome-shaped roof of the new
sports arena in dz was constructed.

$,/";;$+)#54"
354&,;,54,
14,500 m2
354&,;1#4 385,000 m3
354&,;5,+#"
70 m
354&,; 4+) /
36 m
14;511;+,4/45
140 m
%4+) /;1;511;"/5#/#54
1,500 t
911;5+&); 4+) /
3.7 m (inner 2.5 m)
911;5+&);+/
4.7 m (inner 3.2 m)
911;5+&);4&)/ 440 m

8*:;290:$
Our brief was to evaluate the
detailed design for tendon layout
and the bearing system for the roof
ring, as well as for carrying out the
work which included delivery of
stressing system components, plus
the complex post-tensioning of the
roof ring and delivery and
installation of the bearings. In
addition, we undertook further
complex works for a posttensioned beam.

TEAM & TECHNOLOGY

6%7:9 City of dz Office
.67893.869 Skanska S.A.
:-0!7:9 ATJ Archikekci / KiP Sp. z o.o.
8:.*76(6!
BBR CONA internal
BBR CONA external
BBR VT CONA CMI internal
229;7:8%69;':'2:9
BBR Polska Sp. z o.o. (Poland)

8*:;907!
The roof support ring rests on 16
concrete columns (spaced every
26 m) at around 15 m above arena
level. It is a massive concrete
structure which, in cross-section, is
a concrete box shaped like a
leaning rectangle with 0.5 m thick
walls. On the outer side of the

 CONNCT

CONNCT 

CONNCT 

LANDMARK STRUCTURES

SYDNEY TOWER, AUSTRALIA

lmost 30 years after it was opened, Robert Freedman of BBR

Network member .50%#5%0617.354'3 reflects on the construction
and enduring qualities of the Sydney Tower which now stands
together with the Sydney Opera House and the legendary Sydney Harbour
Bridge as one of the famous city center landmarks.

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new heights
Originally constructed as the defining architectural
feature of the Centrepoint retail and commercial
development, the tower is now Sydneys tallest
structure. The 309 m high tower was opened in
August 1981 as a communications tower and
tourist facility. Like its neighbor across the Tasman
Sea in Auckland, the Sydney Tower is a focal point
for all who live in or visit the city

of five levels accommodating two

revolving restaurants and two
observation decks.
The steel shaft is 6.75 m overall
diameter and consists of 28
columns spaced equally around its
perimeter.

)&.&"7+,7.
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The 56 stay cables are formed into

a hyperboloid of revolution in
mathematics, a hyperboloid is a
quadric, a type of surface in three
dimensions in two groups, each
of 28 straight cables. The cables
are anchored to the roof of the
building in a circle of 37.2 m
diameter. From here, the BBR
cables each made up of 235
galvanized wires of 7 mm diameter
rise through an intermediate
coupling point at 90 m, tangentially
to a neck connector on the shaft
140 m above the roof. The cables,
which lead from here to the turret
anchorage at 184 m, each comprise
55 wires of 7 mm diameter. In
plan, the cables appear similar to
spokes of a huge bicycle wheel
this arrangement assists in resisting
torsional moments on the tower.
The cables were manufactured in
Structural Systems Melbourne
factory and transported to site on
timber drums for uncoiling and

.+)7) !,.

When it opened in September 1981, Sydney
Tower was the fourth tallest building in the world.
Before the tower was built, the maximum
allowable height of a Sydney building was 279 m
to allow for the harbours flying boats that were
popular before the modern jet era.
The maximum allowable height was lifted to
305 m with the approval of Sydney Tower. Sydney
Tower still sets the height limit for Sydney
buildings today.

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 CONNCT

10 CONNCT | EDITION 10

2009
Architectural freedom is one of the great
things that BBR technologies provide and
even encourage making the infrastructure
we use more functional as well as attractive.
In CONNCT 2010, the work of BBR Polska
on the Lodz Arena which required a
post-tensioned ring beam to support the
domed roof is a splendid example of what
can be achieved.

The cost of building Sydney Tower was A$ 36

million one third the cost of the Sydney Opera
House a huge amount at the time.
Construction of the Centrepoint Tower now
officially known as the Sydney Tower began in
1975. Its unique supporting net structure,
composed of BBR DINA stay cables, sets it apart
from the crowd.
This project involved the erection of a steel tower
which rose 230 m above the roof of the 12-level
office building in the centre of Sydney, Australia. Its
shaft is stayed by a system of BBR parallel-wire
prestressing cables. The tower is topped by a turret

installation. Stressing was carried out in two

stages at night to reduce the transversing effects
of the sun on the cables during daylight hours.
The weathered effect on the structure is caused
by special alloying elements which react with the
air to form a dense tight oxide film to protect the
steel from corrosion. The appearance, texture and
maturity of the weathered steels patina depends
upon three primary natural factors time, the
degree of exposure and atmospheric
environment. With time, the oxide coating
changes from a rusty red-orange to a dark
purple-brown.
Since it opened, Sydney Tower has welcomed
more than 17 million visitors or four times the
population of Sydney!

+,7 !+&)+,7&+",..7)!!,",

One of the citys annual highlights is The Sydney
Tower Run-Up a staggering 1504-step
endurance race up the stairs of the Sydneys
highest building Sydney Tower. All ages and
types of people take part in this now wellestablished event in the Sydney calendar
The 2008 Tower Run-Up, held in support of The
Heart Foundation, marked the 16th time that
the event had been held and 290 competitors
lined up to take the challenge. The winner
completed the challenge in just seven minutes
49 seconds. Both he and the fastest female
runner have won the opportunity to take their
step-scaling skills to the US with the major prize
of return airfares to New York to take part in
the annual race up the stairs of the 86-storey
Empire State Building in 2009.
G
CONNCT 

2009
This article from CONNCT 2009 about construction
of the Sydney Tower using BBR DINA stay cables as the
unique supporting net structure, is a particular favorite.
Not only did it require innovation during its construction
some 40 years ago, but also quite recent engineering
inspection revealed that the BBR technology is still
performing well today.

TALKING BBR

PORTFOLIO STAY CABLES

2013
The feature in CONNCT 2013 about the Danube Bridge 2
now the New Europe Bridge over the River Danube between
Bulgaria and Romania stands out from the crowd. It was a very
interesting and comprehensive account of how Spanish BBR
Network Member, BBR PTE installed 208 BBR HiAm CONA
stay cables, using the then new BBR HiEx CONA Saddles, as
well as BBR VT CONA CMI post-tensioning.

PORTFOLIO STAY CABLES

DANUBE BRIDGE 2, VIDIN-CALAFAT, BULGARIA & ROMANIA

Major post-tensioning and stay cable bridge construction featuring first use of BBR HiEx CONA Saddles

WALTZING
OVER THE
DANUBE

The BBR Network construction team working on the new Vidin-Calafat

Bridge has performed a finely-tuned sequence of maneuvers, worthy of any
grand ball, to deliver an innovative and massive project. Also known as
Danube Bridge 2, the new structure is a road and railway bridge connecting
the cities of Calafat and Vidin in Romania and Bulgaria respectively and is
the second bridge spanning the River Danube between these two countries.
It forms part of the IV Pan-European Corridor that will allow direct motorway
access between Dresden in Germany and Turkeys largest city, Istanbul.
Diana Cobos, Project Manager on site from BBR PTE the Spanish-based
BBR Network Member describes this marathon of a project.

The Vidin-Calafat Bridge has three distinct

one of 124m and one of 115m all of which

components a low level rail Approach

are sustained by stay cables.

Viaduct with 40m long spans on the

Each of these distinct components involved

Bulgarian river bank, a single-cell box girder

specific construction methods and their

bridge over the Main Navigation Channel

own special technical challenges. For an

and a viaduct over the Non-Navigable

overall impression of the scale of project,

Channel. The latter is 612m long and has

it might help to know that we have installed

eight spans, of which all but the first are

2,100t of BBR VT CONA CMI tendons

80m long. The Main Navigation Channel

most of them 31 strands plus 65,000km

bridge has five spans three spans of 180m,

of plastic duct and 208 stay cables.

Compelling event
The compelling event that drove production
of the first issue of CONNCT was the
massive investment that BBR VT
1

56 CONNCT | EDITION 7

www.bbrnetwork.com 57

International was making in developing the

range of all-new BBR VT CONA CMX

2014
This article from the 2014 edition of CONNCT shows another example of how BBR Network Members overcome the
trickiest of construction challenges. The Keppel Viaduct in Singapore was being extended, yet traffic flows on this vital
route were maintained while construction work was in progress. To accommodate the project needs, among other
measures the BBR team scheduled night-working and just-in-time material deliveries because of the site constraints.
PORTFOLIO BRIDGES

PORTFOLIO BRIDGES

post-tensioning technology and securing

European Technical Approval for each new
system. With this, also came a change in
BBRs business model and the BBR
Network was born. The mission, then as now,
was to communicate news, deliver technical

KEPPEL VIADUCT, SINGAPORE

Carriageway widening

...the live traffic

information and share achievements on an

environment and
limitations imposed

UNCLOGGING
THE BOTTLENECK

by existing structures
and construction a
The Keppel Viaduct was constructed as part

Post-tensioned extension

of the Ayer Rajah Expressway (AYE) from

To accommodate the widening of deck

1983 to 1988. At that time, it was the longest

slabs at both ends of the viaduct, the

vehicular viaduct in Singapore measuring

design proposes an extension of the

2.2km in length and a crucial traffic

existing crossbeam, such that additional

corridor for east-west commuters as it

prestressed precast beams can then be

The Keppel Viaduct an awkward bottleneck on Singapores Ayer Rajah Expressway is being

connects the East Coast Park Expressway

launched upon the new extended structure.

upgraded from a dual three lane carriageway to a dual four lane carriageway. Singapore-based

(ECP) and AYE. Both the ECP and AYE had

For this, a combination of utilizing two

BBR Construction Systems Project Manager, Tan Yeow Koon describes the projects history and
explains how existing site conditions make both the design and construction a major challenge.

international scale with CONNCT

made both the design

been upgraded over the years into major

existing spare PT ducts and installation of

dual four or five lane expressways, whereas

new PT bars was proposed.

the Keppel Viaduct was still only carrying a

To allow the existing crossbeams to carry

dual three lane carriageway. So, when the

the extra loads, new secondary crossbeams

Land Transport Authority (LTA) finalized the

are to be constructed immediately beneath

plan to re-route the ECP-AYE connection

four of the existing eight beams. The new

with a new expressway the Marina Coastal

crossbeams are 25m in length, with a

Expressway (MCE) a study was carried

cantilevered arm of 9m. For this element

out to look into the bottleneck caused by the

of the work, a total of 10 post-tensioning

Keppel Viaduct. While the LTAs objective to

tendons have been proposed, each having

upgrade the dual three lane carriageway into

38 strands of 12.9mm diameter and each

a dual four lane carriageway looked simple

tendon will ultimately have to be stressed

on paper, the live traffic environment and

to 5,320kN.

major challenge.

magazine as a cornerstone of that strategy.

Incidentally, the unusual name of the
magazine was chosen to reflect one of BBRs
best known brands CONA and also the

1 Singapores Keppel Viaduct, once celebrated

for being the longest in the country, had
become a bottleneck on the busy east-west
commuter route.
2 Site conditions and constraints dictated the
use of a T-shaped cantilevered steel truss
tower, designed in modular segments, for
construction of the crossbeams.
3 The completed crossbeams of the Keppel
Viaduct, extended to accommodate an
additional three or four longitudinal beams,
alongside the eight currently existing beams.

concept of connecting with people.

limitations imposed by existing structures

made both the design and construction a
major challenge.

Global venture

Design concept
Singapore Piling & Civil Engineering
(SPACE), one of our sister companies
within BBR Holdings Limited, was awarded

My involvement began in August 2006 when

the design and build contract by the LTA in

February 2011. SPACE drafted in an equally
well-established consultant on vehicular
bridge design YWL Engineering and the

an email from BBR VT Internationals then

first task on hand was to finalize the design

concept for the major upgrading works.
The existing crossbeams are to be extended
to accommodate an additional three or

Chief Technical Officer, Marcel Poser,

four longitudinal beams, alongside the

eight currently existing beams. To achieve
this, the designer proposed an additional
crossbeam, extension to the existing
crossbeam, new columns sandwiching

arrived in my inbox. In true BBR style, even

the existing one, plus the pile-cap resting

above the existing pile-cap with new
foundation pipes. With this design concept,
the proposed structure will be able to

this was a global collaboration my work

accommodate additional longitudinal

beams and the structural capacity of the
1

viaduct will be enhanced.

22 CONNCT | EDITION 8

www.bbrnetwork.com 23

had been recommended by an engineer

from Structural Systems (now SRG Limited)

PORTFOLIO BRIDGES

PORTFOLIO BRIDGES

in Australia, David Pash, with whom I had

worked while he was based in the UK. So, to

MRT STATIONS, PACKAGE S2, MALAYSIA

Precast crosshead construction

cut a long story short, with the help of BBR

PLATFORMS
FOR STATIONS

Network Members, the first edition of

CONNCT was created.

Construction of the first MRT line from Sungai Buloh to Kajang is currently
making good progress. Chang Chee Cheong from BBR Construction
Systems (Malaysia) offers a detailed account of how, over a busy main road,
post-tensioned precast segmental crossheads are being constructed and

Record for the future

installed for three stations on the new line.

We were appointed by Naim Engineering

Structure configuration

the nominated subcontractor for the

Each station comprises nine crossheads,

stations on the route to provide our

located in the center of the road over

specialist post-tensioning expertise for

which the rail line is being constructed.

constructing the 27 precast crossheads for

Five crossheads are being created from

the three stations within Package S2. The

the viaduct piers while the other four are

piers supporting the light rail viaduct also

being built between two viaduct crossheads.

provide the main supports crossheads

There is a 6m long cast in-situ pier segment

for the stations. While work on the viaduct

and from this, three pairs of cantilevering

continues by launching gantry above, the

precast segments are erected using the

stations below are being constructed

balanced cantilever method. The segment

concurrently to ensure readiness for track

lengths of 2.48 + 4.05 + 4.13m give a total

and equipment installation.

crosshead length of 27.3m. We are match

Since then and alongside countless other

things, CONNCT has provided the entire
BBR Network with an archive a record of

casting the segments off-site.

global achievements on which everyone

Construction of in-situ pier & first

segment pair
Post-tensioning tendon ducts are fixed on

can draw to illustrate specific experience or

profiling bar supports in the pier segment.

After casting, construction of the pier above
continues to completion and erection of the
viaduct spans by launching gantry follows,
while station works are in progress below.

track record. Like any ten year old, in many

At night, the first pair of precast segments

is erected on heavy duty scaffolds using
a mobile crane. Each segment weighing
40t is supported by four levelling and

ways CONNCT is only just beginning to

alignment jacks. A stitching gap of 175mm

is allowed to handle the difference in shear
keys between the cast in-situ segment and
the precast segment. After stitching

take its place in the world with the

concrete has gained transfer strength, the

tendons in the first pair of segments are
stressed then the heavy duty scaffolds
are removed.

30 CONNCT | EDITION 9

support and input from the BBR Network,

2

www.bbrnetwork.com 31

2015
The BBR Network's expertize in building overhead precast segmental viaducts for railways is shown to best advantage
by this article from the 2015 edition. It describes a well-organized approach towards producing the infrastructure for
stations on a new MRT line in Malaysia and the team's ability to work with other members of the wider construction
team on the project ensuring that the program is maintained.

we can be sure it will continue to grow and

develop. It has been an honor to share the
BBR journey and I look forward to further
travels with the BBR Network in the future,
through CONNCT.

www.bbrnetwork.com

11

TALKING BBR

ANNUAL BBR GLOBAL CONFERENCE, BANGKOK, THAILAND

Technical updates, networking and knowledge exchange

CONFERENCE NOTES
At the time he attended the 2015 BBR Annual Global Conference, Cezary Sternicki, now BBR HQs Head of Product
Development, had not formally joined the company. As a non-BBR family member, he explains how it was an
excellent occasion to get to know the people in advance and to begin the integration process.

While my background is in the construction

International, there followed briefings on

and civil engineering industry, the size

recent developments in Asia-Pacific

and reach of the BBR Network around the

(Thomas Richli), new technologies (Behzad

world came as a surprise. Equally

Manshadi), supply chain (Josef Lamprecht)

surprising was the discovery that just a

and marketing (Juan Maier). In the second

few people from BBR HQ were responsible

part of these sessions, it became crystal

for organizing the whole of this highly

clear to me what it is that makes the BBR

successful international event.

Network unique. All BBR Network Members

are independent business units that can

1 BBR Network delegates at the 2015 Annual

BBR Global Conference in Bangkok, Thailand.
2 Knowledge sharing was fostered in
unconventional surroundings including
a tuk-tuk race through Bangkok and
exploration of Chao Phraya River canals
on long-tailed speedboats.
3 From the technical sessions, the uniqueness
of the BBR Networks business model
became clear.
4 Captains of the winning team and runners-up
at the BBR Charity Golf Tournament shake
hands. John Mo (left) who led his team to
victory thanks John Taraldsen (right) whose
team came a close second, while Thomas
Richli (center) congratulates them both on
some excellent play.
5 Following the conference, Antonio Caballero
and Thomas Richli visited the Santisuk
Foundation with presents for the children
and donations raised through the BBR Charity
Golf Tournament.

12 CONNCT | EDITION 10

Traditional start

freely adjust to local market requirements

The conference started with the traditional

to best meet their clients expectations.

Charity Golf Tournament. This event offered

Hence, many of them are either highly

a great opportunity for BBR Network

specialized in niche construction areas or

Members to catch up with old friends and

embrace larger portions of the value chain

partners, as well as also enjoying the game

and execute general works in construction.

and supporting those in need. The beneficiary

It was valuable to learn that BBR Global

of this years fund-raising was the Santisuk

Conferences are not only about the heavy

Foundation a non-government organization

stuff and technology related topics they

that helps children from the slums of

also promote the improvement of wider

Bangkok and surrounding area.

business issues. For example, we had a

chance to participate in the workshop led

Conference themes

by Professor Narayanan from the National

Before arriving at the conference, the BBR

University of Singapore about Decision

Networks extraordinary business model

Making for Leaders. Working in small teams

was explained to me, but I only truly

on the tasks, unrelated to daily civil

understood its meaning during the technical

engineering topics, was a good opportunity

sessions. After a warm welcome from

to learn about the BBR Network from a

Antonio Caballero, the CEO of BBR VT

different perspective.

TALKING BBR

Unforgettable experience
The BBR Annual Global Conference is an

unforgettable experience in outstanding

locations, with exceptional people sharing
extraordinary experiences and approaches
Exacting agenda, relaxed evenings

to life and many, many interesting

During the day the agenda was exact to the

conversations. All of this generates some

minute and according to business etiquette,

magnetism around the BBR Network,

meanwhile the evenings had a much more

which attracts unique people to join the

relaxed atmosphere. The latter fostered

organization and stay. This magnetism

knowledge and experience sharing in

must be strong, as there are Members who

unconventional circumstances for

have been within the BBR family for more

instance, during a James-Bond-like tuk-tuk

than 50 years and their uniqueness was

BEST ARTICLE AWARD

race through the streets of Bangkok or

certainly in evidence on the last evening

Winner: KB Vorspann-Technik (Austria)

exploration of Chao Phraya River canals on

during the informal speeches and antics in

long-tail speedboats.

the hotel bar!

2015 BBR AWARD WINNERS

BBR NETWORK PROJECT OF THE YEAR

Station platforms and curved bridge for

MRT & LRT Projects, Malaysia executed
by BBR Construction Services (Malaysia)

Title: Fast turnaround for retail

customers (Shopping center
developments, Austria)
Runner up: SRG Limited (Australia)
Title: Hitting the ground running
(Paradise Dam, Australia)
Highly commended: NASA Structural
Systems LLC & Structural Systems
Middle East
Title: Bridges for reasons & seasons
(Bridges in Bahrain, Dubai & Oman)
BEST PHOTOGRAPHY AWARD

Winner: BBR Contech (New Zealand)

Title: Ground floor achievements
(Retail, distribution & dairy industry
floor slabs, New Zealand)
Runner up: Spnnteknik AB (Sweden)
Title: Strong roots (Arjang & Tanum
Wind Park projects, Sweden)
Highly commended: BBR Construction
Services (Malaysia)
Title: Fast turnaround for retail
customers (IOI City Mall, Selangor,
Malaysia)
5

www.bbrnetwork.com 13

TALKING BBR

NEWS HIGHLIGHTS
Events, celebrations and latest news

OUT-AND-ABOUT WITH
THE BBR NETWORK
In some respects, the essence of BBR technology is about creating links or
bonds and staying connected. Likewise, BBR Network activities during the
past year have mostly been focused on reaching out to various audiences
and strengthening connections.

1 The team from BBR Network Member Marwan

Alkurdi & Partners pose for a photograph in
their exhibition booth at the International
Conference and Exhibition of Mass
Construction (IEOMC) in Amman, Jordan.
2 Jrg Dniker talks with a delegate in the
BBR and Stahlton booth at the 2015 IABSE
Conference in Geneva.
3 In October 2015, BBR HQ moved into its new
offices which, or course, features floor slabs
post-tensioned with the BBR VT CONA CMF
flat system.
4 BBR HQs Juan Maier and Behzad Manshadi
at the BBR Network exhibition booth at
the Multi-Span Large Bridge Conference
in Portugal.
5 The new BBR Project Finder has been
launched, bringing detailed information about
1,000+ projects to your desktop and can be
accessed from the BBR Network website.
6 Voon Yok-Lin of BBR Malaysia makes the first
cut in the companys massive 21st Birthday
cake during celebrations in Kuala Lumpur.

14 CONNCT | EDITION 10

International conferences

Roadshow down under

The BBR Network was represented at

New Zealands major cities Auckland,

four major conferences during 2015. The

Wellington and Christchurch were locations

International Conference and Exhibition

for BBR Contechs road show in July.

of Mass Construction (IEOMC) in Amman,

BBR VT International supported the local

Jordan was held in June and BBR Network

team in their promotional activities with

Member Marwan Alkurdi & Partners had

leading design consultants and construction

an exhibition booth.

companies. Presentations included BBRs

In May, BBR Philippines sponsored the

capabilities, latest post-tensioning range

17th ASEP-IABSE International Convention

with its unique benefits, and experience

in Manilla where Chee-Cheong Chang

in bridge temporary works. Some 60

from BBR CS Malaysia and Thomas Richli

engineers attended the sessions.

from BBR HQ submitted and presented a

technical paper about efficient bridge

Coming of age for BBR Malaysia

construction techniques. BBR also placed

On 12th April 2015, BBR Malaysia celebrated

an exhibition booth at the Multi-Span

their 21st Anniversary at a large function at

Large Bridge Conference in Porto, Portugal

Sunway Pyramid Resort Hotel attended by

which was attended by over 400 delegates

staff and guests. During the evening, 49

from around the world from both academia

long-serving staff with a total of 645 years

and industry.

service between them were recognized

Meanwhile, in September, BBR and

with special awards. To complete the

Stahlton hosted a booth at the 2015

formal celebrations, Managing Director

International Association for Bridge and

Voon Yok-Lin was invited to cut a giant

Structural Engineering (IABSE) Conference

birthday cake and festivities continued late

in Geneva.

into the night.

TALKING BBR

New BBR HQ

Social media

BBR Project Finder

In the middle of October, BBR VT

In response to the changing trends of how

The new BBR Project Finder has been

International opened the doors to its new

companies interact and engage with their

launched and brings detailed information

offices and moved in. The BBR HQ team

most valued customers, staff and

about 1,000+ projects from within the

is now operating from purpose-built

professional associates, BBR has now

massive BBR portfolio to within easy

modern accommodation and happy in

established a social media presence. The

reach. The Project Finder can be accessed

the knowledge that there are floor slabs

BBR Network is now on Facebook, LinkedIn,

from the BBR Network website, by clicking

post-tensioned with the BBR VT CONA CMF

Google+ and YouTube. Also, BBR news is

on the Project Finder tab, or directly at

flat system both above and below them!

now available through an RSS Feed from the

pf.bbrnetwork.com.

