1.

0 Introduction
The Transfloor™ System (also known by the name of the original
licensors - ABE, Filigran, Kaiser-Omnia floor) has been widely used in
Europe and elsewhere for over 40 years. Overseas trends indicate that
this precast flooring system is a favoured method of construction for sus-
pended concrete slabs and in some parts of Europe it accounts for 60%
of all suspended work reaching production rates of 80 million square
metres per year. As a precast flooring system it offers many advantages
over cast in-situ floors while maintaining the full structural integrity and
monolithic requirements of the slab.

In Australia this type of flooring has been in use since 1982 and in
February 1988 Transfloor™ Pty Ltd was purchased by Smorgon ARC and
traded as Transfloor™ Australia Pty Ltd until 1991. Since 1992 the
manufacture of Transfloor™ has been licensed to a number of independent
precast companies. Each agreement allows the manufacturer to market
Transfloor™, in the specified territory, using the same expertise and
technical know how that was developed by Transfloor™.

Figure 1: Curved, irregular shaped panel using Transfloor™

Smorgon ARC is committed to technical support and product development of

Transfloor™. Smorgon ARC also supplies the various manufacturers with
special truss reinforcement and other associated reinforcing and building
products.

Introduction Page 1
 2.0 The Transfloor™ System
The Transfloor™ system uses a combination of precast steel reinforced
concrete panels and a poured in-situ topping as a means of constructing a
suspended concrete slab. The use of site placed steel reinforced concrete
effectively ties all the precast elements together providing safety, rigidity
and structural redundancy.

Transfloor™ Features
Size - A Transfloor™ panel is a factory made precast concrete slab of
variable width up to a maximum of 2.5 metres and variable length, usually
limited to about 12 metres for transport and handling purposes.

Thickness - The panel thickness can be varied and will depend on

reinforcement size and concrete cover. For many applications a nominal
thickness of 55 mm is satisfactory.

Reinforcement - The bottom reinforcement embedded in the panel can

consist of a layer of fabric, the bottom chords of the trusses and additional
reinforcing bars as required by the designer.

Handling - The Transfloor™ trusses provide strength and stiffness for

handling and transport, allow panels to support construction loads with a
minimum of temporary propping, contribute to the bottom steel and to the
top steel and can also serve as continuous bar chairs to support the top
reinforcement.

Weight Saving - Polystyrene void formers, added at the precast factory,

allow for construction of voided slabs with a significant reduction in self
weight (typically 30%).

Flexibility - In contrast with most other prefabricated systems, Transfloor™

imposes few restrictions on designers because there are no standard
panel sizes. The length, width, thickness, plan geometry and
reinforcement steel can be varied to suit design requirements and allow
considerable flexibility for both the Architect and the Engineer.

MAX. PANEL WIDTH - 2500 (TRANSPORT

LIMITATION). LESSER WIDTHS AS REQUIRED
ADJUST NUMBER AND TYPE OF TRUSSES TO SUIT TO FIT JOB DIMENSIONS, BUT MAXIMISE THE
CONSTRUCTION LOADS. 5 TRUSSES IS THE PRACTICAL NUMBER OF FULL WIDTH PANELS TO SECURE
MINIMUM FOR 2500 WIDE PANEL. FOR SLABS BEST ECONOMY.
WITHOUT VOIDS ABOUT 18 TRUSSES ARE POSSIBLE.
USE MAXIMUM 8 TRUSSES IN VOIDED SLABS.

DEPTH OF SITE PLACED CONCRETE ABOVE VOIDS

AS REQUIRED BY DESIGN. MINIMUM 65 WITH
MINIMUM RF62 TOP FABRIC. TOP STEEL AS REQUIRED
BY DESIGN.
120 MIN TRANSVERSE RIB

120 MINIMUM RIB AT INTERNAL ANY LENGTH PANEL

TRUSS. FILLED WITH IN-SITU CAN BE SUPPLIED.
CONCRETE. MAXIMUM 12M FOR EASE
OF TRANSPORT.
180 MINIMUM RIB
LENGTH OF VOID ADJUSTED TO
AT EDGE TRUSSES
SATISFY END SHEAR REQUIREMENTS.

PANEL CONCRETE THICKNESS 50 MINIMUM.

VARY THICKNESS TO SUIT (EG. EXTRA COVER,
DIAMETER BARS ETC.)

PANEL FABRIC RF62 MINIMUM. POLYSTYRENE VOID FORMERS (OF ANY CROSS-SECTION)
HEAVIER IF REQUIRED BY DESIGN. BONDED TO PANEL AT FACTORY (VOID PERCENTAGE IS
VARIABLE FROM ZERO TO ABOUT 35%)

ADDITIONAL BOTTOM STEEL IN THE FORM

OF BARS AS REQUIRED BY DESIGN
(N12, N16, N20 ETC.)

NOTE
TRANSFLOOR UNITS CAN BE MADE TO ANY SIZE AND ANY SHAPE WITHIN THE LIMITS SHOWN ABOVE. SEMICIRCULAR OR RECTANGULAR CUT
OUTS, SKEWED ENDS AND IRREGULAR SHAPES CAN BE USED TO SUIT PARTICULAR JOB REQUIREMENTS.

CHARACTERISTICS OF TRANSFLOOR™ PANELS

Figure 2: Typical characteristics of a Transfloor™ panel

Page 2 Transfloor™ Precast Flooring System

 3.0 Advantages and Applications
The Transfloor™ system is versatile and adaptable for use in a wide variety
of structures including low-rise residential and commercial developments,
high-rise steel and concrete framed structures, bridge decks, culverts and
other civil applications.

Cost Effective Features

Faster construction - Up to 150 m2 per hour can be placed by crane. Total
building time can be reduced significantly (refer Table 1).

Eliminates formwork - Traditional formwork can be totally eliminated.

Transfloor™ panels provide both the working platform and part of the
completed floor.

Reduced propping - Propping requirements are reduced when

compared with traditional formwork which means less cluttering of the
floor below and earlier access by following trades.

Clean and safe - Fewer trades are required resulting in a less

cluttered, cleaner and safer building site. An immediate work platform is
provided.

Lighter structure - Use of polystyrene void formers reduces the self weight
of the slab and provides cost savings in foundations, columns and beams.
The void formers also reduce the volume of in-situ concrete.

Soffit finish - A class 2 off-form grey finish is easily achieved, suitable for
painting with minimum preparation (refer Figure 3).

Balcony Upstands - Can be provided as an integral part of the Transfloor™

panel. Eliminates costly edge formwork and scaffolds. Allows early
installation of temporary or permanent balustrades.

Figure 3: High quality treated soffit finish

Advantages and Applications Page 3

 Advantages and Applications

Traditional Formwork Transfloor™ System

Activity Labour Day/s Hours Activity Labour Day/s Hours

Erect & prop wall panels 2 Dogman 1 16 Erect and prop wall panels 2 Dogman 1 16
2 Labourers 1 16 2 Labourers 1 16

Grout wall panels 2 Labourers 1 16 Grout wall panels 2 Labourers 1 16

Support frames 3 Scaffolders 2 48 Support frames 3 Scaffolders 1 24

Place ply formwork 4 Carpenters 3 96 Place Transfloor™ panels 2 Dogman 1 16

2 Labourers 3 48 2 Carpenters 1 16

Place reinforcement 4 Steel Fixers 2 64 Place top reinforcement 4 Steel Fixers 1 32

Pour concrete 8 Labourers 1 64 Pour concrete 8 Labourers 1 64

Strip formwork and clean up 4 Carpenters 2 64 Remove propping frames 2 Scaffolders 1 16

2 Scaffolders 2 32

Total Cycle (approximate hours) 464 Total Cycle (approximate hours) 216

Typical Cycle 0.62 hrs/m2 Typical Cycle 0.29 hrs/m2

Table 1: Comparison of cycle times and labour requirements for slab over precast walls-Brookland Apartments.
Flexibility in design - Transfloor™ is an engineered product made to suit
individual project requirements. Penetrations, cantilevers and unusual
panel shapes can be easily accommodated (refer Figure 4).

Eliminates bar chairs - If concrete cover and overall slab thickness are
suited to the truss type, top reinforcement can be supported directly on the
Transfloor™ trusses.

Four easy steps to build with TransfloorTM

1. At the time of planning, contact an approved Transfloor™ supplier to

Figure 4: Column penetration in Transfloor™ panel
discuss the use of Transfloor™ for your application.

2. Supplier personnel will then assess and arrange for a preliminary design
and prepare concept layout plans and a quotation.

3. Upon placement of the order a detailed layout plan is prepared based

on the documentation provided. This information is returned to the
builder and engineering consultant for checking and approval.

4. After approval has been obtained for dimensional accuracy and engi-
neering integrity, the panels are produced and delivered to site at a time
Figure 5: Transfloor™ on load bearing block walls specified by the builder.

Figure 6: Transfloor™ panels placed on steel frame structures

Page 4 Transfloor™ Precast Flooring System

 4.0 Material & Product Specification

4.1 Reinforcement
Transfloor™ trusses are fabricated from plain round hard drawn 500L
grade bar conforming to AS4671. The diagonal bars of the truss are
electronically welded to both the top and bottom chords. Weld tests are
carried out at regular intervals as part of the Smorgon ARC Quality
Assurance programme.

All fabric used in the panels is welded wire fabric, grade 500L
conforming to AS4671 and all bar reinforcement is grade 500N
conforming to AS4671.

4.2 Panel concrete

The panel concrete is Normal Class Concrete as defined in AS3600. A
typical concrete specification is given below but the Engineer should also
nominate special class concrete if used.

Minimum strength grade . . . . . . . . . . . . . . . . . . N40

Slump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80 mm
Maximum size of aggregate . . . . . . . . . . . . . . . 14 mm (nominal)
Cement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . General purpose

Figure 7: Reinforcement in casting bed ready for concrete pour

4.3 Polystyrene void formers

The expanded polystyrene (EPS) void formers are made of a light weight
cellular plastic material comprising 98% air. A class SL material is used
having a density of 13.5 kg/m3. All other physical properties of the EPS
are in accordance with AS1366, Part 3-1992. Designers should note that
the EPS is produced with a fire retardant additive that allows it to self
extinguish almost immediately after the fire source is removed. The level of
toxicity of EPS in a fire situation is not greater than that of timber or other
commonly used building materials.

Material and Product Specification Page 5

 Material & Product Specification

4.4 Topping concrete

It is essential that the site concrete, whether placed over panels or over
void formers, is of a high quality, and that placement and curing is of a sat-
isfactory standard to minimise surface cracking due to plastic
shrinkage or other causes.

