CI/SfB
(23) Eq4
Product Part 1 August 2008
Introduction
Lighter Flat Slab Structures
with BubbleDeck
What is the BubbleDeck® System?
Reinforcing mesh, top
Recycled plastic hollow ‘Bubble’ void former
Reinforcing mesh, bottom – cast into
optional 60mm concrete ‘biscuit’
Advantages
Design Freedom
Reduced
Dead Weight
Longer Spans
Green and
Sustainable
Fast
Construction
Want to know more?
BubbleDeck Technical Manual
BubbleDeck Design Guide
Interactive CD ROM with
BubbleDeck slab calculator
are also available
upon request
Email: Info@BubbleDeck-UK.com
Tel: 01691 774242
The engineering solution that radically
improves building design and performance
while reducing the overall cost.
BubbleDeck is a revolutionary method of virtually eliminating concrete from the middle of a floor slab not performing any
structural function, thereby dramatically reducing structural dead weight. BubbleDeck is based on a new patented technique
- the direct way of linking air and steel. Void formers in the middle of a flat slab eliminates 35% of a slabs self-weight
removing constraints of high dead loads and short spans.
Incorporation of recycled plastic bubbles as void formers permits 50% longer spans between
columns. Combination of this with a flat slab construction approach spanning in two
directions – the slab is connected directly to insitu concrete columns without any beams -
produces a wide range of cost and construction benefits including:-
• Design Freedom – flexible layout easily adapts to irregular & curved plan layouts.
• Reduced Dead Weight - 35% removed allowing smaller foundation sizes.
• Longer spans between columns – up to 50% further than traditional structures.
• Downstand Beams eliminated – quicker & cheaper erection of walls and services.
• Load bearing walls eliminated – facilitating MMC with lightweight building envelopes.
• Reduced concrete usage – 1 Kg recycled plastic replaces 100 Kg of concrete.
• Environmentally Green and Sustainable – reduced energy & carbon emissions.
The overall floor area is divided down into a series of planned individual elements, either 3 or
BubbleDeck’s 2.4 metres wide dependant upon site access, which are manufactured off-site using MMC
height saving techniques. These elements comprise the top and bottom reinforcement mesh, sized to suit
allowed 2
floors to be
the specific project, joined together with vertical lattice girders with the bubble void formers
added trapped between the top and bottom mesh reinforcement to fix their optimum position. This
during is termed a ‘bubble-reinforcement’ sandwich which is then cast into bottom layer of 60mm
construction
pre-cast concrete, encasing the bottom mesh reinforcement, to provide permanent formwork
within part of the overall finished slab depth.
On site the individual elements are then ‘stitched’ together with loose reinforcement simply
laid centrally across the joints between elements. Splice bars are inserted loose above the pre-cast concrete layer between
the bubbles and purpose made mesh sheets tied across the top reinforcement mesh to join the elements together. After the
site finishing concrete is poured and cured this technique provides structural continuity across the whole floor slab – the
joints between elements are then redundant without any structural effect – to create a seamless floor slab.
BubbleDeck has proved to be highly successful in Europe since its invention ten years ago. In Denmark and Holland over 1
million square metres of floors have been constructed in the last seven years using the BubbleDeck system in all types of
multi-storey buildings.
BubbleDeck® is a simple solution that eliminates non-working
dead load in floors while fully retaining strength.
Simple site installation
(DECK TYPE A)
• Temporary Support – Propping on parallel beams at 1.8
to 2.4 metre spacing
• Placing Elements – Semi pre-cast elements mechanically
lifted into position
• Joint Reinforcement – Insert loose bottom splice bars
BubbleDeck®
and tie top mesh across joints between elements
is a two-way
• Shear Reinforcement – Insert loose bars across columns spanning hollow
• Edge reinforcement – Insert edge bars and hairpins deck in which
around slab perimeter recycled plastic
• Perimeter shuttering – Fix shuttering to bottom pre-cast bubbles serve the
concrete layer & tie to top mesh reinforcement
purpose of
eliminating
• Soffite shuttering – Prop plywood across tolerance joints
non-structural
between element bays and between elements & columns concrete
• Preparation – Seal joints between elements, clean and
moisten bottom pre-cast concrete layer
• Concreting – Pour, vibrate and float 10mm max.
aggregate in-situ concrete
• Temporary works – Remove, typically after 8 – 10 days,
according to specific site advice.