The completion of this new office block

BBR Network website by subscribing to

Information in this valuable reference

which houses sister company Proceq too,

our newsfeed, you will ensure that you are

database may be viewed using a series of

also completes a significant investment by

always up to date with our latest news and

simple selection tools and resulting data on

major shareholder Tectus AG.

announcements. All media can be accessed

individual projects is also cross-referenced

from links at the footer of our website.

to articles in CONNCT magazine and

external sources. Once your selection is

www.bbrnetwork.com

made, you can even download a handy

reference list in pdf format.
More-and-more project details are being
added on a continuous basis and, over
coming months, we will be extending the
functionality of the Project Finder with a
number of new features.

www.bbrnetwork.com 15

TALKING BBR

PERSPECTIVE
Development in bridge construction technology

EVOLUTIONARY
STRENGTH
Dr.-Ing. Dipl.-Kfm. Hermann Weiher is the founder and owner of Munich-based consulting engineering firm matrics
engineering GmbH and his specialist area of expertize is bridges. Having completed a doctoral degree in the field
of prestressed concrete, his work has included several years as research assistant with the Chair of Concrete
Construction at TU Munich. Meanwhile, Dr. Weiher is an active member of several national and international
committees within fib and IABSE. For this edition of CONNCT, he shares his views on how bridge construction
technology is evolving even within an environment surrounded by regulatory requirements.

The world of construction today is largely

Recently, in the USA in Florida we

bridges, as the complete structure will be

controlled by regulations and guidelines

have seen a governmental shift in bridge

strengthened by its application. There are

aimed at ensuring a structure is built safely

construction technology towards external

relatively few regulations in this area, so

and in a way which ensures its effective

post-tensioning using strands protected

perhaps we will see some innovation here

performance in line with design and service

with grease or wax and now the industry

over coming years.

objectives. This means there has to be a

is trying to adapt. There was a similar

The next step is going to come with the

high degree of conformity in the

situation in Germany in the 1990s when

arrival of extradosed bridges these are

technologies applied to allow comparisons

the government moved away from

very popular in the Japanese market, which

to be made by purchasers.

installing post-tensioning in the webs

was the first to adopt this type of bridge

because of difficulties with concrete

construction. It is an ideal method for

Regulatory developments

placement and also issues with corrosion.

dealing with special span lengths and the

It was in Germany, back in the 1950s, that

Thus, innovation is largely driven by

shape of valleys. These projects literally

work began on developing a new code for

governments who like to have a choice of

play to the strengths of post-tensioning

post-tensioned bridges the first of these

suppliers offering broadly similar

prestressing steel is very strong compared

was DIN 4227 which was published in

technologies and systems. In this

to ordinary steel and the anchorage delivers

October 1953. Obviously, this was early in

environment, companies are not prepared

95% of the strength of the post-tensioning

the industrys experience of post-tensioning

to risk creating an entirely new technology

tendon. Of course, corrosion protection in

and therefore it is not surprising that the

and bearing the financial and administrative

this situation is crucial.

code underwent much revision as bridge

burdens this implies without guaranteed

The advent of ultra high performance

construction continued. By the 1980s, we

returns on their investment.

concrete may also be a game changer.

So far, we have only seen it used for

had quite conservative building codes and

these were further consolidated with the

New applications

single pilot projects or fairly short span

arrival of Eurocodes.

We have, however, seen a change in the

prefabricated bridges.

This has led, certainly in Europe, to a

type of project for which post-tensioning

Post-tensioning improves a bridge

reluctance to innovate the necessary

technology is used. Rehabilitation and

structurally and we certainly never

bureaucracy, testing regimes and costs

strengthening of existing structures with

expect to see the failure under service of

required to secure approvals make this an

post-tensioning has become more common

a post-tensioned bridge, especially if it is

unattractive proposition for many

especially where traffic loads are now

a continuous girder system with high

companies. So, how have construction

greater than originally envisaged and there

redundancy. The bottom line is that

technology providers set about

is perhaps some age-related deterioration.

post-tensioning was a great invention

differentiating themselves?

It is worth mentioning that not every bridge

and, with modern advances in both

can be strengthened using the same method

anchorages and corrosion protection

Government-led change

and, indeed, sometimes strengthening is

which have partly been driven by mass

Progressively, they have worked to improve

not the best solution. Meanwhile, external

application markets, for example, slabs

their systems with anchorages and

post-tensioning is the most common and

or wind turbines the systems are now

corrosion protection being key factors.

best solution for strengthening concrete

really efficient.

16 CONNCT | EDITION 10

PORTFOLIO
18 IN THE SPOTLIGHT
BBR Adrias CEO, Zelimir Bodiroga,
reflects on the companys enviable
20 year track record
BRIDGES
20 SPANNING THE GORGE
with arch closure at the Tamina
Bridge, a precision approach was
needed to dismantle temporary
stay cables, as PT work for the
bridge deck began
BUILDINGS
37 GATEWAY TO SOUTH
EASTERN EUROPE
the new passenger terminal at
Zagreb Airport is taking shape with
the help of some 37,000m2 of slabs
post-tensioned with BBR technology
STAY CABLES
54 VOYAGE OF DISCOVERY
taking a tour of Rzeszw Bridge
reveals exciting moments and
technological achievement
SPECIAL APPLICATIONS
62 INNOVATIVE WATER
TANK SOLUTION
two-way PT concrete panels for
water containment to meet
ground conditions in challenging
environment
MRR
70 COASTAL COMMERCE
PROTECTING THE ASSETS
in a relationship stretching back
20 years, BBR Contech has
ensured that Aucklands vital port
facilities have received quality
repair and remediation

www.bbrnetwork.com

17

IN THE SPOTLIGHT BBR

IN THE SPOTLIGHT
BBR Adria celebrates 20th anniversary

TWO DECADES
OF EXCELLENCE
1

In 2016, BBR Network Member BBR Adria will be celebrating the 20th anniversary of its foundation. We asked
the companys CEO, elimir Bodiroga, to reflect on the companys heritage and engineering achievements.
Today, BBR Adria is a leading construction

BBR HQ, in collaboration with Zurich

Slovenia, Bosnia and Herzegovina,

engineering contractor specializing in

structural engineering design firm CEPAS

Montenegro and other countries of former

post-tensioning operations for buildings

Plan AG, provided an alternative design for

Yugoslavia. Most work has been carried

and bridges, as well as providing remedial

arch erection. This included form travelers

out in our home market, Croatia, although

and marine construction engineering

and featured BBRV stay and back stay

there have been many projects in the other

services. The company is building on the

cables, as well as two temporary steel

territories we cover.

tradition of BBR post-tensioning in the

pylons to stabilize the arch during

region which stretches back over 40 years

construction. Construction also involved

Our first million m2

with more than 15,000t of high value

ground anchors and girders prestressed

Since our foundation, we have installed

strands and tendons used in the

with BBR technology.

post-tensioning for approaching 150

construction of bridges, viaducts,

The wider professional team on the

bridges or viaducts and many buildings,

overpasses, industrial facilities, tanks,

scheme included Conex of Zagreb and

as well as providing ground anchors for

sports halls and other buildings.

also Dr Jure Radic, then a Professor, who

some 70 projects and post-tensioning for

One of our most senior engineers, Zdenko

has more recently played a key role in the

several marina schemes.

Mesek now retired had over 45 years

design of the new Terminal at Zagreb

The companys biggest achievement during

of working with post-tensioning technology.

Airport (see page 37). It was towards the

recent years has been the introduction of

I always remember that he once told me

end of the Maslenica project that BBR

post-tensioning for buildings in the Balkan

that the quality and reliability of BBR

Conex d.d. was formed and the company

region. When I first joined BBR Adria, back

post-tensioning was simply the best and

was owned jointly by BBR HQ and Conex.

in 2004, the company was just starting

if a project was to feature post-tensioning,

Our birthday was actually on 26th October

work on its first such project a large car

then it should be BBR.

1996 and we immediately set up

park at Brnik Airport, near Ljubljana,

headquarters in Zagreb. Since then, the

Slovenia. Numerous projects of various

Company roots

companys name has changed to BBR Adria

sizes then followed and now this core

Construction of the Maslenica Bridge,

and several years later a management

activity represents up to 75% of our

which carries the A1 highway across the

buyout was agreed which has set the firm

turnover not including traditional bridge

Maslenica Straits to the north of Zadar,

on a new and dynamic course for the future.

post-tensioning. In material terms, we

marked a turning point in the history of

Now, BBR Adria has 30 permanent

have completed about a million square

BBR in Croatia.

employees and is active in Croatia, Serbia,

meters of post-tensioned slabs.

18 CONNCT | EDITION 10

IN THE SPOTLIGHT BBR

1 A major business landmark for BBR in Croatia

developed from the project to construct the
Maslenica Bridge.
2 Zagrebs 100m Strojarska Towers
development includes the second tallest
structure in Zagreb and incorporated
BBR VT CONA CMM post-tensioning for the
floor slabs.
3 In 2003, during the restoration works at
Pulas Roman Amphitheater in Croatia, BBR
Adria post-tensioned the roof of what is now
the olive museum, which lies beneath the
arena, with the BBR CONA compact system.
Photograph released into the public domain
by Orlovic via Wikimedia Commons.
4 Re-opened in 2005, the Sloboda Bridge over
the River Danube in Novi Sad, Serbia features
BBR CONA stay cables. The original 1981
bridge had BBR HiAm stay cables, but was
destroyed in NATO airstrikes in 1999. The
bridge is believed to be the only stay cable
bridge in the world to have been built twice.
5 The unique design of the Ptuj Bridge over
the River Drava in Slovenia featured BBR VT
CONA CMI and CME, internal and external,
post-tensioning tendons.
6 Our specialist construction technology and
expertise was required for the realization of
the Zagreb Arena, including post-tensioning
the 86 precast lamellas each 42m high
with the BBR VT CONA CMI internal system
which form the buildings distinctive exterior.

Public recognition

presents. Thinking about this challenging

After just ten years of working with BBR

project again today, I still get goose-bumps

technology and growing our business in the

and for sure, I will be talking about it

region, we were honored by a special award.

almost every day for the next 20 years!

We were presented with a First Croatian

That same year, we enjoyed a very fine

Kuna Award for our efforts in 2006-2007.

co-operation with our colleagues from

The award, from the Institute for Business

fellow BBR Network Member KB Vorspann-

Intelligence, recognized BBR Adrias position

Technik on the Ptuj Bridge project in

in the top 1% of best Croatian companies.

Slovenia. More recent history can be seen

Since then, we have carried out work on

through the pages of CONNCT, which

some of the regions highest profile

have featured our work on the Strojarska

projects. In 2008, we were awarded a major

Towers project as well as articles in this

contract for specialist construction services

edition about the new Passenger Terminal

for the Zagreb Arena. It was a question of

at Zagreb Airport, the Brije

ce Viaduct in

honor for us to achieve the tight program

Sarajevo, Project Ive Mikaca Varadin and

because the eyes of the whole of Croatia

our geotechnical rock anchoring project

were on us, watching and hoping we could

for a pumping station at Bi Bosut.

complete the work in time for the World

The excellent reputation we now enjoy is

Handball Championships. We worked

a direct result of the dedication of every

16-hour days to install the distinctive

member of the BBR Adria team. Their

lamellas our team members took it in

continuous attention to detail enables us

turns to work outside in the wind, snow and

to provide excellence in every aspect of

freezing temperatures. I also remember

customer service and this will be the key

how we finished on 23rd December and

to our continued success in the future.

then ran to the stores for family Christmas

www.bbrnetwork.com 19

PORTFOLIO BRIDGES

20 CONNCT | EDITION 10

PORTFOLIO BRIDGES

TAMINA BRIDGE, CANTON ST GALLEN, SWITZERLAND

Arch closure & start of deck post-tensioning work

SPANNING
THE GORGE

An exciting new arch bridge has been under construction

in the Swiss Canton of St Gallen, as reported in CONNCT
2015 (page 26), and there will soon be a road connection for
the first time between the communities of Pffers and Valens
set high above the stunning Tamina Gorge. Two BBR Network
Members have been contributing leading edge technology
and expertise to the realization of this breathtaking project.
Norbert Bogensperger of KB VT (Austria) and Sascha Weder
of Stahlton (Switzerland), have joined forces to deliver an
update to the story.

www.bbrnetwork.com 21

PORTFOLIO BRIDGES

It was an operation
requiring the handling of
24-strand stay cables up
to 152m long and weighing
around 185t in total.

A landmark event has taken place on the

As you may recall, we worked with the main

Tamina Bridge site since the last edition

contractor on alternative concepts which

of CONNCT arch closure was

have benefited both the program and

FACTS & FIGURES

achieved on 28th March 2015. This means

budget, as well as general buildability.

Deck length 417m

that the final segment forming the arch

These included using our temporary

Number of piers 5

beneath the bridge deck has been placed.

stay cables just once instead of twice,

Height of piers up to 55m

There was, of course, a major celebration

designing the post-tensioning so that less

Arch length 265 m

as the final concrete hopper, suspended

reinforcement was needed and there were

Number of segments 55
(for free cantilever arch construction)

from a crane, flew across the gorge to

less horizontal forces in the abutments.

pour its consignment of concrete. We all

As well as making deck construction cheaper

took a moment to reflect on our

with normal falsework than with free

achievement, the teamwork which had

cantilevering, it is estimated this alternative

led to this point and to think about the

design will lead to the bridge opening taking

work still ahead of us.

place earlier than originally scheduled.

Segment length 5m
Segments launched from Pffers
side 32
Segments launched from Valens
side 23

22 CONNCT | EDITION 10

PORTFOLIO BRIDGES

Temporary stay cables

The arch springs across the gorge from

There were three

two massive abutments and, during

main steps to our

construction, was supported from the up

to 100m high temporary pylons by stay

strategy for this

cables 31 pairs on the arch side and

operation firstly

24 pairs on the back span, a total of 110

stay cables.
The KB VT team, working with members
of the main contractors team, installed

safety, then delivering

the technical solution

the cables at the rate of up to four per week

and finally speed.

on both sides of the gorge simultaneously.

It was an operation requiring the handling
of 24-strand stay cables up to 152m long
and weighing around 185t in total.
The stay cables were fed into position
1 The temporary stay cables were
deconstructed in stages.
2 The upper stressing platform in early 2015,
amid a snowy landscape.
3 Special Y-shaped tendons were developed
for the project by KB VT from the BBR VT
CONA CMX system to fit spacing
requirements in the girder-walls of the arch.
4 Stay cables at the second stage of the
temporary pylon on the Valens side of the
gorge.
5 In March 2015, the final segment was
concreted. Here, the concrete hopper,
delivered by crane to the center of the arch,
is being emptied.
Photographs 1, 2, 4 & 5 courtesy of
Tiefbauamt St Gallen.

using a double winch fixed in the middle of

Stressing

the cross-beams with guide rollers in all

Back and main cables were stressed

directions, it was like a kind of endless rope

simultaneously in small stages. This

hauling system. For stressing operations,

enabled us to have permanent control of

we also used two 7,000kN jacks for the

the pylon position and deflection.

main cables and ten 3,500kN lifting jacks

Deflection limits for the pylons had been

for back span cables.

clearly defined and were strictly observed,

As well as being prepared with several

with real-time adjustments made to the

methods of installation to allow maximum

stressing procedure dependent upon

flexibility, we also had robust safety plans

measured deflections.

and procedures to protect our workers

Our final stressing operation was carried

during materials handling and while

out to ensure the arch position was aligned

working generally on such an exposed site.

correctly to receive the next segment.

www.bbrnetwork.com 23

PORTFOLIO BRIDGES

Deconstruction of stay cables

When construction of the arch had been
completed, we carried out an equally
complex series of actions to remove the

stay cables.
There were three main steps to our
strategy for this operation firstly safety,
then delivering the technical solution and
finally speed.
We released the cables on the main span
using specially adapted monojacks, with
additional wedging for safety reasons.
The back span cables were deconstructed
using lifting jacks or monojacks. Again the
operation was carried out simultaneously
on both pylons with the maximum
difference at any one time being one pair
of stay cables. We adopted releasing
sequences similar to the original stressing
sequences to avoid asymmetric loading
of the now completed arch.
Cables were bundled near the couplers,

cut and then released with the winch

down the arch. Removal of the cables was
carried out according to cable length.

While this was a challenging stage of this

Shorter ones were simply removed by

wonderful project, we recognized that a

crane, while the medium sized cables

complex solution such as this can only be

were bundled, hung on the crane using

delivered if there is mutual trust between

special clamps then lifted and cut at the

all parties. Early involvement in the project

point they exited the cross beam. The

was essential and we learned that there

longest cables were handled similarly,

are no perfect ready-made concepts

but cut a second time at a lower platform

developing them is a live process requiring

for safety reasons leaving around 50m

both engineering skills, innovation and

of cable to be removed later. Dismantling

flexibility. Together, STRABAG, Hltschi

the stay cables took about a week per

& Schurter (now Meichtry & Widmer) and

cross-beam level with two weeks for the

KB VT formed a strong team of solutions-

upper level.

oriented people.

24 CONNCT | EDITION 10

6 Work from the stressing platforms was

undertaken in all types of weather.
7 The falsework structure for bridge deck
construction at the top of the arch.
8 Concrete is delivered to the center of the
bridge by crane and placed by the
construction team.
Photographs 7 & 8 courtesy of Tiefbauamt
St Gallen.

PORTFOLIO BRIDGES

ALMONTE VIADUCT, CACERES, SPAIN

Arch bridge constructed with temporary stay cables

Bridge superstructure
Once the arch had been closed after the
final segment pour, the main contractor
began building a falsework structure to
create the superstructure for the bridge
deck, while also constructing the three
arch supports.
As the KB VT crew were leaving the site,

WORLD RECORD
ARCH BRIDGE

the team from BBR Network Member

Stahlton began the installation of post-

With the placing of the final arch

The 96m viaduct crosses the

tensioning for the bridge deck which is

keystone in August last year,

Alcantara-Garrovillas reservoir and will

being constructed above the arch. The

deck is of a continuous box girder form

Spains Almonte Bridge claimed

carry the AVE high speed railway from

Madrid to Extremadura. The 996m long

and supported at 35-55m intervals.

its place in the list of world records

Almonte Viaduct is the most prominent

Stahltons work on post-tensioning the

for having the longest span for an

structure on this section of high speed

individual sections began in August. We

arched high speed railway bridge.

railway line. The viaduct is divided into

are using the BBR VT CONA CMI internal

1506 and 1906 systems and the number

Like Switzerlands Tamina Bridge,

three distinct parts two access roads

and one central section, the latter

of tendons placed in the box section

temporary stay cables were also

includes the Almonte Bridge, a 384m

varies between four and eight per side,

used here to support construction

span concrete arch bridge.

depending on the span length.

of the arch and Spanish BBR

For the construction of the arch, a total

Starting at the center of the bridge, deck

construction is proceeding towards the

Network Member, BBR PTE has

of 208 BBR HiAm CONA 5506 and 3706

stay cables were used as temporary

abutments in both directions at the

now completed the stay cable

supports while the arch segments were

same time. Our work also includes post-

dismantling process.

being cast in sequence. With the

tensioning for the approach bridges on

concreting of the final segment, the arch

both sides of the gorge.

became self-supporting and the stay

In total, we will be using around 180t of

cables were progressively and carefully

prestressing steel for the BBR VT CONA

TEAM & TECHNOLOGY

CMI internal tendons, some 140

Owner ADIF
Main contractor FCC Construccin
S.A + Conduril
Technology BBR HiAm CONA stay
BBR Network Member BBR PTE, S.L.
(Spain)

anchorages and around 8km of BBR VT

Plastic Duct to ensure added durability
and robustness in this location which is
exposed to the elements.

destressed before being dismantled.

The completed Tamina Bridge is

scheduled to open to traffic in 2017,
forming the first ever direct connection
across the Tamina Gorge between the
Alpine villages of Pffers and Valens.

TEAM & TECHNOLOGY

Owner Tiefbauamt Kanton St. Gallen
Main contractor STRABAG Erni
Meisterbau JV
Structural design Leonhard, Andr
und Partner
Alternative design Hltschi & Schurter
(now Meichtry & Widmer Dipl. Ing ETH/SIA
AG) (arch alternative for JV)
Technology BBR VT CONA CMI internal,
BBR VT Plastic Duct
BBR Network Member Temporary stay
cables: KB Vorspann-Technik GmbH
(Austria), Post-tensioning: Stahlton AG
(Switzerland)

www.bbrnetwork.com 25

PORTFOLIO BRIDGES

BATANG SADONG BRIDGE, SARAWAK, MALAYSIA

Ten span balanced cantilever construction

LONGEST MULTIPLE
SPAN BALANCED
CANTILEVER BRIDGE

The 1.48km long Batang Sadong

Bong Su-Fah, BBR Malaysias

Deflection control

Bridge will be the longest multiple

Construction Manager, together with

The levels of the bridge top and bottom

Chief Prestressing Engineer George

are taken at the following times:

Jacob, outline the balanced cantilever

after advancing form travelers to set

span balanced cantilever bridge

in Malaysia. When completed in

method using form travelers and the

2016, it will stimulate the growth

necessary deflection control procedures

of a new township, Sadong Jaya

being used to ensure the as-built levels

and also link the townships of

of the bridge achieve the design levels.

the levels for next segment

after concreting of both left and right
segments
after stressing of tendons.
The deflections are calculated, plotted on

Simunjan and Sebuyau in

Construction cycle

a graph and then compared with the

Sarawak. BBR Malaysia has been

This massive bridge has nine piers with

theoretical values. If the difference is

engaged by the main contractor

10 spans in a configuration of 75 + 140

significant, the level for the next segment

+ 150 + 175 + 200 + 200 + 175 + 150 +

to be cast is adjusted to bring the deflection

140 + 75m. The bridge has a deck width

into line with the theoretical values.

balanced cantilever piers which

of 11.24m and will carry two traffic lanes

Measurements must be taken early in the

are on bearings, while they

in both directions. The box girder depth

morning shortly after dawn so that

construct the remaining piers. In

is 10.5m at piers, reducing to 3.6m at

temperature gradients on the bridge deck are

midspan. We are working on two piers

minimized. As the top deck slab is exposed

simultaneously with two pairs of form

to the sun, it gets warmer compared to the

construction engineering services

travelers. The typical cycle time to

cooler, concealed deck slab thus, the bridge

for all the piers.

construct a pair of left and right segments

deck levels change during the day. The

is 12 days.

starting point for the leveling is at the axis of

to construct the four challenging

addition, BBR Malaysia is providing

the piers, which forms the reference datum.

26 CONNCT | EDITION 10

PORTFOLIO BRIDGES

1 BBR Malaysia is providing specialist

construction engineering services for the
1.48km long Batang Sadong Bridge which,
when completed, will be the longest multiple
span balanced cantilever bridge in Malaysia.
2 The BBR Malaysia team working on the
Batang Sadong Bridge celebrate completion
of another pair of balanced cantilever
segments. Typical cycle time to construct
a pair of left and right segments is 12 days.

TEAM & TECHNOLOGY

Owner Government of Malaysia
Main contractor KACC Construction
Sdn Bhd
Designer J.H.L Konsult Sdn. Bhd.
Works contractor PPK Sdn Bhd / BBRCS
(M) Sdn Bhd
Technology BBR CONA internal
BBR Network Member BBR Construction
Systems (M) Sdn Bhd (Malaysia)
2

Closure segment

TYPICAL SEGMENT PAIR CONSTRUCTION CYCLE

After completion of the cantilevers, a gap

of two meters remains between the end
of two opposite cantilevers this is to
allow space for tendon stressing with
multi-jacks. One form traveler is removed
and re-erected on another pier. The
second form traveler is launched forward
to connect to the other cantilever to
serve as formwork for the closure pour.
Stitching beams are installed to secure
the two ends of the cantilever from
differential movement during concreting
of the closure segment. The levels of the
two ends are checked.
If the difference is significant more than
30mm the stiff stitching beams are used
to reduce the difference in level. Vertical
prestress bars are stressed with hollow
jacks to pull the ends of the cantilevers up
or down. Alternatively, kentledge concrete
blocks might be placed on top of the deck
to press the cantilever down.
When the concrete strength achieves
40MPa, the bottom and top continuity
tendons are stressed. Finally, the form
traveler is removed and reinstalled on
another pier.
Balanced cantilever cast insitu
construction using form travelers is not a
fast method but it is an efficient way to
build long span bridges over deep and
wide rivers. Materials, including concrete,
can be delivered by barges directly to the
piers. Also, as form travelers can be
reused, construction costs are reduced.