In-situ concrete thickness over void formers will be governed by cover,

quantity, size and laps of top reinforcement. A minimum of 65 mm should
be used.

4.5 Truss specifications

Generic Truss Smorgon ARC Top Chord Height (H) Mass

Reference Product Code Diameter (mm) (kg/m)

T80/10 TRUS8010C 9.5 82 1.77

T110/10 TRUS11010C 9.5 111 1.86
T150/10 TRUS15010 9.5 154 2.06
T190/10 TRUS19010C 9.5 191 2.21
T80/12 TRUS8012C 11.9 83 2.12
T110/12 TRUS11012C 11.9 112 2.21
T150/12 TRUS15012C 11.9 155 2.41
T190/12 TRUS19012C 11.9 192 2.56

Typical Sections:
200 STANDARD PITCH
DIAGONALS 6.0 mm HD WIRE TOP CHORD SIZES
AS SHOWN ABOVE
HEIGHT (H)

W=105
BOTTOM CHORDS 6.0 mm HD WIRE

SECTION ELEVATION

Figure 8: Truss properties and section details

Page 6 Transfloor™ Precast Flooring System

 5.0 Design Principles
The structural design of Transfloor™, or any precast concrete floor
system, should not only deal with the calculation of bending moment and
shear force capacity of the separate units, but also with the total coher-
ence of the floor. In the final stage, the individual components should be
connected in a manner that ensures adequate overall capacity with interac-
tion between the units and the supporting structure. Two distinct stages
must be checked when designing with Transfloor™.

1. The non-composite panel during construction - stresses occurring only

in the precast units resulting from lifting, transportation and the weight
of the wet concrete.

2. The composite floor slab after hardening of the in-situ concrete.

5.1 Design for bending

Accepted principles of Ultimate Strength Theory applies to the design of
Transfloor™ since the finished slab can be considered as monolithic. A
prerequisite for this is that the uptake of shear forces at the interface
between precast and in-situ concrete is proven. The shear capacity, at this
interface, has been shown to be adequate by overseas research
(Reference 1) and some early testing done at the University of Queensland
(Reference 2).

The system is best suited to one way action, however, two way action can
be achieved by eliminating void formers to allow placement of transverse
Figure 9: Biaxial trusses - panels engineered to suit bars. The transverse bars should be placed near the upper surface of the
project requirements panel ensuring that in-situ concrete flows under the bars and anchorage is
achieved. Note that a reduced effective depth for the transverse reinforce-
ment will have to be used.

In a uniaxial design the precast panel will normally contain all of the bottom
reinforcement required in the final design which can consist of a light fab-
ric, truss bottom chords and additional bar reinforcement. It should be
noted that the presence of voids will not usually result in design of the sec-
tion as a tee beam since large amounts of steel are required to shift the
neutral axis below the top of the void. Refer to Figure 10 for a general
cross section of a finished slab.

360 MIN RIB OVER PANEL JOINT 440 MAX POLYSTYRENE VOIDS 120 INTERNAL RIB
NEUTRAL AXIS AT ULTIMATE MINIMUM
LOAD IS USUALLY ABOVE
LAPPED FABRIC
TOP OF VOID
(MIN RF62) TRANSFLOOR TRUSSES
500N EXTRA BARS
SEE FIGURE 8 FOR DETAILS
AS REQUIRED
65 (MIN)
EFFECTIVE DEPTH

SLAB 0.A. DEPTH

VOID
50 (MIN)

20

GRADE N40 500N FXTRA BARS

25 25 CLEAR COVER TO
PANEL CONCRETE AS REQUIRED TRANSVERSE WIRES
RF62 BOTTOM FABRIC

120 565 MAX TRUSS SPACING

PANEL WIDTH 2500 (NOMINAL)

Figure 10: General cross section of finished slab

Design Principles Page 7

 Design Principles

5.2 Precast in-situ interface

The required capacity at the interface can be calculated in accordance
with AS3600 Clause 8.4. The level of surface roughness is somewhat
open to interpretation but can be considered as rough with small ridges
and undulations. The surface roughness achieved during the casting
process is satisfactory when, at the same time, truss web members are
used as shear plane reinforcement.

If an intentionally roughened surface is specified, care should be taken not

to disturb the grain structure of the concrete or dislodge aggregates near
the surface. A vibrated level or light broom finish is all that is required.
Figure 11: Penetrations for services can be cast into
panel
5.3 Vertical shear
If a voided slab is used the shear forces can only be carried by the con-
crete in the rib sections. Voids must be terminated in regions of high shear
(at supports and point loads) and will generally not be included within one
slab depth from the section at which the ribs are just sufficient to resist the
applied shear.

The overall slab thickness is not normally controlled by shear strength

requirements but, when required, the diagonal wires of the trusses may be
treated as inclined stirrups (Reference 1) provided the pitch of the wires
does not exceed the depth of the slab, trusses extend through the full slab
depth and truss spacing does not exceed the recommended stirrup
spacing given in AS3600.

When the precast element is used to form a wide shallow beam (band
beam/slab system on columns) and shear reinforcement is required, the
ligatures should extend over the entire section depth and tie into the pre-
cast element. However, if the actual shear is less than the shear capacity
and the beam depth is less than half the beam width, nominal shear
ligatures can be incorporated as shown in Figure A8 in Appendix A.

5.4 Load distribution

When a slab is subjected to concentrated loads, the distribution of the
load across longitudinal joints should be considered. The transverse load
distribution in composite precast element floors is similar to cast in-situ
floors. Load distribution between precast elements is provided by the
shear resistance of the in-situ concrete section at the joint (Figure 10).
Where trusses are not located adjacent to the joint, additional
transverse bars may be placed in the site concrete over the panel joints.
The inclusion of transverse ribs (Figure 2) would also contribute to the load
distribution capabilities.

Figure 12: Slab and band beam system

Page 8 Transfloor™ Precast Flooring System

 Design Principles

Panel Thickness Panel Width

50mm 2500mm
55mm 2502mm
60mm 2504mm
65mm 2506mm
70mm 2508mm

Table 2 Actual panel thickness and width

Truss type Slab thickness Fire rating

T80 160mm 2 Hours

T110 190mm 3 Hours
T150 230mm 3 Hours
T190 270mm 3 Hours

Table 3: Standard truss thickness and typical fire rating for voided slabs

Note:

1. Table 3 is based on 20 mm cover to top and bottom reinforcement and

minimum 65 mm topping concrete over polystyrene void formers.

2. The overall slab thickness is the minimum that can be used with the
nominated truss type.

3. The actual panel width will depend on the panel thickness used due to
the tapered edge forms.

4. Top reinforcement can be supported directly on trusses when the

above slab/truss combinations are used and reinforcement is arranged
as shown in Figure 10.

5.5 Durability requirements and fire rating

Since Transfloor™ panels are cast in rigid steel forms and are subjected to
intense compaction the reinforcement cover requirements at the bottom of the
slab can be reduced compared to in-situ slabs (AS3600 Table 4.10.3.4). If
severe exposure conditions are specified the panel thickness is increased
to allow for the increased cover requirements.

Fire resistance requirements for slabs constructed with Transfloor™

panels can be determined by referring to clause 5.5.1 (b) and 5.5.3 (a) of
AS3600. If a voided slab is used the effective thickness of the slab is cal-
culated as the net cross sectional area divided by the width of the cross
section. Typical fire resistance periods are shown in Table 3. Higher fire
ratings can be achieved with increased cover to reinforcement and
decreased thickness of polystyrene voids.

Design Principles Page 9

 Design Principles

5.6 Support conditions

The correct detailing of precast concrete involves the consideration of the
design, manufacture and construction requirements at the start of the pro-
ject. It is important to consider detailing during the early design stages so
as to obtain the full benefits of any precast system.

As with in-situ floors, when designing with Transfloor™, attention must be

given to anchoring of steel reinforcement at the supports. Steel
reinforcement end details are specified in AS3600 clause 9.1.3 and the
amount of steel reinforcement to be carried into the support will depend
on the end restraint condition.

Connections between Transfloor™ panels and supporting members pre-

sent few problems since continuity can be provided by lapping the panel
steel reinforcement with steel bars projecting from the supporting beams
or walls. In general, it is sufficient to anchor 50% of the total positive
moment steel reinforcement required at mid span. The bottom chords of
the Transfloor™ trusses which end at the front edge of the support do not
constitute part of this requirement. Therefore the details suggested in
Figure 13: panels connecting to precast walls
Figure 14 can be safely used provided the field steel reinforcement is
satisfactorily anchored above the support

a
a Lsy.t TOP BARS TO ACHIEVE
NEGATIVE MOMENT
CAPACITY

As (STEEL AREA AT END OF PANEL) As (AREA OF SPLICE BAR)

PROVIDE COG IF REQUIRED
FACE OF SUPPORT

(1) PANEL EXTENDS INTO SUPPORT (3) END SUPPORT WITH END RESTRAINT

a Lsy.t

Lsy.t
TOP REINFORCEMENT

As (AREA OF SPLICE BAR)

PROVIDE COG IF REQUIRED
As (AREA OF SPLICE BAR)
(ALTERNATIVE) PANEL CAN PROVIDE COG IF REQUIRED
EXTEND INTO SUPPORT

(2) SPLICE BARS EXTEND INTO SUPPORT (4) INTERMEDIATE SUPPORT WITH SLAB CONTINUITY

REFER TO AS3600 CLAUSE 9.1.3.1 Ast = TOTAL POSITIVE REINFORCEMENT AT MID SPAN
Ast = TOTAL POSITIVE REINFORCEMENT AT MID SPAN As=0.5Ast BUT CAN BE REDUCED TO 0.25Ast WHEN
a=100 FOR As=0.5Ast, A=50 FOR As=Ast THE BENDING MOMENT ENVELOPE HAS BEEN CALCULATED.

SIMPLE SUPPORT - NO END RESTRAINT CONTINUOUS SUPPORT WITH END RESTRAINT

Figure 14: Reinforcement end details conforming to AS3600

Page 10 Transfloor™ Precast Flooring System

 Design Principles

5.7 Design for construction loads

Selecting a panel specification to support construction loads should pro-
vide a panel with sufficient strength and stiffness to carry the mass of wet
concrete and construction live loads without exceeding safe limits for
stress and/or deflection. The loading to be considered at this stage of the
design is based on the Formwork Code AS3610 and will include:

• Precast panel self weight

• Dead load of wet in-situ concrete
• Live loads due to stacked materials
• Live load due to workmen and equipment
Figure 15: Unpropped Transfloor™ panels on • Localised mounding of in-situ concrete during placing.
precast beams
Prop spacing during construction will be controlled by one of the
following criteria.