• Finishing – no further work required, the slab is complete
unless requirement for exposed soffite
BubbleDeck® slab versions
The appropriate BubbleDeck slab version is bespoke engineered to suit building
configuration, span length between supports, applied loadings and vertical
alignment of supports. Indicative spans, based on our standard 20mm concrete
cover to bottom reinforcement mesh providing 1 hour fire resistance, are given
as a guide to what can be achieved.
Version Slab Bubbles Span Cantilever Span Completed Site Concrete
Thickness (Multiple bays) Maximum Length (Single bays) Slab Mass Quantity
mm mm metres metres metres Kg/m2 m3/m2
BD230 230 Ø 180 5 – 8.1 2.2 5 – 6.3 370 0.11
BD280 280 Ø 225 7 – 10.1 2.7 6 – 7.8 460 0.14
BD340 340 Ø 270 9 – 12.5 3.3 7 – 9.6 550 0.18
BD390 390 Ø 315 10 – 14.4 3.8 9 – 11.1 640 0.21
BD450 450 Ø 360 11 – 16.7 4.5 10 – 12.5 730 0.25
Element types
BubbleDeck can be supplied in 3 types of
manufactured elements:
Type A – Filigree Elements, where the bottom of the
‘bubble-reinforcement’ sandwich includes a 60mm thick pre-cast
concrete layer acting as permanent formwork within part of the
finished slab depth replacing the need for soffite shuttering. The
elements are placed on temporary propping, loose joint, shear &
edge reinforcement added, perimeter and tolerance joints shuttered and then the
remaining slab depth concreted.
Most commonly specified being suitable for the majority of new-build projects. Requires fixed or
mobile crane to lift into position due to weight of manufactured
elements as delivered to site.
Type B - Reinforcement Modules
comprising pre-fabricated ‘bubble-
reinforcement’ sandwich elements.
The modules are placed on
traditional site formwork, loose joint,
shear & edge reinforcement added and then
concreted in 2 stages to the full slab depth.
Suitable for suspended ground floor slabs and alteration /
refurbishment projects, particularly where site access is
extremely restricted. Can be manually lifted into position.
Type C – Finished Planks, delivered to the building site as complete
pre-cast factory made slab elements with the full concrete thickness. These
span in one direction only and require the inclusion of supporting beams or walls
within the structure.
Selected BubbleDeck® projects
Le Coie Housing
The largest BubbleDeck structure so far erected in Great Britain was These are only a few of many projects with
completed 6 weeks ahead of programme. The structure comprises 7,800m2 of BubbleDeck floors.
BubbleDeck floor slabs between 3 and 6 stories high supported on in-situ
For many others and new projects see our
reinforced concrete columns. Over £400,000 of savings were realised as a
WEB site: www. BubbleDeck-UK.com
direct result of incorporating BubbleDeck into this project, amounting to a
3% saving off the TOTAL project cost.
The Main Contractor subsequently found the BubbleDeck system
benefits continue throughout the whole construction process with
faster and cheaper erection of external & internal walls plus fast
and easy installation of services below the flat soffites.
Chris Dunne, Project Architect, commented:- “Our original
solution for Le Coie was a steel frame with Bison floor planks &
structural concrete topping in the 5 to 6 storey areas, with load
bearing blockwork supporting a composite metal deck in the lower sections.
The BubbleDeck technique not only saved a considerable sum but simplified
the buildings structure, removing my co-ordination headache of getting
services around or through beams required with a traditional solution. We
were also able to eliminate all load bearing walls down the middle of each
flat, required to support the short spans of composite metal decks, giving
more internal space and fantastic flexibility.
I will definitely consider BubbleDeck
for use on my future projects.”
Media City
This 32.000 m2 building was
constructed with great
transparency, revealing a huge
open atrium. This atrium is the fulcrum and heart of the
building. The spaces are formed in soft, organic
BubbleDeck ®
shapes that allow light to spill onto every
is the ONLY single workplace in the building.
light flat slab To achieve these wide, open, internal
system officially spaces a BubbleDeck structure of
certified for U.K. use post – tensioned 390mm deep
having been granted floor plates, achieving 16 metre
Dutch Technical spans between columns was
Certificate CUR 86, selected - dramatically reducing
recognised in the structure dead weight and
Building Regulations enabling long spans. The flexibility
as equivalent to of BubbleDeck also facilitated
an Agrément construction of the soft flowing, organic
Certificate. shapes forming the floors around the
central atrium.
