LYSAGHT W-DEK Design and Structural steel decking · PDF fileDesign and Structural steel decking system Construction Manual LYSAGHT W-DEK ® s/ptimised to bring greater efficiency,

Design and Construction ManualStructural steel decking system

LYSAGHT W-DEK®

ptimised to bring greater efficiency, speed of construction and economy.Exceptional spanning characteristics (up to 4.1m) reduces propping required.

ne of the best coverage-per-weight of steel which makes it economical.

has excellent concrete displacement characteristics which saves material costs.

2 Lysaght W-Dek Design & Construction Manual 20092

WarrantyBlueScope Lysaght has a number of comprehensive product warranties that cover not only the corrosion performance of the material but also the structural and serviceability performance of a wide range of products.BlueScope Lysaght can back their products with over 150 years experience and credibility. The LYSAGHT brand is widely recognised as setting the benchmark on quality products, and is trusted and respected by our customers and competitors nationwide.

Disclaimer, warranties and limitation of liability

This publication is intended to be an aid for professional engineers and is not a substitute for professional judgement.

Terms and conditions of sale are available at local BlueScope Lysaght sales offices.

Except to the extent to which liability may not lawfully be excluded or limited, BlueScope Steel Limited will not be under or incur any liability to you for any direct or indirect loss or damage (including, without limitation, consequential loss or damage such as loss of profit or anticipated profit, loss of use, damage to goodwill and loss due to delay) however caused (including, without limitation, breach of contract, negligence and/or breach of statute), which you may suffer or incur in connection with this publication.

LYSAGHT®, LYSAGHT W-DEK®, and GALVASPAN® are trademarks of BlueScope Steel Limited A.B.N. 16 000 011 058

The LYSAGHT range of products is exclusively made by BlueScope Steel Limited trading as BlueScope Lysaght.

© Copyright BlueScope Steel Limited March 10, 2009

Produced at BlueScope Lysaght Reseach and Development.

3Lysaght W-Dek Design & Construction Manual 2009 3

Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41. Features and applications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

1.1 Spanning capacities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51.2 Composite action . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51.3 Design efficiency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51.4 Economical design for fire . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51.5 Quicker trouble free installation . . . . . . . . . . . . . . . . . . . . . . . . 51.6 Technical support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

2. Specification and Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62.1 composite slabs. . . . . . . . . . . . . . . . . . . . . . . 62.2 section properties . . . . . . . . . . . . . . . . . . . . . 62.3 Sheeting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72.4 Concrete . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72.5 Reinforcement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72.6 Shear connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72.7 Design methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

3. Formwork design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83.1 Deflection limit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93.2 Formwork design load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

3.2.1 Design for strength . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 3.2.2 Design for serviceability . . . . . . . . . . . . . . . . . . . . . . . . . 10

3.3 Formwork Tables. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114. Composite slab design. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

4.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124.2 Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124.3 Crack control options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134.4 Durability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144.5 Design load. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

4.5.1 Strength load combination . . . . . . . . . . . . . . . . . . . . . . . 14 4.5.2 Serviceability load combination . . . . . . . . . . . . . . . . . . . 14 4.5.3 Superimposed dead load. . . . . . . . . . . . . . . . . . . . . . . . . 14

4.6 Design for Strength in negative regions . . . . . . . . . . . . . . . . . . . 15 4.6.1 Negative bending Strength . . . . . . . . . . . . . . . . . . . . . . . 15 4.6.2 Shear strength . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

4.7 Design for strength in positive regions . . . . . . . . . . . . . . . . . . . . 15 4.7.1 Positive bending Strength . . . . . . . . . . . . . . . . . . . . . . . . 15 4.7.2 Shear strength . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165. Design for fire . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

5.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165.2 Design for insulation and integrity . . . . . . . . . . . . . . . . . . . . . . . 165.3 Design for structural adequacy . . . . . . . . . . . . . . . . . . . . . . . . . . 16

5.3.1 Design loads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165.4 Reinforcement for fire design . . . . . . . . . . . . . . . . . . . . . . . . . . . 175.5 Location of longitudinal reinforcement

for fire design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186. Design Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

6.1 Use of design tables. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196.2 Single span design tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206.3 Interior span design tables. . . . . . . . . . . . . . . . . . . . . . . . . . . . 226.4 End spans design tables. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

7. Construction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 307.1 Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 307.2 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

7.2.1 Propping. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 7.2.2 Laying. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 7.2.3 Interlocking the sheets . . . . . . . . . . . . . . . . . . . . . . . . . . 31 7.2.4 Securing the platform . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 7.2.5 Installing on steel frames . . . . . . . . . . . . . . . . . . . 32 7.2.6 Fastening side lap joints . . . . . . . . . . . . . . . . . . . . . . . . . 33 7.2.7 Fitting accessories for edge form . . . . . . . . . . . . . . . . . . 33 7.2.8 Sealing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 7.2.9 Items embedded in slabs . . . . . . . . . . . . . . . . . . . . . . . . 35 7.2.10 Holes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 7.2.11 Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 7.2.12 Cutting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

7.3 Reinforcement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 7.3.1 Transverse reinforcement . . . . . . . . . . . . . . . . . . . . . . . . 36 7.3.2 Longitudinal reinforcement . . . . . . . . . . . . . . . . . . . . . . . 37 7.3.3 Trimmers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

7.4 Concrete . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 7.4.1 Specification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

7.4.2 Concrete additives. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 7.4.3 Preparation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 7.4.4 Construction joints. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 7.4.5 Placing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 7.4.6 Curing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 7.4.7 When to remove props . . . . . . . . . . . . . . . . . . . . . . . . . . 39

7.5 Finishing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 7.5.1 Soffit and edge form finishes . . . . . . . . . . . . . . . . . . . . . 39 7.5.2 Plastering. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 7.5.3 Change in floor loadings . . . . . . . . . . . . . . . . . . . . . . . . . 39

7.6 Suspended ceilings & services . . . . . . . . . . . . . . . . . . . . . . . . 40 7.6.1 Plasterboard. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 7.6.2 Suspended ceiling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 7.6.3 Suspended services. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 408. Composite beams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

8.1 Shear stud capacities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 419. References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

Contents


BackgroundLYSAGHT W-DEK is a new innovative profiled steel decking which brings greater economy and design freedom to building with composite concrete slabs. Our design engineers scoured the globe to find the best “W”- profiles in the world. After careful examination, our engineers incorporated the best aspects of each profile into new . The profile has been specifically developed for Australian high tensile steels - which makes one of the best performing ‘W’ profiles in the world.

is a profiled zinc-coated high tensile steel decking for use in the construction of composite floor slabs. It has exceptional composite performance – no additional reinforcement is required in most applications.

It can be used as formwork during construction and as a reinforcement system in composite slabs.

Our increased understanding of composite slabs, together with testing in our NATA-accredited laboratory and leading Australian universities, has paid off with an optimised product, which provides significant cost savings for projects.

has exceptional spanning characteristics and spans up to 4.1 metres, reducing the need for supporting structures.

The built-in properties of high tensile steel are maximised in the design and fabrication of the deck profiles which result in products with high strength-to-weight ratio. is currently the most economical structural steel decking in Australia for typical applications because it provides widest cover per weight of steel.

The profiled ribs are 78mm in height, resulting in having excellent concrete displacement characteristics and minimal propping requirements. This speeds up installation and makes the costs of delivery, erection and structural framing significantly lower than for other systems.

ScopeThis manual provides information on the design of formwork, propping, composite slabs and design for fire and some information for composite beams.

This manual is developed to the latest versions of the relevant AustralianStandards and Eurocodes.

Conditions of useThis publication contains technical information on the following grades of

:

0.75 mm thickness

1.00 mm thickness

Additionally, software allows you to get quicker and more economical solutions with a range of options. Call Steel Direct on 1800 641 417 to obtain additional copies of the Design Manual and Software.

Where we recommend use of third party materials, ensure you check the manufacturer's requirements. Diagrams are used to explain the requirements of a particular product. Adjacent construction elements of the building that would normally be required in that particular situation are not always shown. Accordingly aspects of a diagram not shown should not be interpreted as meaning these construction or design details are not required. You should check the relevant Codes associated with the construction or design.

WarrantiesOur products are engineered to perform according to our specifications only if they are installed according to the recommendations in this manual and our publications. Naturally, if a published warranty is offered for the product, the warranty requires specifiers and installers to exercise due care in how the products are applied and installed and are subject to final use and proper installation. Owners need to maintain the finished work.4


1. Features and ApplicationsContact Steel Direct for advice on the design of concrete frame buildings. Use on masonry buildings is acceptable if the requirements of Section 7 are satisfied.

1.1 Spanning Capacities has superior spanning capacities. 1.0 mm BMT

can span up to 4.1 metres when used on steel framed construction.

After careful examination, our engineers incorporated the best aspects of each profile into new developed specifically for high tensile steel. This resulted in a new innovative and optimised shape for

, having flange stiffeners and deep embossments, which act as web stiffeners, to increase the load carrying capacity.

Due to the large depth of the profile, an increase of the flexural rigidity reduces deflections.

1.2 Composite ActionGenerally speaking, a profiled steel sheet forms permanent and integral formwork for the concrete slab. Commonly, the ribs of the profiled sheeting are perpendicular to the centreline of the steel I-section which supports it. The stud shear connectors are welded through the thin steel sheeting into the top flange of the steel beam. This creates a shear connection in the longitudinal beam by way of the mechanical shear connectors, as well as in the direction transverse to the beam by the embossments in the profiled sheeting. It is this connection that allows a transfer for forces and gives composite members their unique behaviour.

has exceptional composite performance and leads to no additional reinforcement requirement in most applications.

1.3 Design Efficiency

The range of gauges available (0.75 mm and 1.0 mm) allows much closer matching of design requirements and deck performance.