• Bending moment capacity determined by limiting the tensile stress in

the panel concrete to less than the characteristic tensile strength.

Truss Overall Truss spacing (mm)

Type Slab Thk 565 450 320 200 565 450 320

T80/10 160 2.1 2.2 2.3 2.5 2.3 2.3 2.3

180 2.0 2.1 2.2 2.4 2.2 2.3 2.4

T110/10 190 2.2 2.3 2.5 2.7 2.5 2.5 2.7

200 2.2 2.2 2.4 2.7 2.4 2.5 2.6
220 2.1 2.2 2.3 2.6 2.4 2.5 2.6

Maximum span between temporary supports (m)

T150/10 230 2.4 2.6 2.8 3.1 2.8 3.0 3.1
250 2.3 2.5 2.7 3.0 2.8 2.9 3.1

T190/10 270 2.6 2.8 3.0 3.4 3.2 3.3 3.5

300 2.5 2.6 2.9 3.3 3.1 3.2 3.4
320 2.4 2.6 2.8 3.2 3.1 3.2 3.4
350 2.3 2.5 2.7 3.1 3.0 3.1 3.3
400 2.2 2.3 2.5 2.9 2.9 3.0 3.1

T110/12 190 2.4 2.5 2.7 3.1 2.7 2.8 3.0

200 2.4 2.5 2.7 3.0 2.7 2.8 3.0
220 2.3 2.4 2.6 2.9 2.7 2.8 2.9

T150/12 230 2.8 2.9 3.2 3.6 3.2 3.4 3.6

250 2.7 2.8 3.1 3.4 3.2 3.3 3.5

T190/12 270 3.0 3.2 3.5 3.9 3.7 3.8 4.0

300 2.9 3.0 3.3 3.7 3.6 3.7 3.9
320 2.8 2.9 3.2 3.6 3.5 3.7 3.8
350 2.7 2.8 3.1 3.5 3.5 3.6 3.7
400 2.4 2.7 2.9 3.3 3.4 3.5 3.6
Solid Slab Voided Slab

SPAN

For a more detailed design, go to the VIP section at www.smorgonarc.com.au

Table 4: Propping requirements - single span during construction

Design Principles Page 11

 Design Principles
• Bending moment capacity may also be governed by the compressive
stress in the top chord of the truss. This should be limited so that
buckling of the top chord does not occur.

• Shear capacity will be determined by the buckling strength of the truss

diagonal wires.

Load capacities and thus distance between temporary supports will

depend on panel thickness, truss spacing and whether the slab is
voided or solid. The unpropped spans given in Tables 4 and 5 have been
calculated by analysing the Transfloor™ panel as an uncracked section
using a transformed area method to determine stresses in
concrete and steel during construction.

Since this is a serviceability limit state design, unfactored loads have been
used. The tensile stress in the panel concrete is limited to (AS3600,
.6 f'c Clause. 6.1.1.2) and the compressive force in the truss wires is
limited to AS4100 Clause. 6.1

Truss Overall Truss spacing (mm)

Type Slab Thk 565 450 320 200 565 450 320

T80/10 160 2.4 2.5 2.6 2.8 2.6 2.7 2.8

180 2.3 2.4 2.5 2.7 2.5 2.6 2.7

T110/10 190 2.5 2.6 2.8 3.1 2.8 2.9 3.1

200 2.5 2.6 2.7 3.0 2.8 2.9 3.0
220 2.4 2.5 2.6 2.9 2.8 2.8 3.0

Maximum span between temporary supports (m)

T150/10 230 2.8 2.9 3.2 3.6 3.3 3.4 3.6
250 2.7 2.8 3.0 3.4 3.2 3.3 3.5

T190/10 270 2.7 3.1 3.4 3.9 3.6 3.8 4.0

300 2.5 3.0 3.3 3.7 3.6 3.7 3.9
320 2.4 2.8 3.2 3.6 3.5 3.6 3.8
350 2.6 2.8 3.0 3.4 3.4 3.6 3.8
400 1.9 2.3 2.9 3.2 3.3 3.4 3.6

T110/12 190 2.8 2.9 3.1 3.5 3.1 3.2 3.4

200 2.7 2.8 3.1 3.4 3.1 3.2 3.4
220 2.6 2.7 2.9 3.3 3.1 3.1 3.3

T150/12 230 3.1 3.3 3.6 4.0 3.7 3.9 4.1

250 3.0 3.2 3.5 3.9 3.6 3.8 4.0

T190/12 270 2.7 3.3 3.9 4.4 4.1 4.4 4.6

300 2.5 3.0 3.8 4.2 3.9 4.2 4.5
320 2.4 2.8 3.6 4.1 3.8 4.2 4.4
350 2.2 2.6 3.5 3.9 3.7 4.1 4.3
400 1.9 2.3 3.1 3.7 3.4 3.9 4.1
Solid Slab Voided Slab

SPAN SPAN

TEMPORARY SUPPORT DURING CONSTRUCTION

For a more detailed design, go to the VIP section at www.smorgonarc.com.au

Table 5: Propping requirements - two or more spans during construction

Page 12 Transfloor™ Precast Flooring System

 Design Principles
Tables 4 and 5 can be used to determine propping requirements,
provided construction loads are specified as in AS3600, the Transfloor™
panel has a minimum thickness of 55 mm and is reinforced with at least
RF62 fabric, and the load from stacked materials does not exceed 4 KPa
prior to placement of top concrete.

Where special construction loads are specified and the above

conditions do not apply, the determination of prop spacing is possible
using the TranSpan™ software. This software is available from an
approved Transfloor™ supplier or can be accessed by visiting Smorgon
ARC’s web site on http://www.smorgonarc.com.au.

5.8 Deflection during construction

At typical propping spans of up to 2.7 m tests have shown that
deflections under construction loads should not exceed 2 mm.

In cases where unpropped spans exceeding 3.0 m are proposed the

deflection should be checked to ensure it does not exceed the limits set in
AS3600. Conventional transformed section methods can be used to pre-
dict the elastic behaviour of a Transfloor™ panel but note that the load
used to calculate deflections during construction should be the dead load
only (wet concrete and panel).

1200 PS

A TIMBER HEADER USED

AS EDGE FORM

BEAM
BAND
PS

SLAB
PS
PS

BEAM
BAND

PART PLAN A

EXAMPLE: 200 O/ALL VOIDED SLAB WITH TRUSSES AT 500 CRS, MAX PS = 2800 MM.
400 O/ALL BEAM WITH TRUSSES AT 400 CRS, MAXIMUM PS = 2300 MM.
PS = MAXIMUM PROP SPACING (REFER TABLES 4 AND 5).

BAND BEAM PS PS PS BAND BEAM

SLAB PANEL

BAND BEAM TIMBER HEADER TIMBER HEADER

PANEL USED AS EDGE
FORM OR BAND
BEAM UPTURN

TYPICAL SECTION A-A

Figure 16: Typical propping layout

Design Principles Page 13

 6.0 Final Slab Design
Tables 6 and 7 can be used to to estimate values for the final slab design.
However, it should be noted that this information is indicative and should
only be used for estimating purposes and does not replace the need for a
qualified design Engineer. The calculations are based on the following cri-
teria.

1. Design is to AS3600 Clause 7.2 and Section 9.

2. Cover to reinforcement = 20 mm (exposure classification A2).
3. Concrete class: 32 MPa for in situ topping and 40 MPa for precast.
4. Bottom steel reinforcement content to include RF62 fabric (min).
5. Superimposed loads include a dead load of 0.5 KPa, the remainder is
live load.
6. In-situ concrete allows for polystyrene void formers and is given in m3/m2

360 mm RIB OVER PANEL JOINT 440 mm POLYSTYRENE VOIDS 120 mm INTERNAL RIB
NEUTRAL AXIS AT ULTIMATE
LOAD IS USUALLY ABOVE
LAPPED FABRIC
TOP OF VOID
(MIN RF62) TRANSFLOOR TRUSSES
500N EXTRA BARS
SEE FIGURE 8 FOR DETAILS
AS REQUIRED
EFFECTIVE DEPTH

D (SLAB O/A DEPTH)

65
VOID
d
GRADE N40 500N EXTRA BARS
25 25 PANEL CONCRETE AS REQUIRED 20 mm CLEAR COVER
TO TRANSVERSE WIRES
RF62 BOTTOM FABRIC

120 565 mm TRUSS SPACING

Figure 17: Slab section relating to Tables 6 and 7

2
Slab Depth SW Reinf. (Kg/m ) In situ Superimposed load (KPa) for span (m)
Conc
D d KPa Top Bot. 8.5 8.0 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5

160 55 3.3 3.1 4.3 0.080 2.2 4.1 5.9

190 55 3.6 3.1 5.4 0.090 2.0 3.5 5.2 7.3 10.5

230 55 3.9 3.1 6.5 0.104 2.5 3.7 5.0 6.7 9.1 12.3

270 55 4.3 3.1 7.5 0.120 2.5 3.7 4.8 6.2 8.1 10.5 13.8

300 55 4.6 3.1 7.9 0.130 2.0 2.8 3.7 4.7 6.1 7.8 10.0 12.8

Table 6: Single simply supported span (voided slab)

2
Slab Depth SW Reinf. (Kg/m ) In situ Superimposed load (KPa) for span (m)
Conc
D d KPa Top Bot. 9.5 9.0 8.5 8.0 7.5 7.0 6.5 6.0 5.5 5.0 4.5

160 55 3.3 4.4 4.3 0.080 0.5 2.5 4.5

190 55 3.6 4.9 5.0 0.090 1.5 2.5 4.1 5.5 7.5

230 55 3.9 5.6 6.1 0.104 2.0 3.4 4.5 5.8 7.5 9.7

270 55 4.3 6.1 6.8 0.120 2.5 3.3 4.3 5.4 6.8 8.6 10.9

300 55 4.6 6.7 7.6 0.130 2.5 3.2 4.0 5.0 6.2 7.6 9.4 11.7

Table 7: Multiple continuous span (voided slab)

Page 14 Transfloor™ Precast Flooring System

 7.0 Seismic Conditions
Although Australia is classified as a “low risk” area, in terms of
earthquake damage, the need for seismic design in building structures
was highlighted by the Newcastle earthquake of 1989. Building structures
are to be designed for earthquake loading depending on the “earthquake
design category” as specified in AS1170.4.