Day 1 Day 2
After completion of cantilever tendons, left and right form travelers are advanced outwards from
the pier to construct the next pair of segments. The levels of the form travelers are adjusted upwards
to the required precamber level in anticipation of the downward deflection during concreting of the
segment. Also considered in the precamber value is the effect of post-tensioning of the cantilever
tendons causing the cantilevers to deflect upwards, but these magnitudes are relatively small
compared to the deflection due to weight of concrete segments.
Calculation of the theoretical deflection takes into account the different creep and modulus of
elasticity of the segments which are cast at different times.
Day 2 Day 4
The installation of the reinforcement usually begins on the lighter segment to minimize the out of
balance moment on the pier. After fixing the bottom and web reinforcement, the bottom tendon
ducts and anchorages are installed.
Day 4 Day 7
Works are carried out on the top slab soffit and outer web formwork. Next comes the fixing of top
slab reinforcement and tendon ducts and top cantilever anchorages.
Day 7 Day 9
Closing of the inner side formwork is completed and tie rods are secured to contain the high pressure
during concreting.
Both segments are cast with Grade 50 concrete, on the same day, using cranes secured on barges in
a near balanced cantilever way. This is done by alternating the concreting between the left and right
segments in several stages. The bottom slab of the lighter segment is concreted first, followed by the
bottom slab of the heavier segment, and then back to the lighter segment to concrete the webs and
then repeating the same on the heavier segment. Then followed by concreting the lighter segments
top slab and finally the top slab of the heavier segment.
Day 9 Day 11
After 24 hours, the web formworks are rotated to detach from the cast concrete surface and kept
moist for concrete curing. Meanwhile, strands are threaded into the empty ducts and anchor heads
are fixed in preparation for stressing.
Day 11 Day 12
When the concrete has achieved the required concrete transfer strength of 40MPa, the cantilever
tendons are stressed. Upon completion of stressing, the form travelers are launched to the next
segment position. Two 750t jacks are used to stress a pair of 3106 tendons or 2206 tendons.
The 2206 tendons can also be stressed with 500t jacks.

www.bbrnetwork.com 27

PORTFOLIO BRIDGES

GULLI BRIDGE, NORWAY

Incrementally launched river bridge

OPTIMIZED BRIDGE
CONSTRUCTION
Gulli Bridge is part of the new highway between Oslo and Stockholm.
The new 741m long bridge crosses Norways longest river, the Glomma,
and at the eastern end of the bridge is the city of Kongsvinger home
of Norwegian BBR Network Member, KB Spennteknikk. Stig Solbjr,
Technical Manager, describes the bridges setting, how it was
designed under new guidelines and constructed to be durable.

28 CONNCT | EDITION 10

PORTFOLIO BRIDGES

1 The 741m long Gulli Bridge, part of the new

Oslo-Stockholm highway, crosses the River
Glomma close to Norwegian BBR Network
Member KB Spennteknikks head office in
Kongsvinger. Photograph by Byggenytt.
2 Aerial view of the completed Gulli Bridge
where the team supplied, installed and
stressed 19,000m of BBR VT CONA CMI PT
tendons and supplied purpose-made TOBE
pot bearings for installation after the
incremental launching operation. Photograph
by Jon Ivar Shus.
3 The value engineering exercise resulted in the
selection of incremental launching as the
bridge building method. Photograph courtesy
of Grzegorz Gucwa, Skanska.
3

At 621km long and with a drainage basin

Optimized bridge design

The bridge has 32 precast concrete

covering 13% of the country, the Glomma

The Gulli Bridge was designed under new

elements with a unit length of 25m all

or Glma is Norways longest and

guidelines set out by the Norwegian

built in the production plant, a temporary

largest river. It runs from Lake Aursund

Road Department. Value engineering

factory created on site, on the northern

near Rros in Sr-Trndelag and ends when

workshops were held between the selected

side of the river and incrementally

it flows into the Oslofjord at Fredrikstad.

contractor and client to find an optimized

launched in two week cycles.

Major tributaries include the Vorma river,

solution for the construction project with

We supplied, installed and stressed

which runs from Lake Mjsa Norways

respect to program and budget. The cost

19,000m of BBR VT CONA CMI 1206

largest lake and joins the Glomma at Nes.

savings are then shared between the client

post-tensioning tendons and assisted the

This is a particularly significant connection

and contractor.

main contractor with personnel for the

because the River Lgen ends in Lake

From this value engineering exercise, came

incremental launching. We also supplied

Mjsa where drainage waters from the

a proposal by the contractor to use the

32 purpose-made TOBE FR-4 pot

large Gudbrandsdal valley collect and

incremental launching method a common

bearings that were installed after the

thereby, via the Vorma, the River Glommas

choice in European countries other than

incremental launching process and two

flow is significantly increased.

Norway for the bridges construction.

ETIC EJF 500 expansion joints one at

Historically, the Glomma has been a major

each end of the bridge, produced by the

transportation route famous for once

French BBR Network Member.

being Norways leading log floating river as

Bridge design

it flows through some of the richest forest

The collaboration between the owner and

districts. Over the years, the combination

contractor resulted in a slight change in

of raw materials, water power and easy

the curvature of the bridge and extended

transport has fostered development of

spans from 40 to 50m, which reduced

TEAM & TECHNOLOGY

industry along the Glomma. Some of the

the number of columns. The River

countrys largest manufacturing and

Glomma has a high water flow and difficult

processing installations are found

ground conditions due to spring flooding.

around the rivers mouth, where supplies

In addition, the incremental launching

of timber and hydropower have been

method simplified the crossing of the

supported by excellent port facilities.

railway, which passes under the bridge.

Owner Statens Vegvesen

Main contractor Skanska Norge AS
Consultant Dr. Ing. Aas Jakobsen
Technology BBR VT CONA CMI internal,
bearing, expansion joint
BBR Network Member KB Spennteknikk
AS (Norway)

www.bbrnetwork.com 29

PORTFOLIO BRIDGES

MERSEY GATEWAY BRIDGE, RUNCORN-WIDNES, CHESHIRE, ENGLAND

BBR post-tensioning for bridge deck

NEW GATEWAY
FOR MERSEY
A second road crossing over the River Mersey in North West England has been a long
held aspiration for many and now the new bridge is taking shape. Roger Stables, of
BBR Network Member Structural Systems (UK) Limited, tells the story of the bridges
history and his companys role in the construction project.

1 Artists impression of the completed

Mersey Gateway Bridge between Runcorn
and Widnes.
2 Aerial view of bridge construction site with
completed trestle bridge and showing all
three cofferdam sites, as well as the Silver
Jubilee Bridge in background.
3 Aerial view of the north cofferdam where
excavation for a pylon base is underway.
Photographs 1, 2 & 3 courtesy of
www.merseygateway.co.uk.

30 CONNCT | EDITION 10

The River Mersey flows for some 70 miles

on the southern side, around 1.5km to

from its source near the town of Stockport

the east of the Silver Jubilee Bridge.

to the city of Liverpool before flowing into

More than just forging a connection and

the Irish Sea. On its journey, the river

easing congestion, it is hoped that the

narrows between Runcorn and Widnes,

bridge will be a catalyst for regeneration

in the Borough of Halton, and it was here

and new and inward investment in the

that the Silver Jubilee Bridge was first

local area and north west as a whole.

opened in 1961. As the only vehicular

The Merseylink Consortium consisting

crossing of the Mersey in the Halton area,

of sponsors Macquarie Capital (Australia),

and with the increase in road traffic over

FCC Construccin S.A. (Spain) and BBGI

the last 50+ years, the road bridge and

was selected as preferred bidder for

local highway network has been under

the project in June 2013 and will be

severe pressure despite bridge widening

responsible for the design, building,

and strengthening work in the 1970s.

financing and operation of the bridge for

Now, a major new six-lane toll bridge is

30 years. Financial close was achieved in

under construction between Widnes on

2014 and construction work began on

the northern bank of the river and Runcorn

7th May the same year.

PORTFOLIO BRIDGES

This particular design

was chosen as it
maximizes benefits
for users and the local
community while
minimizing impact on
the environment.

Construction methodology
Three cofferdams were built in the river
to allow excavation for the bases of the
bridge pylons. Meanwhile, a temporary
trestle bridge was built to allow access
to the site.
Span-by-span construction of the main
bridge deck began in autumn 2015. The
team is using Europes longest Movable
Scaffolding System (MSS) which
measures 157m long and weighs in at
around 1,700t. Named Trinity to reflect
the unusual three pylon design and the
three companies within the Merseylink
Civil Contractors Joint Venture Kier
Infrastructure and Overseas Limited,
Samsung C&T ECUK Limited and FCC
Construccin S.A. the MSS is capable

of casting spans up to 70m long.

Post-tensioning technology
Specialist companies BBR PTE S.L.,
Structural Systems (UK) Ltd and VSL

TEAM & TECHNOLOGY

DBFO Merseylink Limited
Main contractor Merseylink Civil
Contractors Joint Venture: Kier
Infrastructure and Overseas Limited,
Samsung C&T ECUK Limited and FCC
Construccin S.A.
Structural designers Merseylink Design
Joint Venture: Flint & Neill, Aecom, Eptisa
and Fhecor
Technology BBR VT CONA CMI internal
BBR Network Member Structural
Systems (UK) Limited & BBR PTE (Spain)

Bridge design

Systems (UK) Ltd have formed a joint

The Mersey Gateway Bridge is of a cable-

venture known as BSV Mersey JV in

stayed design, similar to the Second

order to offer the Mersey Gateway project

Severn Crossing Bridge but with three

with what we believe to be the most highly

pylons instead of two. The outer two pylons

skilled and optimized specialist service

will be 110m (north) and 125m high (south),

within our field an approach considered

while the central pylon will be shorter, at

essential for such a high profile and

80m high. The bridge will have a river span

technically challenging project.

of 1km and, with the approach viaducts

When completed in 2017, the new bridge

on either side, will have a total length of

will carry three traffic lanes across the

2.13km. This particular design was chosen

River Mersey in each direction and link

as it maximizes benefits for users and the

Runcorns Central Expressway with main

local community while minimizing impact

highways to the M62 motorway and

on the environment.

towards Liverpool.

www.bbrnetwork.com 31

PORTFOLIO BRIDGES

VIADUCT, SARAJEVO, BOSNIA AND HERZEGOVINA

BRIJECE
New road bridge relieves traffic in capital city

DETOUR AROUND
SARAJEVO
At around 720m long, the Brijece Viaduct is a key component of the 10km
Sarajevo Bypass scheme which will reduce traffic congestion in the city
center and connect the city with the A1 highway. The viaduct is located on
the 4km approach road which connects the Bypass to Sarajevo. Tomislav
Lopandic of BBR Adria, describes his companys work on the project.

32 CONNCT | EDITION 10

1 The 720m long, 11-span Brijece Viaduct is

a key component of the 10km Sarajevo
Bypass scheme which will reduce traffic
congestion in the city center and connect
the city with the A1 highway.
2 The viaduct was post-tensioned in stages
using BBR VT CONA CMI internal tendons
consisting of 14 x 15.7mm diameter strands.

PORTFOLIO BRIDGES

Post-tensioning & stressing

We post-tensioned the viaduct in stages
using BBR VT CONA CMI internal tendons
consisting of 14 x 15.7mm diameter strands.
The BBR Adria team carried out tendon
stressing four days after casting the deck
or after the C35/45 concrete had
achieved a minimum of 70% of its design
strength. The higher concrete strength
permitted the use of less local anti-bursting
reinforcement, thus reducing congestion.
The tendons were each stressed to a
force of 2,856kN. Around 653t of
1,860MPa prestressing steel was installed
in the viaduct.
Timescales & completion
The first phase of construction started
towards the end of 2013 and was
completed in early 2014. In this period we
executed 10 slabs. With the selection of a

new main contractor in April 2015, the

second phase of construction began and
a further 42 slabs had been constructed
by the time it finished in October 2015.
Completion of the Brije
ce Viaduct will
not only improve traffic conditions on
Construction of the Sarajevo Bypass was

other access roads around Sarajevo, but

divided into three sections and the Brijece

also offer motorists a faster and more

Viaduct is in Lot 2 which covers the stretch

comfortable journey.

from Butila junction to Brijece. After the

For BBR Adria, the Brijece Viaduct project

new road crosses the Brijece Viaduct, it

has been an exceptional logistical and

splits into two one road goes to Stup and

technological success even in the face

the other to Rajlovac.

of a short program and involving the

execution of up to four separate slabs at

Project overview

the same time. Installation, tensioning and

The viaduct is designed for speeds of up to

grouting were performed by one engineer

100km/h and is 11.75m wide which allows

and three BBR specialists. This project has

two 3.5m wide lanes and a 2.5m wide

clearly demonstrated the experience and

emergency lane, along with other features.

resourcefulness that the BBR Adria team

In all, we have been working on six separate

is able to bring to every new project.

structural elements for this viaduct which

crosses the roundabout at Brijece, the
M13 road and a dual track railway line.
The viaduct has 11 spans, supported at
between 28 and 35m intervals, and was
built in two separate packages. Package 1
has two independent carriageways carried
on bridges, the left carriageway is 360m
long and the right is 363m. It also features
access and exit ramps which have two
3.5m wide lanes and are each 125m long.
Package 2, consists of two 359m long
parallel structures. All structures were built
in stages the main viaduct in 11 stages
and the ramps in four. In total, 1,691m of
road has been created for the project.

TEAM & TECHNOLOGY

Owner JP CESTE BiH Federation
Main contractor GP GP d.d.
Designers Ipsa Institut, Trasa d.o.o.
Technology BBR VT CONA CMI internal
BBR Network Member BBR Adria d.o.o.
(Croatia)

www.bbrnetwork.com 33

PORTFOLIO BRIDGES

BATANG SEMARIANG BRIDGE, SARAWAK, MALAYSIA

High capacity self-advancing beam launcher saves on program & budget

SELF-ADVANCING
TO SUCCESS
The Batang Semariang Bridge

The overall bridge length is 300m and

of tendons and then launching the U-shape

project was initiated by the state

consists of eight equal spans of 37.5m

beam to the designated span using mobile

each, crossing over the Semariang River.

cranes. After this, the deck slab would be

The bridge is designed as a continuous

cast and finished with second stage

of a new route to link Petrajaya

span structure with expansion joints only

stressing works. The purpose of this was

the new state government

at the two abutments. The 14.5m wide

to reduce the launching weight and thus

administration hub to Kuching,

deck accommodates two traffic lanes in

avoid the costs, time and risks involved in

each direction. Each span comprises

using high capacity mobile cranes and

three prestressed box shaped beams

heavy temporary bridge access. In this

Project Manager Chok Moi Chun

with each precast beam weighing 170t.

region, 40m long precast beams are

and Assistant Technical Manager

Based on our good track record and

commonly used and typically they weigh

Tie King Bang describe how the

construction engineering experience, we

100-130t and only rarely as much as 170t.

were awarded the whole bridge package

The improved approach we adopted

from piling, precasting of beams,

involves use of a beam launcher with

changed to enable fast and

post-tensioning, beam launching to

capacity to launch 40m long precast beams

cost-effective construction of

completion of the bridge superstructure.

weighing up to 180t. With the high lifting

government of Sarawak as part

capital of Sarawak. BBR Malaysias

construction methodology was

capacity of the beam launcher, thanks to

this new multi-span river bridge.

34 CONNCT | EDITION 10

Optimized construction methodology

the triangular truss system, the box shaped

The original construction method involved

beams could be cast in full section and

casting the U-section of the box-shaped

stressed to the required force in just one

beam only, followed by partial stressing

stage at the casting yard.

PORTFOLIO BRIDGES

Tendon configuration

Bridge sub-structure

level adjustment and transverse shifting of

Six BBR CONA internal bonded tendons

Each bridge pier is supported by three

the beam launcher. It also has an additional

are installed in each post-tensioned precast

1.2m diameter vertical bored piles and two

feature which enables beam lifting using a

box girder beam. As the re-engineered box

0.75m diameter raked bored piles for lateral

single triangular truss. This is useful when

section has a higher moment of inertia and

stability. The three vertical piles continue

the need arises to deliver the outer beam

stiffness, all the tendons can be stressed

above the pile cap to form the vertical

towards the end of a crosshead without

to the required design force in one stage

piers which support the crosshead. The

extending the transverse rail or having

with a 500t capacity multijack before the

crosshead supports the three boxed beams

additional temporary support.

beam is delivered to the beam launcher.

and was also designed to handle the

After launching the three beams, the end

temporary loads from the beam launching

Construction cycle & program

and intermediate diaphragm beams and

operation. The span-by-span construction

The construction cycle for each span is

side stitching of the deck slab are

method means that the offset point of

approximately one month and can be divided

constructed. A pair of BBR CONA internal

applied load from the launching works

into three main stages self-advancing of

tendons in each diaphragm beam is

and one side span are unavoidable. The

beam launcher, beam launching works and

stressed before the deck is completed and

crosshead is designed to resist torsion

in-situ construction works. Self-advancing

stable, then the beam launcher advances

force at every pier support. Also, the

of the beam launcher and launching of three

to the next span.

axial and bending capacity of the high

precast box girder beams takes seven days.

piers were analyzed and checked based

In-situ construction, involving construction

on eccentric load from the launching

of diaphragm beam and deck slab stitch,

works. The beam seating area on the

requires approximately three weeks the

crosshead is enlarged to reduce localized

beam launcher then advances to the next

compressive stress on the concrete.

span. The overall construction program

1 The bridge pier crossheads support the

three boxed beams and were also
designed to handle temporary loads from
beam launching operations.
2 BBR Malaysias alternative construction
proposal for the Batang Semariang Bridge
involved using a beam launcher to handle
the 40m long precast beams which weigh
up to 180t.

for this bridge is 15 months. Six months

Self-advancing beam launcher

program time was allocated for piling

Our existing beam launcher was upgraded

works up to substructure level and eight

the 140t winches were replaced with a

months for launching works and in-situ

180t system and the launcher was equipped

construction of the bridge superstructure.

with the facility to advance to the next span

Construction time and costs are greatly

by its own self-advancing mechanism. The

reduced by using a self-advancing high

TEAM & TECHNOLOGY

beam launcher is 72m long for cantilevering

capacity beam launcher for multiple span

Owner Government of Malaysia

Main contractor Zecon Dredging Sdn Bhd
Designer J.K. Bersatu Sdn. Bhd.
Bridge subcontractor BBR CS (M) Sdn Bhd
Technology BBR CONA internal
BBR Network Member BBR Construction
Systems (M) Sdn Bhd (Malaysia)

to the front pier and is comprised of double

bridge construction. As it is self-advancing,

trusses, each truss is divided into six equal

mobile cranes are not needed to shift the

modules connected with high tensile bars.

beam launcher. With the high load capacity

It has two main support legs and three

of the beam launcher, heavier beams can

auxiliary support legs attached to hydraulic

be launched and tendon stressing reduced

jacks and a motorized trolley system for

to one stage instead of two.

www.bbrnetwork.com 35

PORTFOLIO BRIDGES

PROJECT IN PICTURES
Rail Bridge, Otaio River, New Zealand

GOING WITH THE FLOW

A new rail bridge in New Zealand is expected to perform for more
than 100 years and for that some credit must go to the CONA CMX
post-tensioning range of solutions.
The 126m bridge spans the Otaio River in

BBR Contech supplied, installed, stressed

the South Canterbury region of New

and grouted 12 post-tensioned BBR VT

Zealands South Island. As reported in

CONA CMI 0906 multi-strand tendons into

CONNCT 2015, it replaces a steel and

each unit.

timber structure built more than a century

The process took around four months and

ago that, according to rail infrastructure

the new NZ$5 million bridge opened for

manager KiwiRail, was no longer economical

business soon afterwards. Its new location,

to repair.

which is better aligned with the rivers

TEAM & TECHNOLOGY

The new bridge, which is located about six

channels, should help to prevent future

Owner KiwiRail
Main contractor McConnell Dowell
Constructors
Structural engineer Novare Design
Technology BBR VT CONA CMI internal
BBR Network Member BBR Contech
(New Zealand)

meters downstream of the old one, is

damage during major floods.

constructed of concrete beams and

Nothing remains of the old Otaio rail bridge

columns and nine spans of 14m-long precast

today, but thats progress for you. Instead,

concrete deck units. Working with main

the new bridge is conveying freight to places

contractor McConnell Dowell Constructors

north and south and, all going well, will

and engineering specialist Novare Design,

carry on doing so for another century.

36 CONNCT | EDITION 10

PORTFOLIO BUILDINGS

NEW PASSENGER TERMINAL, INTERNATIONAL AIRPORT ZAGREB, CROATIA

Post-tensioned floor slabs as alternative design proposal

GATEWAY TO SOUTH
EASTERN EUROPE
Zagrebs Pleso Airport first opened in 1962 and both the runway and passenger terminal
were extended significantly in the 1970s. However, since the turn of the century, the
number of passengers passing through has doubled to around 2.5 million per year. While
recent expansion of the existing terminal has eased pressure on facilities, work on the
construction of a second passenger terminal capable of handling 5 million passengers
annually is now underway. Goran Tomii
c of BBR Adria reports on the project.

www.bbrnetwork.com 37

PORTFOLIO BUILDINGS

An international competition was held to

The project is funded by French

find the best design for the new terminal and

consortium ZAIC consisting of Aroport

the proposal put forward by a consortium

de Paris and Btiment International

of Croatian architects including IGH d.d.

Airport who were awarded the

(Civil Engineering Institute of Croatia) and

concession by the Croatian government

architects Velimir Neidhardt, Branko Kincl

to build the new passenger terminal

and Jure Radi

c was declared the winning

and manage the airport for 30 years.

solution. Their undulating form for the

The design and build contract was let to

building was inspired by the local landscape

the Meunarodna Zrac

na Luka Zagreb

and reflects the shape of the mountainous

and Bouygues Btiment International

backdrop of the city.

Joint Venture.

1 To increase capacity at Zagreb's Pleso

Airport, a second passenger terminal
capable of handling five million passengers
annually is now under construction.
2 By April 2015, work had begun on installation
of the frame for the undulating roof form
and was well-advanced by the end of June.
3 The south, east and west faades are
designed as flat aluminum curtain walls with
structural glazing.
4 The new passenger terminal at Pleso Airport
in Zagreb begins to take shape.
4

38 CONNCT | EDITION 10

PORTFOLIO BUILDINGS

The structure was

initially designed to be of
prefabricated concrete
construction, however,
following a proposal by
the contractor, it was
rapidly redesigned to
be of monolithic posttensioned construction.

Design & layout

The new passenger terminal is a four level
building comprising a rectangular main
section and extending into two asymmetrical
wings the western for international
departures and arrivals, the eastern for
domestic traffic. Lower levels will be used
for arrivals and the upper for departures.
On the northern faade, there are eight
passenger boarding bridges connecting
with 16 departure gates inside the building.
The structural frame of the building
consists of circular reinforced concrete
columns, post-tensioned concrete beams
and slabs, plus four reinforced concrete
communications cores.
Above the concrete structure is a rippling
steel space frame which links the roof of
the main building and passenger boarding
bridges with the northern faade. The
south, east and west faades are designed
as flat aluminum curtain walls with
structural glazing. The roof is partially
glazed and partially covered with the very
latest in aluminum cladding.
Construction overview
The total area of the corrugated steel roof
is 25,000m2, while three concrete floors
not including the ground slab have an
area of about 45,000m2. The central
section of the terminal building has a
footprint of 130 x 136m and there are
no expansion joints due to the layout of
seismic walls located near the very ends
of the ground plan.
The structure was initially designed to be
of prefabricated concrete construction,
however, following a proposal by the
contractor, it was rapidly redesigned to be
of monolithic post-tensioned construction.
www.bbrnetwork.com 39

PORTFOLIO BUILDINGS

Ceilings & floors

The beams here measure 1,600 x 550mm

The horizontal ceiling structure was

and between them is an 180mm thick slab.

resolved to be of monolithic post-tensioned

Beams in the upper level floors sit on a

construction. All three levels of ceiling

14.4 x 14.4m column grid. They extend in

panels have longitudinal and transverse

both directions and are 3,000mm wide by

pouring strips. These pouring strips reduce

550mm deep, with a 250mm thick infill slab.

the surface area of the first phase of

Larger openings that interrupt the

construction on sections up to 60-70m long.

continuity of these beams are resolved with

FACTS & FIGURES

The predominant grid sizes are 7.2 x 14.4m

reinforcement at the edge of the openings,

37,000m2 post-tensioned slabs

for the ground floor and 14.4 x 14.4m for

so that loads are transferred to the adjacent

8,000m2 reinforced concrete slabs

first and second floors.

beams. One exception is where the pillars

25,000m2 roof

Post-tensioned slabs were designed as

of the top floor are offset from the main

280t BBR VT CONA CMM tendons

shallow, wide beams. The first floor slab has

axis and, here, their forces are taken by

beams running in the longer 14.4m direction.