1.2 mm BMT is not available in the design tables and software. However, a solution with 1.2 mm BMT is available subject to enquiry.

1.4 Design for Fire composite slabs can be designed for up to 4 hours of

fire rating. Guide tables in our manual are developed for fire periods of 60 and 90 minutes. Where necessary, additional bottom fire reinforcement is given in these tables. Our software can be used if other fire periods are required.

Negative fire reinforcement is an additional design option in our design software.

1.5 Quicker Trouble-Free InstallationThe installation of follows traditional methods for quick and easy installation. It is available in long lengths so large areas can be quickly and easily covered to form a safe working platform during construction. provides a cover width of 700 mm, which is the widest cover per weight of steel currently available in Australia.

1.6 Technical SupportContact Steel Direct on 1800 641 417 for access to our technical support services. BlueScope Lysaght Technology at Chester Hill, NSW, together with your local BlueScope Lysaght Technical Sales Representatives, can be called upon also to provide comprehensive information regarding the correct use of for engineers, architects and builders.

Lysaght W-Dek Design & Construction Manual 200966

Figure 2.1LYSAGHT W-DEK profile dimension and reinforcement

Figure 2.2profile and dimensions

78mm

700mm

713.6mm

ssenkcihTl

l

anoitces-ssorFull Cfoaera

Effective secondmoment of area

mmTMB Ahs mm 2 m/

x 01 4 mm 4 m/

TMB00.1

W-DECK

TMB57.01.00 11.63 1414 119.90.75 8.85 1060 77.5

Notes: 1. Self weight is given for Z350 coating. 2. Effective second moment of area varies depending on span values in a table. Values are given for longest spans only.

Table 2.1

Self Weight(kg/m2)

LYSAGHT W-DEK

b

D yb

SHEETINGELASTIC

CENTROID

dcb tbm (BMT)

Cover width 700

EmbossmentsBar reinforcement

Concrete

LYSAGHT W-DEK

Meshreinforcement

2. Specification and Design2.1 LYSAGHT W-DEK composite slabs

2.2 LYSAGHT W-DEK Section Properties


2.3 Sheeting is rolled-formed from hot dipped, zinc-coated, high

tensile steels in base metal thickness (BMT) of 1.0 and 0.75 mm.

1.2 mm BMT is not available in the design tables and software. However, the solution using 1.2 mm BMT is available subject to enquiry.The steel conforms to:

The coating is Z350 (350 g/m2 minimum coating mass) or Z450 (450 g/m2

minimum coating mass) is available subject to enquiry.

Embossments on the top of flanges and web embossing provide the mechanical connection between the steel and concrete.

2.4 ConcreteAll tables have been developed for the 32 MPa grade of concrete with normal density of 2400 kg/m3 (wet density). Other concrete grades are available in the software.

2.5 Reinforcement

effects, as flexural negative reinforcement over supports and in some instances for fire engineering purposes and as bottom tensile reinforcement. It shall comply with the requirements of AS/NZS4671:2001.

the software. D500N is used only in the tables.

bars for negative and fire reinforcement in addition to 500L shrinkage mesh.

2.6 Shear ConnectorsExtensive testing has been conducted in our NATA-registered lab and the University of Western Sydney. Shear stud capacities are available for secondary and primary composite beams. Those capacities can be achieved using conventional reinforcement in secondary beams and specific reinforcement developed by One Steel/University of Western Sydney in primary beams.

For more information refer to Section 8 of this Manual: Composite Beams.

2.7 Design MethodsThere are a number of ways you can design concrete slabs using

:

Eurocodes and data from this manual.

design software. This is also likely to produce a more economical design.

However, if in doubt you should get advice from a specialist where required.


3. Formwork DesignThe formwork shall be designed in accordance to AS3610 - 1995 and AS2327.1.

capacities and stiffness have been derived from tests conducted at our NATA-accredited laboratory at BlueScope Lysaght Technology, Chester Hill, NSW.

Our design tables can be used to detail acting as a structural formwork, provided the following conditions are satisfied:

minimum bearing of 50 mm at the ends of the sheets, 100 mm minimum bearing length for interior supports.

or intermediate splicing or jointing longitudinally.

shall be restrained.

sheeting ends shall be securely fixed at all permanent and temporary supports to the supporting structure

l/Ls) of any two adjacent spans does not exceed 1.2 (i.e. Ll/Ls 1.2).

during the construction phase can be ignored in design.

Figure 3.1 formwork

Endsupport

Interiorsupport

Interiorsupport

Slab span L Slab span L

LYSAGHT W-DEK

Outline ofconcrete

Equal sheeting spans L'

Temporaryprops

Temporaryprops

50mmminimum

Bearing on LYSAGHT W-DEK

(Not less than100 mm where sheeting is continuous.) 50mm

minimum

Interiorsupport


3.1 Deflection LimitsAS-3610—1995 Formwork for concrete, defines five classes of surface finish (numbered 1 to 5) covering a broad range of applications and AS2327.1.

We recommend a deflection limit of span/240 for the design of composite slabs in which good general alignment is required, so that the soffit appears straight when viewed as a whole. We consider span/240 to be suitable for a Class-3 and 4 surface finish and, in many situations, Class 2. Where alignment affects the thickness of applied finishes (for example vermiculite), you may consider a smaller limit of span/270 to be more suitable.

We consider span/130 to be a reasonable maximum deflection limit appropriate for profile steel sheeting in situations where visual quality is not significant (Class 5).

3.2 Formwork Design Loads must be designed as formwork for two stages of

construction according to AS 3610-1995 and AS2327.1.

Stage I

Prior to the placement of the concrete:

concrete,

When a live load due to stacked materials can be adequately controlled on the site at less than 4 kPa, the reduced design live load must be clearly indicated on the formwork documentation. (1kPa in tables from Section 3.3)

Stage II

During placement of the concrete up until the concrete has set (until fcmreaches 15-MPa and concrete is able to act flexurally to support additional loads such as stacked materials).

NOTE: No loads from stacked materials are allowed until the concrete has set.

formwork span only is loaded - with live loads, loads due to stacked materials and wet concrete. The has sufficient capacity for a concentrated point load of 2.0 kN for all spans and BMT. It is not necessary to perform formwork capacity checks for concentrated loads.


3.2.1 Design For Strength

Design bending capacities

The positive bending moment should be calculated using partial plastic theory. Negative moments over supports should not exceed the values given in Table 3.1.

If the negative bending moment over the support obtained from linear elastic analysis exceeds the design negative bending capacity - negative moments shall be redistributed into positive area such as negative moment does not exceed value given in the tables.

Bending moment in positive areas shall not exceed design moment capacity given in Table 3.1.

Shear (web crippling) capacity of end support

Interior supports shall not be checked for shear. The design shear capacity ( Vu,sh) for end bearing length of 50 mm or more, is :

( Vu,sh) = 25 kN/m (0.75 BMT)

( Vu,sh) = 38 kN/m (1.0 BMT)

3.2.1 Design For Serviceability

The maximum vertical deflection ( ), at completion of the concrete placement in all spans, is calculated using:

d

ef is calculated as follows:

For 0.75 BMT

Ief = Minimum of 775000mm4

or

Maximum (Ll 4

For 1.00 BMT

Ief = Minimum (406500+Ll 4

where Ll is in mm.

Table 3.2

Values of coefficient kd for calculation of (The maximum vertical deflection always occurs in the end span for these conditions.)

10

Table 3.1W-DEK moment capacities Design positive Design negative Capacity Capacitytbm u.sh (kN/m u.sh (kN/m

1.00.75

1.0 9.73 7.20.75 Minimum value of: 3.2

(i) 6.61(ii) 3.46 + 1.26Ll

where Ll is in metres (distance between centres of permanent or temporary supports)


NOTES: 1. Continuous maximum spans are limited as given in composite slab tables for interior spans and total 6000mm limit.2. Maximum formwork spans are based on Ll/240 deflection limit and ratio of two adjacent spans equal 1:1.3. Use software to get longer spans with Ll/130 deflection limit and wider supports.4. 1kPa Live Load due to stacked materials is used.

No props

Slab thickness, mm 130 135 140 145 150 160 175 200Single span 3100 3050 3000 2950 2900 2850 2750 2600Two spans 4100 4050 4000 3950 3900 3800 3650 3500Three or more spans 3800 3750 3700 3650 3600 3500 3400 3200

1 prop


Formwork table 1.00 BMT

Formwork table 0.75 BMTNo props


1 prop


3.3 Formwork tables


4. Composite Slab Design4.1 GeneralThis chapter discusses the parameters upon which our design tables and software are based. Solutions to your design problems may be obtained by direct reference to either our design software, or our design tables in this Manual.

Design data about composite performance of slabs withhave been obtained from full scale slab tests conducted at the University of Newcastle.

4.2 ApplicationOur design tables and software can be used to design composite slabs with provided the following conditions are satisfied:

ƒ´c is in the range 25 MPa to 40 MPa (as specified in AS-3600—2001). The concrete density c may be for normal weight concrete, taken as c 2400kg/m3.

AS 3600—2001, Section 19.

have a minimum bearing of 50 mm at the ends of the sheets, and 100 mm at intermediate supports over which sheeting is continuous.

L1) to the shorter slab span ( Ls ) of any two adjacent spans does not exceed 1.2, that is L1/Ls 1.2.

uniformly-distributed and static in nature.

vertical loads applied to the slab.

profiles can be used in conjunction with this manual. High values of u,Rd responsible for composite performance can only be achieved due to advanced features of .Refer to Table 4.1 for longitudinal shear resistance values.

steel must be in accordance with AS 3600—2001, Clause 19.2, and the design yield stress, ( ƒsy ), must be taken from AS 3600—2001,Table 6.2.1, for the appropriate type and grade of reinforcement, and manufacturers’ data.

accordance with AS 3600—2001, Clause 19.1.

must not be spliced, lapped or joined longitudinally in any way.

of the slab.