Seismic considerations for Transfloor™ will follow the same design rules as
for in-situ floors but will require adequate detailing to achieve
seismic integrity at the connections. The main criteria to consider are:

• maintain structural integrity without collapse of all or a significant part of

the structure;

• achieve ductility of both precast elements and their connections;

• provide structural continuity;

• design and detail structural elements such that they may be

produced economically and erected easily.

7.1 Structural integrity

It has generally been found that in-situ floor slabs, acting monolithically
with supporting beams, are very capable of transmitting lateral forces
unless the number of large openings is excessive.

Transfloor™, acting monolithically, will adequately transmit lateral loads

through diaphragm action. The strength and ductility of the overall
structural system will depend on the integrity of the joint detailing and in
particular, the connections between the floor (horizontal diaphragm) and
the supporting structure.

The majority of reported damage (Reference 3.0) caused to precast

construction during earthquakes is confined to the joints and connections
and can be summarised as follows:

PRECAST PANELS WITH

REINFORCED TOPPING SLAB
DIAGONAL COMPRESSION FORCES TIE BARS IN SLAB TO
IN FLOOR CARRY SHEAR TO WALL

EDGE BEAM AS COMPRESSION CHORD

Figure 18: Transfloor connecting to precast walls

EDGE BEAM AS TENSION CHORD

BEAMS ACT AS TIES (STIRRUPS) SHEAR RESISTED

BY WALL

Figure 19: Actions in a typical diaphragm

Seismic Conditions Page 15

 Seismic Conditions
• Failure of connection between wall panel and roof system resulting in
roof failure, tilting of wall panels and increased stresses in the lower
level floor connections.

• Failure of connection between wall panel and floor system.

• Flexibility of thin cast in-situ topping slab that forms the horizontal
diaphragm causing overstressing and cracking resulting in
separation from the precast elements.

The 1988 earthquake in Armenia highlighted some of the problems caused

by inadequately detailed precast construction (Reference 3). A common
form of construction for medium rise residential buildings was to use
precast concrete panels or frames for the vertical elements and precast
concrete floor planks without the addition of a topping slab. These precast
systems performed poorly due mainly to the inadequate provision of viable
load paths through inadequate tying of the horizontal floor planks to the
vertical elements and to each other for effective diaphragm action.

7.2 Diaphragm action

Horizontal loads from earthquakes are usually transmitted to the vertical
cores or shear walls by the roof and floor acting as horizontal diaphragms.
The floor can be analysed by the ‘strut and tie’ method or by considering
the floor to act as a deep horizontal beam. The central core, shear walls or
other stabilising components act as supports with the lateral loads being
transmitted to them as shown in Figure 19.

As stated by Clough (Reference 4), “In zones of high seismic intensity, or

with configurations which impose large in-plane compatibility forces under
lateral load, diaphragms joined by cast in place reinforced concrete usually
are satisfactory”. It is essential to ensure that the topping is adequately
bonded to the precast elements such as in precast element floors where
the topping is bonded by mechanical connectors (wire truss as in-plane
reinforcement). Without this, separation can occur and the topping may
buckle when subject to diagonal compression from diaphragm action.

MIN 25% OF TOP REINFORCEMENT AT THE

SUPPORT TO BE CONTINUOUS THROUGHOUT INTERNAL
EXTERNAL ANCHORED CONCRETE INSERTS
THE SPAN WALL
WALL
SUPPORT SUPPORT
SUFFICIENT CONTINUITY REINFORCEMENT CONTINUOUS REINFORCEMENT TO
TO DEVELOP FULL NEGATIVE MOMENT AT BE AT LEAST 33% OF TOP
FACE OF SUPPORT REINFORCEMENT

CONTINUOUS REINFORCEMENT TO BE AT
LEAST 33% OF TOP REINFORCEMENT. MIN 50% ALL BOTTOM REINFORCEMENT TO BE
BARS TO DEVELOP FULL STRENGTH AT CONTINUOUS THROUGH THE SUPPORT TO DEVELOP
FACE OF SUPPORT. FULL STRENGTH AT FACE OF SUPPORT

TYPICAL SLAB REINFORCEMENT DETAILS FOR EARTHQUAKE LOADING (REFER AS3600, APPENDIX A)

Figure 20: Detailing requirements for earthquake loading

Page 16 Transfloor™ Precast Flooring System

 Seismic Conditions

7.3 Detailing requirements for seismic loads

Designers should ensure that not only is there an adequate load path for
forces that need to be transferred between the diaphragm and any lateral
force resisting elements, such as walls or frames, but that
connections are detailed such that they adequately transfer the
anticipated loads.

The comments in this section relate to ‘Intermediate Moment Resisting

Frames’, defined in AS3600 (Reference 8) as ‘moment resisting frames of
ductile construction’, complying with the additional requirements of
‘Appendix A’ in AS3600. The intent of these special detailing
requirements is to improve the ductility and reduce the vulnerability of
concrete structures in a manner consistent with the relatively low
seismic hazard in Australia. The detailing requirements shown in Figure 20
are therefore not onerous and relate to steel reinforcement continuity,
anchorage and lapping.

7.4 Slab and band beam systems

In high seismic regions building codes (ACI and New Zealand Standard)
tend to discourage wide shallow beams by imposing limitations on the
maximum beam width. Also, 75% of the longitudinal beam bars are
required to be within the column width. Since the main difficulty with wide
beams is placing all the required joint ties, Irvine and Hutchinson
(Reference 5) recommend that the steel reinforcement ratio (Ast/bd) be
restricted to 0.02 or less, so as to reduce this problem. The designer
should ensure that the column has sufficient ductility to prevent a column
side sway failure (soft storey collapse).

The above requirements apply to high seismic regions. The University of

Melbourne has conducted research to investigate the behaviour of wide
band beams in low seismic regions. At this stage the current requirements
of AS3600 (Reference 8) can be used, see Figure 21.

EXTERNAL LIG SPACING AS PER MIN 2 CLOSED TIES AT LAP EXTERNAL

COLUMN APPENDIX A OF AS3600 COLUMN

2D (MIN) CLOSED TIES AT D/2 OR 300 MAX 2D (MIN)

D

COLUMN AND EDGE BEAM

STEEL REINFORCEMENT NOT SHOWN MIN TOP AND BOTTOM STEEL REINFORCEMENT
TO BE 20% OF Ast AT EITHER SUPPORT

NOTCH PANEL
TRANSFLOOR PANEL
AROUND COLUMN
TRUSSES NOT SHOWN
CONTINUITY STEEL REINFORCEMENT MIN 33% OF CONTINUITY STEEL REINFORCEMENT
NEGATIVE MOVEMENT STEEL REINFORCEMENT MIN 33% OF NEGATIVE MOMENT
REINFORCEMENT SPLICE TO DEVELOP
PROVIDE COGS TO DEVELOP FULL STRENGTH AT STRENGTH OF BAR
FACE OF SUPPORT

Figure 21: Detailing requirements for earthquake loading

Seismic Conditions Page 17

 8.0 Manufacture and Installation

8.1 Manufacture
The manufacture of Transfloor™ panels takes place in a factory
environment where a system of controls and checks ensures optimum
product quality.

Panels are cast on steel forms using high strength concrete, externally
vibrated, to ensure thorough compaction and uniform density.

After an initial curing period of approximately 24 hours the panels are

stripped, stacked and stored ready for delivery.

Figure 22: Concrete is discharged at a controlled

rate by an electrically operated concrete spreader
8.2 Delivery
Panels are stacked and transported by semi-trailers in approximately 150
m2 loads. Stacking bearers should be provided at approximately 1.5 m
centres to minimise stresses during transport.

The laying sequence should be pre-determined and communicated to the

Transfloor™ supplier prior to manufacture. This will enable stacks to be
stored and then loaded in reverse order of placement so that the top panel
on the stack is the first to be placed on site. The only exception being in
the case of a load of mixed panel sizes when small panels are loaded on
the top of the stack irrespective of the placing sequence. The erector
Figure 23: Lifting of Transfloor panels from casting should be prepared to site stack units delivered out of sequence due to
table loading requirements. However, such panels may be placed directly in
position if their locations can be accurately fixed prior to commencement
of panel placing.

8.3 Installation
Where the Transfloor™ panels are not designed to sustain construction
loads over the clear span without intermediate supports, a simple
system of frames and props with timber headers is normally erected prior
to arrival of panels on site (see Figure 16).

Prop spacing should be specified by the design engineer and will vary
according to the type and number of trusses in the Transfloor™ panels and
the construction loads to be supported. Tables 4 and 5 can be used to
determine the required prop spacing or alternatively contact an approved
Transfloor™ supplier for more information.
Figure 24: Panels in storage ready for delivery to
site

Page 18 Transfloor™ Precast Flooring System

 Manufacture and Installation

8.4 Lifting and placing

Panels 55 mm thick have a typical weight of 135 kg/m2. In cases where
the spreader is used for lifting, the weight of the spreader (about 500 kg)
must be added to the panel weight to determine the maximum load for lift-
ing. It is important to ensure that the crane selected has adequate capaci-
ty at the reach required to place all panels. If crane capacity is limited, it
may be necessary to limit the size of panels to ensure that the load/reach
capacity of the crane is not exceeded.

During production each panel is marked with an identification number cor-

responding to the panel numbers on the layout drawing. This ensures that
panels are placed in the correct position in the structure.

Panels up to 8.5 metres in length can be lifted by crane using four chains.
The chain hooks must be attached to the top chord of the trusses as
shown in Figure 26. The lifting capacity has been verified by testing for this
method. Panels between 8.5 and 10 m long may require a lifting frame.
Lifting point locations should be marked on shop drawings.

Placing rates of up to 10 panels per hour can be achieved with a crew of

two men on the deck, crane driver and dogman. Where panels of 6 m
length or greater are supplied, the placing rate can be approximately 150
m2 per hour.
Figure 25: Site lifting - typical 4-point lift

ALWAYS ATTACH HOOK OR SHACKLE

THROUGH BOTH TOP AND DIAGONAL WIRES

90
MAX

1/4 L 1/4 L

NOTE 1. ATTACH LIFTING HOOK TO SECOND TRUSS FROM EDGE OF PANEL.

2. GENERALLY LIFT PANELS AT 1/4 POINTS. PANELS UP TO 8.5M LONG CAN BE LIFTED WITH FOUR CHAINS.
3. PANELS GREATER THAN 8.5M LONG MAY REQUIRE AN EIGHT POINT LIFT OR A LIFTING FRAME.