3,000 x 850mm reinforced beams.

5,000t reinforcement bar

40 CONNCT | EDITION 10

PORTFOLIO BUILDINGS

5 The roof is partially glazed and partially

covered with the very latest in aluminum
cladding.
6 A total of 280t of steel prestressing strand
was used for the BBR VT CONA CMM
monostrand tendons.
7 Post-tensioned slabs were designed as
shallow, wide beams and, as pictured here,
for the first and second floors, arranged on
a 14.4m x 14.4m grid.
8 By October 2014, work on site had reached
a peak and BBR Adria was installing
post-tensioning for several slabs at the
same time.

Post-tensioning
We used around 280t of BBR VT CONA
CMM tendons with strand of 150mm2
cross-sectional area and 1,860MPa
characteristic tensile strength. There were
many benefits offered to the project by
this BBR technology including factory
provided corrosion protection, speed and
ease of laying, larger tendon eccentricity
and small friction losses which allowed
prestressing of the larger 60-70m sections.
Proportionately, more tendons are
grouped in the reinforced beams, while
fewer tendons pass through the slabs at
equal distances. In the beams, the tendons

are profiled using a parabolic curve. The

radius of curvature of the tendons above
the columns is R = 4m, which gives an
optimal minimum breaking load (MBL).
For the 180 and 250mm thick slabs, outside
of beam zones, we adopted the free tendon

Completion of new terminal

layout which significantly simplifies and

Construction work began in summer 2014

accelerates installation. By request of the

and concrete construction was completed

investor, the tendons in the 3,000 x 550mm

in February/March 2015. The BBR Adria

beams near columns have been grouped in

team has finished its tasks, but work

such a way that, if necessary at some stage

continues around the site on the external

in the future, four 400 x 400mm openings

building envelope, roads to connect the

could be created without having to cut or

new facility to the existing road network

interfere with the PT tendons. Due to their

and, finally, there will be a testing and

high stiffness, some seismic walls will

commissioning phase. We are all looking

subsequently be made monolithic with the

forward with great excitement to late

slab and, until then, will rely on temporary

2016, when the new passenger terminal is

short columns.

scheduled to open for business.

TEAM & TECHNOLOGY

Investor International Airport Zagreb
Architects IGH dd (Civil Engineering
Institute of Croatia), Velimir Neidhardt,
Branco Kincl and Jure Radic
Main contractor KAMGRAD d.o.o.
Structural designers Dr.sc. Jure Radic,
Milan Crnogorac, Predrag Presecki
(PT slabs)
Technology BBR VT CONA CMM
monostrand
BBR Network Member BBR Adria d.o.o.
(Croatia)

www.bbrnetwork.com 41

PORTFOLIO BUILDINGS

WIRI INLAND PORT, AUCKLAND, NEW ZEALAND

Post-tensioned slabs for cold storage

CONNECTING
SEA & LAND
When you have a port management company as a client, you would quite
naturally expect to work by the sea. Not so in New Zealand, where BBR
Contechs long-standing partnership with Ports of Auckland Ltd (POAL)
and concrete floor specialist Conslab extended in 2015 to an inland project
and a port of a very different kind.

Originally established around 2005, the Wiri

productive uses for valuable real estate

Inland Port is a 15-hectare freight handling

formerly used to store empty containers.

hub located in South Auckland. It is about

The Wiri Inland Port has proved a great

25km from the seaport, but crucially close

investment, says Pete Algie, Asset

to two key state highways and the North

Manager for POAL. When the rail siding

Islands main trunk railway line.

opened in 2010 we ran four trains a week

between the seaport and the hub, today

Ground-breaking service

we run 21 and are looking to increase that

The hub exploits these attributes to

number further.

provide a ground-breaking service for

exporters and importers of containerized

goods the ability to drop off and pick

up their containers without having to
negotiate the often congested Auckland
motorways to get to and from the
central-city seaport. They can use road
and rail to transport their containers in or
out of the hub, while the containers are
moved between the seaport and the hub
via a dedicated rail siding, usually at night
and during the weekends.
Completing the process, the hub offers
all the e-commerce and border clearance
services available at the seaport, which
means containers can be unsealed and
their goods dispatched directly to points
north and south.
The benefits of this innovative approach
are significant a dramatic reduction in
the number of central city truck trips
and therefore reduced carbon emissions
and traffic delays for other road users
a more convenient drop-off and pick-up
location for cargo owners, a more efficient
supply chain, less cargo handling and an
opportunity for POAL to find more
2

42 CONNCT | EDITION 10

PORTFOLIO BUILDINGS

It was no easy task, with a

tightly constrained site and
a single entry point making
access a challenge for all
the contractors involved.

New cold store development

The latest development at the hub and
the reason for the BBR Contech project
is an 11,800m2 cold store which is capable
of handling around 20,000 pallets of
frozen goods.
Working with Conslab and main contractor
Ebert Construction, BBR Contech installed
post-tensioning into four slabs for the cold
store between June and August 2015 two
were 175mm thick and two were 190mm,
the latter was required to hold heavy-duty
pallet racking. It was no easy task, with a
tightly constrained site and a single entry
point making access a challenge for all the
contractors involved.
The work was complicated by the fact
that the foundation for the slab was a layer
of polystyrene insulation, says Terry
Palmer, BBR Contech Project Manager.
There was no choice but to pump the
concrete through hoses from the outside to
avoid damaging the insulation and the PT
ducts. It was extremely labor intensive!
Pete Algie says that, while the Wiri Inland
Port project was very different from BBR
Contechs typical seaport work for POAL
(see page 70), the two stories demonstrate
the range of services that BBR Contech
performs across the POAL asset base.

1 The latest development at Wiri Inland

Port required construction of four
post-tensioned slabs.
2 Two post-tensioned slabs were 175mm
thick and two were 190mm the latter
has been designed to support heavy duty
pallet racking.
3 Construction of the post-tensioned slabs
was complicated as the foundation for the
slab was a layer of polystyrene, so concrete
was pumped from the outside to avoid
damage to the insulation and PT ducts.

TEAM & TECHNOLOGY

Owner Ports of Auckland Ltd
Main contractor Ebert Construction
Concrete flooring specialist Conslab
Technology BBR CONA flat
BBR Network Member BBR Contech
(New Zealand)

www.bbrnetwork.com 43

PORTFOLIO BUILDINGS

PROJECT HIGHLIGHTS
Post-tensioned slab solutions for buildings

GLOBAL APPEAL & VALUE

TEAM & TECHNOLOGY
1 Developer VMD PROMET d.o.o.

Main contractor TEAM d.d.

Designers Kreimir Tarnik,
Predrag Presecki & Goran Tomiic
(PT slabs)
Technology BBR VT CONA CMM
monostrand
BBR Network Member BBR Adria
d.o.o.

The advantages of post-tensioned ground and floor slabs, as well as

transfer floor plates, is being recognized all around the world. The benefits
whether concerning aesthetics and practicalities, or time and cost are
being delivered by BBR Network Members whose skill is also acknowledged
by their regular customers.

2 Owner Knowledge Vision Sdn Bhd

Main contractor Pembinaan Yuen

Seng Sdn Bhd
Technology BBR CONA internal
BBR Network Member BBR
Construction Systems (M) Sdn Bhd
(Malaysia)
3 Owner Government of Western

Australia
Design & build contractor John
Holland Pty Ltd
Technology BBR VT CONA CMI
internal
BBR Network Member SRG Limited
(Australia)
4 Owner Sistema Plastics

Main contractor Haydn & Rollett

Concrete flooring specialist Conslab
Technology BBR CONA flat
BBR Network Member BBR Contech
(New Zealand)
5 Owner Government of Western

Australia
Main contractor City Busport
Alliance (Perth Transport Authority,
Brookfield Multiplex and BG&E)
Technology BBR VT CONA CMI
internal
BBR Network Member SRG Limited
(Australia)
6 Developer Halter AG

Main contractor Feldmann Bau AG +

Estermann AG
Consulting engineer Suisseplan
Ingenieure AG
Technology BBR VT CONA CMI
internal
BBR Network Member Stahlton AG
(Switzerland)

1 Project Graharova, Zagreb, Croatia.

2 Almyra Residence, Bandar Putri@Bangi
development, Malaysia.
3 Perth Childrens Hospital, Perth,
Western Australia.
4 Sistema Plastics Warehouse, New Zealand.
5 Perth Busport, Perth, Western Australia.
6 Mall of Switzerland, Ebikon, Switzerland.

44 CONNCT | EDITION 10

2 Advantages for all

BBR Malaysias Yan Mung Chung designed
1 Maximizing space with PT

the 1.5m thick post-tensioned transfer floor,

Following the Strojarska Towers project,

using BBR CONA internal tendons, for the

VMD Promet and BBR Adria, have continued

Almyra Residence four 30-storey tower

their successful cooperation for the Project

blocks over a common podium car park, part

Grahorova scheme, also in Zagreb, Croatia.

of the Bandar Putri@Bangi development,

The building consists of two underground

south of Kuala Lumpur. The PT transfer floor

garages and four to six upper business and

offers a reduced structural depth and

residential floors. The underground structure

aesthetic flat slab soffit, as well as reducing

is square shaped, while the upper part

formwork, props and backprop costs and

consists of an L-shaped residential/business

construction program, compared with the

area and square shaped retail space.

originally planned 1.8m deep reinforced

The 4,500m2 foundation slab and the

concrete beams. It is no wonder that

underground garage ceilings were post-

structures designed with post-tensioned flat

tensioned. The ceiling of the retail space has

slabs are increasingly common in this region.

also been constructed as a post-tensioned

A two stage casting was adopted whereby

slab. BBR VT CONA CMM monostrand

one layer of concrete was cast and first

technology was installed on the project.

tendons stressed to support the weight of

The large spans of up to 17.5m mean

the second stage concrete. For columns

there are fewer columns in the garages, so

with shear loads, drop caps up to 600mm

maneuvering is much easier and the retail

deep were used to increase the punching

area is more spacious.

shear capacity.

PORTFOLIO BUILDINGS

We believe in surrounding ourselves with competent,

trusted partners. These guys [Conslab & BBR Contech]
have consistently delivered in terms of performance
and value and they meet and often exceed our
expectations. The longevity of our partnership reflects
this theyre the experts at what they do and are as
committed as we are to maintaining a healthy and

5 Top down construction

Australian BBR Network Member SRG was

rewarding relationship.

contracted to provide the post-tensioning

Kim Barrett, Managing Director, Haydn & Rollett, New Zealand

to the roof slab and entry portals of the

new underground Perth Busport, part of
the Perth City Link Project. Top down
construction was chosen because of the
sites close proximity to the recently
completed rail tunnel and because it
does not require extensive formwork.
Prior to excavation beneath to create the
main concourse, the 800mm thick roof
slab was constructed on the ground. It
covers an area of approximately 213 x 46m
with no movement joints and is designed to
support future multi-storey buildings above.
The project involved placing 9,000m3 of
concrete and 1,500t of rebar. The
post-tensioning works included installation
4 Cementing a relationship
Over the past 15 years, New Zealands
BBR Contech has formed a great working

of BBR VT CONA CMI post-tensioning

tendons which were up to 46m long and
required 150t of steel prestressing strand.

relationship with concrete flooring

specialist Conslab and, through Conslab,
property developer and builder Haydn &
Rollett. This relationship has led to some
27 post-tensioned flooring projects
together, covering an area of 280,000m2.
In 2015, a commission for a 45,000m2
3 Major & complex work
The Perth Childrens Hospital will replace

post-tensioned slab for a factory and

the existing Princess Margaret Hospital

through the 300,000m2 mark for this

for children, built over 100 years ago.

partnership and took BBR Contechs

SRG was contracted to install 220t of

total tally of PT slab projects to more than

6 Largest in Switzerland

prestressing strands in the post-tensioned

two million square meters!

With 46,000m2 of retail space and around

beams for 120,000m2 of suspended floors

This most recent project was the largest

140 shops, Mall of Switzerland in Ebikon is

over nine storeys. Works also included

ever undertaken for the New Zealand-based

set to become the largest shopping

supply and installation, sealing and

manufacturing company, Sistema Plastics.

destination in central Switzerland. An

grouting of almost 3,000m of temporary

The flooring project involved 14 pours to

adjoining car park with 1,600 spaces is also

movement joints across the project.

create a 170mm thick, 300m x 150m

under construction. In addition, 12 cinema

The project was broken into four main work

structure comprising coupled slabs with

screens, a hotel and apartments are

areas and was serviced by five tower cranes.

two permanent movement joints in the

planned for the site. BBR Network Member

The complex nature of the project and space

longest direction. It required more than

Stahlton is using the BBR VT CONA CMI

constraints on site created many challenges

200t of 15.2mm strand a massive

internal system, with both fixed and

throughout construction including

investment that will ensure a strong,

movable anchors, to provide post-tensioned

just-in-time material deliveries, craneage

robust surface for both vehicle traffic and

beams and floor slabs for the shopping

coordination and coordination between

a very high-spec automated racking

center and one-way post-tensioned floor

construction zones and other trades.

system that is the largest in New Zealand.

slabs for the car park.

distribution center in Auckland, broke

www.bbrnetwork.com 45

PORTFOLIO BUILDINGS

IVE MIKACA, VARADIN, CROATIA

Transfer plate construction for diversity of building use

PRACTICAL SOLUTION
FOR MULTI-FUNCTIONAL
BUILDINGS
In modern buildings designed for residential and commercial use, the
vertical axis of the walls and columns must often allow three different uses
of the structure. Firstly, there is an underground garage, next a business
area mostly placed on ground floor and thirdly, several residential floors.
Goran Tomii
c of BBR Adria describes the solution his company has been
successfully providing for such buildings in Croatia.

The key was to

To deliver all of these three different

The ground and first floor slabs were

have the transfer

functions in one building, we have found

built with larger spans of up to 12m and

that the construction of a transfer plate

then the upper residential floors were

plate on the first floor

is an effective and practical solution.

constructed above them. The key was to

to accept the upper

At Ive Mikaca, the transfer plate is a

have the transfer plate on the first floor

slab consisting of shallow beams

to accept the upper walls and columns

walls and columns

(2,400 x 700mm) in both directions and

as vertical loads. So, the first floor acts

as vertical loads.

a slab thickness of 220mm between

like a foundation slab for the upper floors.

them. Seismic resistance was achieved

The tendons in the transfer plate were

with two staircase and lift cores and

stressed in several phases these

faade frames made of a rigid beams

followed construction of each upper floor.

and columns the Vierendeel system.

46 CONNCT | EDITION 10

PORTFOLIO BUILDINGS

BARANGAROO DEVELOPMENT, SYDNEY, AUSTRALIA

Progress report from citys largest construction project

MASSIVE
WATERFRONT
REGENERATION
It was back in 2011 that we constructed

Barangaroo is the largest construction

drawing, installation, stressing and

the first building in this way in Varadin,

project in Sydney since the turn of the

grouting. SRG also undertook post-

Croatia. Since then, we have delivered

millennium a 22-hectare harbor-front

tensioning works for the Napoleon

four similar building projects for the same

urban renewal project that involves the

Bridge that spans across Sussex Street.

customer. Around 20t of BBR VT CONA

complete transformation of the western

SRGs civil engineering team also

CMM tendons were embedded in each

edge of Sydneys CBD. The site involves

completed the stressing of beams used

building each of which feature floor

three areas Barangaroo Reserve,

for the Barangaroo Reserve cultural

areas of 800m2.

Central Barangaroo and Barangaroo

space. This project involved the

There are many benefits of this kind of

South. When finished, the former

construction of a land bridge supporting

construction. It is possible to have

container port will be transformed into

a park, complete with bicycle paths,

bearing walls outside of the apartments,

a mix of office and residential towers,

walking tracks, retaining walls, water

giving future potential buyers or clients

plus recreational spaces such as public

mains, trees and grassed areas over the

freedom to arrange the rooms as they

waterfront walks and parks.

top of a large 17m high 18,000m2 open

wish. Also, the underground parking

SRG has worked alongside Lendlease,

floor space.

garages have fewer walls and columns,

the developer and main contractor for

so maneuvering vehicles is much easier

Barangaroo South and the main

and sight-lines clearer.

contractor for the Barangaroo Reserve,

After these four projects in Varadin, a

as the five year program of works has

new investor has decided to build the first

progressed. SRG's role has focused on

building with a transfer plate in Cakovec

the post-tensioning works, including

not far from Varadin. This project is still

three multi-storey towers and additional

in progress and, here, we decided to go a

slabs, entailing close to 2,500t of 15.2mm

step further and prestress a foundation

steel prestressing strand.

plate to reduce slab thickness.

In the last year, SRG has completed

substantial post-tensioning works on the
commercial office towers and apartments
at Barangaroo South, including shop

TEAM & TECHNOLOGY

Developer Lendlease (Barangaroo
South), Barangaroo Delivery Authority
(Headland Park), Transport for NSW
(Wynard Walk)
Main contractor Lendlease (Barangaroo
South & Headland Park), Thiess
Contractors (Wynard Walk)
Subcontractor Ward Civil (Wynard Walk),
Baulderstone (Headland Park)
Technology BBR CONA flat, MRR range,
PT bar
BBR Network Member SRG Limited
(Australia)

1 The BBR Adria team is seen here working on

the post-tensioned foundation slab for a new
building. After recognizing the benefits of
post-tensioned transfer plates in nearby
Varadin, the new investor decided to
commission the first building in Cakovec to
feature a transfer plate.
2 The Ive Mikaca scheme is the latest in a
series of multifunctional buildings
constructed with a transfer plate.

TEAM & TECHNOLOGY

Developer Marlex Invest d.o.o.
Designers Miljenko Kovac, Predrag
Presecki (PT slabs)
Main contractor Megrad 3B d.o.o.
Technology BBR VT CONA CMM
monostrand
BBR Network Member BBR Adria d.o.o.
(Croatia)

www.bbrnetwork.com 47

PORTFOLIO BUILDINGS

POST-TENSIONED FLOORS, NEW ZEALAND

350,000m2 of PT floors delivered in 14-year relationship with international commercial property specialist

LONG-TERM
PARTNERSHIP
FOR QUALITY
Some might call it a match made in heaven, but the BBR Networks more pragmatically minded
post-tensioning specialists in New Zealand simply call it a successful partnership. Theres certainly
proof in the numbers in a 14-year long working relationship, BBR Contech has designed and
installed BBR post-tensioning for 46 floors for commercial property specialist Goodman. Together,
they have created an impressive total of 350,000m2 of post-tensioned floors equating to around
50 rugby pitches this is a significant achievement in anyones terms.

The post-tensioned floors, ranging in size

from 2,000m2 to 30,000m2, have been
installed in five business parks in Auckland,
all owned and managed by Goodman
Property Trust an NZX listed entity which
has a NZ$2.2 billion property portfolio
and around a million square meters of
rentable space in business parks, industrial
estates, office parks and warehouse and
distribution centers.
Goodmans success reflects its focus on
owning, managing and developing only
premium-quality properties in New
Zealands main distribution centers of
Auckland and Christchurch. All of its assets
offer modern, highly functional spaces for
a range of customer uses and many
provide on-site facilities, such as gyms,
cafs, banks and childcare services.
Located close to major arterial routes and
city centers, they have attracted around
250 customers including global brands
such as DHL, BMW, Toll and Woolworths
and are delivering enviably high
occupancy and retention rates. A number
have also won awards for their architectural
merit, environmental sustainability and
investment performance.
1

48 CONNCT | EDITION 10

PORTFOLIO BUILDINGS

Post-tensioned
flooring is definitely
my first choice where
its an appropriate
option and Id
certainly recommend
it to others.
Peter Yendell, Infrastructure Manager, Goodman

Insistence on PT floors

effectively throughout their lifecycles, as

Goodman has specified PT floors for

this ultimately improves their long-term

about half of its total property portfolio.

environmental and financial performance.

According to Peter Yendell, Goodmans

PT floors offer a number of advantages

Infrastructure Manager, the companys

over the alternatives. For a start, they're

decision to use the technique reflects its

stronger so they can handle heavier loads,

commitment to long-term investments

and they have a total absence of joints,

and insistence on quality at every stage of

which reduces the risk of cracking and

the construction process.

avoids joint degradation. They also have a

We operate in a competitive market where

more attractive appearance, are easier to

our ability to attract and retain high-caliber

maintain and have longer lifespans and

customers depends on the quality of our

they provide us with flexibility for fit-outs,

properties, he says. We strongly believe

which is vital in meeting our customers

in building well and managing our assets

specific operational needs.

1 BBR Contechs regular customer, Goodman,

owns, manages and develops premium
quality properties for a range of clients
including global brands such as BMW.
2 The award winning Ford Building in the
Highbrook Business Park incorporates a
post-tensioned concrete floor system
providing largely column-free interior space
with minimal structural depth.
3 At East Tamakis Highbrook Business Park,
BBR Contech installed a 30,000m2 slab
for Goodman tenant DHL Excel.
4 Kmarts principal distribution hub on the
M20 estate in Manukau City where, since
2008, BBR Contechs post-tensioned floors
have provided effective solutions for the
construction of 11 separate facilities.
5 Fliway one of New Zealands largest
logistics providers has its Auckland branch
office at Westney Industry Park where BBR
Contech has installed post-tensioned floors
for 10 of the parks buildings.

www.bbrnetwork.com 49

PORTFOLIO BUILDINGS

14 years of performance
The BBR Contech-Goodman partnership
began in 2002 at The Gate, a premium
industrial estate in Penrose. Working with
head contractor Haydn and Rollett, Allied
Concrete and concrete floor specialists
Conslab, the BBR Contech team designed
and installed eight PT slabs in four years,
with floor areas ranging from 2,000m2 to
10,000m2 and totaling 36,000m2.
In the 10 years since then, the team has
applied its post-tensioning expertise to:
Goodmans flagship property, the
world-class Highbrook Business Park,
which is situated on 150 hectares of
landscaped grounds and parkland in East
Tamaki. Between 2006 and 2014 BBR
Contech installed the PT for 21 floors
covering a total 172,700m2 the largest
being a 30,000m2 slab in 2007 for

Goodman tenant DHL Exel. The estate

continues to be actively developed, with a
further 42.6 hectares of land still available.
M20 Business Park, which offers more
than 100,000m2 of warehouse and office
space in the heart of Manukau City.
BBR Contech installed PT for 8,000m2
of flooring for tenant James Halstead
Flooring in 2008 and has since installed
a further 43,000m2 in 10 more buildings,
the most recent in 2015. At the M20
estate, post-tensioned floors have been
an effective way of designing and building
over a combination of hard and soft pile
raft systems, allowing the elimination of
pile caps and ground beams.
Savill Link, a warehouse estate for both
medium and heavy industrial uses, in
which BBR Contech installed PT for
26,400m2 of flooring one slab of
6,400m2 and the other 20,000m2 in

2011 and 2013.

Westney Industry Park, a premium
industrial space located next to Auckland
International Airport, whose occupants
include Cotton On, DSL, DHL, Fliway,
Linfox Logistics and Supply Chain

International perspective

Solutions. BBR Contech worked on the

Goodmans commitment to excellence and

site between 2006 and 2008, installing

its extensive customer base expose it to

PT for 57,700m2 of flooring in 10 of the

trends and developments on a global scale.

parks 16 buildings.

Peter says that New Zealand appears to

Asked why he keeps coming back to BBR

use post-tensioned flooring to a far greater

Contech, Peter says: As a company that

degree than do Goodmans counterparts

specializes in designing and installing

around the world.

post-tensioned floors, they offer very

This may be because of customer

sound engineering solutions that meet

specifications, personal preferences and

our customers needs. They work in close

engineering and cost considerations, but it

partnership with concrete floor specialist

still surprises me, he says. Post-tensioned

Conslab and our numerous building teams

flooring is definitely my first choice where

to consistently deliver a quality product

its an appropriate option and Id certainly

that meets our budget.

recommend it to others.