Millennium Tower
Originally designed with hollow core planks, late in the
design stage it was determined that BubbleDeck would
realise considerable cost and time savings. Adopting
BubbleDeck also reduced the structural floor zone City Hall and Offices
depth due to omission of beams, lowering the BubbleDeck’s superior cantilevering ability
overall building’s height. achieved 3.3 metre cantilevers from a
Another consideration was the lack of storage 280mm deep slab with 7.5 metre internal
space on the building site which is located close to spans between columns. The building
major arterial roads and streets. The floors were on provides a City Hall and financial centre
average erected, cast and completed in half the for Danske Bank containing 4,000 m2
time - 4 days instead of 8 days – it would have floor area. The slender slab without any
taken to construct with hollow core planks. Half beams secures maximum light from the
way through constructing the structure it was facades, which is enhanced by an internal
decided to add another 2 floors which was made atrium. This project won “Building of the
possible within the overall height of the original building Year 2004” award for offices and
due to BubbleDeck reducing structural floor depth. commercial buildings.
Solid deck comparison
A BubbleDeck slab has the same applied load carrying capacity with As an example for BD280 slab version, with 1 hour fire
only 50% of the concrete required for a solid concrete slab, or with resistance, d is 260mm so 39xd indicates a maximum 10.14
the same slab thickness has twice the load carrying capacity using metre continuously supported (multiple bay) span; 30xd
65% of the concrete required by a solid concrete slab. indicates a maximum 7.8 metre simply supported (single bay)
span, and 10.5xd indicates a maximum 2.73 metre cantilever is
Schematic design basic principle potentially feasible. This basic principle has been verified for
As a general guide for project scoping purposes the maximum achievable
dead loadings up to 4.5 Kn/m2 following full calculations on
spans for each BubbleDeck slab depth is usually determined by deflection
many projects as a generally reliable indication. We can refine
limitations. This criteria is controlled by the ratio of span / effective depth
this estimation method by full calculation and we would be
(L/d) stipulated in BS8110 or EC2 and modified by applying a factor of 1.5,
pleased to give you advice on a specific project.
permitted to take account of BubbleDeck’s dramatically lower dead weight
than traditional solid flat slabs. Post tensioning
L/d 30 for simply supported floors (single spans) When mega spans are required
L/d 39 for continuously supported floors (multiple spans) (above 15 metres) we can provide
a Post–Tensioned (PT)
L/d 10.5 for cantilevers.
BubbleDeck solution. The above
The effective depth of a BubbleDeck slab is the overall depth less standard deflection limits can be
20mm concrete cover (achieving 1 hour fire resistance) from the bottom increased by up to 30% more
mesh reinforcement to underside of the slab. Where 90 minute fire with post-tensioned
resistance is required deduct 25mm off overall slab depth, or for 120 BubbleDeck slabs.
minute fire resistance deduct 30mm off overall slab depth. In the case of
spanning onto columns without beams use the longest dimensions
between columns, where the slab will span onto walls or beams use the
shortest span dimension.
Solid slab BubbleDeck ® BubbleDeck ®
same thickness same capacity
Carrying capacity
Slab Dead load
Relative values in % of solid slab
Carrying capacity
Dead load
25
75
50
50
25
40 Green credentials
Dead load / Carrying capacity 3:1 1:1 1.5:1
By virtually eliminating concrete in the middle of a slab BubbleDeck
Absolute values in % of solid slab makes a significant contribution to reducing environmental impact.
Carrying capacity 100 200 100
Slab dead load 100 65 50 Guidance from the ODPM requires the direct environmental effects of buildings
Utility value of 300 200 to be considered, including usage of natural resources and emissions resulting
concrete increased
from construction. Not only is concrete usage reduced by up to 50% within a
A BubbleDeck has twice the capacity with 65% concrete and the
same capacity with 50% concrete compared to a buildings structure but knock-on benefits can be realised through reduced
solid slab. foundation sizes. BubbleDeck can make a big contribution towards achieving
BREEAM targets.