Figure 26: Lifting of Transfloor™ Panels

All bearing surfaces for Transfloor™ panels should be level to ensure align-
ment between units and to minimise twisting of panels. Where panels are
to sit on block work or precast walls, the bearing surfaces may require
levelling with concrete mortar. An alternative is to provide temporary, care-
fully aligned props immediately adjacent to the walls.

Manufacture and Installation Page 19

 Manufacture and Installation

8.5 Services and edge forms

Conduits for electrical, communications, water and other services are
installed as for in-situ concrete slabs. A hot wire cutter is used to quickly cut
polystyrene void formers to accommodate conduits. Generally
penetrations smaller that 150 mm are made by core-drilling the precast
panel. Larger penetrations can be formed during manufacture.

Fixing of edge forms can usually proceed while services are being
installed. A turnbuckle engaging truss wires can be used as a
connection device for edge forms. Appendix A, Figure A6, includes edge
form details.
Figure 27: Temporary props are positioned prior
to placing panels

Figure 28: In-situ concrete is reduced by use of polystyrene void formers

8.6 Top reinforcement and in-situ concrete

Immediately following installation of services and edge forms, fixing of top
reinforcement steel is carried out and the slab is then ready for pouring the
top layer of concrete.

The thickness of topping concrete above polystyrene generally should not

be less that 65 mm. Additional top steel reinforcement, fabric (mesh) laps,
fabric (mesh) wire diameter and other factors may require this topping
thickness to be increased to ensure that steel reinforcement is fully embed-
ded and adequate cover is provided. This aspect should be considered at
the design stage (refer to section 5.0, ‘design principles’).

8.7 Ceiling finish

Transfloor™ panels are manufactured in rigid steel beds and the soffit fin-
ish achieved is ‘Class 2’ as described in AS3600. The joint between pan-
els, if left unfilled, is referred to as a shadow joint, in that a light and shade
effect is created between the two prefabricated units. This type of ceiling
finish requires no treatment and is quite acceptable as an off-form grey
concrete finish. In fact, the surface finish achieved is quite superior to that
achieved with conventional forming products.

Page 20 Transfloor™ Precast Flooring System

 Manufacture and Installation
In situations where the slab soffit is to be used as an exposed ceiling and
a painted surface is required, then the joint can be filled and a
textured paint finish applied directly to the panel. If the joints are
subject to differential movement then the use of a cement based repair
mortar with high bond strength should be used to fill the joint. If no
differential movement were expected then the use of a plaster-based
material would be acceptable. A flat paint finish is possible after a skim
coat of plaster.

TRANSFLOOR PANEL

25
PANEL SOFFIT

Figure 29: Unpainted soffit finish showing shadow (A) SHADOW JOINT
point

TRANSFLOOR PANEL

FOAM BACKING ROD

25 PANEL SOFFIT

(B) FILLED JOINT

Figure 30: Transfloor™ panel soffit joint

Manufacture and Installation Page 21

 9.0 Transfloor™ Bridge Decking
Transfloor™ is used in composite bridge construction and has been
approved by state road authorities, providing safer and more efficient
construction of bridge superstructures. Figure 31 shows a typical bridge
deck section constructed with Transfloor™ panels (70 to 90 mm thick)
which, when topped with in-situ concrete, become an integral part of the
deck slab. Panels are made with trusses and steel reinforcement uninter-
rupted but with full-length gaps or continuous concrete block-outs, which
coincide with beam locations to accommodate the shear connectors. This
allows placement of panels directly over precast concrete or steel beams.

The Transfloor™ panel can cover the entire width of a bridge, including the
cantilever beyond the external beams, thus eliminating the need for form-
work and additional scaffolding. This application for Transfloor™ has been
widely accepted and shown to be very cost effective in terms of speed of
erection, safety in construction (instant safe working platform), efficient use
of materials (no lost formwork) and significantly reduced traffic interference.

Figure 31: Ready made bridges - Transfloor™ bridge deck panel being lifted into position

9.1 Design details

The design can be carried out assuming full composite action between the
precast panel, in-situ topping and the supporting beams. The
in-situ concrete topping fills the gaps over the beams and ensures an
effective connection with ligatures on precast beams or shear studs on
steel beams. During construction Transfloor™ trusses provide the
cantilever strength and negative moment strength over the beams.

The slab reinforcing steel can be designed in accordance with the

Austroads Bridge Design Code and, in view of the discontinuity at panel
joints, the slab could be considered as spanning one way transversely
over the beams. However, research carried out by Buth et al (Reference 6),
for similar precast systems, has demonstrated that using this approach is
conservative and that the joints can be disregarded.

Page 22 Transfloor™ Precast Flooring System

 Transfloor™ Bridge Decking
9.2 Load distribution - panel to panel connection
A commonly debated topic of past and current research has been the abil-
ity of similar deck systems to distribute wheel loads in the
longitudinal direction and the corresponding effect of the joints between
adjacent panels.

Continuity at the joint is provided by the in-situ portion of the deck and
research results indicate that the presence of the joint is not detrimental to
the load distribution performance of the bridge deck system (Reference
6,9 and 10).

Test results on two systems of longitudinal reinforcement:

Figure 27: Temporary props are positioned prior to
1. longitudinal reinforcement placed directly on top of panels, and
placing panels
2. splice bars, on top of panels and across joints,

in addition to the normal longitudinal steel reinforcement indicated the

in-situ concrete topping successfully transferred wheel loads across joints.
The supplementary joint reinforcing steel did not improve the
performance and in all tests with wheel loads near the panel joint, the
mode of failure was punching shear (Reference 6). Even at failure loads
there were no tensile cracking observed at the bottom of the in-situ
topping directly over the panel joints.

SHEAR STUDS WELDED TO BEAMS

AFTER PLACEMENT OF TRANSFLOOR IN-SITU CONCRETE
C BEAM C BEAM

TRANSFLOOR PANEL (TRUSSES AND

REINFORCEMENT ARE CONTINUOUS)
DETAIL 'A' (FIGURE 35)
CANTILEVER BEAM SPACING

BRIDGE DECK SECTION

CONTINUITY REINF
O/ALL TRUSS HEIGHT (IF REQUIRED) TRANSVERSE REINF TOP REINFORCEMENT TRUSSES
(SEE FIGURE 8) (MAIN BARS) TOP COVER
SLAB DEPTH
PANEL THK

CLEAR COVER TO
RF72 FABRIC
0.5 (TS) TRANSVERSE WIRES
N50 PANEL
0.5 (TS) * TRUSS SPACING (TS) MIN PANEL REINF
CONCRETE
PANEL WIDTH (2436 MAX)
* TRUSS SPACING AS REQUIRED SEE
"Design For Construction Loads" (SECTION 5.7)
TYPICAL SECTION AA

Figure 33: Typical bridge deck details

Transfloor™ Bridge Decking Page 23

 Transfloor™ Bridge Decking
Further research and testing (Reference 10) has indicated a tendency for
shrinkage and thermal cracks to form directly over the panel joints but
these cracks do not adversely affect the ability of the deck slab to transfer
wheel loads across joints. Since these cracks extend down approximately
half way through the topping slab, it was concluded that the distribution
reinforcement performs better when placed toward the top to control
shrinkage and thermal cracking than when placed at the bottom of the
topping slab in an attempt to control flexural cracking.

American studies on in-service bridges (Reference 10) have indicated that

a level of transverse reinforcement (reinforcement in the same direction as
beams) equivalent to 230 mm2/m is satisfactory. AASHTO has adopted
230 mm2/m as the minimum transverse steel reinforcement in deck panels
of similar decking systems. The level of this steel reinforcing content
should be left to the discretion of the design Engineer. However, it should
be noted that projects in Australia have been completed with the steel
reinforcement content between 230 and 985 mm2/m.
Figure 34: Thomson River Bridge - Victoria
9.3 Bearing of bridge deck panels
Composite bridge deck panels must be supported on the bridge
girders by a permanent bearing material providing continuous and solid
support. The permanent bearing material should consist of mortar, grout,
concrete or steel. Use of soft fibrous material may lead to the bridge deck
acting as simple spans over girders rather than continuous spans and
delamination at the ends of the precast panels may occur.

SHEAR STUDS WELDED TO BEAMS

AFTER PLACEMENT OF TRANSFLOOR

70 40
TYP MIN

PROVIDE BEARING STRIPS OF

TRANSFLOOR PANEL (TRUSSES AND VARIABLE THICKNESS TO SUIT
REINFORCEMENT ARE CONTINUOUS) CROSSFALL AND CAMBER.
(25X25 HIGH DENSITY POLYSTYRENE
STRIPS ARE SUITABLE)

STEEL BEAM

DETAIL 'A'

Figure 35: Temporary bearing detail for bridge deck panels

Page 24 Transfloor™ Precast Flooring System

 Transfloor™ Bridge Decking
If grout or concrete is used as the permanent bearing, a temporary bearing
system must be used to support the panels during
construction. Temporary bearing systems designed to remain in place
include continuous strips of compressible material such as high density
polystyrene and bituminous fibreboard. Rigid material such as hard plastic
shims, which are left in place, will continue to provide the
primary support for deck panels should the permanent grout or
concrete shrink. This may result in undesirable cracking over these rigid
bearing points.
Figure 36: Cantilever portion of bridge
deck is unpropped during construction 9.4 Construction practice for bridge decks
1. Temporary bearing materials, which are designed to remain in place,
must be compressible.

2. The height of the temporary bearing strip must be adequate to allow

grout or concrete to flow under the panel.

3. Deck panels should extend a minimum of 40 mm beyond the

temporary bearing material.

4. Venting is required when grout or concrete is used. This can be

accomplished by leaving small gaps in the bearing strips at
approximately 1200 mm intervals.

5. The top concrete should first be placed in continuous strips over gird-
ers and allowed to flow under panels before being placed on the
remaining deck. This procedure improves the flow of concrete under
panel ends, helps eliminate air pockets and places concrete under
panel ends before the temporary bearing strips are compressed due to
the weight of wet concrete.

Figure 37: Bridge deck panel on prestressed concrete beams

Transfloor™ Bridge Decking Page 25

 10.0 References
1. Hartmut Koblenz, “Precast Concrete Floors, Part 2” Betonwerk
Fertigteil - Tecknik, (BFT), Bauverlag GmbH, Concrete Precasting Plant
and Technology, issue 6/1994.

2. J. Glynn, “Test of Transfloor™ Precast Floor Units”, Glynn Tucker and

Associates, University of Queensland, Report No. 7650, 1981.

3. Sanders P.T. (et al), “Seismic Behaviour of load Bearing Precast

Construction in Australia”, Steel Reinforcement Institute of Australia,
1995.