AS 2327.1, Clause 4.2.3, composite action must be assumed to exist between the steel sheeting and the concrete once the concrete in the slab has attained a compressive strength of 15 MPa, that is ƒ´cj 15 MPa. Prior to the development of composite action during construction, potential damage to the shear

allowed.

regions shall be arranged in accordance with the Figures 4.1 and 4.2. Refer to AS3600-2001, clause 9.1.3 for more information on detailing of tensile reinforcement in one way slab.


Figure 4.1 Pattern 1 for conventional reinforcement

Figure 4.2 Pattern 2 for conventional reinforcement when imposed load exceeds twice the dead load

Little or norestraint atend support

0.3Ln

Negativereinforcement

LYSAGHT W-DEK

Ln Ln

Restraint atend supportby mass of wall

Continuous overinterior support

0.3Ln

0.3Ln

L (span)

Concrete slab

Wal

l

Wal

l

Cover

Wal

l

Wal

l

L (span)

Minimum 70mm

Minimum 50mm

min

imum

100

mm

Little or norestraint atend support

0.3Ln

LYSAGHT W-DEK

Ln Ln

Restraint atend supportby mass of wall

Continuous overinterior support

0.3Ln

0.3Ln

L (span)

Concrete slab

Wal

l

Wal

lCover

Wal

l

Wal

l

L (span)

1/3 of negativereinforcement

4.3 Crack Control options Tables and software are developed to the latest recommendations of AS3600-2001, Clause 9.4.1 regarding flexural crack control. Our design tables for continuous spans assume full crack control. The software allows full and relaxed crack control.

fs in the reinforcement and the design crack width – a smaller bar diameter may result in less reinforcement being necessary.

AS3600-2001, Clause 9.4.


4.4 Durability

The exposure classification relevant to the design of slabs are A1, A2, B1 and B2 as defined in AS 3600—2001, Clause 4.3.

The minimum concrete cover (c) to reinforcing steel, measured from the slab top face, must comply with AS-3600—2001, Table 4.10.3.2.

4.5 Design Loads

4.5.1 Strength load Combinations

For strength calculations, design loads for both propped and unpropped construction must be based on the following load combinations.

Pattern loading shall be considered according to AS3600-2001 Clause 7.6.4.

As per AS3600-2001

1 25 1 5. .G G G Qc sh sup

and for bending (composite) and shear capacity in positive (with top outer fibre of concrete in compression) areas. (as per prEN 1994-1-1)

1.35

where Gc Gsh =Gsup = superimposed dead load (partitions, floor tiles, etc.) Q = live load

4.5.2 Serviceability Load Combinations

Deflections due to loading applied to the composite slab should be calculated using linear elastic analysis in accordance with AS3600-2001,Clause 3.4. and 8.5.3. Note that the live load (Q) is applied after the removal of any temporary props and after the addition of any deflection-sensitive finishes. The loading pattern of vertical load should be considered in the analysis as per AS3600-2001, Clause 7.6.4 for short term loads.

Loads for crack control shall be in accordance AS3600-2001 Clause 9.4.1.

4.5.3 Superimposed Dead LoadThe maximum superimposed dead load assumed in our design tables is 1.0 kPa. Use design software for other loads.

1 5.G G G Qc sh sup


4.6 Design for Strength in Negative Regions4.6.1 Negative Bending StrengthFor the bending strength design in negative moment regions, the presence of the sheeting in the slab is ignored and the slab shall be designed allowing for 50% void area between ribs. For this purpose, use the provisions of AS3600-2001, Section 9.

The minimum bending strength requirement of AS 3600-2001, Clause 9.1 must be satisfied.

4.6.2 Shear StrengthNegative moment regions must be designed for shear strength, to satisfy AS 3600-2001, Section 9. The negative moment region of composite slab shall be calculated allowing for voids between ribs which are 50% of cross sectional area within decking profile.

4.7 Design for Strength in Positive Regions4.7.1 Positive Bending StrengthPositive-moment regions are designed for bending strength such that at every cross-section the design positive moment capacity is not less than the design positive bending moment capacity.

Positive bending capacity shall be calculated as per prEN1994-1-1 Clause 9.7.2. Partial shear connection theory shall be employed using values of

u,Rd in Table 4.1.

4.7.2 Shear StrengthThe positive shear capacity can be calculated as per Eurocode 2 Clause 4.3.2.3

Table 4.1LYSAGHT W-DEKLongitudinal shear resistance

BMT u,Rd (kPa)

0.75 1151.0 185


5.3 Design for Structural Adequacy5.3.1 Design LoadsUse AS1170.1 Clause 2.5 together with Design load for fire Wf = 1.1G + l Q

5. Design for Fire5.1 GeneralThe composite slabs shall be designed for fire conditions in accordance to AS 3600-2001. The entire soffit of slab is assumed to be exposed to fire over both positive and negative moments regions. Temperature distribution through a cross section of a composite slab subject to fire is affected by the geometry of sheeting profile.

Reduction factors are applied to allow for the adverse effect of elevated temperatures on the mechanical properties of concrete and steel. Values of these reduction factors shall be derived from the relationships given in AS 3600-2001, Clause 5.9.

Our tables may be used to detail composite slabs when the soffit is exposed to fire provided the following conditions are satisfied:

of the sheeting ribs for both room temperature and fire conditions.

temperature conditions in accordance to this manual.

nature.

penetrating, embedded or encased services) to provide the appropriate fire resistance period. Alternatively the local provision of suitable protection (such as fire spray material) will be necessary.

b= 140mm as per Figure 5.1 and 5.2 designates zone where fire and negative reinforcement shall be placed.

5.2 Design for Insulation and IntegrityMinimum required overall depth (D) of slabs for insulation and integrity for various fire resistance periods is given in Table 5.1.

These values are derived from test results.

FireResistance

Period Depth(Minutes) (D) mm

6090120180240

130135145170190

Table 5.1 Minimum overall depth (D) of LYSAGHT W-DEK slabs for insulation and integrity


Figure 5.1Details of reinforcement for fire design

0.3 Ln

L

LYSAGHT W-DEK

LYSAGHT W-DEK

LYSAGHT W-DEK

LYSAGHT W-DEK

Concrete

Fire detail 1

Concrete

Ddct

Ast–

Ln

0.3 Ln

L

Concrete

Fire detail 2

Ln

Ast– Ast.f

–

Concrete

ybD

xb xb

Ast+Ast.f

+Ast, transverse

Ast- Ast.f

+

Mesh(longitudinal - wires not shown)

Mesh(longitudinal - wires not shown)

Ast, transverse

xb xb

Ast–

Ast.f–

5.4 Reinforcement for Fire Design The arrangement of reinforcement for fire design is shown in Figure 5.1. Fire reinforcement may be necessary, in addition to mesh and negative reinforcement required by our tables for composite slab design.

the plastic hinges.

st,f- for Fire detail 1 is in a single top layer

at a depth of dct below the slab top face (refer to figure 5.1). This detail is applicable to continuous slabs only

st,f+ for Fire detail 2 is in a single bottom

layer at a distance of yb above the slab soffit (refer to Figure 5.1). This detail is applicable to both continuous and simple spans.

is designated Ast,f+ in our tables (D500 N with bar diameter = 12 mm or

less).

st-) and the additional fire reinforcement

(Ast,f+ or Ast,f

- as applicable), must be located as shown in Figure 5.1 & 5.2.

both options.


LYSAGHT W-DEK

Concrete

xbxb

Permissible zone forlongitudinal fire reinforcement Ast.f

+, Ast.f

- and A-

st

yb

Ast.- (Ast.f

-)

Ast.f+

Transverse supporting bars(shrinkage mesh)

Fig. 5.2Permissible zone for location of longitudinal fire reinforcement for Fire Detail 1 & 2.

Negative reinforcement A-st may be placed anywhere outside permissible

zone (See fig. 5.2) if design for fire is not required.

5.5 Location of Longitudinal Reinforcement for Fire DesignThe longitudinal bars which make up Ast.f

+, Ast.f- or A-

st should be located within the zone shown in Figure 5.2.

xb = 140mm

yb = varies depending on the diameter of the supporting bar


KEY - Continuous Spans

Notes: 1. Areas without cells mean that a design solution is

not possible.2. Single spans do not require top tensile reinforcement,

relevant cells are not shown.3. All spans are centre to centre.4. A dash (-) means no fire reinforcement

is necessary.5. N/A means a design solution with this particular fire

rating is not possible.6. Top tensile/negative reinforcement is additional to

shrinkage mesh area

Table 6.1 Shrinkage mesh used with tables.

6. Design Tables6.1 Use of Design TablesThe design parameters specific for each table are given on the top of tables:

The rest of parameters are common for all tables and listed below:

1c = 32MPa.

3.

W used as a structural deck with thickness 0.75 or 1.0mm BMT

incremental deflection.

mesh specified in Table 6.1. If negative fire reinforcement is required, at least one bar per rib should be placed. Smaller bar diameter may result in less negative and fire reinforcement.