BubbleDeck®
Every 5,000 m2 of BubbleDeck floor slab can save:-
floors make a
• 1,000 m3 site concrete.
substantial • 166 ready mix lorry trips.
contribution to • 1,798 Tonnes of foundation loads – or 19 less piles.
reducing carbon • 1,745 GJ energy used in concrete production & haulage.
emissions arising • 278 Tonnes of CO2 – green house gas – emissions.
from construction.
Consider the benefits
Data based on typical 4,500 m2 Office Building with 7.5 x 7.5 metre multiple
spans between in-situ or precast concrete columns.
Slab Site Concrete Site Concrete Total Slab Embodied CO2
Depth Volume Quantity Dead Load Energy Emissions
(mm) m3 / m2 m3 (Tonnes) (Giga Joules) (Tonnes)
Solid Slab 310 0.31 1,395 3,376 3,278 522
BubbleDeck 230 0.11 495 1,758 1,707 272
BD SAVES 80 0.20 900 1,618 1,571 250
Assumptions:
1) Lightweight external envelope (curtain walling or equal).
2) Typical office live load 2.5 kN/m2 + 1.5 kN/m2 for lightweight partitions, computer floor, finishes & services.
3) Overall stability braced by stair / lift core shear walls in both cases.
4) Energy from materials transport – cement 50 miles, aggregate 10 miles (to ready mix plant) and concrete 5
miles (to site).
BubbleDeck structures are also Sustainable with the system allowing frame re-use for future
purposes. The envelope and all internal work can be removed from a BubbleDeck building
and the original frame simply refitted for a new purpose. The two way spanning nature of
BubbleDeck slabs allows any internal layout to be reconfigured to new uses within the
original design load parameters.
B U B B L E D E C K
Service options
We provide two alternative Service Options covering provision of design, detailing, drawing production,
element manuifacture and supply of all components to site completely ready for construction:-
Option A – Full Floor Design by BubbleDeck (BD)
1. Initial Enquiry & consultation / advice / meetings (FOC).
2. Schematic design of Deck Type and Report (FOC).
3. Quotation for Detail Design, Drawing Production, Element Manufacture & Supply, based on estimated amount
of reinforcement required per m2 (FOC).
4. Acceptance of Quotation and order / payment for Detail Design
and Drawing Production.
5. Detail Design of BubbleDeck floors by BD, Detail Design of all
other elements (foundations, columns, external envelope &
roof) by Clients Agents or others.
The
6. Submission of Detail Design to Clients Agents & Building
Control for approval. BubbleDeck®
7. Production of manufacture and site installation
drawings by BD, including pre-cast elements ready
for manufacture and all required loose system is based
reinforcement.
8. Submission of Production Drawings to Clients
Agents for approval.
upon the patented
9. Adjusted Quotation, based on final amount of
reinforcement per m2. integration
10. Acceptance of Adjusted Quotation & Order for
Element / Reinforcement manufacture,
production & supply to site. technique - the
11. Advice to Clients Main Contractor & Agents on Site Installation & Construction.
12. Manufacture of Elements & supply to Site.
13. Advice to Main Contractor during Site Installation & Construction.
direct way of
14. Site Inspections of Erection, Loose Reinforcement and sign–off by BD prior to final
concrete pour. linking air and
Option A under-written by BD’s £2M Professional Indemnity Policy and Product Guarantee.
steel.
Option B –Structure & BubbleDeck Floor Design by Clients Agents
1. Initial Enquiry & consultation / advice / meetings (FOC).
2. Advice on Deck Type, element layout and design (FOC).
3. Quotation for Element Production & Supply, based on Clients Agents estimated reinforcement per m2 (FOC).
4. Detail Design of BubbleDeck floors and all other elements (foundations, columns, external envelope & roof)
by Clients Agents or others.
5. Submission of Detail Design to BD for review & comment.
6. Production of manufacturing drawings by BD, production of site installation drawings by Clients Agents,
including all required loose reinforcement.
7. Submission of site installation drawings to BD for review & comment.
8. Adjusted Quotation, based on final amount of reinforcement per m2.
9. Acceptance of Adjusted Quotation & Order for Element / Reinforcement manufacture, production
& supply to site.
10. Advice to Clients Main Contractor & Agents on Site Installation & Construction.
11. Manufacture of Elements & supply to Site.
12. Site Inspections and sign – off by Clients Agents prior to final concrete pour.
Option B under-written by BD’s Product Guarantee.
WEB: www.BubbleDeck-UK.com