50 CONNCT | EDITION 10

TEAM & TECHNOLOGY

Owner Goodman Property Trust
Technology BBR CONA flat
BBR Network Member BBR Contech
(New Zealand)

PORTFOLIO BUILDINGS

GUOCO TOWER, SINGAPORE

Progress report on high rise PT construction project

REACHING FOR THE SKIES

Guoco Tower located on top of the

The Tanjong Pagar Development is a

The post-tensioned beams are 700mm

Tanjong Pagar MRT Station, at the

mixed scheme comprising a six storey

deep and vary in width from 1,000mm to

podium and two towers of 20 and 64

3,000mm. The deep deck system

storeys respectively. The 64-storey tower

comprises 1.2mm thick steel sheets formed

Peck Seah Street will be Singapores

will house 38 floors of Grade A office

into tapered ribs of 250mm deep and

tallest building when completed.

space and 26 floors of residential

100-190mm wide at 600mm spacing, with

Singapore-based BBR Construction

apartments, while the 20-storey tower

a 150 to 180mm thick structural topping.

will be a 200-room hotel.

There is a seven meter maximum clear span

The structural system used for the tower

between beams. The slab was analyzed and

progress report of work on this

consists of one way post-tensioned

checked as a plate to mobilize the torsional

spectacular project.

beams with deep deck system slabs.

stiffness of the beams and columns.

junction of Choo Guan Street and

Systems provide a photographic

1 The Guoco Tower takes shape as part of

Singapores Tanjong Pagar mixed
development.
2 View of a typical deep deck slab, at the Guoco
Tower site, where there is a maximum clear
span of seven meters between beams.

TEAM & TECHNOLOGY

Developer Guocoland Limited
Architect Skidmore, Owings & Merrill
LLP (SOM)
C&S consultant Arup (Singapore) Pte. Ltd
Main contractor Samsung C&T
Corporation
Technology BBR CONA internal
BBR Network Member BBR Construction
Systems Pte. Ltd. (Singapore)
2

www.bbrnetwork.com 51

PORTFOLIO BUILDINGS

Q22, WARSAW, POLAND

PT slabs for high rise building

CHANGING THE
WARSAW SKYLINE
For the last two years,
BBR Polska has been delivering
specialist post-tensioning
technology and know-how for
the construction of one of the
tallest high-rise buildings in
Warsaw. Bartosz ukijaniuk,
BBR Polskas Design Team &
Works Manager, tells of the
companys role in the
realization of the 155m high
office building, known as Q22.
The building is being constructed on
the site of a former hotel which was
demolished to make way for new offices.
With an address in the heart of Warsaws
business district and vision of providing
first class office space, this has been
an extremely prestigious building project
right from the design stage, through
project management and site
supervision, onto the execution of the
various elements. It would be no
surprise, therefore, to learn that only
top class specialists were invited to join
the project.
Building layout
The building has five underground levels
and 42 storeys above ground, 39 of
which are post-tensioned. The first 16
above ground levels form an 84m x 30m
podium from which the 26-storey
tower pentagonal on plan, 55 x 30m
begins to rise. The total slab area is
around 58,800m2 and the whole building
will offer some 50,000m2 of office
space and also house many amenities
including restaurants, fitness area and
lockers for cyclists.
1

52 CONNCT | EDITION 10

PORTFOLIO BUILDINGS

Post-tensioning

Construction phases & schedule

There were uneven spans between columns

Construction of the building was divided

and walls, thus some areas of the slabs

into two phases. Firstly, the tower part was

were heavily post-tensioned, some areas

constructed, then secondly, when the tower

only have tendons in column strips and

reached level 20, work on the podium

some have no post-tensioning at all. We

section began.

used the BBR VT CONA CMF system for

The construction schedule was extremely

all the slabs. In addition, a few edge beams

tight. Each whole level including walls,

were post-tensioned with 1206 BBR VT

columns and slabs was constructed in

CONA CMI tendons due to long spans

five days.

and deflection limitations.

Such a challenging time schedule fostered

The slabs were designed, by Buro Happold

good cooperation between all teams

engineers, to be post-tensioned with flat

involved in the execution process. The

bonded tendons. Our design scope was to

very detailed planning of the construction

deliver the detailed tendon layout. Close

sequence, carried out by the highly skilled

cooperation between the design parties

and experienced frame contractor

BBR Polska, gp-projekt and Buro Happold

engineers, was extremely important.

resulted in an excellent performance on

Despite the challenges, the construction

site. At this point, it is also important to

process went smoothly.

mention that the detailed designs for

The realization of our part of the project

post-tensioning and mild reinforcement

took about ten months. During this time we

were coordinated along with other detailed

installed 153t of stressing steel in almost

elements such as faade fixing design,

2,000 tendons and for the grouting, we

design of the mounting for the temporary

used almost 55t of cement.

wind shields (structures needed during the

For the BBR Polska team, it was a fantastic

lifting process) and other temporary and

experience to work on such a project and

permanent structural and finishing items.

a great opportunity to demonstrate the

advantages that PT technology brings to
the construction of high-rise buildings.
Working in the confined space of a single
slab pour, together with mild reinforcement
fixers and under time pressure where the

1 The extremely prestigious Q22 project will

provide first class office space in Warsaws
business district.
2 With very tight schedules, the project fostered
good cooperation by all teams involved.
Photograph courtesy of gp-projekt sp. z o.o.
3 Inspection of one of the completed levels
each of which including walls, columns
and slabs was constructed in five days.
Photography courtesy of Micha Stefanowicz.

complete installation of tendons for one

slab pour took only one day, was a challenge
which we overcame with great success.
We hope that our experience, in terms of
both execution and design, will be called
upon in the future to benefit other high-rise
buildings that will be constructed in Poland.

For the BBR Polska

team, it was a fantastic
experience to work on
such a project and a
great opportunity to
demonstrate the
advantages that PT
technology brings to
the construction of
high-rise buildings.

TEAM & TECHNOLOGY

Developer & general contractor Echo
Investment S.A.
Architect Kurylowicz & Associates
Sp. z o.o.
Structural design (inc PT) Buro Happold
Polska Sp z o.o.
PT detailed design gp-projekt sp. z o.o.
& BBR Polska Sp. z o.o.
Frame contractor Modzelewski & Rodek
Sp. z o.o.
Project management & supervision
Gleeds Polska Sp. z o.o.
Technology BBR VT CONA CMF flat,
BBR VT CONA CMI internal
BBR Network Member BBR Polska
Sp. z o.o. (Poland)

www.bbrnetwork.com 53

PORTFOLIO STAY CABLES

RZESZW BRIDGE, RZESZW, POLAND

Speedy stay cable installation

VOYAGE OF
DISCOVERY
By the time Kate Janikowska, Press Officer of BBR Polska, arrived at the
Rzeszw Bridge site with her camera, the team had already installed
the last stay cable and the official opening of the bridge was rapidly
approaching. She thought that there would be nothing new to photograph,
but her visit soon became an exciting voyage of discovery.

It was relatively late when I reached the

construction site late in the day and
towards the end of the construction phase,
the last stay cable had already been
installed. There was a certain stillness
about the place and the site looked quiet
compared to the hectic earlier days of
the project.
This was a shock, so I checked the date.
Had the appointment really been made
for today? The site was definitely the
right one this was the only thing I could
be sure of, as I had spotted Rzeszws
massive new landmark from way off in
the distance.
The security guard explained that most
teams had already left the site and
would be back tomorrow, only the BBR
team was still there they would work
until at least 7pm, but they were all inside
the pylon.
After texting my hosts and a short wait at
the barrier, BBR Polskas Chief Engineer
Master Builder Tomasz Borsz appeared,
waving and hurrying towards me. On
hearing my concerns about the apparent
lack of anything significant being underway,
Tomasz set out to prove just how exciting
the project still was even at this
1

54 CONNCT | EDITION 10

advanced stage so close to completion.

PORTFOLIO STAY CABLES

www.bbrnetwork.com 55

PORTFOLIO STAY CABLES

Significant moment

which belongs to Rzeszw Power Plant

As we stood beside the new bridge deck,

and it also had to be crossed without

Tomasz pointed to the gap between the

using piers. Thus a cable-stayed bridge,

deck and its temporary supports. The

with a 107.2m high pylon, was considered

bridge was now suspended by the stay

the perfect solution.

cables. This meant that the 64 BBR HiAm

For all these reasons, Rzeszw now has a

CONA stay cables were fully installed and

landmark bridge and the contractor has

doing their job as intended.

had the opportunity to design and

construct a cable-stayed structure, a

Cable-stayed solution

solution normally only chosen for crossing

It really was 30 years ago that the northern

the major Vistula or Odra rivers, as Poland

inner by-pass of the city had first been

has no dramatic topographical features.

envisaged, as a response to predictions

that Rzeszw city center would soon need
relief from traffic congestion. It was
planned that West-East transit traffic was
to be transferred to the new bypass.
Rzeszw is the biggest city in south east
Poland and, since 1999, has been the
capital of Podkarpackie Voivodeship.
At first, the large size of the bridge seemed
surprising, as was the decision to erect a
cable-stayed structure over a watercourse
only several meters wide but the bridge
spans more than just the Wisok river.
One of the design requirements was to
reduce the number of piers, both in the
river and on the flood plain, as the area is
protected under the Natura 2000
environmental scheme. Next, there is a
water reservoir adjacent to the river,

56 CONNCT | EDITION 10

1 BBR Polskas Chief Engineer Tomasz Borsz

hosted many visits to the site, as well as
leading the stay cable installation team.
2 Rzeszw Bridge at night, just after the official
opening ceremony. Photograph courtesy of
Porr Polska Infrastructure SA / press material.
3 Late in the afternoon, the Rzeszw Bridge
site looked still and silent, as most of the
BBR Polska team were at work on top of or
inside the pylon.
4 A significant moment the stay cables were
now carrying the weight of the bridge.
5 The completed bridge pile heads of the
temporary supports are still visible in the river
beneath and awaiting dismantling and the
concrete base rings filling with underwater
concrete by divers. Photograph courtesy of
Porr Polska Infrastructure SA / press material.

PORTFOLIO STAY CABLES

The bottom of the power plant water

reservoir is covered with an HDPE liner
which had to be cut each time a pile was
to be driven, thus avoiding uncontrolled
tears in the liner.
So, for each pile, a diver would jump into
the water, cut the liner, then the pile was
driven to the exact co-ordinates and
covered with a prefabricated collar made
of HDPE lining material. Next, the collar
had to be pressed with a concrete ring
and filled with aggregate. When the
temporary supports are dismantled, the
piles will be cut and the rings will be filled
with concrete poured under water.
Exciting trip upwards
Next, Tomasz escorted me to the top of
the pylon so that I could examine more
closely one of the places in which our
4

team had been working.

The pylon, shaped like an inverted tuning
fork, is essentially a reinforced concrete
structure with a box cross-section,
strengthened with steel inserts located at

The 64 stay cables,

Fancy footwork

the upper stay cable anchorages. The 64

The new bridge has five spans (30 + 30 + 30

stay cables, arranged in four sets of 16

arranged in four

+ 150 + 240m). There are six piers two of

cables each, spread from the pylon in two

sets of 16 cables

which are abutments, three others tie-down

planes like a fan.

the back span and the last one is the pylon.

The live end anchorages in the pylon are

each, spread from

The structure was incrementally launched,

spaced every 1.7m, while the passive

the pylon in two

so there were 22 temporary supports

anchorages are at 12m intervals in the

11 on each side of the bridge and these

deck between the carriageway and the

planes like a fan.

required some really fancy footwork.

lanes for pedestrians and cyclists.

www.bbrnetwork.com 57

PORTFOLIO STAY CABLES

View from the top

appreciation of the work scope and fast

The view from the top of the pylon was

program, it is easy to understand why

simply stunning. However, the view down

Tomasz Borsz believes that Bilfinger

inside the pylon was even more impressive.

Infrastructure should receive a special

There were around five stepladders leading

award for their excellent site organization.

downwards and I could just make out the

It may look simple, commented Zygmunt

high visibility safety vests and helmets of

Dereszkiewicz, Bilfinger Infrastructures

the BBR team working way below us. The

bridge works manager, but actually, the

reason that the site looked empty is that

achievement is a direct result of BBR

most members of the BBR team were

Polskas experience and ability to

inside the pylon and therefore not visible.

cooperate in extreme conditions as each

It was hard to imagine that, just a few

structure is different. They are a perfectly

months before, steel fixers and concrete

organized team, said Konrad Przymorski,

placers were working above the heads of

also from Bilfinger Infrastructure, but its

the BBR team.

really great that the cables have now been

Also, some of the crew were working inside

installed because when they were laid out

the deck where they were injecting the

on the deck you couldnt walk or drive on it,

anchorages with resin and installing end

he added with a smile.

protection caps both procedures are

Experience is certainly an important factor.

for corrosion protection. This site, like

Our team has applied BBR stay cable

many similar projects, has two extreme

technology to several dozen structures

environmental conditions the wind at

most frequently between 30 and 120m

of the anchor zone a steel pipe to carry

the top is fearsome while inside the deck,

high, all with long cables and a large

the cable and an anti-vandal pipe.

it is incredibly hot.

number of strands. While the stay cables

Having never seen it before, I consulted

Progress has been really breathtaking

in Bydgoszcz, our previous stay cable

Tomasz Borsz who explained that

the whole project, along with the access

project, have a significant cross-section

measurements would be taken during a

roads, was completed in less than two

from 72 to 109 strands the largest

structural monitoring phase. The results

years. Stay cable installation was carried

stays in Rzeszw have 114 strands.

of the monitoring will form the basis for

out at a cracking pace by the 16-man BBR

On closer inspection of the BBR HiAm

establishing damping parameters and

Polska team who finished their work in just

CONA stay cable pipes which feature

then the most optimal BBR damping

nine weeks.

helical ribs as a primary countermeasure

device will be selected. It is currently

The safe, comprehensive and effective

against cable vibration I noticed

envisaged that BBR Viscous Dampers

scheduling of numerous phases, trades

something interesting. There was space

will be installed in half of the stay cables.

and workers has been an outstanding

to install a damping device. The damper

We will await with great interest to see

feature of this project. Now having an

housing is located between the bottom

what decisions are made.

58 CONNCT | EDITION 10

PORTFOLIO STAY CABLES

Special visitors

Trade secrets

Once inside the site office, I was shown

My musings were suddenly interrupted

some photographs among them, pictures

when I hit my leg on something hard under

of Messrs Voon, King and Seven from

the table. It was a box and just as I was

BBR Malaysia on site, here in Rzeszw.

about to look inside, Tomasz warned me

Tomasz described how stay cable

Dont touch! Thats the Chief Engineers

specialists are always curious about the

Stay Cable Tool Box. Then, he relaxed a

approach to cable installation techniques

little: Well, OK you can have a look, but

taken by teams worldwide. While it may

no photographs inside are our specialist

seem that installation is carried out in

tools. In the box, I saw some tiny wedges

exactly the same way for every project, in

Tomasz would not let me take one and

fact no two structures are identical.

something that looked like pliers. Thats

There had been other guests too. Dr Behzad

enough, said Tomasz abruptly, Im taking

Manshadi from BBR VT International Ltd

the box with me.

came to observe the installation and

Thus, my exploration was over when

performance of the BBR CONA HiAm

Tomasz left the office with his precious

system. Also, Gnter Damoser of KB

box and, incidentally, my coffee as well.

Vorspann-Technik GmbH had also been

It was clearly time for me to leave and

on site several years earlier, he had

reflect on how the devil is always in the

hosted Tomasz at his Sava Bridge

detail. This project has not just been about

construction site in Belgrade and this was

the huge stay cables, kilometers of strand

a return invitation. The two engineers had

and tons of steel, but also about taking

a brainstorming session about the most

care of the small details which, to the

effective technological solutions on their

casual observer, are hard to see in the

respective projects.

shadow of the imposing 107m high pylon.

6 The stunning view downwards from the top

of the pylon.
7 Right to left: Messrs Voon, King and Seven
from BBR Malaysia taking a well-earned
break after helping the BBR Polska team
with cable installation during their visit to the
Rzeszw Bridge site.
8 The BBR Polska team assembles at the top
of the pylon, ready to go home at the end of
the day.

TEAM & TECHNOLOGY

Owner Gmina Miasto Rzeszw
Architect Promost Consulting
Designer Mosty Gdansk
Main contractor Porr Polska
Infrastructure (formerly Bilfinger
Infrastructure)
Technology BBR HiAm CONA stay
BBR Network Member BBR Polska
Sp. z o.o. (Poland)

www.bbrnetwork.com 59

PORTFOLIO STAY CABLES

ELIZABETH QUAY PEDESTRIAN BRIDGE, PERTH, AUSTRALIA

Hanger installation & heavy lifting

ARCHITECTURAL
HIGHLIGHT ON
THE WATERFRONT
The BBR Network Member in Australia, SRG, has played a crucial role in the construction of the iconic
centerpiece feature, of Perths exciting new Elizabeth Quay development a double arch pedestrian
and cyclist bridge. Richard Blair of SRG provides an overview of the project.

Elizabeth Quay is a major Western

Australian development project currently
under construction in Perths central
business district being delivered by the
State Government. Located on the north
shore of the Swan River, the Elizabeth
Quay development is a A$2.6 billion
project designed to revitalize Perth and
embrace one of citys best natural assets.
The project is a significant development
for the city and will feature a stunning
inlet connected by 1.5km of continuous
boardwalks and promenades, delivering
great public leisure spaces, new hotel and
short stay accommodation and
contemporary inner city living opportunities.
Landmark bridge
Working together with Decmil and Hawkins
Civil under the DASSH Joint-Venture, we
were contracted by Leighton Broad to
bring the unique double arch bridge design
to life, through technical engineering and
construction work.
The 20m high double arch, cable-stayed
suspension bridge is the first of its kind
in Perth. In line with Australias many
renowned port and waterfront icons,
the Elizabeth Quay bridge will create a
striking architectural feature for the
future precinct and the city, connecting
the ferry terminal and Williams Landing to
the new Island.
1

60 CONNCT | EDITION 10

PORTFOLIO STAY CABLES

Lifting experience
SRGs expertise in innovative structural
engineering and detailed civil infrastructure

HENDON PARK FOOTBRIDGE, AUCKLAND, NEW ZEALAND

PT expertise for pedestrian and cycling bridge

has been integral to bringing the ambitious

architectural design to reality. The bridge
has been under construction since early
2014 and, last year, the massive 86t arches
were constructed and lifted into place.
Due to the size and shape of the arches,
lifting and erecting each structure was no
easy feat, the boom radius did not allow
the arch lift to be completed in a single
operation. A 275t crawler crane and
hydraulically adjustable intermediate prop
were utilized to support the arch at a lower
level before tracking the crane back to

STRIKING
SIMPLICITY

complete the lift. This complex process

was made possible through the expertise

If there were a competition for the most beautiful bridge in New

and hard work of a number of skilled

Zealand, the list of contenders would be a long one but the latest kid

structural and civil engineers, structural

steel fabricators and site operatives.

on the block could very well steal every prize going.

Hangers

The team at BBR Contech are thrilled to

arctic white, will curve through space,

Our extensive experience with

be part of the 320m-long Hendon Park

connecting to a sculpted arch via a

cable-stayed structures saw the in-house

Footbridge project, a key element in the

complex cable configuration that forms

design and operation of the bespoke

largest and most ambitious road scheme

a hyperbolic paraboloid.

cable stressing assemblies, with a pair

ever undertaken in New Zealand. Called

BBR Contech has supplied PT bars for

of 30t center hole jacks applying the

the Waterview Connection, the NZ

two massive concrete abutments that

loads to enable pin engagement.

Transport Agency's NZ$1.4 billion project

will take the load of the main arch bridge.

A total of 16 hangers tie the arches and

will provide the final link in a 48km

It has also supplied all 39 steel hanger

bridge deck together. Each span

motorway ring route around Auckland city

bars helping to create a bridge that

comprises a mix of 25, 30 and 35mm

easing congestion on state highways

will be loved, lingered on and talked

diameter hangers in varying lengths to

elsewhere in the network, enabling better

about for many years to come.

best suit the load case at each location.

connections for motorists and improving

Having completed the main structural

links to the citys northern and southern

elements of the bridge, the next steps in

neighbors.

TEAM & TECHNOLOGY

the project will see the deck and

The simple, elegant and utterly beautiful

architectural finishes installed ahead of

pedestrian and cycling bridge was designed

the opening to the public.

by Beca and Warren & Mahoney Architects

For SRG, it has been a privilege to be

and is being built by the Well-Connected

involved in this significant development

Alliance. Its ten span concrete deck with a

for the city of Perth and to deliver this

central 80m span over SH-20, finished in

Developer NZ Transport Agency

Architect Warren & Mahoney
Designer Beca
Main contractor Well-Connected Alliance
Technology PT bars, steel hangers
BBR Network Member BBR Contech
(New Zealand)

important component of the project for

Leighton Broad.

1 One of the two massive 86t arches being

lifted into place for Perths new double arch
cable-stayed suspension bridge.

TEAM & TECHNOLOGY

Owner Metropolitan Redevelopment
Authority
Architect ARUP
Designer ARUP
Main contractor Leighton Broad
Technology Heavy lifting, hangers
BBR Network Member SRG Limited
(Australia)

www.bbrnetwork.com 61

PORTFOLIO SPECIAL APPLICATIONS

ONSLOW WATER TANKS, WESTERN AUSTRALIA

Post-tensioned precast panels

INNOVATIVE WATER
TANK SOLUTION
BBR Network Member SRG
recently completed a major
project for Western Australias
Water Corporation to construct
two 5ML water storage tanks
and associated pipelines, in the
town of Onslow, 1,400km north
of Perth, on the Pilbara coast.
The recent development of several large
gas field projects in the vicinity of Onslow
was driving town growth and increased
water demand. The existing town water
supply infrastructure had reached its
capacity and two new water storage tanks
were needed to ensure the township has
sufficient water to meet its current and
future needs.
Innovative bid
A tank design and construct contract was
issued with the option to submit bids for
the construction of either steel or concrete
tanks. SRGs project team submitted a
successful bid to construct concrete tanks
based on an innovative post-tensioned
method. The advantage of using concrete
is that it requires less ongoing maintenance
than steel and lasts up to 100 years.
SRG developed pioneering precast panels,
post-tensioned in two directions, to
overcome any potential cracking in the
precast concrete. The panels were cast in
Perth and then transported to site where
they were stitched together using a
customized concrete mix that responded
to the harsh environmental conditions.
This process ensures the concrete is
kept in compression in both directions.
Should a micro-crack occur in the
concrete, the panels have been designed
to self-seal effectively closing the crack.
1

62 CONNCT | EDITION 10

PORTFOLIO SPECIAL APPLICATIONS

First in Australia
The contract also required that the tanks,
which weigh 6,000t, be constructed on
sandy ground. Because of the potential for
ground settlement, under the weight of the
tanks, each tank site was pre-loaded with fill
material to self-compact prior to the tanks
being constructed. Specialist settlement
sensors were obtained from the US for this
part of the project, which was the first time
this technology had been used in Australia.
SRG was the principal contractor for this
project and responsible for the full
management of the design, construction,
testing and commissioning of the two
water tanks. This also involved managing
contractors and consultants who were
also on site.
This contract was, however, not without its
environmental challenges. Over the course
of the project there were cyclones and
floods. Nevertheless, the team was able to
overcome these weather events to deliver
a successful outcome on-time for the client
all the while working in the relentlessly
extreme heat of the Pilbara region.
2

I am writing to thank you and the

SRG team for the great work
undertaken in the design and
construction of the two 5 ML water
storage tanks and associated
pipelines at Onslow, WA.
This project has been challenging
given its remote location and
climate. However, these challenges
have been overcome through
detailed planning and organization

SRG has consistently

1 SRG developed pioneering precast panels
which were cast in Perth and transported
to site for erection.
2 The 6,000t tanks had to be constructed
on sandy ground, so each tank site was
pre-loaded with fill to self-compact and
specialist sensors were used for the
first time in Australia to monitor any
potential settlement.
3 Members of SRGs senior management visit
site to review the completed project. Left to
right: David Macgeorge (Managing Director),
Radwan Hamoshi (Project Manager), Kim
Boyd (Regional Manager Construction).

demonstrated its commitment to

managing the existing environmental
TEAM & TECHNOLOGY
Client Water Corporation Western
Australia
Main contractor SRG Ltd
Technology Precast PT panels
BBR Network Member SRG Ltd
(Australia)

conditions and maintaining a safe

worksite during the entire project.
Scott Shand, Project Director, Regional Water Conveyance

www.bbrnetwork.com 63

PORTFOLIO SPECIAL APPLICATIONS

BIBOSUT PUMPING STATION, VINKOVCI, CROATIA

Permanent & temporary ground anchors
2

ANCHORING FOR
AGRICULTURE
Several droughts during earlier years of the 21st century have endangered the stability of agricultural
production in Croatia. Now, as part of a national project to improve irrigation and land and water
management, a new pumping station is under construction near Vinkovci, in the Bi-Bosut area
with some expert help from local BBR Network Member, BBR Adria. Goran Tomiic
outlines the
project which involves the regions largest ground anchoring operation in the last five years.