144050 570

Fire reinforcement required for fire resistance of 90

minutes (mm2/m)

Top tensile (negative) reinforcements over supports (mm2/m)

Fire reinforcement required for fire resistance of 60 minutes (mm2/m)

KEY - Single Spans

50 570

Fire reinforcement required for fire resistance of 90 minutes (mm2/m)

Bottom reinforcement required for fire resistance of 60 minutes (mm2/m)

Depth Mesh130 SL62135 SL62140 SL62145 SL62150 SL62160 SL72175 SL72200 SL82


Single Spans 130 mm slab

Span Characteristic Imposed Load Qk (kPa)(mm) 1.5 2 2.5 3 4 5.0 7.5 101800 60 N/A 70 N/A 70 N/A 80 N/A 90 N/A 100 N/A 130 N/A 150 N/A2000 90 N/A 90 N/A 100 N/A 110 N/A 120 N/A 140 N/A 170 N/A 210 N/A2200 120 N/A 130 N/A 130 N/A 140 N/A 160 N/A 180 N/A 220 N/A 260 N/A2400 150 N/A 160 N/A 170 N/A 180 N/A 200 N/A 220 N/A 280 N/A 330 N/A2600 190 N/A 200 N/A 210 N/A 230 N/A 250 N/A 280 N/A 340 N/A2800 230 N/A 250 N/A 260 N/A 270 N/A 300 N/A 330 N/A3000 280 N/A 290 N/A 310 N/A 330 N/A 360 N/A3200 330 N/A 350 N/A 370 N/A 390 N/A3400 380 N/A 410 N/A3600380050005200

Single Spans 135mm slab Span Characteristic Imposed Load Qk (kPa)(mm) 1.5 2 2.5 3 4 5 7.5 102000 80 N/A 80 N/A 90 N/A 90 N/A 100 N/A 120 N/A 150 N/A 180 N/A2200 100 N/A 110 N/A 120 N/A 120 N/A 140 N/A 150 N/A 190 N/A 230 N/A2400 130 N/A 140 N/A 150 N/A 160 N/A 180 N/A 200 N/A 240 N/A 290 N/A2600 170 N/A 180 N/A 190 N/A 200 N/A 220 N/A 240 N/A 300 N/A2800 200 N/A 220 N/A 230 N/A 240 N/A 270 N/A 290 N/A3000 240 N/A 260 N/A 270 N/A 290 N/A 320 N/A 350 N/A3200 290 N/A 310 N/A 320 N/A 340 N/A3400 340 N/A 360 N/A 380 N/A3600 390 N/A38004000

Single Spans 140mm slab

Span Characteristic Imposed Load Qk (kPa)(mm) 1.5 2 2.5 3 4 5.0 7.5 102200 90 N/A 100 N/A 100 N/A 110 N/A 120 N/A 140 N/A 170 N/A 200 N/A2400 120 N/A 130 N/A 130 N/A 140 N/A 160 N/A 170 N/A 210 N/A 250 N/A2600 150 N/A 160 N/A 170 N/A 180 N/A 200 N/A 210 N/A 260 N/A 310 N/A2800 180 N/A 190 N/A 200 N/A 220 N/A 240 N/A 260 N/A 320 N/A3000 220 N/A 230 N/A 240 N/A 260 N/A 280 N/A 310 N/A3200 260 N/A 270 N/A 290 N/A 300 N/A 330 N/A3400 300 N/A 320 N/A 340 N/A 350 N/A3600 350 N/A 370 N/A380040004000


Span Characteristic Imposed Load Qk (kPa)(mm) 1.5 2 2.5 3 4 5.0 7.5 102200 100 9080 100 90 110 100 110 110 120 120 140 150 170 180 2002400 110 120 110 130 120 140 130 140 140 160 160 170 190 210 230 2402600 140 150 140 160 150 170 160 180 180 190 190 210 240 250 280 3002800 170 180 180 190 190 200 200 210 210 230 230 250 280 3003000 200 220 210 230 220 240 230 250 260 270 280 3003200 240 250 250 270 260 280 280 290 300 320 330 3503400 280 290 290 310 310 320 320 3403600 320 340 340 350 350 3703800 360 38040004200

6.2 Single Spans



Span Characteristic Imposed Load Qk (kPa)(mm) 1.5 2 2.5 3 4 5.0 7.5 102800 100 110 100 120 110 130 110 130 130 150 140 160 170 190 200 2203000 120 140 130 150 140 150 140 160 160 170 170 190 210 230 240 2603200 150 170 160 170 160 180 170 190 190 210 200 220 240 260 290 3103400 180 190 190 200 190 210 200 220 220 240 240 260 290 3103600 210 230 220 240 230 250 240 260 260 280 280 3003800 240 260 250 270 260 280 270 290 300 3204000 270 290 290 310 300 320 310 3304200 310 330 320 340440046004200

Single Spans 150 mm slabSpan Characteristic Imposed Load Qk (kPa)(mm) 1.5 2 2.5 3 4 5.0 7.5 102400 100 110 100 120 110 120 120 130 130 140 140 160 170 190 210 2202600 120 140 130 150 140 150 150 160 160 180 180 190 210 230 250 2702800 150 170 160 180 170 190 180 190 200 210 210 230 260 280 310 3203000 180 200 190 210 200 220 210 230 240 250 260 270 310 3303200 220 230 230 250 240 260 250 270 280 290 300 3203400 250 270 270 280 280 300 290 310 320 3403600 290 310 310 330 320 340 340 3603800 340 350 350 37040004200


Span Characteristic Imposed Load Qk (kPa)(mm) 1.5 2 2.5 3 4 5.0 7.5 103000 80 100 80 100 90 110 90 120 100 130 110 140 140 160 170 1903200 100 120 110 130 110 130 120 140 130 150 140 170 170 200 200 2303400 120 150 130 150 140 160 140 170 160 180 170 200 210 230 240 2703600 150 170 160 180 170 190 170 200 190 210 200 230 240 270 280 3103800 180 200 190 210 190 220 200 230 220 250 240 260 280 3104000 210 230 220 240 230 250 240 260 260 280 280 3004200 240 260 250 270 260 280 270 290 290 3204400 270 290 280 310 290 320 310 3304600 300 330 320 340 330 3604800 340 37050005200


Span Characteristic Imposed Load Qk (kPa)(mm) 1.5 2 2.5 3 4 5.0 7.5 102600 90 110 100 120 110 120 110 130 120 140 140 160 170 190 200 2202800 120 140 130 140 130 150 140 160 160 170 170 190 210 230 250 2703000 150 170 160 170 160 180 170 190 190 210 210 230 250 2703200 180 200 190 210 200 220 210 230 230 250 250 2703400 210 230 220 240 230 250 240 260 270 290 290 3103600 250 270 260 280 270 290 280 300 310 3303800 280 300 300 320 310 330 330 3504000 320 340 340 3604200