4. Clough D.P., “Considerations in the Design of Precast Concrete for

Earthquake loads”, Journal of Prestressed Concrete Institute, Vol. 27,
No. 2. pp 78-107.

5. Irvine H.M. and Hutchinson G.L., “Australian Earthquake Engineering

Manual” 3rd Edition, Techbooks, 1993.

6. Buth, Eugene, Furr H.L., and Jones H.L., “Evaluation of a Prestressed

Panel, Cast in Place Concrete Bridge”, Research Report 145-3, Texas
Transportation Institute.

7. Furr H.L. and Ingram L.L., “Cyclic Load Tests of Composite

Prestressed-Reinforced Concrete Panels”, Research Report 145-4F,
Texas Transportation Institute.

8. Standards Australia, “AS3600 - 2001 Concrete Structures”.

9. Kluge, Ralph W. and Sawyer H.A., “Interacting Pretensioned Concrete

Form Panels for Bridge Decks”, PCI Journal, Vol. 20, No. 3.

10. Jones H.L. and Furr H.L., “Study of In Service Bridges Constructed
with Prestressed Panel Sub-decks”, Research Report 145-1, Texas
Transportation Institute.

Page 26 Transfloor™ Precast Flooring System

 11.0 Appendix A
11.1 Typical construction details for multi-level buildings

Sutton Place - Melbourne

Holiday Inn - Darwin

Brookland Apartments - Melbourne

Appendix A Page 27
 11.0 Appendix A

40 mmTHICK POLYSTYRENE
VOID FORMER (OPTIONAL)

Figure A1: Typical reinforcement arrangements in slabs

70 mmTHICK POLYSTYRENE
VOID FORMER (OPTIONAL)

Figure A2: Typical reinforcement arrangements in slabs

Page 28 Transfloor™ Precast Flooring System

 Appendix A

110 mm THICK POLYSTYRENE

VOID FORMER (OPTIONAL)

TYPICAL SLAB SECTION T150/10 TRANSFLOOR™ TRUSS

(All dimensions in millimetres (mm))

Figure A3: Typical reinforcement arrangements in slabs

150 mm THICK POLYSTYRENE

VOID FORMER (OPTIONAL)

TYPICAL SLAB SECTION T190/10 TRANSFLOOR™ TRUSS

(All dimensions in millimetres (mm))

Figure A4: Typical reinforcement arrangements in slabs

Appendix A Page 29
 Appendix A

DURING PRODUCTION PANELS ARE TAGGED WITH IDENTIFICATION

NUMBERS CORRESPONDING TO THE PANEL LAYOUT DRAWING.
THIS ENSURES SIMPLIFIED AND CORRECT PLACEMENT OF PANELS

(All dimensions in millimetres (mm))

Figure A5: Typical panel layout diagram

TYPICAL SECTION - WIDE SHALLOW BAND BEAM

GALVANISED STEEL UPTURN PRECAST CONCRETE UPTURN

Figure A6: Band beam edge form options

Page 30 Transfloor™ Precast Flooring System

 Appendix A

BAND BEAM ELEVATION

TYPICAL SECTION A-A

TYPICAL EDGE BEAM BAND DETAIL AT COLUMN

Figure A7: Typical slab and band beam sections

Appendix A Page 31
 Appendix A

(a) USE ONLY FOR NOMINAL SHEAR REINFORCEMENT

(NO EXCESS SHEAR)

(b) USE WHEN SHEAR REINFORCEMENT IS REQUIRED

TO RESIST EXCESS SHEAR

Figure A8: Band beam with ligatures

Page 32 Transfloor™ Precast Flooring System

 Appendix A

SECTION ALONG SLAB BAND WHERE BANDS INTERSECT

BAND BEAM TO COLUMN DETAIL BAND BEAM TO COLUMN DETAIL

50 mm STEP IN SOFFIT LARGE STEP IN SOFFIT

SLAB CONNECTION (SIDE TO SIDE) SLAB CONNECTION (SIDE TO SIDE)

WITH 50 mm STEP IN SOFFIT WITH 100 mm STEP IN SOFFIT

Figure A9: Steps in band beam soffit

Appendix A Page 33
 Appendix A

BEAMS WITHIN SLAB THICKNESS

65 mm (TYP)

BAND BEAM SECTION WHERE BEAM WIDTH EXCEEDS 2500 mm

40 mm MIN PANEL BEARING

SLAB TO PRECAST BEAM

Figure A10: Typical beam details

Page 34 Transfloor™ Precast Flooring System

 Appendix A

MOVEMENT JOINT AT BLOCK WALL MOVEMENT JOINT AT CORBEL

SLAB/BAND EXPANSION JOINT (IN-SITU BEAM)

SLAB/BAND EXPANSION JOINT (TRANSFLOOR™ BEAM)

Figure A11: Typical movement joints

Appendix A Page 35
 Appendix A

25 mm RECESS IN 40 mm MIN PANEL BEARING

SOFFIT STEP AT INTERNAL WALL

CHANGE IN SLAB LEVEL AT PRECAST WALL

IN-SITU STEP

Figure A12: Change in slab soffit level

Page 36 Transfloor™ Precast Flooring System

 Appendix A

Figure A13: Cantilever and balcony details

Appendix A Page 37
 Appendix A

*16mm clear provides tolerance for location of the wall. An alternative detail is to place the panel on the wall with
40mm bearing as shown for “PRECAST INTERNAL WALL”.

Figure A14: Typical wall connection details

Page 38 Transfloor™ Precast Flooring System

 Appendix A

25 mm RECESS IN PRECAST WALL

EXTERNAL WALL WITH BALCONY

PRECAST BALCONY EDGE

WALL SUPPORT AT TRANSITION TRANSFLOOR™ CONNECTION

TO IN-SITU SLAB TO IN-SITU STAIRS

Figure A15: Other miscellaneous details

Appendix A Page 39
 Appendix B
B1 - EXAMPLE CALCULATION - ESTIMATE DESIGN
Estimate Design & Detailed Design

Effective span (continuous slab) 6000 mm

Superimposed dead load 0.5 kPa
Live Load 2 kPa
Deflection limit L/250
Cover to reinforcement 20 mm

From Table 7:
Overall slab thickness 190 mm
Panel thickness 55 mm
Polystyrene void former thickness 65 mm (from Appendix A)
Slab self weight 3.6 kPa
Average bottom reinforcement 5.0 kg/m2
Average top reinforcement 4.9 kg/m2
Average in-situ concrete 0.090 m3/m2

B2 - EXAMPLE CALCULATION - DETAILED DESIGN

Effective span (continuous slab) 6000 mm

Overall slab thickness 190 mm
Cover to reinforcement 20 mm
In-situ concrete strength 32 MPa

Panel length 6000 mm

Panel width 2500 mm
Panel thickness 55 mm

Polystyrene voids length 5525 mm

Polystyrene voids width 440 mm
Polystyrene voids thickness 65 mm
Number of Polystyrene voids 4
Polystyrene volume 0.0421 m3/m2

Slab self weight 3.62 kPa

Superimposed dead load 0.5 kPa
Live load 2.0 kPa
Ultimate load 8.15 kPa 1.25DL + 1.5LL

Page 40 Transfloor™ Precast Flooring System

 Appendix B
DEFLECTION CRITERIA
Short term factor Xs 0.7
Long term factor X1 0.4
Deflection limit 0.004 span/250
Span/depth Lef/d 39.2

SLAB DESIGN
MINIMUM THICKNESS
Ln/Ds 31.58
70(1/wK)1/3 32.06 Ln/Ds < 70(1/wK)1/3

BOTTOM REINFORCEMENT
BENDING
Ultimate design bending moment 26.68 kNm wl2/11
Effective depth d 158 mm
Fsy 500 MPa
fc' 32 MPa AS3600-2001 Cl 8.1.2.2 (b)
gamma 0.822
Ast 449 mm2/m
b 1000 mm
Mu 33.37 kNm
phi Mu 26.96 kNm phi Mu ≥ M*
Ast/bd 0.00284
0.22(D/d)2 f'cf /fsy 0.00216 Ast/db > 0.22(D/d)2 f'cf /fsy AS3600-2001 CI 8.1.4.1
ku 0.0636 <0.4 AS3600-2001 CI 8.1.3
dn 8.25 mm gamma ku d AS3600-2001 CI 8.1.2.2 (b)

TOP REINFORCEMENT
BENDING
Ultimate design bending moment 29.35 kNm wl2/10
Effective depth d 159 mm
Fsy 500 MPa
fc' 50 MPa Transfloor panel strength
gamma 0.696 AS3600-2001 CI 8.1.2.2 (b)
Ast 480 mm2/m
b 1000 mm
Mu 36.72 kNm

Page 41 Appendix B
 Appendix B
phi Mu 29.38 kNm phi Mu ≥ M*
Ast/bd 0.00302
0.22 (D/d)2 f'cf/fsy 0.00267 Ast/db> 0.22(D/d)2 f'cf/fsy AS3600-2001 CI 8.1.4.1
ku 0.051 <0.4 AS3600-2001 CI 8.1.3
dn 5.65 mm gamma ku d AS3600-2001 CI 8.1.2.2 (b)

SHEAR
Ultimate Shear Force at support Vs* 28.13 kN 1.15 wl/2
Vuc 127.53 kN B1B2B3bvdo(Ast f’c/bv do).333 AS3600-2001 CI 8.2.7.1
phi Vuc 89.27 kN phi Vuc ≥ Vs*
Ultimate Shear Force of void Vv* 26.19 kN 1.15 wI/2
bv 296 mm
Vuc 56.62 kN B1B2B3bvdo(Ast f’c/bv do).333 AS3600-2001 CI 8.2.7.1
phi Vuc 39.63 kN phi Vuc ≥ Vv*

DEFLECTION
Lef/d 37.74
k3 k4 ((delta/lef) Ec/Fd.ef)0.333 39.05 Lef/d<k3 k4 ((delta/lef) Ec/Fd.ef)0.333 AS3600-2001 CI 9.3.4.1

CRACK CONTROL
Fd.ef1 6.12 kPa G + 1xQ AS3600-2001 CI 9.4.1(a)
Fd.ser 5.52 kPa G + Xs x Q

M* s.1 bottom 20.04 kNm wl2/11

M* ser bottom 18.07 kNm wl2/11
dn.uncr 97.38
lg 5.52E+08 mm4 bD3/12
Mcrit 17.43 kNm 3 Ig/(D/2) AS3600-2001 CI 9.4.1(a)
M*s.1 > Mcrit so critical tensile zone
Wider cracks can be tolerated AS3600-2001 CI 9.4.1(b)
Max bar spacing 300 mm AS3600-2001 CI 9.4.1(b) iii
Actual bar spacing 200 mm