1 The first and second rows of anchors were

installed at an angle of 6 and the third and
fourth line at an angle of 15 spacing was
at 2.5m.
2 Aerial view of the site, showing amelioration
channel, with construction of the pumping
station on its alignment and River Sava in
the background.

TEAM & TECHNOLOGY

Owner Hrvatske vode
Main contractor Eurco d.d.
Designer Institut IGH d.d
Technology BBR VT CONA CMG ground
BBR Network Member BBR Adria d.o.o.
(Croatia)

64 CONNCT | EDITION 10

The new 16.4 x 20.5m pumping station

Reinforced walls

will provide water for irrigation through

Construction of the pumping station began

the controlled release of water from the

with reinforced concrete retaining walls.

Sava River to raise low water levels in the

The 11m deep construction pit is rectangular

amelioration channel. The station, which

with an area of just over 805m2. It has been

is located in the amelioration channel,

designed and constructed with reinforced

will have a total pumping capacity of

concrete retaining walls featuring four rows

10m3/s using four pumps with a flow

of ground anchors. The walls will also form

rate of 2.5m3/s each and be capable of

part of the pumping station itself. The

pumping to a height of four meters.

function of the retaining walls is three-fold

The 16.4 x 8.8m section of the project

to preserve the stability of the vertical

dealing with drainage takes the form of

excavation of the construction pit, prevent

cascading pools of differing heights.

the hydraulic fracturing of the soil inside

These allow water to overflow towards the

the pit and, finally, as a part of the ongoing

amelioration channel, leaving sediment

construction of the pumping station.

behind while slowing down water flow and

To support these functional requirements,

having the environmentally beneficial

the retaining walls have been designed so

effect of increasing oxygen levels in the

that the four meter entrances are in an

water as it mixes with the air

area of low permeability silty clay which

prevents water seeping through the bottom
of the excavation.

PORTFOLIO SPECIAL APPLICATIONS

HATAITAI BUS TUNNEL, WELLINGTON, NEW ZEALAND

Ground anchoring and grouting

STRENGTH,
RESILIENCE &
PERFORMANCE
A high-profile project in New Zealands capital city is harnessing
BBR Contechs extensive experience in ground anchoring and grouting.
The Hataitai Bus Tunnel opened in 1907,

To achieve this, the team installed a

providing much-needed access for trams

total of five full-scale proof anchors and

running between Wellington city and the

30 double-corrosion-protected anchors

eastern suburbs of Kilbirnie and Hataitai.

using 32mm and 40mm PT bars. It was

In 1963, electric trolley buses replaced the

a complex process that included water-

trams and, today, buses continue to travel

tests for the drilled anchor boreholes,

Ground anchors

the tunnels 365m length, making about

preliminary grouting and re-drilling,

The BBR VT CONA CMG ground anchors

2,400 journeys a week.

full-scale on-site suitability and pull-out

comprise four strands, each with a

A structural assessment in 2014 revealed

tests and repeated cycles of high-

cross-sectional area of 150mm2 and a

that, while the tunnel was likely to

pressure post-grouting for all the

characteristic tensile strength of 1,860MPa.

withstand a reasonably large earthquake,

ground anchors.

The anchors are founded in layers of sand

the adjacent hillside and old tunnel

Comprehensive project and noise

and gravel of medium or thick compaction

entrances could come down and block

management plans ensured minimal

and stressed to 400kN.

the route.

disruption for bus schedules, passengers,

The first and second rows of anchors

This was the cue for BBR Contech and

local residents and businesses.

were installed at an angle of 6 and the

a six-month project starting in November

third and fourth line at an angle of 15,

2014. Technically demanding owing to

they are spaced 2.5m apart. We installed

the site itself and poor ground conditions

a total of 5,526m of temporary anchors

in places, it included strengthening the

and 2,511m of permanent anchors.

tunnel portals by excavating for and

constructing new vertical buttresses and

Further stages

wing extensions on both sides of each

After the excavation of the foundation

entrance and attaching a new

pit, the base plate and inner walls of the

reinforced-concrete ground beam across

pumping station will then be executed,

the top of each portal.

TEAM & TECHNOLOGY

Owner Wellington City Council
Designer Opus International Consultants
Technology PT bar ground anchor
BBR Network Member BBR Contech
(New Zealand)

along with the floodgates. To achieve a

monolithic effect for the structure, a
connection needs to be created between
the structure and the inner structure
of the retaining walls. This will be
accomplished by installing fasteners
(dowels) in the retaining walls.
The geotechnical anchors installed in
the northern and southern retaining
walls are permanent corrosion protected
anchors, while those in the western and
eastern walls are temporary and serve
only while the retaining walls are needed
to protect the construction pit. We have
installed a total of 83 permanent and
234 temporary anchors for the project.

www.bbrnetwork.com 65

PORTFOLIO SPECIAL APPLICATIONS

SWISS PT INNOVATION
Non-standard applications meet customer needs

LIMITLESS APPLICATIONS
FOR POST-TENSIONING
BBR technology has always
proved flexible and its innovative
use for non-standard applications
1 Railway Bridge Lotto 781 in Bellinzona.
Two short BBRV tendons were installed as
seismic protection.
2 Tendons passing from foundation into the
pier of Railway Bridge Lotto 781.
3 Railway Bridge Lotto 782 in Bellinzona two
short BBRV tendons fix the bridge deck to
the pier.
4 Post-tensioned steel girder for Terminal 2 at
Zurich Airport. The dead end anchorage can
be seen on the left, with the deviation saddle
in the center.
5 The House of Natural Resources, ETH Zurich
provides offices and also serves as a pilot
installation for studying the structural
performance of wood from deciduous trees,
combined with post-tensioning.
6 The House of Natural Resources, ETH Zurich
the laminated beams of each span are
connected to the hardwood columns only
by one post-tensioning tendon which has
been pushed through the central cavity of
the beams thus they are flexurally rigid.

66 CONNCT | EDITION 10

1 Seismic protection for railway viaduct

Near Bellinzona in Switzerland, 15 piers
of a 1,010m long railway viaduct had to
be stabilized by anchoring into the

to meet customer requirements

foundation blocks. The requirements for

is embraced the world over. Jrg

this project were:

Dniker of Swiss-based BBR

tendon length approx. 3.5m

Network Member, Stahlton AG,

reports on several projects from
the past year where his company
has supported engineers in
devising and implementing

tendon force between 5,270 and

8,933kN MBL
tendon must permit for adjustment due
to settlement of -50/+140mm
angular rotation of +/-1.4 degree
tendon must be electrically isolated
On either side of the central guide bearing,

innovative yet practical solutions

Stahlton proposed the use of BBRV wire

to construction challenges using

tendons with 82, 102 or 139 galvanized

BBR post-tensioning systems.

7mm diameter wires encapsulated in thick

walled PE ducts filled with a flexible grout
to protect against corrosion.

PORTFOLIO SPECIAL APPLICATIONS

4 Wood strong enough for PT

In Switzerland, wood from deciduous trees
is mostly burned, used for heating pellets
or sold abroad. In the opinion of Professor
Andrea Frangi from the Institute of Structural
Engineering at the ETH in Zurich, this is very
uneconomic. He believes it would be more
sustainable, if the hardwood were first to be
used for structural components, after that it
could be processed into chipboard and finally
it still could be burned in high temperature
ovens to provide heating.
Together with his students, he searched for
an optimized use for wood from deciduous
trees, utilizing its good performance and the

higher strength compared to pine. Finally,

on the campus of the ETH Zurich, he
constructed a four storey building The
House of Natural Resources which acts

TEAM & TECHNOLOGY

1 Owner Swiss Federal Railway

represented by AlpTransit San

Gottardo SA
Main contractor Consorzio MPC c/o
Muttoni SA
Designer Consorzio Ingegneri c/o
Brenni engineering SA
Technology BBRV wire
2 Owner Swiss Federal Railway

represented by AlpTransit San

Gottardo SA
Main contractor Consorzio MPC c/o
Muttoni SA
Designer Consorzio Ingegneri c/o
Filipini & Partner SA
Technology BBRV wire
3 Owner Flughafen Zurich AG

Main contractors Baltensperger AG,

Schneider Stahlbau AG
Designer STB Schnyder + Tobler
Technology BBRV wire external
4 Owner Eidgenssische Technische

Hochschule Zurich (ETH)

Main contractor Hring & Co. AG
Designer ETH Zrich, Institut fr
Baustatik und Konstruktion (IBK)
Technology BBR CONA unbonded

2 PT to avoid bearing displacement

as pilot installation and office building at

For the neighboring 443m long railway

the same time. Over its lifetime, it will be

bridge, the starting position was different.

monitored for forces, deformations,

To take up the huge forces of a train braking

vibrations, temperature and humidity.

on the bridge and to avoid displacement at

The two wooden storeys of the house consist

the bearings, the requirements for the PT

of a three dimensional frame structure on a

tendons were:

column grid of 3 x 6.5m without any

tendon length 5.5 to 12.2m

supporting walls. The laminated beams of

tendon force MBL between 1,990 and

each span are connected to the columns

5,270kN, two tendons per pier

tendon type must be exchangeable and
electrically isolated

only by one monostrand post-tensioning

tendon which has been pushed through the
central cavity of the beams (4 x 0.6) thus

We proposed the use of external BBRV wire

they are flexurally rigid. Special anchorages

tendons improved with electrical insulation.

permit for regulation of the tendon force or

the replacement of the load cell. A novelty is

3 Deflection control for load transfer

the composite slab of beech wood panels

Modifications to Zurich Airports Terminal 2

and concrete. The panels act as formwork

required the creation of large new openings

as well as tension elements for the concrete.

for placing escalators. The existing slabs

Machined recesses within the 40mm thick

were a composite construction of steel

beech veneer panels take over the bond and

beams and concrete slabs. Six new steel

shear forces.

beams up to 25m long had to be installed.

The post-tensioning details for this project

Two external post-tensioning tendons

were:

consisting of 52 x 7mm diameter

tendon type unbonded PT tendons

prestressing steel wires each with an MBL

(greased, PE-coated monostrand)

of 3,340kN, allowed deflection control

tendon length 19.85m x 16 tendons

during load transfer from the existing slab

stressing force 700kN (MBL = 1,116kN).

onto the new steel girders.

www.bbrnetwork.com 67

PORTFOLIO SPECIAL APPLICATIONS

UNIVERSITY RESEARCH EQUIPMENT, AUCKLAND & CANTERBURY, NEW ZEALAND

Testing facilities realized for two earthquake laboratories

SUPPORTING
ENGINEERING
EXCELLENCE

With around 20,000 earthquakes

The BBR Contech team has a decades-

recorded each year most recently

long connection with this work

In June 2015, the University of Aucklands

educating undergraduates as guest

Centre for Earthquake Engineering Research

lecturers on post-tensioning and concrete

called on BBR Contech to provide specialist

quakes of 2010/11 it is no wonder

durability, supporting a wide range of

grouting services for a shake table in its

that New Zealand is often called

seismic and other research projects

new, fully enclosed test hall part of the

the Shaky Isles. It is equally no

and, of course, providing an extensive

largest seismic testing facility in Australasia.

range of services both to repair

The halls facilities are used for testing

earthquake-damaged structures and to

large-scale structural components and

universities have made a significant

stop the damage happening in the first

assemblies and to simulate earthquake

investment in research on the

place. In 2015, these connections blended

forces, with technology enabling real-time

nature and effects of earthquakes,

nicely into one, with two university-based

views of the test results.

projects that will enable students to test

The shake table is an integral part of these

new theories in practical, hands-on ways.

experiments. Embedded in a pit and

the devastating Christchurch

wonder that the countrys

with the aim of ensuring that

1 Shaking things up in Auckland

buildings can withstand the severest

measuring about 3.6m x 2.4m, it comprises

of quakes and, most importantly,

an 800mm-high concrete plinth with steel

protect the people within them.

mounting points, to which is attached a

large, 65mm-thick steel plate that can
impose earthquake movements when
loaded with a building structure.
BBR Contechs role was to grout the steel
plate in place using vibration resistant epoxy
mortar. While this may sound
straightforward, it actually required three
phases over two days of intense
concentration and incredible attention
to detail to ensure that the plate was
absolutely level, the grout was free of voids
and the plate itself capable of shaking to
international research standards. The team
had only one chance to get it right and of
course they succeeded, overcoming the
dual challenges of a complex under-plate
structure and the need to work quickly to
place the 300 liters of grout within the
working pot life and thus ensure an effective
epoxy bond.
The team also supplied PT bars for another
part of the test hall a 13m wide x 3.7m-high
strong wall and a 13m x 7.5m strong floor.

68 CONNCT | EDITION 10

PORTFOLIO SPECIAL APPLICATIONS

Together, they enable students to assess

the seismic capabilities of buildings up to
three storeys high, with test assemblies
connected to the wall and floor via fixings
at 500mm centers.
Elsewhere at the University of Auckland,
BBR Contech has continued to support a
PhD students research into the
performance, design and use of FRP
anchors to transfer forces from FRP strips
into or through structural elements. The
aim is to produce a robust design process
for these anchors, so that efficient and
strong FRP solutions can be developed
for structures with complex geometries.

1 The shake table pit showing the concrete

plinth and steel mounting points for the
65mm thick steel plate which will replicate
earthquake movements.
2 The new fully-enclosed test hall takes shape
at the University of Aucklands Centre for
Earthquake Engineering Research.
3 Construction of the University of
Canterburys new structural earthquake
laboratory is underway and due for
completion in March 2016.
4 Facilities at Canterbury will include a
300m2 strong floor and an L shaped
strong wall, both requiring post-tensioning.

TEAM & TECHNOLOGY

1 Owner University of Auckland

Technology Grouting, PT bar

BBR Network Member BBR Contech
(New Zealand)
2 Owner University of Canterbury

Main contractor Dominion

Constructors
Project manager The Project Office
Structural engineer Aurecon
Technology BBR VT CONA CMI
internal, PT bar
BBR Network Member BBR Contech
(New Zealand)

2 More walls & floors further south

total length of 28m. The floor and wall

About 1,000km south of Auckland, the

will feature cast-in inserts at 400mm

University of Canterbury is building a

centers to allow test rigs to be attached.

new, multi-million-dollar structural

Working with main contractor Dominion

earthquake laboratory as part of its

Constructors, structural engineering

Canterbury Engineering the Future

firm Aurecon and project manager

program, which includes earthquake

The Project Office, BBR Contech will

repairs, building extensions and new

supply, install, stress and grout 96 PT

buildings for the College of Engineering.

bars and 15 post-tensioning tendons in

The new building will combine flexible

the wall and floor. It is an enormous

learning spaces with room to test

investment more than 3,600 cast

full-scale building systems under a variety

inserts and coupler adaptors are needed

of load conditions. Its facilities will include

for the inserts alone, while the total

a 300m2 strong floor and an L-shaped,

complement being imported for the job

9.2m high, 1.6m thick strong wall with a

weighs about 80t!

www.bbrnetwork.com 69

PORTFOLIO MRR

PORT OF AUCKLAND, NEW ZEALAND

Repairs for busy maritime facilities

COASTAL COMMERCE
PROTECTING
THE ASSETS

70 CONNCT | EDITION 10

PORTFOLIO MRR

Way back in 1995, New Zealands

BBR Contech completed its first
wharf repair project at the Port
of Auckland. It must have gone
well, because 20 years later the
relationship is as strong as ever
and BBR Contech remains
the repairer of choice for Ports
of Auckland Ltd (POAL) and its
main consultant Beca.

Established in the 1840s, the Port of

Auckland is New Zealand largest and
busiest container and international trade
port, connecting the countrys importers
and exporters with more than 160 ports
in nearly 70 nations. It handles 37% of
New Zealands total seaport trade and
31% of its trade across all ports, including
airports. It is also New Zealands main
port for cruise liners and vehicle imports.
In the past 20 years, BBR Contech has
been involved with repairs to six wharves
associated with POAL operations the
Fergusson container terminal, the
Bledisloe multi-purpose terminal which
includes a third container-ship berth
and the Captain Cook, Freyberg, Jellicoe
and Queens Wharves, which handle
everything from general or breakbulk
cargo to steel, timber, vehicles and dry
and liquid bulk products.
The Port of Auckland operates 24-hoursa-day, seven-days-a-week, so its vital
that we keep it in good condition, says
Pete Algie, Asset Manager for POAL,
which manages the commercial freight
and cruise ship harbor facilities.
Its a constant process of monitoring,
assessment, repair and remediation,
especially given that many of the wharves
are more than 50 years old. Time, tides
and traffic have inevitable effects, and we
need to manage the risks of damage and
corrosion to the decks and the beams
and piles beneath.

www.bbrnetwork.com

71

PORTFOLIO MRR

It was a big project

completed in a
very constrained
environment, but
we managed to
finish four weeks
ahead of schedule.

Twenty years of service

Most of BBR Contechs projects have
involved conventional repair techniques,
such as injecting epoxy resin to prevent
the ingress of sea water to concrete deck
slabs, and using hydro-demolition followed

by applications of dry-spray gunite to

exposed and damaged substructures.
The latter approach has been particularly
common, most notably in 2011 when
BBR Contech repaired the 100-year-old

Unfortunately the substructure was badly

Queens Wharf, the largest job of its type

in need of repair, so we were called in to

ever undertaken in New Zealand.

fix it. That meant removing and reinstating

Queens Wharf was designated party

more than 190m3 of concrete and

central for the 2011 Rugby World Cup,

replacing a significant amount of reinforcing

says Mark Kurtovich, BBR Contechs

bar essentially replacing two-thirds of the

Development Manager. Thousands of

wharfs substructure.

people were expected to gather there to

It was a big project completed in a very

watch the games and enjoy a wide range

constrained environment, but we managed

of concerts and other entertainment, so a

to finish four weeks ahead of schedule. With

number of stakeholders needed assurance

all the other projects going on at the same

that it was structurally safe and sound at

time, that went a long way to easing the

the time and into the future.

pressure on both the wharf and the client.

72 CONNCT | EDITION 10

Aerial view of the busy Port of Auckland.

Photograph courtesy of Ports of
Auckland Ltd.
2 The BBR Contech team carrying out
repairs to the sea wall between Jellicoe
and Freyberg wharves.
3/4 Replacing reinforced concrete on
Freyberg Wharf, named after the former
Governor-General of New Zealand, was a
challenging project.
5 Queens Wharf was ready for its role as
party central during the 2011 Rugby World
Cup, thanks to completion of a massive
structural repair program by BBR Contech.

PORTFOLIO MRR

They also had to

meet our rigorous
health and safety
standards and comply
with our environmental
management policy.
It could have been a
big headache, but
somehow they
made it easy.
Peter Algie, Asset Manager, Ports of Auckland Ltd

The BBR Contech guys had to contend

with huge machines constantly on the
move around the wharves, as well as the
hazards of the marine environment when
working on the substructures not only
the water and the tides, but also the tugs
and other shipping vessels that constantly
come and go.
They also had to meet our rigorous health
and safety standards and comply with our
Other POAL projects have included

environmental management policy. It could

designing, installing and commissioning a

have been a big headache, but somehow

cathodic protection system for the

they made it easy.

Fergusson container terminal in 2000, and

repairing breastworks at Captain Cook Wharf

Highly rated performers

in 2012. Then in 2014 another big project

Pete says this ability to deliver with

came along, this one involving five different

minimal fuss is one of many qualities that

wharves at the same time. It included:

have made BBR Contech a partner of

completing conventional concrete

choice for POAL and Beca. They recognize

repairs to the Queens Wharf breastworks

replacing a 15m2 section of heavily

Owner Ports of Auckland

Structural consultant Beca
Technology MRR range
BBR Network Member BBR Contech
(New Zealand)

which plans can change at short notice.

reinforced concrete on the deck of

Theyre quick to adapt without complaint,

Freyberg Wharf a complex project

they do a great job in keeping our wharves

given the large amount of steel involved

up to scratch and they leave the sites

and the challenges of working in a busy

clean and tidy. Everyone at the port is very

operational area

happy with BBR Contech great work,

undertaking substructure concrete

TEAM & TECHNOLOGY

that we work in a dynamic environment in

great attitude.

repairs and installing Fabriform under

BBR Contech has more recently helped

Jellicoe Wharf and the Fergusson and

POAL with a diagnostic assessment of the

Bledisloe container terminals. Originally

ports wharf condition. This will contribute

developed by Construction Techniques

to the companys asset management

in the 1960s, Fabriform is made by

strategy and its long-term repair and

pumping highly fluid concrete mix into

remediation strategy.

specially woven fabric envelopes, which

Were keen to look beyond conventional

are pre-positioned in areas vulnerable to

repair techniques which may no longer

erosion, such as seawalls.

meet our needs to alternative approaches

This was a particularly challenging project

such as a greater use of cathodic protection

as it was based in some of the busiest

systems, says Pete. BBR Contechs

parts of the port and therefore a relatively

practical experience will make a valuable

dangerous workplace, says Pete Algie.

contribution to our plans.

www.bbrnetwork.com 73

PORTFOLIO MRR

HAMMERSMITH FLYOVER, WEST LONDON, ENGLAND

Bearing replacement for major arterial road flyover

UKS LARGEST & MOST

COMPLEX PROJECT
The Hammersmith flyover is an important four lane highway route linking the west with central
London and is used by around 70,000 vehicles each day. When it opened in 1961, it was the first of
its kind and featured the latest in construction engineering. Mark Bond from BBR Network Member
Structural Systems UK tells how, over 50 years later, they have now contributed to its 21st century
makeover with know-how and teamwork, resulting in the successful completion of one of the UKs
largest and most technically complex strengthening projects.

1 Great precision and control was necessary to

lower the new spherical bearings into the pits.
2 The Hammersmith flyover, an important route
linking west and central London takes traffic
over the Hammersmith gyratory system.
Photograph released into the Public Domain
by Patche99z via Wikimedia Commons.

TEAM & TECHNOLOGY

Client Transport for London (TfL)
Main contractor Costain Limited
Lead designer Ramboll Parsons
Brinckerhoff
Technology MRR range
BBR Network Member Structural
Systems (UK) Limited

We were appointed by main contractor

Specialist works undertaken

Costain during the Early Contractor

We undertook a huge volume of work for

Involvement (ECI) phase in 2014, as

this project including:

part of their contract with Transport for

LVDT movement monitoring at 240

London (TfL) to strengthen and repair

discreet locations, each capable of

the flyover. This involved designing a

recording structural movements down

hydraulic jacking system that was capable

to 0.1mm longitudinally, laterally and

of the lifting the flyover whilst also

supporting the bridge under dynamic
loading during the day when it was under
live traffic conditions a key strategy
for the buildability of the scheme.

in rotation.
Permanent pier strengthening to the
piers made up of 48 high tensile bars
and steel bracketry.
Vertical box beam strengthening with
336 embedded and load tested bars.
Temporary pier strengthening made up
of 240 high tensile bars and individual,
bespoke bearing plates.
Pit wall strengthening consisting of 960
embedded, load tested and stressed
high tensile bars.
Installation and subsequent removal
of 15 temporary bearings, each
weighing 2,100kg.
Removal of existing bearings and
steelwork some 6,000kg at each
pier location.
Installation of 34 permanent bearings,
each weighing up to 2,400kg each.
Design, installation and operation of 12
multipoint, synchronized jacking systems
for the simultaneous control of the
vertical and lateral movement of the
structure. Each of the application jacks
weighed 750kg and was capable of
accommodating 16,000kN.
24 hour/7 day working and monitoring
and, yes, we even had a Merry
Christmas on site.