Interior Spans 135 mm slab

Span Characteristic Imposed Load Qk (kPa)(mm) 1.5 2 2.5 3 4 5.0 7.5 10

200080 80 80 80 80 80 80 130- N/A - N/A - N/A - N/A - N/A - N/A - N/A - N/A




280080 80 80 90 130 170 280 380- N/A - N/A 10 N/A - N/A - N/A - N/A - N/A 10 N/A

300080 80 90 120 170 220 340 46020 N/A 30 N/A 10 N/A - N/A - N/A - N/A 10 N/A 20 N/A

320090 100 110 160 210 260 41050 N/A 10 N/A 10 N/A - N/A - N/A - N/A 20 N/A

3400110 120 140 200 250 320 48020 N/A 10 N/A - N/A - N/A 10 N/A 10 N/A 20 N/A

3600130 150 200 230 300 37010 N/A - N/A 10 N/A 10 N/A 20 N/A 20 N/A

3800160 200 200 270 350 43010 N/A 10 N/A 10 N/A 20 N/A 20 N/A 30 N/A

4000200 200 230 320 41020 N/A 20 N/A 20 N/A 30 N/A 30 N/A

4200210 240 270 370 47020 N/A 30 N/A 30 N/A 30 N/A 40 N/A

4400240 270 310 42030 N/A 40 N/A 40 N/A 40 N/A

4600270 300 350 47040 N/A 40 N/A 50 N/A 50 N/A

4800300 340 39050 N/A 50 N/A 60 N/A

5000340 390 44060 N/A 60 N/A 70 N/A

520037070 N/A

5400







260070 70 70 70 100 140 230 320- N/A - N/A - N/A 10 N/A - N/A - N/A - N/A - N/A

280070 70 70 90 140 180 290 40020 N/A 30 N/A 40 N/A - N/A - N/A - N/A - N/A 10 N/A

300070 70 100 130 180 220 35050 N/A 70 N/A 50 N/A - N/A - N/A - N/A 10 N/A

320080 90 130 160 220 270 42060 N/A 50 N/A 20 N/A - N/A 10 N/A 10 N/A 20 N/A

3400100 120 180 200 260 33050 N/A 20 N/A 10 N/A 10 N/A 10 N/A 20 N/A

3600130 180 200 240 310 39050 N/A 10 N/A 10 N/A 20 N/A 20 N/A 30 N/A

3800180 180 240 280 370 45010 N/A 20 N/A 20 N/A 20 N/A 30 N/A 40 N/A

4000180 200 280 330 42020 N/A 30 N/A 30 N/A 30 N/A 40 N/A

4200210 240 330 38030 N/A 30 N/A 40 N/A 40 N/A

4400240 270 370 43040 N/A 40 N/A 50 N/A 50 N/A

4600270 310 42050 N/A 50 N/A 60 N/A

4800300 35060 N/A 60 N/A

5000340 40070 N/A 70 N/A

520038080 N/A

5400

6.3 Interior Spans




2200100 100 100 100 100 100 120 170- - - - - - - - - - - - - - - -

2400100 100 100 100 100 100 160 230- - - - - - - - - - - - - - - -

2600100 100 100 100 100 130 200 290- - - - - - - - - - - - - - - -

2800100 100 100 100 130 160 260 350- - - - - - - - - - - - - - - 10

3000100 100 100 120 160 200 310 430- - - - - - - - - - - - - 10 10 20

3200100 110 120 150 200 250 370 510- 10 - - - - - - - 10 - 10 10 20 10 N/A

3400120 130 150 180 240 300 440- - - - - 10 - 10 - 10 - 20 10 30

3600140 160 170 230 280 350 510- 10 - 10 - 10 - 10 10 20 10 20 20 N/A

3800170 190 230 260 330 400- 10 - 20 10 20 10 20 10 30 20 30

4000230 230 230 300 380 46010 20 10 20 10 30 10 30 20 30 30 40

4200230 240 260 340 430 53010 30 20 30 20 30 20 40 30 40 30 N/A

4400250 270 300 390 49020 30 20 40 30 40 30 40 40 N/A

4600280 300 330 44030 40 30 40 30 50 40 50

4800310 340 370 50030 50 40 50 40 60 50 N/A

5000340 370 42040 60 50 60 50 60

5200380 410 46050 60 60 70 60 70

5400410 45060 70 60 80

560045070 80

5800







300090 90 90 120 170 220 320 440- N/A - N/A - N/A - N/A - N/A - N/A - N/A 10 N/A

320090 110 120 150 220 260 39020 N/A 10 N/A - N/A - N/A - N/A - N/A 10 N/A

3400110 130 140 190 250 310 46010 N/A - N/A - N/A - N/A - N/A 10 N/A 20 N/A

3600140 150 220 230 290 360- N/A - N/A - N/A 10 N/A 10 N/A 20 N/A

3800160 220 220 270 340 420- N/A 10 N/A 10 N/A 10 N/A 20 N/A 20 N/A

4000220 220 230 310 390 48010 N/A 10 N/A 20 N/A 20 N/A 30 N/A 30 N/A

4200220 240 260 360 45020 N/A 20 N/A 20 N/A 30 N/A 30 N/A

4400250 270 300 400 51020 N/A 30 N/A 30 N/A 40 N/A 40 N/A

4600280 300 340 46030 N/A 40 N/A 40 N/A 40 N/A

4800310 340 380 51040 N/A 50 N/A 50 N/A 50 N/A

5000340 380 43050 N/A 50 N/A 60 N/A

5200380 42060 N/A 60 N/A

540041070 N/A

5600




2600 270 270 270 270 270 270 270 270- - - - - - - - - - - - - - - -

2800 270 270 270 270 270 270 270 410- - - - - - - - - - - - - - - -

3000 270 270 270 270 270 270 410 410- - - - - - - - - - - - - - - -

3200 270 270 270 270 270 270 410 430- - - - - - - - - - - - - - - -

3400 270 270 270 270 270 410 410 500- - - - - - - - - - - - - - - 10

3600 270 270 270 270 410 410 430 580- - - - - - - - - - - - - 10 - N/A

3800 270 270 270 410 410 410 500- - - - - - - - - - - 10 - 20

4000 270 270 410 410 410 410 580- - - - - - - 10 - 10 - 10 10 N/A

4200 270 410 410 410 410 450- - - 10 - 10 - 10 - 20 10 20

4400 410 410 410 410 420 510- 10 - 10 - 20 - 20 10 20 10 30

4600 410 410 410 410 480 580- 20 - 20 10 20 10 30 10 30 20 N/A

4800 410 410 410 410 54010 30 10 30 10 30 20 30 20 N/A

5000 410 410 410 420 60010 30 20 30 20 40 20 40 30 N/A

5200 410 410 430 46020 40 20 40 30 40 30 50

5400 410 440 470 51030 40 30 50 40 50 40 60

5600 440 470 51040 50 40 60 40 60

5800 480 51040 60 50 60

6000 51050 70



2400110 110 110 110 110 110 150 220- - - - - - - - - - - - - - - -

2600110 110 110 110 110 120 200 280- - - - - - - - - - - - - - - -

2800110 110 110 110 120 160 250 340- - - - - - - - - - - - - - - 10

3000110 110 110 120 160 200 300 410- - - - - - - - - - - - - 10 - 10

3200110 120 130 150 190 240 360 480- - - - - - - - - - - 10 - 10 10 20

3400120 140 150 180 240 290 420- - - - - - - 10 - 10 - 10 10 20

3600150 160 180 240 280 340 490- 10 - 10 - 10 - 10 - 20 10 20 20 N/A

3800170 190 240 250 320 390- 10 - 10 - 20 - 20 10 20 10 30

4000200 240 240 290 370 450- 20 10 30 10 20 10 20 20 30 20 30

4200240 240 270 340 420 51010 20 10 30 10 30 20 30 20 40 30 N/A

4400250 270 300 380 48020 30 20 30 20 30 20 40 30 40

4600280 310 330 430 53020 40 30 40 30 40 30 50 40 N/A

4800310 340 370 48030 40 30 50 40 50 40 50

5000340 370 410 53040 50 40 50 40 60 50 N/A

5200380 410 45040 60 50 60 50 70

5400410 450 50050 70 60 70 60 N/A

560045060 70

5800

6000




2800300 300 300 300 300 300 300 300- - - - - - - - - - - - - - - -

3000300 300 300 300 300 300 300 450- - - - - - - - - - - - - - - -

3200300 300 300 300 300 300 450 450- - - - - - - - - - - - - - - -

3400300 300 300 300 300 300 450 450- - - - - - - - - - - - - - - -

3600300 300 300 300 300 450 450 530- - - - - - - - - - - - - - - 10

3800300 300 300 300 450 450 460 610- - - - - - - - - - - - - 10 - N/A

4000300 300 300 300 450 450 520- - - - - - - - - - - 10 - 10

4200300 300 450 450 450 450 590- - - - - - - - - 10 - 10 10 20

4400300 450 450 450 450 470- - - 10 - 10 - 10 - 10 - 20

4600450 450 450 450 450 530- 10 - 10 - 10 - 20 - 20 10 30

4800450 450 450 450 490 590- 10 - 20 - 20 10 20 10 30 20 30

5000450 450 450 450 550 650- 20 10 20 10 30 10 30 20 30 20 N/A

5200450 450 450 460 61010 30 10 30 20 30 20 40 30 N/A

5400450 450 470 500 67020 30 20 40 20 40 30 40 30 N/A

5600450 470 510 54020 40 30 40 30 50 30 50

5800480 510 550 58030 50 30 50 40 50 40 60

6000520 550 59040 50 40 60 50 60



3000350 350 350 350 350 350 350 350- - - - - - - - - - - - - - - -

3200350 350 350 350 350 350 350 350- - - - - - - - - - - - - - - -

3400350 350 350 350 350 350 350 520- - - - - - - - - - - - - - - -

3600350 350 350 350 350 350 520 520- - - - - - - - - - - - - - - -

3800350 350 350 350 350 350 520 520- - - - - - - - - - - - - - - -

4000350 350 350 350 350 520 520 570- - - - - - - - - - - - - - - -

4200350 350 350 350 520 520 520 650- - - - - - - - - - - - - - - -

4400350 350 350 350 520 520 560 820- - - - - - - - - - - - - - - N/A

4600350 350 520 520 520 520 630- - - - - - - - - - - - - 10

4800350 520 520 520 520 520 700- - - - - - - - - - - - - 10

5000520 520 520 520 520 560- - - - - - - - - 10 - 10

5200520 520 520 520 520 610- - - - - 10 - 10 - 10 - 20

5400520 520 520 520 570 680- 10 - 10 - 10 - 10 - 20 - 20

5600520 520 520 530 630- 10 - 20 - 20 - 20 10 30

5800520 520 540 570 690- 20 - 20 - 20 10 30 10 30

6000520 550 580 610- 20 10 30 10 30 10 30


End Spans 130 mm slab


1800 70 70 70 70 70 70 70 100

- N/A - N/A - N/A - N/A - N/A 10 N/A 30 N/A 30 N/A

2000 70 70 70 70 70 70 100 160

- N/A 10 N/A 10 N/A 10 N/A 20 N/A 30 N/A 40 N/A 50 N/A

2200 70 70 70 70 70 80 150 220

20 N/A 30 N/A 30 N/A 40 N/A 50 N/A 60 N/A 60 N/A 80 N/A

2400 70 70 70 70 90 120 200 280


2600 70 70 70 90 120 180 260 360


2800 70 80 100 120 180 210 320 440


3000 90 100 130 180 210 260 390

130 N/A 130 N/A 120 N/A 100 N/A 120 N/A 130 N/A 170 N/A

3200 110 130 180 190 250 310 470

150 N/A 140 N/A 120 N/A 130 N/A 140 N/A 160 N/A 210 N/A

3400 180 180 200 240 300 370

130 N/A 150 N/A 150 N/A 150 N/A 170 N/A 190 N/A

3600 180 190 240 280 360 440

180 N/A 180 N/A 170 N/A 180 N/A 210 N/A 230 N/A

3800 200 230 290 330 420

200 N/A 200 N/A 200 N/A 210 N/A 240 N/A

4000 230 270 360 380

230 N/A 220 N/A 230 N/A 250 N/A

4200 270 360

250 N/A 250 N/A

4400 360

270 N/A

4600



200080 80 80 80 80 80 100 150

- N/A - N/A - N/A 10 N/A 10 N/A 20 N/A 30 N/A 40 N/A

220080 80 80 80 80 80 140 210


240080 80 80 80 90 120 200 270