M*s.1 top 22.04 kNm wl2/10

M*ser top 19.88 kNm wl2/10
lg 5.72E+08 mm4 bD3/12
Mcrit 18.05 kNm 3 Ig/(D/2) AS3600-2001 CI 9.4.1(a)
M*s.1 > Mcrit so critical tensile zone
Assuming wider cracks can not be tolerated, for example with
tiled floor finishes. (If carpeted floor or timber floating floor, then
wider cracks could be tolerated)

Page 42 Transfloor™ Precast Flooring System

 Appendix B
Ast.min 570 mm2 3 ksAct/fs AS3600-2001 CI 9.4.1(b) ii
Max bar spacing 300 mm AS3600-2001 CI 9.4.1(b) iii
Max steel stress 300 MPa AS3600-2001 CI 9.4.1(b) Note 2
Ec 28600 MPa
n 6.99 Es/Ec
dn 29.49 mm 0.5 b dn2=nAst (d-dn)
lcr 6.48E+07 mm4 0.33 b dn3 + n Ast (d-dn)2
lef.ser 4.44E+08 mm4 lcr + (lg - lcr)(Mcr/Mser)3
fscr 5.8 MPa M y/l
Max steel stress 300 MPa >fscr AS3600-2001 CI 9.4.4 (b) iv
lef.s.1 3.43E+08 mm4 lcr + (lg - lcr)(Mcr/Ms.1)3
fscr.1 8.3 MPa M y/l
0.8fsy 400 MPa >fscr.1 AS3600-2001 CI 9.4.4 (b) v

PROPPING DURING CONSTRUCTION

From Table 5:
Truss Type T110/0 190 thick slab
Voided Slab-Truss spacings 320 mm
Span between props 3.1 m

320 mm truss spacings selected to reduce propping of 6 m span to a single prop mid-span of the panel
reduce void width by 40 mm to 400 mm to accommodate the 8 trusses required for the 2500 wide panel

REINFORCEMENT

PANEL (BOTTOM REINFORCEMENT)

Required from design 449 mm2/m Ultimate Bending
Provided in Panel
8 T110/10 trusses over 2500 mm 181 mm2/m
RF92 287 mm2/m

Total 468 mm2/m

IN-SITU SLAB (TOP REINFORCEMENT OVER SUPPORTS)

Required from design 570 mm2/m Flexural Crack Control Governs
Provide N12-175 628 2
mm /m
If wider cracks can be tolerated in the top of the slab, the reinforcement could be reduced to 480mm2 (Y12-225)

Page 43 Appendix B
 Appendix C
TranspanTM TransfloorTM Design Software Output
Introduction The purpose of the following calculations is to determine the maximum simply supported
double span for a Transfloor panel given structural properties and construction loads.

SPAN SPAN

TEMPORARY SUPPORT DURING CONSTRUCTION

The panel must comply with the stability, strength and service limit state criteria specified
in AS3610-1995 Formwork for Concrete (Ref. [2]).

Stability The panel must resist overturning, uplift and sliding under the action of all the appropriate
load combinations:
a) Overturning: In the case of a simply supported span overturning is not applicable

b) Uplift: The panel must resist forces from the appropriate load combination causing uplift.
Uplift is commonly caused by wind loads that are beyond the scope of this analysis and there
fore uplift is not considered.

c) Sliding: The panel and its supports must resist forces from the appropriate load
combination causing sliding.
AS3610 requires that formwork resist an applied horizontal live load of 1 kN/m plus the lateral
pressure of concrete.

Stage II – during placement of concrete.

1.5QuhC + 1.5PC < 0.8GR + (fR) (1)

Strength The Panel must resist the bending and shear action effects from all the appropriate load
combinations. In the case of a simply supported panel the following load combinations are
appropriate:
Stage I – prior to placement of concrete.
1.25G + 1.5Quv + 1.5M1 (2)
Stage II – during placement of concrete.
1.25G + 1.25Gc + 1.5Quv + 1.5M2 (3)
1.25G + 1.25Gc + Qc (4)
Stage III – after placement of concrete.
1.25G + 1.5Gc + 1.5Quv + 1.5M3 (5)
Stiffness The panel stiffness must be such that the deformation under the appropriate load
combination does not exceed the limits specified in Ref. [2]. In the case of a simply
supported panel the following load combinations are appropriate:

Stage II – during placement of concrete.

G + Gc (6)
Stage III – after placement of concrete.
G + Gc + M3 (7)

Surface Finish The surface finish of the panel soffit conforms with the physical quality of a “Class 2”
surface finish as specified in Ref. [2].

Page 44 Transfloor™ Precast Flooring System

 Appendix C
Panel Capacity The strength and stiffness of the panel is dependent on the truss, panel size and geometry.
During construction the applied loads are resisted by the action of the truss members and
panel concrete. The resistance provided by any mesh or additional reinforcement bars is
ignored.
The following structural checks are performed:

Stability a) Sliding
b) Overturning

Strength a) Top Chord Tension

b) Top Chord Tension
c) Bottom Chord Compression
d) Bottom Chord Tension
e) Concrete Compression
f) Diagonal Compression

Service a) Deflection
b) Cracking

The limit state resistance is calculated for each case.

Maximum Span The maximum span is selected on the basis that the design action, calculated from the
factored load combinations, does not exceed the capacity of the panel.

A summary of the calculations showing the maximum span for each action is given in the table
below:

Design Max. Span

Action (m)

Positive Bending 3.25

Negative Bending 3.20
Shear 14.18
Cracking 3.60
Deflection 3.54

The Maximum span for the given configuration is therefore:

Maximum Span 3.20 mm

Stability The formwork assembly including the Transfloor panel, falsework and connections are required
to be designed to transfer the following limit state design load to anchorage or reaction points:
Limit State Sliding Load, H* 1.5 kN/m
Stacked Materials
The maximum span is based on the live load for stacked materials, before and after
placement of concrete, being limited to a maximum of 2.0 kPa.
This load must be clearly indicated in the formwork documentation and construction
control put in place to ensure it is not exceeded.

Appendix C Page 45
 Appendix C

Assumptions 1 Vertical and horizontal action effects from environmental loads have been ignored.

2 The value for stacked materials during Stage I (M 1) applies also to Stage III (M3) and
during Stage II the value for stacked materials (M2) is 0 kPa.

3 The effects of form face deflection and construction tolerances can be ignored.

4 The deviations specified for surface undulation, in Ref[2], will be interpreted as the
deflection criteria for the panel as per the following table:

Surface Surface Span/Deflection

Quality Undulation Ratio
Class Tolerance
(mm)

2 3 500
3 5 300
4 8 188

5 The welds connecting the diagonal wires to the top and bottom chord of the truss are
capable of transmitting the full design action effects.

6 Truss geometry is as per the following table:

Wire Size (mm)

Truss
Type Top Bottom Diagonal Height
T80/10 10 6.3 6.3 82
T110/10 10 6.3 6.3 111
T150/10 10 6.3 6.3 154
T190/10 10 6.3 6.3 191
T110/12 12.5 6.3 6.3 112
T150/12 12.5 6.3 6.3 155
T190/12 12.5 6.3 6.3 192

Page 46 Transfloor™ Precast Flooring System

 Appendix C
Panel Properties
Overall Slab Thickness, d 190 mm
Minimum Cover to Bottom Reinforcement 20 mm
Concrete Density, r 2500 kg/m3
Concrete Strength at Loading, f cm 50 mPa
Concrete Modulus of Elasticity, E cj 38007 mPa
Panel Width, b 2500 mm
Panel Thickness, t p 55 mm
Number of Truss per Panel, n t 8
Number of Voids, n v 4
Void Width, b v 400 mm
Void Thickness, t v 75 mm
Class of Surface Finish 2
Construction
Loads
Panel Dead Load, G 1.3 kPa
In-situ Slab Dead Load, Gc 2.1 kPa
Construction Live Load, Quv 1.0 kPa
Concrete Mounding Load, Qc 3.0 kPa
Stacked Materials, M1 2.0 kPa
Stacked Materials, M 2 0.0 kPa
Stacked Materials, M 3 2.0 kPa
Load
Combinations

Stage Load Combination Load Unit Equation

Stability
II 1.5QuhC + 1.5PC < 0.8GR + (φR) (1)
Strength

I 1.25G + 1.5Q uv +1.5M1** 6.2 kPa (2)

II 1.25G + 1.25Gc + 1.5 Quv +1.5M2** 5.9 kPa (3)
II 1.25G + 1.25Gc +Qc* 7.4 kPa (4)
III 1.25G + 1.25Gc + 1.5 Quv +1.5M3** 8.9 kPa (5)

II Stiffness

G + Gc 3.5 kPa (6)

II G + Gc + M3** 5.5 kPa (7)

(7) * Although AS3610 specifies that Qc will apply over an area of 1.6 m x 1.6 m, it has
been applied over the full area of the panel.
** - The loads from stacked materials (M) may apply to one span only.
Design Load
Therefore the design loads are as follows:

Strength, w* 8.9 kPa

Service, ws* 5.5 kPa

Appendix C Page 47
 Appendix C
Truss Properties
Transfloor Truss Type, T T110/10
Average Truss Spacing, Ts 312 mm Ref.[1]
Truss Height, Th 111 mm
Truss Bar Yield Strength, fsyt 450 mPa

Top Chord Bar Diameter, dt 10 mm

Area, At 628 mm2
Strut Length, Lt 200 mm
Effective Length, It 180 mm
Radius of Gyration, rt 3 mm
Slenderness Ratio, It /rt 72 OK

Diagonal Bar Diameter, dw 6.3 mm

Area, Aw 499 mm2
Angle of Web, q 48 degrees
Strut Length, Lw 149 mm
Effective Length, Iw 120 mm
Radius of Gyration, rw 1.6 mm
Slenderness Ratio, Iw /rw 76 OK

Bottom Chord Bar Diameter, db 6.3 mm

Area, Ab 499 mm2
Strut Length, Lb 200 mm
Effective Length, Ib 180 mm
Radius of Gyration, rb 1.6 mm
Slenderness Ratio, Ib /rb 114 OK

Mesh Mesh Size F62

Wire Diameter, dm 6.3
Area, Am 390 mm2
Transformed
Section For serviceability limit state the panel is analysed as an uncracked section using the
Transformed Area method to determine the stresses in the steel and concrete.