74 CONNCT | EDITION 10

PORTFOLIO MRR

Structural Systems approach to

engagement and collaboration was
exemplary and they were a pleasure
to work with from the early stages
of developing and agreeing the
conceptual arrangements for
jacking through to the detailed
implementation. The challenges
that we collectively faced were
significant and Structural Systems
were proactive and positive
throughout the process leading to
delivery of a successful solution and
in working to the extremely high levels
of precision required, all within an
extremely demanding programme.
Matthew Collings, Project Director,
Ramboll Parsons Brinckerhoff, Lead Designer

Jacking system

the full bearing replacement process for

Using our specialist experience, we worked

one pier from 43 working days for the

collaboratively with the project team to

first pier, down to just 21 days for the last,

develop bespoke jacking and monitoring

from first lift to final de-jacking onto

systems to minimize risks.

permanent bearings.

The system allowed the flyover to be

Even when the complete program sequence

supported by hydraulic jacks on up to five

was changed by designers mid-way through

The challenge for the project team

was to carry out the works to
strengthen and refurbish the flyover
with minimal effect on the flow of
traffic. This could not have been
achieved without the support and
co-operation throughout the supply
chain, of which Structural Systems
Ltd (SSL) played a significant part.
SSL devised a methodology so that
any works to replace the bearings,
that had an effect on traffic, were
carried out during night-time
possessions of the flyover between
22:30-05:00hrs, which was
implemented without any over-runs
into the morning peak. They also
constantly improved their
methodology to reduce the number
of night-time possessions required.
This was all carried out against a
main programme which was changing
due to the realization of unforeseen
risks, to which SSL worked
proactively with the project team to
the mitigate delays. Overall SSL
have been a critical part of the
delivery of a successful project.

piers at any one time, allowing bearing

the works due to unforeseen bridge

Graham Carter, Transport for London

replacement to be performed

conditions, together, we were able mitigate

simultaneously whilst achieving a precise

the delay. The team achieved every one of

tolerance by accurate monitoring of load/

the clients milestone dates throughout the

levels across pier groups. This feat of

project and achieved practical completion

hydraulic engineering not only enabled the

a month ahead of program.

flyover to remain open during the day, but

We now look forward to taking our creativity

also ensured maximum efficiency during

in designing and delivering a workable

bearing replacement work.

solution to these complex engineering

The SSL UK mobile jacking control unit was

requirements, along with our trusted

custom-built to connect into our bridge

management techniques, forward to our

SSL were asked to deliver a

technically complex sequence of
pier strengthening, jacking and
bearing replacement, safely without
disrupting peak time traffic flows
and all to an accuracy of 0.1mm,
which is exactly what they did
without issue or incident.

monitoring and hydraulic jack system.

next challenge.

Andy Bannister, Project Manager, Costain

Changing the bearings

Engineering skills to appreciate included

Changing the bearings was especially

installing up to 2,400kg bearings to a 0.1mm

tricky, as they were situated within two

accuracy in all planes and in relation to the

meter deep pits which were only fractionally

adjacent bearing, all surveyed and installed

wider than the piers themselves. The

within the two meter deep pit under the

replacements were spherical bearings

bridge. Site congestion was high as the

which were considerably larger than the

continuously re-orientated bridge was

old roller bearings, making their handling

supported by primary hydraulic jacks while

and fitting a complex task in itself.

being monitored by sensors to ascertain the

From each pit, 6,000kg of existing bearings

exact position of the piers and abutments.

and stools were removed and replaced with

7,000kg of temporary works in the form of

Project delivery

temporary bearings, jacks and plate to

The Health and Safety Plans for the lifting

enable the bearing change. Then, 5,000kg

and jacking operations were carefully

of new bearings were installed and all the

coordinated and closely supervised which

temporary works removed.

resulted in no loss-of-time incidents.

We improved project delivery by reducing

www.bbrnetwork.com 75

PORTFOLIO MRR

MIDTOWN & ROYAL DOMAIN APARTMENTS, MELBOURNE, AUSTRALIA

Faade remediation projects

TAKING THE
LEAD IN FAADE
REMEDIATION
A major project at one of the busiest intersections in Melbourne has recently
been finished, reports Andrew Bray of Australian BBR Network Member
SRG. The project involved completing remedial works to the Midtown
faade, situated on the corner of Bourke and Swanson Streets in the middle
of the citys thriving CBD, for client ISPT.
1

ISPT is one of Australias largest unlisted

1 Stakeholder satisfaction

center of Melbourne most of these

property fund managers with over A$11

The building was fully tenanted at the time,

activities were completed during the night or

billion of funds under management

with a number of high profile businesses

outside of normal working hours, with liaison

through investments in office, retail,

such as banks and telecommunications

required between the City of Melbourne,

industrial and residential properties.

companies continuing to trade as work

Yarra Trams and all essential services

They own high quality property and

was carried out. With many high profile

including the police and fire brigade.

create office and retail spaces that meet

stakeholders, client liaison was crucial in

Thanks to the strong relationships we had

the changing needs of their tenants.

order for the works to run to program, whilst

developed with the numerous stakeholders

Our project was for remediation work to

maintaining unencumbered access to shop

who had an interest in the project including

the seven storey main tower and adjoining

fronts and commercial properties so that

the client ISPT and Melbourne City Council,

two storey building and involved concrete

they could continue with their daily business.

constraints were overcome through intense

and render repairs, brickwork repairs,

With little road access, coverway gantries

logistics planning and weekly meetings

glass window replacement and repairs

were erected over Little Bourke Street and

between all parties involved in the project.

and coating works, as well as a major

along the front faades of Bourke and

roof upgrade to the two storey building.

Swanston Street. Mixed use access

Cohesive project team

The works were deemed necessary after

including swing stage scaffolds, booms,

The cohesive nature of the project team

independent engineering inspections

scissors, rope access and mobile scaffolds

ensured that all matters were discussed

indicated full faade remediation was

were incorporated into the works to enable

transparently with a key focus on ensuring

required to fix spalled concrete and

all traffic road and pedestrian to

that unencumbered access for the works

detached render.

continue to use the building as normal,

to continue were met, whilst abiding by

Remediation projects are always very

whilst maintaining visibility to the site to

the City of Melbourne requirements and

intricate and detailed and Midtown was

ensure that third parties were not deterred

requests for all tenancies to remain

no different. SRG is skilled at managing

from entering businesses and the arcade

operational. In most cases, months of

projects of this nature one of the

area of the building.

planning were necessary given that

reasons why it was a success.

The major challenge for the project was

another major construction site was also

co-ordination with, and communication to,

underway nearby, which meant that traffic

the many stakeholders involved in the

management was required for necessary

project, which also required a myriad of

crane lifts so neither project was delayed.

planning permits and compliance with

This clearly demonstrates our ability to

noise restriction regulations.

take a leadership role and the transparent,

It is significant that SRG coordinated

high-integrity approach we take to all

material delivery and scaffolding to the

our projects.

76 CONNCT | EDITION 10

PORTFOLIO MRR

Excellence Award
The project was completed ahead of
schedule, to budget and to the high
standards clients have come to expect
from SRG. In recognition of the complexity
of the work, we were also awarded the
Australasian Concrete Repair Association
(ACRA) Award for Excellence for Building
and Remediation over A$2M for the

Midtown Faade Project.

As a result of the works carried out at
Midtown, its faade now adds quality to
the appearance of one of the busiest mall
precincts of the city. It was a remarkable

Initially the client wanted to split the

project, undertaken with our usual great

contract into two separate stages to

attention to detail.

minimize the impact on residents,

however, once SRG commenced works

2 Royal Domain Apartments

on site, the feedback from tenants who

Aaron Callegari of SRGs Services

were encouraged by the buildings facelift

Division reports that the team has

and the quality of workmanship being

completed remedial works at the Royal

performed, meant that phase two of the

Domain Apartments on St Kilda Road,

works was brought forward.

also in Melbourne.

In addition to the positive comments

The faade includes many decorative

received from the client and major

architectural mouldings made of polystyrene

stakeholders, the main material supplier

which had become detached from the main

for the project has also praised the

concrete structure. These elements are

outstanding quality and workmanship of

being reattached using stainless steel pins,

our remedial technicians.

as well as a comprehensive patching and

Congratulations to everyone who has

coating system to revitalize the iconic

been involved in this project living up to

buildings faade.

our value of excellence.

1 Work underway on the Midtown faade at

one of Melbournes busiest intersections.
2 Close-up view of the SRG team at work on
remediation of the Midtown faade.
3 Work is almost completed on the facelift at
the Royal Domain Apartments.

TEAM & TECHNOLOGY

1 Client ISPT

Technology MRR range

BBR Network Member SRG Limited
(Australia)
2 Client Royal Domain Plaza Owners

Corporation
Technology MRR range
BBR Network Member SRG Limited
(Australia)

www.bbrnetwork.com 77

PORTFOLIO MRR

BARWON RIVER BRIDGE, WINCHELSEA, VICTORIA, AUSTRALIA

Strengthening infrastructure with carbon fiber technology

NEW STRENGTH
FOR BRIDGE
As part of major improvements to the Princes Highway, Andrew Bray
from Australian BBR Network Member SRG, reports that his company
has strengthened a bridge over the Barwon River in Winchelsea,
Victoria with carbon fiber.
2

When a wooden bridge was constructed

In total over 3km of carbon fiber

What is carbon fiber?

over the picturesque Barwon River in the

laminate was required to strengthen

Carbon fiber is an extremely strong

mid 1800s, the town of Winchelsea was

the three spans of the bridge.

and lightweight material consisting of

created and a new gateway to the

crystalline filaments of carbon and is

western districts of Victoria was established.

Construction challenges

Floods swept away the first Barwon Bridge

Challenges of the project included close

in 1849 and a new bluestone bridge was

monitoring of environmental conditions

How does carbon fiber

opened in 1867. During the next century,

to ensure the carbon fiber adhesive

strengthening work?

a second bridge was constructed adjacent

achieved a suitable bond strength and

Carbon fiber strengthening involves

to the bluestone bridge. It is this bridge

some design modifications required at

the external application of carbon fiber

that we have been working on.

the bridge piers.

materials to concrete in order to

All works were completed ahead of

increase the flexural, shear, axial or

Project outline

program and to the satisfaction of the

seismic resistance of a structure.

Strengthening works commenced in

client, VicRoads, and the head

There are other materials with similar

January last year, following the installation

contractor, Cut and Fill. This is a

properties to carbon fiber, including

of a fixed scaffold access system set up

testament to the great work carried out

Kevlar or aramid which can also be

beneath the 61m long bridge to span over

by our crew.

used to strengthen structures.

the Barwon River.

In addition to the vast experience that

These materials are typically referred

SRG was responsible for the provision

SRG has acquired in applying FRP both

to as fiber reinforced polymers (FRP)

of access, supply and installation of

fabric and plate to a host of different

and are available as either a fabric

carbon fiber strengthening and various

structures, our in-house design capability

wrap or as stiff laminate plates.

associated works, including concrete

is available to support the requirements

They are generally applied using a

repair to deteriorated sections of the bridge.

engineers and owners alike.

high strength epoxy resin to bond the

used as a strengthening material.

material to the structure in accordance

with an engineering design.

1 Strengthening work was carried out from a

fixed scaffold access system set up beneath
the 61m long river bridge.
2 Over 3km of carbon fiber laminate was installed
to strengthen three spans of the bridge.

TEAM & TECHNOLOGY

Client VicRoads
Main contractor Cut and Fill
Technology MRR range
BBR Network Member SRG Limited
(Australia)
1

78 CONNCT | EDITION 10

TECHNOLOGY
80 RESEARCH & DEVELOPMENT
introducing the BBR VT CONA
CMI Electrically Isolated Tendon
which offers the highest possible
corrosion protection
83 TECHNICAL UPDATE
latest European Technical
Assessments secured for BBR
technologies plus information
about the updated BBR E-Trace
trading & QA platform
86 TECHNIQUES
insight into the installation of the
CONA CMI Electrically Isolated
Tendons provided by Jrg Dniker
of BBR Network Member Stahlton
88 INSIGHT
background to the market for
electrically isolated post-tensioning
tendons and perspective for the
future

www.bbrnetwork.com 79

TECHNOLOGY

BBR VT CONA CMI ELECTRICALLY ISOLATED TENDON

Most advanced multi-strand post-tensioning system

HIGHEST POSSIBLE
CORROSION
PROTECTION
The European assessed BBR VT CONA CMI Electrically Isolated Tendon (EIT) is the most advanced
multi-strand post-tensioning system with the highest possible level of corrosion protection PL3
as specified in the latest fib recommendations. Dr. Behzad Manshadi, BBR VT Internationals Head
of Research & Development outlines the features and benefits of the system.

ype

te t

E
ype

pla

ng

ari

Be
s

and

Str

es

n
tio

cap

tec

Pro

80 CONNCT | EDITION 10

dg
We

or
nch

hea

m
tru

tic

s
Pla

tru

uct

ic D

t
pet

RV

BB

st
Pla

TECHNOLOGY

The ultimate PT system

Anchorage configuration

Key features

Quality control, durability and long-term

The main components in the anchor zone of

High electrical resistance minimizing

monitoring of PT tendons are required.

the CONA CMI EIT system are the protection

Combined with a simple and non-

cap, wedges, anchor head, isolation ring,

destructive method of measuring the

load transfer element (bearing trumplate)

impedance of the tendons makes this

and trumpet. In the anchorage zone, the

the ultimate post-tensioning system for

BBR VT Plastic Duct is connected to the

achieving the highest level of protection

trumpet and the strand bundle is spread

Highest possible protection level (PL3)

PL3.

out towards the anchor head, where each

according to fib recommendation to

The CONA CMI EIT is a multi-strand

strand is individually locked with a CONA

enhance safety and provide superior

post-tensioning system for internally

CMX wedge. Lastly, the protection cap with

bonded applications and provides

the help of the isolation ring encapsulates

excellent performance including

the whole anchor head and wedges. CONA

situations where enhanced safety,

CMI EIT tendons can also be coupled with

corrosion protection, quality control,

the Type H fixed coupler.

durability and long-term monitoring of

Thick corrugated BBR VT Plastic Ducts

post-tensioning tendons are required.

eliminate the ingress of water and

chlorides and anchor head encapsulation

risk of stray currents causing

electro-chemical corrosion of steel
Thick corrugated BBR VT Plastic
Ducts prevent water and chloride
ingress

long term durability

Continuous monitoring of electrical
impedance resulting in early
detection warning system
Standard tendon sizes from 02 to 31
strands. Larger sizes upon request
Optimized for 15.7mm diameter,
1,860MPa strand

Standard sizes

prevents stray currents from causing

The standard tendon sizes range from

electro-chemical corrosion of the

available utilizing an advanced

02 to 31 seven-wire prestressing strands.

prestressing steel. This combined with

proprietary load transfer element for

Both 15.3mm strands with a cross

a simple and continuous method of

very small center spacing & edge

sectional area of 140mm2 and 15.7mm

measuring the impedance of the tendons

strands with a cross-sectional area of

makes CONA CMI EIT the ultimate

150mm2 are possible, whereas the

post-tensioning system for achieving the

maximum characteristic tensile strength

highest level of protection with an early

Fixed couplers for joining tendons

for both strands is 1,860MPa.

detection warning system.

BBR VT Plastic Ducts filled with high

But theres even more the system has

Operation & advantages

been successfully tested in accordance

The CONA CMI EIT is the most compact

with procedures specified by the latest fib

and light-weight system available on the

recommendation (Bulletin 75) and, thus,

market. The tendon force is transferred

the BBR VT CONA CMI EIT range has been

to the concrete using an advanced and

approved for the optional use category

proprietary three-plane load transfer

electrically isolated tendon in accordance

element, allowing for very small center

with EAD 160004-00-301 which

spacing and edge distances at the

supersedes ETAG 013 and in accordance

anchorage. Furthermore, the full post-

with the Swiss guideline Leitfaden fr die

tensioning load can be applied at very

technische Zulassung von Spannsystemen

in der Schweiz.

low concrete strength fcm,0=19/23MPa.

Most compact & light-weight system

distances at anchorages
Application of full post-tensioning
force at very low concrete strengths

performance BBR grout

European Technical Assessment and
CE marking

1 The BBR VT CONA CMI Electrically Isolated

Tendon (EIT) is the most advanced
multi-strand post-tensioning system for
eliminating the ingress of chlorides and
preventing stray currents from causing
electro-chemical corrosion of the steel.

www.bbrnetwork.com 81

TECHNOLOGY

BBR VT CONA CMI ELECTRICALLY ISOLATED TENDON

Testing of anchorage-duct assembly & BBR VT Plastic Duct system

PUTTING
TECHNOLOGY
TO THE TEST
BBR VT International has a long track record and commitment to testing of
its new technology and techniques before making them available for use
worldwide. The BBR HQ R&D team now share some aspects of their testing
procedures for BBR VT CONA CMI Electrically Isolated Tendons (EIT).
1

EIT performance of BBR VT CONA CMI

Electrical resistance, together with the

anchorage-duct assembly

temperature behavior of the testing

This test was carried on the anchorage-

specimen, were measured and recorded

duct assembly, again in accordance with

over a period of 112 days. The test

fib Bulletin 75: Polymer-duct systems

for internal bonded post-tensioning.
A BBR VT CONA CMI anchorage
consisting of 12 strands of 15.7mm
diameter each, ring wedges, bearing
trumplate, steel ring, anchor head,
trumpet and plastic protection cap
was assembled and connected to a
specimen of ID 75 BBR VT Plastic Duct
using a BBR VT round duct slip-on
coupler. The connection was sealed using
a heat-shrinkable sleeve.
The test specimen was immersed vertically,
for almost four months, inside a container
filled with saturated Ca(OH)2 (calcium
hydroxide) solution. During this time, the
electrical resistance was measured using
an LCR meter between the bar connected
to the bearing trumplate and the electrical
wire connected to the anchor head and
protruding from the protection cap.
The level of electrolyte and quantity of
Ca(OH)2 were continuously monitored
by pH indicator paper and found to be
between 12-13. The temperature of the
testing room was also measured by
thermometer and recorded, together with
each electrical resistance measurement.

procedure fully meets the intent of the

1 These two images show how a fully

assembled specimen BBR VT CONA CMI
anchorage was immersed for almost four
months in a container filled with saturated
Ca(OH)2 solution and electrical resistance
was measured, along with temperature.
2 This graph shows that measured electrical
resistance, over a period of 112 days, of
the BBR VT CONA CMI EIT specimen
considerably exceeded the specified
minimum value of 15kOhm.
3 One meter specimens of three configurations
of all sizes of BBR VT Plastic Duct were
immersed in water for more than 24 hours
and the measured electrical resistance of all
permutations of the duct system exceeded
the specified minimum value of 2,000kOhm.

test specification and the measured

electrical resistance considerably
exceeded the specified minimum value
of 15kOhm during the entire duration of
the test. Thus, the BBR VT CONA CMI EIT
complies with the requirement given by
EAD 160004-00-301 which will replace
ETAG 013 and in accordance with the
Swiss guideline Leitfaden fr die
technische Zulassung von Spannsystemen
in der Schweiz.

50
Electrical Resistance (kOhm)
Temperature (C)
Acceptance Criteria (15kOhm)

3000

40
35
30

300

25
20

30

15
10

5
0

0
0

20

40

60

Time (day)
2

82 CONNCT | EDITION 10

45

80

100

Temperature C

Electrical Resistance (kOhm)

30000

TECHNOLOGY

TECHNICAL UPDATE
BBR E-Trace

UP-TO-DATE TRADING
& QA PLATFORM
The BBR Networks internet-based trading and quality assurance
platform has been updated and enhanced. BBR VT Internationals
Product & Quality Manager, Christian Roost, talks us through the
strategy and changes.
BBR E-Trace our in-house developed

comfortable to operate. Then our

internet-based software links all

programmers invested more than 500

members of the Global BBR Network

working hours in reprogramming the

including BBR PT Specialists, BBR

system to the newest code standards

Component Manufacturers (CMs) and

and yet more programming hours to

ETA Holder, BBR VT International. This

make new features and tools. The

comprehensive e-commerce platform

purpose of the new code was to create

EIT performance of BBR VT Plastic

leads users through the quality process,

a faster and yet robust platform which

Duct system

ensuring that each step through the

can be easily extended for future BBR

The test was carried out on BBR VT plastic

production and supply chain is properly

systems and applications. New features,

duct in accordance with fib Bulletin 75.

documented and recorded. The platform

such as the kit generator, are already

In order to confirm the electrical resistance

facilitates the everyday work of all BBR

established and have been used many

properties of the duct system intended

Network Members and also supports

times, providing a superlative increase

for use with EIT tendons meeting the

effective supply chain management.

of productivity in terms of sourcing to

PL3 criteria, three duct configurations

Essentially, the BBR E-Trace platform

the BBR Network.

were tested the duct alone, duct with

allows us to achieve 100% traceability

The updated BBR E-Trace has been online

connector and duct with connector and

of every single BBR component, as well as

now for six months and feedback has

vents. One test per size was performed

an optimal full Factory Production Control,

been very positive. We are continuously

on all duct sizes and each configuration

both essential to ensure and maintain

working on this trading system to ensure

mentioned above.

the CE marking in BBR systems.

that the platform remains up-to-date.

A one meter specimen was prepared in

After more than five years since the

The team here is looking forward to

each case and the ducts with connectors

launch of BBR E-Trace, it was time to

developing still further new tools and

were sealed using heat-shrinkable sleeves.

update the system and add some new

features to make BBR E-Trace even

A steel rod was concentrically installed

features. First of all, we have changed

more useful for our customers and

into the test specimens and the duct

the design and the navigation to be more

component manufacturers.

specimens were filled with tap water and

thereafter both ends of the specimen
ducts were sealed.
The electrical resistance was measured
while the test specimens were immersed
horizontally for more than 24 hours in a
water tank with their ends sealed against
the walls of basins inserted into the tank.
To achieve this, an LCR meter was used
to record resistance between the bar
which was in contact with water inside
the duct, and the basin that was connected
to the water tank.
The measurements of electrical resistance
for all permutations of the duct system
specimens exceeded the specified
minimum value of 2,000kOhm.

www.bbrnetwork.com 83

TECHNOLOGY

TECHNICAL UPDATE
New approvals, extensions & renewals

TRIO OF NEW
TECHNICAL
ASSESSMENTS
Over recent months, three new assessments have been secured for technologies within the BBR VT CONA
CMX range. European Technical Assessment for the CONA CMO system has been secured, along with new
assessments for the CONA CMB and CONA CMI systems.

BBR VT CONA CMO onion

The European Technical Assessment, ETA-15/0808, of the
new BBR VT CONA CMO anchorage has been issued. The key
features and benefits of this new multi-strand post-tensioning
system are:
For internally bonded post-tensioned applications particularly
in very thin concrete cross-section such as slabs
Economical solution for fixed-end anchorages
compatible with BBR VT CONA CMF, CONA CMI SP and
BT systems
Standard tendon sizes from 2 to 6 seven-wire prestressing
strands
Optimized for 12.9mm & 15.7mm diameter, 1,860MPa strands
Full stressing at very low concrete strength (fcm,0=21/26MPa)
No anti-bursting or splitting reinforcement required
Equipped with an innovative clip-lock design of the bulb-strand
spacer, increasing productivity during anchorage installation
Very small center spacing and edge distances at anchorages
Compatible with corrugated flat or round tendon duct utilizing
either galvanized steel or plastic material.