260080 80 80 80 120 160 250 340


280080 90 100 120 160 200 310 420


3000100 110 120 150 200 250 380

100 N/A 100 N/A 100 N/A 90 N/A 100 N/A 110 N/A 140 N/A

3200120 140 200 200 250 300 450

120 N/A 110 N/A 100 N/A 110 N/A 120 N/A 140 N/A 180 N/A

3400150 200 200 230 290 360

130 N/A 120 N/A 120 N/A 130 N/A 150 N/A 170 N/A

3600200 200 220 270 350 420

130 N/A 150 N/A 150 N/A 160 N/A 180 N/A 200 N/A

3800210 230 260 320 400

160 N/A 170 N/A 170 N/A 180 N/A 210 N/A

4000240 270 310 380

190 N/A 190 N/A 200 N/A 210 N/A

4200270 310 380

210 N/A 220 N/A 230 N/A

4400380 380

230 N/A 250 N/A

4600

6.4 End Spans




2200 90 90 90 90 90 90 140 220


2400 90 90 90 90 90 110 190 260


2600 90 90 90 90 120 150 240 330


2800 90 90 100 120 150 220 300 400


3000 100 120 130 150 220 240 360 490


3200 130 140 160 220 240 290 430

90 N/A 100 N/A 90 N/A 100 N/A 110 N/A 120 N/A 150 N/A

3400 150 220 220 220 280 350 510

110 N/A 100 N/A 110 N/A 120 N/A 130 N/A 150 N/A 180 N/A

3600 220 220 220 270 340 410

110 N/A 120 N/A 130 N/A 140 N/A 150 N/A 170 N/A

3800 220 230 260 310 390 470

140 N/A 140 N/A 150 N/A 160 N/A 180 N/A 200 N/A

4000 240 270 300 360 450

160 N/A 170 N/A 180 N/A 190 N/A 210 N/A

4200 280 300 340 410

180 N/A 190 N/A 200 N/A 220 N/A

4400 310 400 400

210 N/A 220 N/A 230 N/A

4600 400

230 N/A

4800



2200100 100 100 100 100 100 130 190

- 20 - 20 10 20 10 20 10 30 20 30 30 50 50 60

2400100 100 100 100 100 110 180 250

10 30 20 30 20 30 20 40 30 40 30 50 50 60 60 80

2600100 100 100 100 120 150 230 320

30 40 30 50 40 50 40 60 50 60 50 60 70 80 90 100

2800100 100 110 120 150 190 290 390

50 60 60 70 50 70 60 70 60 70 70 80 90 100 110 120

3000110 120 130 150 230 230 350 470

70 80 70 80 70 90 70 80 80 90 90 100 110 130 140 N/A

3200130 150 160 230 230 280 420

80 100 80 90 80 100 80 100 100 110 110 120 140 150

3400160 180 230 230 280 340 490

90 110 90 110 100 110 100 120 120 130 130 140 160 N/A

3600190 230 230 260 330 390

100 120 110 120 120 130 120 140 140 150 150 170

3800230 240 260 300 380 450

120 140 130 140 140 150 150 160 160 180 180 190

4000250 270 290 350 430

140 160 150 170 160 180 170 180 190 200

4200280 310 340 400

160 180 170 190 180 200 190 210

4400320 340 420

190 200 200 210 210 230

4600420 420

210 230 220 240

4800

5000



SpanCharacteristic Imposed Load Qk (kPa)

(mm) 1.5 2 2.5 3 4 5.0 7.5 10

2400110 110 110 110 110 110 170 240

10 20 10 30 10 30 20 30 20 40 30 40 40 60 60 70

2600110 110 110 110 120 140 240 310

20 30 20 40 30 40 30 50 40 50 40 60 60 70 80 90

2800110 110 110 120 150 180 280 370

30 50 40 60 50 60 50 60 50 70 60 70 80 90 100 110

3000110 130 140 150 190 240 340 450

60 70 60 70 50 70 60 70 70 80 80 90 100 110 120 140

3200140 150 170 180 240 270 400

60 80 70 80 70 80 80 90 90 100 100 110 120 140

3400160 180 200 240 270 330 470

80 100 80 100 90 100 90 110 100 120 120 130 150 160

3600190 240 240 250 320 380 550

90 110 100 110 110 120 110 130 120 140 140 150 170 N/A

3800240 240 260 300 370 440

110 120 120 130 120 140 130 150 150 160 160 180

4000250 270 300 340 420 500

130 140 140 150 150 160 150 170 170 190 190 N/A

4200280 310 330 390 480

150 160 160 170 170 180 180 190 200 210

4400320 340 370 440

170 190 180 200 190 210 200 220

4600350 440 440

190 210 200 220 220 230

4800440

220 230

5000

5200



2600 270 270 270 270 270 270 270 410

- 20 - 20 - 20 10 20 10 30 20 30 30 50 50 60

2800 270 270 270 270 270 270 410 410

10 30 10 30 20 30 20 40 30 40 30 50 50 70 70 80

3000 270 270 270 270 270 270 410 410

20 40 30 40 30 50 30 50 40 60 50 70 70 80 90 100

3200 270 270 270 270 270 410 410

40 50 40 60 40 60 50 60 60 70 70 80 90 100

3400 270 270 270 270 410 410 420

50 70 50 70 60 80 60 80 70 90 80 100 110 130

3600 270 270 410 410 410 410 490

60 80 70 90 70 90 80 100 90 110 100 120 130 150

3800 270 410 410 410 410 410

80 100 90 100 90 110 100 120 110 130 120 140

4000 410 410 410 410 410 450

100 110 100 120 110 130 120 140 130 150 150 160

4200 410 410 410 410 430 510

110 130 120 140 130 150 140 160 150 170 170 190

4400 410 410 410 410 490

130 150 140 160 150 170 160 180 180 200

4600 410 410 410 430

150 170 160 180 170 190 180 200

4800 410 430 440

170 190 190 200 200 210

5000 430

200 220

5200




2800300 300 300 300 300 300 300 450

- 20 - 20 10 20 10 30 10 30 20 40 30 50 50 60

3000300 300 300 300 300 300 450 450

10 30 20 30 20 30 20 40 30 40 30 50 50 70 60 80

3200300 300 300 300 300 300 450 450

20 40 30 40 30 50 30 50 40 60 50 60 70 80 80 100

3400300 300 300 300 300 450 450

40 50 40 60 40 60 50 60 60 70 60 80 80 100

3600300 300 300 300 450 450 450

50 60 50 70 60 70 60 80 70 90 80 100 100 120

3800300 300 450 450 450 450 510

60 80 70 80 70 90 80 90 90 100 100 110 120 140

4000300 450 450 450 450 450

80 90 80 100 90 100 90 110 100 120 120 130

4200450 450 450 450 450 470

90 110 100 120 100 120 110 130 120 140 140 150

4400450 450 450 450 450 530

110 130 120 130 120 140 130 150 140 160 160 170

4600450 450 450 450 510 600

130 140 130 150 140 160 150 170 160 180 180 N/A

4800450 450 450 470 570

140 160 150 170 160 180 170 190 190 200

5000450 450 490 510

160 180 170 190 180 200 190 210

5200490 490

180 200 190 210

5400500

200 220

5600



3000 350 350 350 350 350 350 350 520

- - - - - 10 - 10 - 10 - 20 10 30 20 40

3200 350 350 350 350 350 350 350 520

- 10 - 20 - 20 - 20 10 30 10 30 20 40 40 60

3400 350 350 350 350 350 350 520

- 20 10 30 10 30 10 30 20 40 20 40 40 60

3600 350 350 350 350 350 520 520

10 30 20 40 20 40 20 40 30 50 40 60 50 80

3800 350 350 350 350 520 520 520

30 50 30 50 30 50 40 60 40 70 50 70 70 90

4000 350 350 350 350 520 520 520

40 60 40 60 50 70 50 70 60 80 70 90 90 110

4200 350 350 520 520 520 520

50 70 60 80 60 80 70 90 70 100 80 110

4400 350 520 520 520 520 520

70 90 70 90 80 100 80 100 90 110 100 120

4600 520 520 520 520 520 520

80 100 90 110 90 110 100 120 110 130 120 140

4800 520 520 520 520 520 570

100 120 100 120 110 130 110 140 130 150 140 160

5000 520 520 520 520 560 630

110 130 120 140 120 150 130 150 150 170 160 180

5200 520 520 520 550 600

130 150 140 160 140 170 150 170 170 190

5400 520 530 560 590

150 170 150 180 160 180 170 190

5600 540 570 610

160 190 170 200 180 200

5800 580 620

180 210 190 220

6000


7. Construction

7.1 Safety is available in long lengths, so large areas can be quickly

and easily covered to form a safe working platform during construction. One level of formwork gives immediate protection from the weather, and safety to people working on the floor below. The minimal propping requirements provide a relatively open area to the floor below.

It is common sense to work safely, protecting yourself and work mates

as personal protection of eyes and skin from sunburn, and hearing from noise. For personal safety, and to protect the surface finish of

, wear clean dry gloves. Don’t slide sheets over rough surfaces or over each other. Always carry tools, don’t drag them.

Occupational health and safety laws enforce safe working conditions in most locations. Local laws may require you to have fall protection which includes safety mesh, personal harnesses and perimeter guard rails where they are appropriate. We recommend that you adhere strictly to all laws that apply to your State.

is capable of withstanding temporary construction loads including the mass of workmen, equipment and materials as specified in Section 3.0 of this manual. However, it is good construction practice to ensure protection from concentrated loads, such as barrows, by use of some means such as planks and/or boards.

7.2 Installation is delivered in strapped bundles. If not required for

immediate use stack sheets or bundles neatly and clear of the ground, on a slight slope to allow drainage of water. If left in the open, protect with waterproof covers.

Figure 7.1Typical layout

Bearing of LYSAGHT W-DEK(Not less than 100 mm

where sheeting iscontinuous)

Cover

Bearing of LYSAGHT W-DEK(Not less than 50 mm

at end of sheets)

LYSAGHT W-DEK

Concrete slab

p

Props whererequired

Slab span(Interior span)

Props whererequired

Slab spanEnd span)

Cover


7.2.1 ProppingIt is a common practice to specify unpropped formwork, however, depending on the span of a slab, temporary propping may be needed between the slab supports to prevent excessive deflections or collapse of the formwork.

formwork is normally placed directly on prepared propping. Props must stay in place during the laying of formwork, the placement of the concrete, and until the concrete has reached the strength of 15 MPa.