Steel Elastic Modulus, Es 200000 mPa

Concrete Elastic Modulus, Ecj 38007 mPa
Modular Ratio, n 5.3
Distance from Soffit to Top Chord 140 mm
Transformed Top Chord Area 3306 mm2
Distance from Soffit to Bottom Chord 29 mm
Transformed Bottom Chord Area 2625 mm
Panel Concrete Area 137500 mm
Distance to the Neutral Axis, yg 30.1 mm
Second Moment of Inertia, Ig 7.59E+07 mm4

Page 48 Transfloor™ Precast Flooring System

 Appendix C
Capacity
Calculations
Top Chord
Compression In accordance with AS4100 – 1998 Steel Structures (Ref.[3]), Clause 6.1
Ν∗ ≤ φ α c Ν s
where φ 0.9
Section Jcapacity, N s= A t f syt 283 kN
λn 96.6
αa 17.6
αb -1.0
λ 79.0
η 0.2
ε 1.3
αc 0.7
Limit State Capacity, φαcNs 175.0 kN
Truss Height, Th 111 mm
Limit State Moment Capacity, M*tc 19.4 kNm
Top Chord
Tension In accordance with AS4100 – 1998 Steel Structures (Ref.[3]), Clause 7.1

Ν∗ ≤ φ Α g f y

where φ 0.9
Limit State Capacity, φAg fy 254.5 kN
Truss Height, Th 111 mm
Limit State Moment Capacity, M*tt 28.2 kNm
Bottom Chord
Compression In accordance with AS4100 – 1998 Steel Structures (Ref.[3]), Clause 6.1
Ν∗ ≤ φ α c Ν s

where φ 0.9
Section Capacity, N s= Abfsyt 224.4 kN
λn 153.3
αa 12.6
αb -1.0
λ 140.7
η 0.4
ε 0.8
αc 0.3
Limit State Capacity, φαcNs 66.0 kN
Truss Height, Th 111 mm
Limit State Moment Capacity, M*bc 7.3 kNm

Appendix C Page 49
 Appendix C

Bottom Chord
Tension In accordance with AS4100 – 1998 Steel Structures (Ref.[3]), Clause 7.1

Ν∗ ≤ φ Α g f y

where φ 0.9
Limit State Capacity, φAg fy 202.0 kN
Truss Height, Th 111 mm
Limit State Moment Capacity, M*b 22.4 kNm
Panel Concrete
Compression The maximum concrete compressive force is given by:
Ν ∗ ≤ 0.68 f cm t p b

therefore
Limit State Capacity, N*c 4675.0 kN
Truss Height, Th 111 mm
Limit State Moment Capacity, M*pc 518.9 kNm
Diagonal
Compression In accordance with AS4100 – 1998 Steel Structures (Ref.[3]), Clause 6.1
Ν∗ ≤ φ α c Ν s

where φ 0.9
Section Capacity, N s= Abfsyt 224.4 kN
λn 101.8
αa 17.1
αb -1.0
λ 84.7
η 0.2
ε 1.2
αc 0.6
Limit State Capacity, N* 130.8 kNm

Page 50 Transfloor™ Precast Flooring System

 Appendix C

Tensile Cracking AS3600, Ref[4] requires the maximum flexural stress in the concrete under short
term service loads to be limited to

0.5 f ’c

The limit state service moment can be calculated from:

0.5 f cm I g
M*=
y g

therefore
Limit State Service Moment Capacity, M*c 8.9 kNm

or

AS3600 also provides an alternative of limiting the increment in steel stress to 150 mPa.

Steel Stress 150 mPa

Area of Bottom Chord Steel, Ab 499 mm2
Area of Mesh, Am 390 mm2

Total Area of Steel 889 mm2

Equivalent Axial Force, N* 133.3 kN
Truss Height, Th 111 mm
Stability Check Limit State Service Moment Capacity, M*c 14.8 kNm

Sliding The force causing sliding must be transferred to an anchorage or reaction point
on the permanent structure or foundation.
Limit state horizontal live load, Quh 1.0 kN/m
Limit state lateral concrete pressure, P 0.1 kN/m
Limit State horizontal design load, H* 1.5 kN/m

Appendix C Page 51
 Appendix C

Span
Calculations
Positive Bending The positive moment capacity of the panel is given by the following:

Top Chord Compression, M*tc 19.4 kNm

Bottom Chord Tension, M*bt 22.4 kNm

Design Moment, M* 19.4 kNm

The maximum span can be calculated from the following equation:

1 2M *
wb
therefore
Positive Bending Maximum Span, S b 3.25 m

Negative Bending The negative moment capacity of the panel is given by the following:
Top Chord Tension, M*tt 28.2 kNm
Compression of Concrete Panel, M*pc 518.9 kNm
Bottom Chord Compression, M*bc 7.3 kNm Ignored in this
calculation
Negative Bending Design Moment, M* 28.2 kNm

The maximum span can be calculated from the following equation:

8M *
wb
therefore
Negative Bending Maximum Span, S b 3.20 m

Shear The shear capacity of the panel is governed by the compression of the truss diagonal.
The maximum span can be derived from the following equation:

( 2N *sinθ
(
w sb
therefore
Shear Maximum Span, S v 14.18 m

Page 52 Transfloor™ Precast Flooring System

 Appendix C

Cracking The moment capacity of the panel is given by the following:

Flexural Cracking, M* c 14.8 kNm

The maximum span can be calculated from the following equation:

1 2M *
c
therefore
Cracking Maximum Span, Sc 3.60 m

Deflection The maximum deflection of the panel can be calculated from the following equation:

Δ= 0.0074w s

bS4

To maintain the specified class the following Span/Deflection ratio must be achieved:

Span/Deflection Ratio, β 500

Therefore the maximum span can be calculated from:

( 135Ecj Ig
(
βw s b
therefore
Deflection Maximum Span, S d 3.54 m

References 1 Smorgon ARC, Transfloor Technical Manual, Smorgon ARC, Melbourne.

2 Standards Association of Australia, AS3610-1995 Formwork for Concrete,

Standards Association of Australia, Sydney, 1995.

3 Standards Association of Australia, AS4100-1998 Steel Structures, Standards

Association of Australia, Sydney, 1998.

4 Standards Association of Australia, AS3600-1994 Concrete Structures, Standards

Association of Australia, Sydney, 1994.

Appendix C Page 53
 Appendix D

Construction Practice
Delivery

Panels are delivered in stacks on semi-trailers, approximately 150m2 per load. Stacks are normally loaded onto
the truck in reverse order of placement so that the top panel on the stack is the first to be placed on site. The
only exception being in the case of a load of mixed panel sizes when small panels are loaded on the top of the
stack irrespective of placing sequence. This should be the only circumstance which requires a panel to be
grounded on site before placing. However, such panels may be placed directly in position if their location can be
accurately fixed prior to commencement of panel placement.

Installation

Except in cases where the TransfloorTM panels are designed to sustain construction load over the clear span
without propping, a simple system of frames and props with 150 x 100 timber headers is normally erected prior
to arrival of panels on site. Prop spacing should be specified or shown on the engineer’s drawing and will vary
according to the type and number of trusses in the TransfloorTM panels and the construction loads to be
supported. Prop spacing generally varying from 1.8 to 2.4 metres is typical for slabs.

Crane Capacity

TransfloorTM 55mm thick has an average weight of 145kg/m2. In cases where the spreader is used for lifting, the
weight of the spreader (500kg) must be added to the panel weight to determine the maximum load for lifting. It
is important to ensure that the crane selected has adequate capacity at the reach required to place all panels.

Alternatively, where crane capacity is limited it may be necessary to limit the size and weight of panels to ensure
that the load/reach capacity of the crane is not exceeded.

Lifting and Placing

During production, each panel is marked with an Identification number corresponding to the panel layout
drawing so that the placement of each panel in it’s correct position in the structure is simplified.

Most panels up to about 8 metres in length containing truss types T110 or T150 can be lifted by crane using four
chains, the hooks being attached to the top bars of the TransfloorTM trusses.

In windy conditions it may be preferable to lift long panels using a 16 hook spreader.

For lifting and placing panels a crew of two men on the deck should achieve a placing rate of approximately 10
panels per hour.

Services

After a reasonable area of floor has been covered with panels a stable deck is available for following trades to
commence work. Conduits for electrical and communications services and water reticulation pipes are installed
as for in-situ concrete slabs. A hot wire cutter is used to quickly chase into polystyrene void formers to
accommodate conduits.

Generally penetrations smaller than 200mm diameter shall not be included in the panel. Small penetrations such
as those required for waste pipes and electrical outlets are make by core drilling through the 55mm TransfloorTM.

Page 54 Transfloor™ Precast Flooring System

 Appendix D

Cracking of Panel

The TransfloorTM panel may exhibit cracking for a number of reasons, eg.
• Incorrect loading of stacking on site.
• Poor handling techniques.
• Inadequate propping.

Minor cracking will not affect the structural integrity of the final slab, however, if more severe cracking (i.e. crack
widths greater than 0.2mm) has occurred it should be inspected by a suitably qualified engineer.

Top Steel and In-Situ Concrete

Immediately following Installation of services, fixing of top steel is carried out and the slab is then ready for
pouring of site placed concrete.

The thickness of topping concrete above polystyrene will be shown on drawings, but generally should not be
less than 70mm, additional top reinforcement fabric wire diameter and other factors may require this topping
thickness to be increased in some cases, to ensure that reinforcement is fully embedded and adequate cover
provided.

Edge Forms

Fixing of edge forms can usually proceed while services are being installed. A turn buckle engaging truss wires
may be used as a connection device for edge forms.

Appendix D Page 55
 Appendix E

TransfloorTM Quotation Checklist

1. TransfloorTM................................................................... = $ As quoted per m2

2. Crane Hire.................................................................... = $_____________per m2

Typically 10 panels can be placed per hour after the crane is conveniently
located

3. Propping.......................................................................= $_____________per m2
See quotation for propping centres.

4. Labour...........................................................................= $_____________per m2
Typically 2 men are required to place the above 10 panels/hr.

5. Topping concrete..........................................................= $_____________per m2

*See quotation for topping thickness estimate

6. Top steel....................................................................... = $_____________per m2

See quotation for top steel mass estimate.

7. Labour for steel and concrete placement....................= $_____________per m2

8. Edge Boards.................................................................= $_____________per m2

9. Pumps, Buckets, etc....................................................= $_____________per m2

10. Sealing the joint between the panel.............................= $_____________per m2

See Figure 30 for details.

Total Cost per m2.........................................................= $_____________per m2

Total Area......................................................................= $_____________m2

Total Cost......................................................................= $_____________

End of Report

Page 56 Transfloor™ Precast Flooring System