1 The new BBR VT CONA CMO Onion

multi-strand anchorage, with a flat array
of onion-bulb strand ends, is designed for
internally post-tensioned applications
particularly suited to use in very thin
concrete cross-sections, such as slabs.
2 The features of the BBR VT CONA CMB
Band system make it ideal for use in the
prestressing of wind towers and also the
strengthening of bridges and tanks.
3 As well as for silos, nuclear power plants,
stadiums and a wide range of other special
applications, the BBR VT CONA CMI
internal system, with its superior cryogenic
performance, is perfect for LNG/LPG
tank applications.
1

84 CONNCT | EDITION 10

TECHNOLOGY

BBR VT CONA CMB band

The BBR VT CONA CMB Band European Technical
Assessment ETA-10/0065 has been issued. The new
assessment is based on the previous CONA CMB European

BBR VT CONA CMI internal

Technical Approval and has the following key features:

The European Technical Assessment ETA-06/0147 has

been issued for BBR VT CONA CMI, the most up-to-date

For external unbonded post-tensioned applications

and advanced multi-strand post-tensioning technology.

Standard tendon sizes from 1 to 16 seven-wire

Compared to the previous CONA CMI European Technical

prestressing strands
Optimized for 140mm2 & 150mm2, 1,860MPa strands

Approval, this assessment incorporates the following new

key features:

as well as for 165mm2, 1,820MPa compact strands

Consists of bands with 1, 2, or 4 prestressing strands
Offering a high level of corrosion protection, it is widely
used for the prestressing of wind towers, strengthening
of bridges and tanks
Steel prestressing strands are factory provided with a
corrosion protective material and an extruded double or
single HDPE protective sheathing
Tendons with single sheathing and tendons with double

Extending the optional uses of the system:

Tendon for cryogenic applications
Encapsulated tendon
Electrically isolated tendon (see pages 80 & 81)
Introduction of new BBR system grouting accessories:
Grouting & protection caps
Accessories for inlets and outlets
New 2-segment CONA CMX 06 wedge Type Z this

sheathing are each in two configurations:

wedge can be used on the full CONA CMX range of

individual strands connected with webs

post-tensioning systems and is particularly useful in

European Technical Assessment

ETA 06/0147

Unbonded Band Post-tensioning System with 01 to 16 Strands

European Technical Assessment

ETA 15/0808

BBR VT CONA CMB SP

(Type H and Type F) from properly gripping the strand.

Bonded Post-tensioning System with 04 to 31 Strands

A complete series of the latest approvals

along with CAD drawings and technical brochures
is available for download from our website
www.bbrnetwork.com/downloads/approvals.html

the wedge teeth of conventional 3-piece wedges

BBR VT CONA CMI

Full stressing at concrete strength (fcm,0=29/35MPa).

geotechnical applications where soil and mud may clog

Onion Post-tensioning system

individual monostrands without interconnections

BBR VT CONA CMO

(monolithic configuration)

European Technical Assessment

ETA 10/0065

www.bbrnetwork.com 85

TECHNOLOGY

TECHNIQUES
Enabling monitoring of PT tendons with BBR VT CONA CMI EIT

QUALITY
WITH
CONTROL

BBR HQ and BBR Network

If it can be verified that post-tensioning

available. In Switzerland, the EIT standard is

Member Stahlton AG have

tendons are encapsulated and completely

not only applied to post-tensioning systems,

watertight, it is safe to assume that no

but also to permanent soil or rock anchors.

been working closely

corrosion will occur on the steel strands,

together to extend the

anchor heads and wedges. Taking this a

Responsibilities, purpose & planning

BBR VT CONA CMI system

stage further, if it is possible to monitor this

To fulfil the high requirements for EIT

to EIT standards which will

at any point during the lifecycle of the

tendons, it is essential that the

tendons, meaningful predications can be

responsibilities of all companies involved

made about the health of the post-tensioning.

owner, consulting engineer, supervisors,

from additional features,

Furthermore, reliable electrical isolation

contractors and PT specialist are clearly

such as monitoring

will protect the steel post-tensioning strands

understood and outlined.

of the post-tensioning

from any damage caused by sparking of

From the outset, the purpose that the EIT

any stray current passing through the

tendons are to serve protection against

tendon. The risk of stray currents arises

stray current, performance monitoring or

Swiss BBR Network Member,

mainly when the post-tensioned structure is

fatigue should be specified by the client, as

Stahlton AG, presents some

located near to railway tracks and especially

this will dictate the EIT system specification.

background information and

around installations using direct current

Where there are no national acceptance

(DC), such as rail or tramways.

criteria and tolerable rate of failures

allow customers to benefit

installation. Jrg Dniker of

a pictorial overview of key

available, then the system must be specified

stages in the installation of

Collaborative development based

according to the aim of the EIT tendons

the CONA CMI EIT system.

on experience

and the project prior to execution.

To extend the BBR VT CONA CMI system

Complete wiring installation diagrams

to meet the EIT standard, BBR VT

including the earthing concept and location

International has been working closely

of the measuring control box or boxes

together with Swiss BBR Network Member

should be completed at project design

Stahlton AG because of their long track

stage. All project team members will need

record of working with electrically isolated

to understand the interfaces between the

tendons using both the BBRV wire and

EIT system and their own work elements.

CONA strand systems.

It is also important that a thorough risk

The first bridge executed with EIT tendons

assessment and management process be

by Stahlton was back in 1996. Since then,

agreed by all parties, as effectiveness of an

it has become common in Switzerland to

otherwise high quality EIT installation by a

construct railway and highway bridges, as

PT specialist may be affected by the work

well as other important structures which

of others on the project.

are subject to aggressive environmental

The improved protection level offered by

influences like de-icing salt or stray current,

the BBR VT CONA CMI EIT post-tensioning

using electrically isolated tendons. Or

system is an important milestone on the

sometimes the EIT approach is chosen just

road to achieving more durable and

so the option of monitoring the system is

maintainable structures.

1 Pictured here working with the site team,

Jrg Dniker (top) believes that the improved
protection level offered by the BBR VT CMI
EIT post-tensioning system is an important
milestone on the road to achieving more
durable and maintainable structures.

86 CONNCT | EDITION 10

TECHNOLOGY

STEP-BYSTEP GUIDE
1

BBR VT Plastic Duct is cut to

length, then vents at high and low
points are built in and sealed to the
duct using a heat shrinkable sleeve.

2 Once the ducting and bearing

trumplates have been positioned
and sealed with heat shrinkable
sleeves, the steel strands are
pushed through the duct in the
normal way.
3 The anchor head, wedges and
wedge retaining plate can now
be installed and the electrical
measuring cable, in this case a
25mm2 cross-section wire for
measuring stray current, can be
fixed to the anchor head.

4 A plastic protection cap is placed

over the anchor head to seal it off.
Various strengthened positions
in the cap allow for holes to be
drilled for mounting the grouting
port and cable gland to suit the
local situation. For this particular
construction project, the standard
grout connection has been closed
and sealed with silicone and a
yellow cap, as space limitations
meant that the grout pipe could
not be placed from behind. Thus,
a new hole was drilled in the side
of the cap which is not visible in
4

the picture.
5 Wiring of the tendons to the
measuring box. The location of
the measuring box, along with the
earthing concept and overall
wiring scheme must be planned
well in advance.
6 The connection of the wiring to
the measuring box is the final
stage in installing the BBR VT
CONA CMI Electrically Isolated
Tendon system. Shown here is a
measuring box for four tendons,
plus an earth cable.

www.bbrnetwork.com 87

TECHNOLOGY

INSIGHT
Construction technology to promote sustainability

MAKING GREENER
FOOTPRINTS
With the benefit of increased knowledge about the way in which we live and our environment, it has
been clear for some years now that taking a sustainable approach is important to our own health
and well-being and that of our planet. Dr. Behzad Manshadi, BBR VT Internationals Head of
Research & Development reviews how key developments in the field of construction technology
have and continue to reduce the environmental impact of the industrys activities.

Environmental
Priorities

Sustainable
Construction

Social
Priorities

Economic
Priorities

Back in 1987, the United National General

is a crucial factor in lowering the structures

Assembly Report of the World Commission

long-term environmental impact.

on Environment and Development,

Optimum corrosion protection of post-

entitled Our Common Future, defined

tensioning tendons to prevent ingress of

sustainable development as development

water and thus chloride induced corrosion

that meets the needs of the present

for high-strength steels has been a critical

without compromising the ability of future

factor in the long-term performance of

generations to meet their own needs.

post-tensioned concrete structures.

Sustainability has been described as at

Meanwhile, practically no non-destructive

the point where economic, social and

techniques are available for monitoring and

environmental priorities converge and this

inspection of these tendons.

applies equally to the construction sector.

In the last two decades, the BBR Network

For our industry, these priorities can be

and indeed the whole industry has

defined as:

adopted a multi-layer approach to corrosion

Economic whole life approach,

protection for new post-tensioning tendons

maintenance & decommissioning

to achieve the required serviceability, safety

and user disruption

and durability.

Social neighbors, users and

construction workers
Environmental minimizing impact,

1 Sustainability has been described as at the

point where economic, social and
environmental priorities converge and this
applies equally to the construction sector.
2 Following the fib recommendation, several
bridges and viaducts for new high-speed
railway lines have been designed and
constructed with simply supported spans
realized with partial or total pre-casting of
the decks.
3 The electrically isolated anchorages permit
easy monitoring and inspection of the tendons
simply by measuring the electrical impedance
between the high-strength steel inside the
ducts and the normal external reinforcement.

88 CONNCT | EDITION 10

Evolution of electrically isolated tendons

At the beginning of the 1990s, a new

CO2 (entire lifetime), reusability

generation of thick-walled corrugated

and recyclability

polymer ducts for bonded internal tendons

The use of post-tensioned concrete offers

was developed and gradually introduced

advantages when measured against all of

onto the market. The main purposes of

these criteria. Post-tensioning originally

these ducts was generally to improve the

developed in the 1940s in response to

performance of the enclosed tendons

materials shortages was the first key

and last on the list of their possibilities

construction technology development on

was to make electrical monitoring of the

the road to greater sustainability.

tendons feasible.
In 2000, based on industry applications

Sustainable post-tensioning
Considerations for the creation of a
sustainable post-tensioned structure must
include both the short and long-term impacts
of the structure. Durability of construction

and actual knowledge, fib Bulletin 7:

Corrugated plastic ducts for internal
bonded post-tensioning was issued as a
non-enforceable guideline for corrugated
plastic ducts.

TECHNOLOGY

The first so-called Electrically Isolated

This guideline recommended a multi-layer

standardizing the direction of EIT technology

Tendons (EIT) were developed in Switzerland

protection approach as design strategy and

has been the new fib recommendation

in the mid-1990s when the post-tensioning

three categories for post-tensioning tendons

industry, Swiss Federal Road Authorities,

in terms of corrosion protection were

Swiss Federal Railways and research

proposed:

institutions jointly worked on the system

Category (a) tendons in traditional

fib Bulletin 75: Polymer-duct systems for

internal bonded post-tensioning which was
published in 2014. Compared to fib Bulletin
7 issued in 2000, this adds extensive
information about material components,
fabrication processes, on-site installation,
as well as testing and approval for the duct
systems. In particular, Chapter 7 and Annex
B provide testing details that can be
considered as a solid basis for European
(EAD 160004-00-301) and Swiss guidelines
for standard evaluation of encapsulating
and EIT performance of the duct system
and anchorage duct assembly.
Electrically isolated tendons are now a
proven system with which to enhance the
durability of structures with post-tensioning
tendons and thus a definite trend towards
large worldwide usage of these tendons
in a sustainable construction manner is
anticipated.
The main factors influencing the success of
electrically isolated tendons are high quality
material and components, along with a
detailed design focused on the critical
aspects, proper testing, the personnel skills
and experience in execution and the respect
of well-established construction procedures.
BBR HQ provides the highest quality
construction technology and is committed
to both testing and training, while the
BBR Network is qualified to advise at the
earliest stages of a project and provide
professional installation of all BBR
technology, including BBR VT CONA CMI
Electrically Isolated Tendons.

components, their design, inspection and

associated monitoring techniques.
The EIT technology used a tight polymer
duct to encapsulate the high-strength steels
and reduce fretting fatigue, grouting that
creates a protective alkaline environment

corrugated steel duct.

Category (b) tendons specifies use
of corrugated polymer ducts for
enhanced protection.
Category (c) tendons must be
electrically isolated.

for the strands and an isolation element to

The guideline gave indications for the choice

electrically isolate the anchor head and

of the tendon category, measuring

wedges from the ground and the rest of the

instructions, limits of the electrical

structure.

resistance and orientation for the

The electrically isolated anchorages permit

interpretation of results.

monitoring and inspection of the tendons

The guideline became the basis for

by measuring the electrical impedance

publishing the fib Bulletin 33: Durability

between the strands and the external

of post-tensioning tendons introducing

worldwide three protection levels (PL).
Electrically isolated tendons fulfill the
requirements of the highest protection
level PL3 according to this fib Bulletin.

normal reinforcement. Monitoring over time

allows the identification of the penetration of
water containing chloride at defects in
the ducts and coupling joints. Thus, for the
first time, a simple and cost-effective early
warning system was available to provide

Present position

alerts as to whether maintenance of

In the last 20 years, an increasing number

post-tensioning tendons was required.

of bridges, flyovers and viaducts have been

constructed mainly in Switzerland with

Swiss guidelines made global

electrically isolated tendons according to

Based on substantial experiences of using

Protection Level 3 (PL3). Similar systems

tendons with thick-walled corrugated ducts

following the fib recommendation have

with or without electrical isolation, a first

recently been applied in Italy for the design

guideline Massnahmen zur Gewhrleistung

and construction of several bridges and

der Dauerhaftigkeit von Spanngliedern in

Kunstbauten was published jointly by the
Swiss Federal Railways (SBB) and the Swiss
Federal Roads Authority (ASTRA) in 2001.

viaducts for new high-speed railway lines

on simply supported spans realized with
partial or total pre-casting of the decks.
The most recent development in

www.bbrnetwork.com 89

THINKING ALOUD
David Macgeorge, Managing Director of SRG Limited the BBR Network Member for Australia, Hong Kong and the Middle East
explores how harnessing a changing environment leads to business strength

OWNING A
CHANGING
ENVIRONMENT
We often operate under challenging conditions, tight deadlines and in
complex situations. Owning these changing environments and having the
courage to harness challenges is key to defining what a business stands for.
Given the innovative history and track record of BBR, this is something that
fellow BBR Network Members will understand and endorse completely.

90 CONNCT | EDITION 10

Against this backdrop, our Prime Minister

we work in. They are able to combine

has put innovation at the top of his agenda

specialist areas of engineering, outside of

and has recently released a policy that

the standard field of structural engineering,

focuses on start ups, research institutes and

to design solutions that ensure simplicity

the wider economy. Innovation has a place

and affordability. In fact, we have just

at the business table no matter the size of

patented our first new product and it is now

your organization and is vital to success in

being distributed around the world.

times of turbulent market conditions.

Tackling problems that others wont has

In the past year, we have embarked on a

allowed us to grow a business stream and

journey to reshape our business and enable

means were known in the industry as

it to compete successfully in these

innovative problem solvers. Having the

challenging construction and resource

courage to act when problems are brought

market conditions. We took what some

to us continues to deliver dividends for our

might regard as a bold approach and

business and customers.

completely rebranded our business. In

In addition, we have built a strong alliance of

doing this, we sent a clear message to our

partners, business units and team members

investors, market, business partners and

that has ensured our success this year. I

indeed our own staff. Our rebranding has

believe that in difficult environments good

been about moving away from siloed

people and good companies stand up and

business units knowing that we needed to

add value to industry. Central to this is using

harness the power of the group as a whole.

the power of the group and having the

Uniting the company has allowed us to

courage to act.

leverage our combined expertise, skills and

The BBR Network is a powerful group full of

technical excellence and has carved out

innovative and technical minds there is a

niche offerings and services that allow us to

terrific opportunity to further leverage the

continue to succeed and prosper.

power of the group to own and capitalize on

One way in which we have leveraged our

an ever-changing environment. As a

talent is through the formation of a

member of the group since 1961, we look

dedicated team, who create products that

forward to building on the partnership and

solve technical challenges in the industries

owning changing environments together.

BBR DIRECTORY

HEADQUARTERS
BBR VT International Ltd
Ringstrasse 2
8603 Schwerzenbach-Zurich
Switzerland
Tel +41 44 806 80 60
Fax +41 44 806 80 50
www.bbrnetwork.com
info@bbrnetwork.com

EUROPE
AUSTRIA
KB Vorspann-Technik GmbH
Weitwrth 25
5151 Nussdorf a.H.
Tel +43 6272 407 90
Fax +43 6272 407 90 11
www.kb-vt.com
office@kb-vt.com
BOSNIA & HERZEGOVINA
see Croatia

RUSSIA
see Germany

BULGARIA
see Spain

LITHUANIA
see Austria

CROATIA
BBR Adria d.o.o.
Kalinovica 3, 10000 Zagreb
Tel +385 1 3839 220
Fax +385 1 3839 243
www.bbr-adria.com
bbr-adria@bbr-adria.com

MONTENEGRO
see Croatia

DENMARK
see Norway
ESTONIA
see Austria
FINLAND
see Norway
FRANCE
ETIC S.A.S.
3 rue de Marly
78 000 Versailles
Tel +33 1 39 50 11 20
Fax +33 1 39 50 11 03
www.etic-sas.fr
contact@etic-sas.fr
GERMANY
KB Vorspann-Technik GmbH
Bahnhofstrasse 108
82166 Grfelfing
Tel +49 89 72 44 969-0
Fax +49 89 72 44 969-12
www.kb-vt.com
office@kb-vt.com

NETHERLANDS
Spanstaal Ballast Nedam Infra
Specialiteiten B.V.
Nijverheidstraat 12, 4143 HM Leerdam
Post Address: PO Box 236, 4140 AE Leerdam
Tel +31 345 63 92 00
Fax +31 345 61 91 07
www.infraspecialiteiten.nl
info@infraspecialiteiten.nl
NORWAY
KB Spennteknikk AS
Siva Industrial Estate
Norvald Strands veg 19-21
Postboks 1213, 2206 Kongsvinger
Tel +47 62 81 00 30
Fax +47 62 81 00 55
www.spennteknikk.no
spennteknikk@spennteknikk.no
POLAND
BBR Polska Sp. z o.o. (Head Office)
ul. Annopol 14, 03-236 Warszawa
Tel +48 22 811 50 53
Fax +48 22 676 92 31
www.bbr.pl
bbrpolska@bbr.pl

KOSOVO
see Croatia

BBR Polska Sp. z o.o.

ul. Tarnogorska 214a, 44-105 Gliwice
Tel +48 32 331 47 98
Fax +48 32 330 24 11
www.bbr.pl
bbrpolska.gliwice@bbr.pl

LATVIA
see Austria

PORTUGAL
see Spain

LICHTENSTEIN
see Switzerland

ROMANIA
see Spain

SERBIA
see Croatia
SLOVENIA
see Croatia
SPAIN
BBR Pretensados y Tcnicas Especiales, S.L.
Antigua Carretera N-III, Km. 31, 150
28500 Arganda del Rey, Madrid
Tel +34 91 876 09 00
Fax +34 91 876 09 01
www.bbrpte.com
bbrpte@bbrpte.com
SWEDEN
Spnnteknik AB
Sjngsvgen 7,
192 72 Sollentuna
Tel +46 8 510 678 10
Fax +46 8 510 678 19
www.spannteknik.se
info@spannteknik.se
SWITZERLAND
Stahlton AG
Hauptstrasse 131
5070 Frick
Tel +41 44 938 99 00
Fax +41 44 422 11 16
www.stahlton.ch
info@stahlton.ch
UKRAINE
see Poland
UNITED KINGDOM
Structural Systems (UK) Ltd
12 Collett Way
Great Western Industrial Estate
Southall, Middlesex, UB2 4SE
Tel +44 20 8843 6500
Fax +44 20 8843 6509
www.structuralsystemsuk.com
info@structuralsystemsuk.com

www.bbrnetwork.com 91

BBR DIRECTORY

AFRICA
LESOTHO
see South Africa
SOUTH AFRICA
Structural Systems (Africa)
Group Five House, 9 Country Estate Drive
Waterfall Business Estate
Jukskei View, Johannesburg 2090
Tel +27 10 060 1555
Fax +27 86 616 7482
www.structuralsystemsafrica.com
info@sslafrica.com
SWAZILAND
see South Africa

MIDDLE EAST
BAHRAIN
see United Arab Emirates

AMERICAS
EASTERN CANADA
Canadian bbr Inc.
3450 Midland Ave.
Scarborough
Ontario M1V 4V4
Tel +1 416 291 1618
Fax +1 416 291 9960
mducommun@bbrcanada.com

92 CONNCT | EDITION 10

OMAN
Structural Systems Limited (Oman Branch)
Office A-11, Al Souroh Building
Al Ghala Industrial
PO Box 1946, PC-130
Muscat
Sultanate of Oman
Tel +968 2459 5279
Fax +968 2459 5252
www.bbrstructuralsystems.com
bbr@bbrstructuralsystems.com
QATAR
see United Arab Emirates

UNITED ARAB EMIRATES

NASA Structural Systems LLC
(Head Office)
Office M 03, Bu Shaqar Building
Garhoud, PO Box 28987
Dubai
Tel +971 4 2522 501
Fax +971 4 2522 502
www.bbrstructuralsystems.com
bbr@bbrstructuralsystems.com
Structural Systems Middle East LLC
Office 38
Sheikh Abdullah Bin Zayed Al Nahyan
Industrial Area
Musaffah-2, P O Box 126740
Abu Dhabi
Tel +971 2 5554 347
Fax +971 2 5554 348
www.bbrstructuralsystems.com
bbr@bbrstructuralsystems.com

BBR DIRECTORY

ASIA-PACIFIC
HONG KONG
SRG (Hong Kong)
Office 606
6/F Shun Feng International Centre
182 Queens Road East
Wan Chai
Tel +852 3598 8518
MACAU
see Hong Kong
MALAYSIA
BBR Construction Systems (M) Sdn Bhd
No.17, Jalan Sg. Jeluh 32/191
Kawasan Perindustrian Kemuning, Seksyen 32
40460 Shah Alam
Selangor Darul Ehsan
Tel +60 3 5636 3270
Fax +60 3 5636 3285
www.bbr.com.my
enquiry@bbr.com.my
PHILIPPINES
BBR Philippines Corporation
Suite 502, 7 East Capitol Building
No.7 East Capitol Drive
Barangay Kapitolyo
Pasig City, Metro Manila 1603
Tel +632 638 7261
Fax +632 638 7260
info@bbr.com.ph
SINGAPORE
BBR Construction Systems Pte Ltd
BBR Building
50 Changi South Street I
Singapore 486126
Republic of Singapore
Tel +65 6546 2280
Fax +65 6546 2268
www.bbr.com.sg
enquiry@bbr.com.sg
THAILAND
see Singapore
VIETNAM
see Singapore

AUSTRALIA
SRG Limited
Level 1, 338 Barker Road
Subiaco WA 6008
Tel +61 8 9267 5400
Fax +61 8 9267 5499
www.srglimited.com.au
info@srglimited.com.au
SRG Limited
Suite 3, Level 1, 75 Carnarvon Street
Silverwater NSW 2128
Tel +61 2 8767 6200
Fax +61 2 8767 6299
www.srglimited.com.au
info@srglimited.com.au

FIJI
see New Zealand
NEW ZEALAND
BBR Contech
15 Kerwyn Ave, East Tamaki
PO Box 51-391
Pakuranga, Auckland 2140
Tel +64 9 274 9259
Fax +64 9 274 5258
www.contech.co.nz
akl@contech.co.nz

SRG Limited
Unit 1/12 Commerce Circuit
Yatala, Queensland 4207
Tel +61 7 3442 3500
Fax +61 7 3442 3555
www.srglimited.com.au
info@srglimited.com.au

BBR Contech
27 Port Road, Seaview
PO Box 30-854
Lower Hutt, Wellington 5040
Tel +64 4 569 1167
Fax +64 4 569 4269
www.contech.co.nz
wgn@contech.co.nz

SRG Limited
112 Munro Street
South Melbourne
Victoria 3205
Tel +61 3 9296 8100
Fax +61 3 9646 7133
www.srglimited.com.au
info@srglimited.com.au

BBR Contech
7A Birmingham Drive, Middleton
PO Box 8939
Riccarton, Christchurch 8440
Tel +64 3 339 0426
Fax +64 3 339 0526
www.contech.co.nz
chc@contech.co.nz

Additional BBR technology licenses have been granted in Europe, Asia-Pacific and Americas for more information, please contact the BBR Headquarters.

www.bbrnetwork.com 93