Propping generally consists of substantial timber or steel bearers supported by vertical props. The bearers must be continuous across the full width of LYSAGHT W-DEK formwork.

Propping must be adequate to support construction loads and the mass of wet concrete. Maximum propped and unpropped spans are given in Section 3.3.

7.2.2 Laying must be laid with the sheeting ribs aligned in the

direction of the designed spans. Other details include the following:

sheets continuously over each slab span without any intermediate splicing or jointing.

sheets end to end. Centralise the joint at the slab supports. Where jointing material is required the sheets may be butted against the jointing material.

sheets across their full width at the slab support lines and at the propping support lines.

the minimum bearing is 50 mm for ends of sheets, and 100 mm for intermediate supports over which the sheeting is continuous.

7.2.3 Interlocking the SheetsOverlapping ribs of sheeting are interlocked.

Place the female lap rib overlapping the male lap rib of the first sheet at an approximately 45º angle to the one previously laid, and then simply lower it down, through an arc (see Figure 7.2) until the laps engage.

If sheets don’t interlock neatly (perhaps due to some damage or distortion from site handling or construction practices) use screws to pull the laps together tightly (see Section 7.2.6, Fastening side-lap joints).

Position LYSAGHT W-DEK sheet at a 45º angle. Interlock sheets by lowering female lap of sheet over male lap through an arc.

Figure 7.2Method of interlocking adjacent sheets


7.2.4 Securing the Platform

Once laid, provides a stable working platform. shall be fixed to supporting structure at all permanent and temporary

supports with screws or nails or equivalent. Where additional security is needed you can use:

Take care if you use penetrating fasteners (such as screws and nails) because they can make removal of the props difficult, and perhaps result in damage to the

7.2.5 Installing LYSAGHT W-DEK on Steel Frames

may be installed directly on erected structural steel works.

General fastening of LYSAGHT W-DEK

The sheeting shall be fixed to the structural steel using spot welds, or fasteners such as self-drilling screws or equivalent.

Place the fixings (fasteners and spot welds) in the flat areas of the pans adjacent to the ribs or between the flutes. The frequency of fixings depends on wind or seismic conditions and good building practice. However at least one fastener per pan shall be provided at all supports.

Use one of the fixing systems as appropriate.

with self-drilling screws or spot welds or equivalent.

hexagon head screws or equivalent.

hexagon head screws or equivalent.

welded must be free of loose material and foreign matter. Where the LYSAGHT W-DEK soffit or the structural steel works has a pre-painted surface, securing methods other than welding may be more appropriate. Take suitable safety precautions against fumes during welding zinc coated products.

Fastening composite beamsStud welding through the sheet has been considered a suitable securing

fixing by one of the methods mentioned above is necessary to secure the sheeting prior to the stud welding. Some relevant welding requirements are:

scale, rust, moisture, paint, over spray, primer, sand, mud or other contamination that would prevent direct contact between the parent material and the

sheets, special welding procedures

Figure 7.3Positions for fixing to steel framing

Fixing at sheeting supports

10-24x16mm hex. head self-drilling screw, midwaybetween embossments.

Figure 7.4Fixing at a side lap


7.2.6 Fastening Side lap joints If sheeting has been distorted in transport, storage or erection, side-lap joints may need fastening to maintain a stable platform during construction, to minimise concrete seepage during pouring, and to gain a good visual quality for exposed soffits (Figure 7.4).

7.2.7 Fitting accessories for EDGE FORMEDGE FORM is a simple C-shaped section that simplifies the installation of most slabs. It is easily fastened to the sheeting, neatly retaining the concrete and providing a smooth top edge for quick and accurate screeding. We make it to suit any slab thickness.

EDGE FORM is easily spliced and bent to form internal and external corners of any angle and must be fitted and fully fastened as the sheets are installed. There are various methods of forming corners and splices. Some of these methods are shown in Figures 7.5 and 7.6.

Fasten EDGE FORM to the underside of unsupported panels every 350mm. The top flange of EDGE FORM must be tied to the ribs every 700mm with hoop iron 25mm x 1.0mm (Figures-7.7). Use 10–16 x 16mm self-drilling screws.

Tie top flange of EDGE FORM,to LYSAGHT W-DEK ribs, with hoop iron,every 700 mm maximum.

Fastening positions

Fasten EDGE FORM to the undersideof unsupported LYSAGHT W-DEK at 350 mm maximum centres.

EDGE FORM

LYSAGHT W-DEK

LYSAGHT W-DEK

EDGE FORM

Hoop iron

EDGE FORM

Hoop iron

Fastening bottom flange of EDGE FORM

Fastening top flange of EDGE FORM

Figure 7.5Typical fastening of EDGE FORM to


7.2.8 Sealing Seepage of water or fine concrete slurry can be minimised by following common construction practices. Generally gaps are sealed with waterproof tape or by sandwiching contraction joint material between the abutting ends of sheet. If there is a sizeable gap you may have to support the waterproof tape. (Figure 7.8).

External corner

Internal corner

Splicing two pieces

1. Notch top flange for the required angle

2. Cut 'V' in bottom flange

3. Bend corner of EDGE FORM to the required angle, overlapping bottom flanges.

1. Cut top and bottomflanges square.

1. Cut-back top and bottom flanges of one EDGE FORM section approximately 200mm.2. Cut slight taper on web.3. Slide inside adjoining EDGE FORM, and fasten webs with at least 2 screws

2. Bend EDGE FORM to required angle.

3. Fasten top flange, each side of corner, to LYSAGHT W-DEK rib, 100mm maximum from corner.

Figure 7.8Use waterproof tape to seal joints in sheets and end capping to seal ends

EDGE FORMA galvanised section that creates a permanentformwork at the slab edges—cut, mitred andscrewed on site. Stock length: 6100 mm

Brackets from hoop iron

Figure 7.7Fabrication accessories for

Figure 7.6Fabrication of formwork is easy with

Lysaght W-Dek Design & Construction Manual 2009 3535

Figure 7.9Zones for location of items embedded in slabs

7.2.9 Items Embedded in SlabsIncluded are pipes and conduits, sleeves, inserts, holding-down bolts,chairs and other supports, plastic strips for plasterboard attachment,contraction joint material and many more.

Location of items within the slab (Figure 7.9)

Minimise the quantity and size of holes through sheeting,by hanging services from the underside of .

LYSAGHT W-DEK

Top-face reinforcement

Bottom-face reinforcement

Zones for pipes and other itemslaid parallel with the ribs

Zone for pipes laid across the ribs(between top and bottom reinforcement)

Concrete

7.2.10 Holes acts as longitudinal tensile reinforcement similarly

to conventional bar or fabric reinforcement does in concrete slabs.Consequently, holes in sheets, to accommodate pipesand ducts, reduce the effective area of the steel sheeting and canadversely effect the performance of a slab.

Some guidelines for holes are (Figure 7.10):

distance of 15 mm from the rib gap.

support of the slab less than one tenth of a clear span.

Zone for holes throughsheet in central pan

Max. diameter 110 mm

15 mmminimum

Ln

Location of holes relative tosupports in continuous slabs

Location of holes in sheet

Interior supports

Zone for holesin continuous slabs

Minimum0.1 Ln

Minimum0.1 Ln

Figure 7.10Zones for location of holes through .


Concretecover

LYSAGHT W-DEK

Barreinforcement

Dept

h of

com

posi

te s

lab

Meshreinforcement

(fabric)sheeting

Transverse wires of mesh

Figure 7.11Typical cross-section of a slab showing common termsFor fire reinforcement requirements, see Figure 5.2.

7.3.1 Transverse Reinforcement

Transverse reinforcement is placed at right-angles to the ribs of . Deformed bar or fabric reinforcement may be used. In most

applications the transverse reinforcement is for the control of crackscaused by shrinkage and temperature effects, and for locating longitudinalreinforcement

To control flexural cracking in the top face of the slab, transversereinforcement in the top-face may be required over walls or beams whichrun in the same direction as the sheets.

For ease of construction, reinforcement for control of cracking due toshrinkage and temperature is usually fabric reinforcement.

7.2.11 InspectionWe recommend regular qualified inspection during the installation, to be sure that the sheeting is installed in accordance with this publication and good building practice.

7.2.12 CuttingIt is easy to cut sheets to fit. Use a power saw fitted with an abrasive disc or metal cutting blade. Initially lay the sheet with its ribs down, cut through the pans and part-through the ribs, then turn over and finish by cutting the tops of the ribs.

7.3 Reinforcementsheeting acts as longitudinal tensile reinforcement.

The condition of sheeting should be inspected before concrete is poured.

Reinforcement in slabs carries and distributes the design loads and controls cracking. Reinforcement is generally described as transverse and longitudinal in relation to span, but other reinforcement required for trimming may be positioned in other orientations. Figure 7.11 shows a typical cross-section of a composite slab and associated terms.

Reinforcement must be properly positioned, lapped where necessary to ensure continuity, and tied to prevent displacement during construction. Fixing of reinforcement shall be in accordance with AS 3600 - 2001 Clause 19.2.5.

To ensure the specified minimum concrete cover, the uppermost layer of reinforcement must be positioned and tied to prevent displacement during construction.

Where fabric is used in thin slabs, or where fabric is used to act as both longitudinal and transverse reinforcement, pay particular attention to the required minimum concrete cover and the required design reinforcement depth at the splices—splice bars are a prudent addition.

Always place chairs and spacers on pan areas. Depending upon the type of chair and its loading, it may be necessary to use plates under chairs to protect the , particularly where the soffit will be exposed. Transverse reinforcement may be used for spacing or supporting longitudinal reinforcement.

37Lysaght W-Dek Design & Construction Manual 2009

7.3.2 Longitudinal ReinforcementLongitudinal reinforcement is positioned to carry design loads in the same direction as the ribs of . Deformed bar or fabric reinforcement may be used.

Top-face longitudinal reinforcement is usually located over interior supports of the slab and extends into approximately a third of the adjoining spans.

Bottom-face longitudinal reinforcement is located between supports of the slab but, depending upon the detailing over the interior supports, it may be continuous, lapped, or discontinuous. Bottom-face longitudinal reinforcement may be placed on top of or below transverse reinforcement.

Location of top and bottom-face longitudinal reinforcement in elevated temperatures requires special design. (Figure-5.2)

7.3.3 TrimmersTrimmers are used to distribute the design loads to the structural portion of the slab and/or to control cracking of the concrete at penetrations, fittings and re-entrant corners. Deformed bar or fabric reinforcement may be used.

Trimmers are sometimes laid at angles other than along or across the span, and generally located between the top and bottom layers of transverse and longitudinal reinforcement. Trimmers are generally fixed with ties from the top and bottom layers of reinforcement.

7.4 Concrete 7.4.1 Specification The concrete is to have the compressive strength as specified in the project documentation and the materials for the concrete and the concrete manufacture should conform to AS 3600 - 2001.

7.4.2 Concrete AdditivesAdmixtures or concrete materials containing calcium chloride or other chloride salts must not be used. Chemical admixtures including plasticisers may be used if they comply with AS 3600 - 2001 Clause 19.

7.4.3 PreparationBefore concrete is placed, remove any accumulated debris, grease or any other substance to ensure a clean bond with the sheeting. Remove ponded rainwater.

7.4.4 Construction JointsIt is accepted building practice to provide construction joints where a concrete pour is to be stopped. Such discontinuity may occur as a result of a planned or unplanned termination of a pour. A pour may be terminated at the end of a day’s work, because of bad weather or equipment failure. Where unplanned construction joints are made, the design engineer must approve the position.

In certain applications, the addition of water stops may be required, such as in roof and balcony slabs where protection from corrosion of reinforcement and sheeting is necessary.

Construction joints transverse to the span of the sheetingare normally located at the mid-third of a slab span) and ideally over a line of propping. Locate longitudinal construction joints in the pan (Figure 7.12).

It may be necessary to locate joints at permanent supports where sheeting terminates. This is necessary to control formwork deflections since formwork span tables are worked out for UDL loads.

Form construction joints with a vertical face—the easiest technique is to sandwich a continuous reinforcement between two boards.


Concrete

LYSAGHT W-DEKProp

Form boards sandwichingcontinuous reinforcement.Lower board shaped to match LYSAGHT W-DEK profile

Concrete

Form boards sandwichingcontinuous reinforcement.

Transverse construction joint

Longitudinal construction joint

It may be necessary to locate joints at permanent supports where sheeting terminates to control formwork deflections.

Figure 7.12Typical construction joint

7.4.5 PlacingThe requirements for the handling and placing of the concrete are covered in AS 3600 - 2001 Clause 19.1.3.

The concrete is placed between construction joints in a continuous operation so that new concrete is placed against plastic concrete to produce a monolithic mass. If the pouring has to be discontinued for more than one hour, depending on the temperature, a construction joint may be required.

Start pouring close to one end and spread concrete uniformly, preferably over two or more spans. It is good practice to avoid excessive heaping of concrete and heavy load concentrations. When concrete is transported by wheel barrows, the use of planks or boards is recommended.

During pouring, the concrete should be thoroughly compacted, worked around ribs and reinforcement, and into corners of the by using a vibrating compacter. Ensure that the reinforcement remains correctly positioned so that the specified minimum concrete cover is achieved.

Unformed concrete surfaces are screeded and finished to achieve the specified surface texture, cover to reinforcement, depths, falls or other surface detailing.

Surfaces which will be exposed, such as and exposed soffits, should be cleaned of concrete spills while still wet, to reduce subsequent work.

Prior to recommencement of concreting, the construction joint must be prepared to receive the new concrete, and the preparation method will depend upon the age and condition of the old concrete. Generally, thorough cleaning is required to remove loose material, to roughen the surface and to expose the course aggregate.


7.4.6 Curing

After placement, the concrete is cured by conventional methods, for example, by keeping the slab moist for at least seven days, by covering the surface with sand, building paper or polythene sheeting immediately after it has been moistened with a fine spray of water. Follow good building practice. Be particularly careful when curing in very hot or very cold weather.

Until the concrete has cured, it is good practice to avoid concentrated loads such as barrows and passageways with heavy traffic.

7.4.7 When to Remove Props

Various factors affect the earliest time when the props may be removed and a slab initially loaded. Methods of calculating times and other guides are given in AS-3610—1995, Clause 5.4.3

7.5 Finishing

7.5.1 Soffit and EDGE FORM Finishes

For many applications, gives an attractive appearance to the underside (or soffit) of a composite slab, and will provide a satisfactory ceiling — for example, in car parks, under-house storage and garages, industrial floors and the like. Similarly, will give a suitable edging. Additional finishes take minimal extra effort.

Where the soffit is to be the ceiling, take care during construction to minimise propping marks (refer to Installation — Propping),and to provide a uniform surface at the side-laps (refer to Installation — Fastening Side-lap joints).

Exposed surfaces of soffit and may need cleaning and/or preparation for any following finishes.

7.5.2 Plastering

Finishes such as vermiculite plaster can be applied directly to the underside of with the open rib providing a positive key. With some products it may be necessary to treat the galvanised steel surface with an appropriate bonding agent prior to application.

Plaster-based finishes can be trowelled smooth, or sprayed on to give a textured surface. They can also be coloured to suit interior design requirements.

7.5.3 Change of Floor Loadings

Where a building is being refurbished, or there is a change of occupancy and floor use, you may need to increase the fire resistance of the

composite slabs. This may be achieved by the addition of a suitable fire-protection material to the underside of the slabs.


7.6 Suspended Ceilings and Services7.6.1 PlasterboardA soffit may be covered with plasterboard by fixing to battens.

Fixing to battensSteel ceiling battens can be fixed directly to the underside of the slab using powder-actuated fasteners. The plasterboard is then fixed to ceiling battens in the usual way (Figure-7.13).

Plaster board

Concrete

Batten

Figure 7.13Fixing plasterboard to

7.6.2 Suspended Ceiling Ceilings are suspended from hangers attached to eyelet pins power driven into the underside of the slab.

7.6.3 Suspended ServicesServices such as fire sprinkler systems, piping and ducting are easily suspended from slabs using traditional installation methods to support these services.


8. Composite BeamsResearch by BlueScope Lysaght Technology, University of Sydney and University of Western Sydney was conducted to determine the design parameters of composite beams with .

Primary and secondary composite beams can be designed in accordance with AS 2327.1 provided the following design rules are followed:

in the haunch in the primary composite beams. Refer to Figure 8.1. Contact Steel Direct for more information.

secondary composite beams) shall be used. Refer to Figure 8.2.

composite beams).

at 300mm spacing on tops of ribs.

beams provided minimum overhang is 600 mm, alternatively follow AS2327.1 requirements

Primary beams can be designed as continuous - prEN1994-1-1 or BS5950-3.1:1990 should be followed.

8.1 Shear Stud Capacities120mm long shear studs (115mm after welding) with 19mm nominal shank diameter shall be used. Capacities of shear studs in primary beams with single rows of studs (see Figure 8.1) shall be determined without applying reduction factors. Contact Steel Direct for reinforcement options and capacity of studs when two rows of studs are necessary and capacity of shear studs in secondary beams.


Steel beam

Mesh reinforcement orequivalent

Staggered single shear studs

Bar reinforcement

Staggered pairs of studs

Alternate location of single studs

Figure 8.1Primary beams

Slab reinforcement

LYSAGHTW-DEK

LYSAGHTW-DEK 240mm

150mm

9.5mm

7.5mm

19mm stud x 115mm high after welding(may be single studs as shown or

pairs of 60 - 80mm transverse centres)

HAUNCHMESH - STRAIGHTSupported directly on top of LYSAGHT W-DEK and placed

centrally in haunch.

Haunch and studs not necessarily centred over steel beam (omitted for clarity).

HaunchmeshHandlebar when necessary

Figure 8.2Shear stud position in secondary beam (alternate location - single studs)


9. References

Commentary

Section 3.1 Code of practice for design of simple and continuous composite beams

for buildings

Part 1-1 General rules and Rules for buildings

Part 1-2 General rules – Structural fire design

Disclaimer, warranties and limitation of liabilityThis publication is intended to be an aid for all trades and professionals involved with specifying and installing LYSAGHT products and not to be a substitute for professional judgement.Terms and conditions of sale available at local BlueScope Lysaght sales offices.Except to the extent to which liability may not lawfully be excluded or limited, BlueScope Steel Limited will not be under or incur any liability to you for any direct or indirect loss or damage (including, without limitation, consequential loss or damage such as loss of profit or anticipated profit, loss of use, damage to goodwill and loss due to delay) however caused (including, without limitation, breach of contract, negligence and/or breach of statute), which you may suffer or incur in connection with this publication.© Copyright BlueScope Steel Limited 9 March, 2009

Information, brochures and your local distributor

1800 641 417Please check the latest information which is always available at www.lysaght.comBLUESCOPE, LYSAGHT, LYSAGHT W-DEK, EDGE FORM, GALVASPAN & ZINCALUME are registered trademarks of BlueScope Steel Limited, ABN 16 000 011 058. THE LYSAGHT ® range of products is exclusively made by BlueScope Steel Limited trading as BlueScope Lysaght. Printed by BMP 1M0309

LYSAGHT W-DEK Design and Structural steel decking · PDF fileDesign and Structural steel decking system Construction Manual LYSAGHT W-DEK ® s/ptimised to bring greater efficiency,

Documents