Smorgan ARC - Transfloor Design Manual PDF

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Smorgon ARC-Transfloor™ Design Manual

Your guide to faster floors

Se r vi ce r e i nfor ce d by e xp e r i e nce .

Smorgon ARC is a Division of The Australian Steel Company (Operations) Pty Ltd ABN 89 069 426 955 Smorgon ARC National Office 528 Ballarat Road Sunshine 3020 Australia Copyright© Smorgon ARC 1999 First published 1998 Second Edition 2001 All rights reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without the prior written permission of Smorgon ARC. Every attempt has been made to trace and acknowledge copyright but in some cases this has not been possible. The Publishers apologise for any accidental infringements and would welcome any information to redress the situation. Transfloor™ is a trademark of Smorgon ARC. The information and illustrations in this publication are provided as a general guide only. The publication is not intended as a substitute for professional advice which should be sought before applying any of the information to particular projects or circumstances. In the event of purchase of goods to which this publication relates, the publications does not form part of the contractual arrangements with Smorgon ARC. The purchase of any goods is subject to the Smorgon ARC terms and conditions of sale. Smorgon ARC reserves the right to alter the design or discontinue any of its goods or services without notice. Whilst every effort has been made to ensure the accuracy of the information and illustrations in this publication, a policy of continual research and development necessitates changes and refinements which may not be reflected in this publication. If in doubt please contact the nearest Smorgon ARC sales office.

Transfloor™ Precast Flooring System

Preamble This Technical Manual has been prepared by Smorgon ARC to facilitate the design of suspended concrete slabs covering a wide range of applications using the Transfloor™ flooring system. It is intended to be used as a technical guide for construction loading and it is a requirement of use that any designs prepared using this Technical Manual be examined and verified by a competent and qualified structural engineer. The manual contains comprehensive data on the properties of Transfloor™ trusses and describes some of the typical details required to achieve an equivalent monolithic slab. The procedures are based on established design methods and material properties for conventional steel reinforced concrete structures. Design criteria relating to bending, shear capacity, anchoring of reinforcement, transverse reinforcement, support conditions and any general design and construction procedures shall be referred to and approved by an industry registered structural design engineer.

Transfloor™ Precast Flooring System

Contents 1.0

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

2.0

The Transfloor™ System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

3.0

Advantages and applications. . . . . . . . . . . . . . . . . . . . . . . . . . . 3

4.0 4.1 4.2 4.3 4.4 4.5

Material and product specifications . . . . . . . . . . . . . . . . . . . . . . 5 Reinforcement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Panel concrete. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Polystyrene void formers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Topping concrete . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Truss Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

5.0 5.1 5.2 5.3 5.4 5.5 5.6 5.7 5.8

Design principles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Design for bending . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Precast in-situ interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Vertical shear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Load distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Durability requirements and fire rating . . . . . . . . . . . . . . . . . . . . 9 Support conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Design for construction loads . . . . . . . . . . . . . . . . . . . . . . . . . 11 Deflection during construction. . . . . . . . . . . . . . . . . . . . . . . . . 13

6.0

Final slab design. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

7.0 7.1 7.2 7.3 7.4

Seismic conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Structural integrity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Diaphragm action . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Detailing requirements for seismic loads . . . . . . . . . . . . . . . . . 17 Slab and band beam systems. . . . . . . . . . . . . . . . . . . . . . . . . 17

8.0 8.1 8.2 8.3 8.4 8.5 8.6 8.7

Manufacture and installation . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Manufacture. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Delivery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Lifting and placing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Services and edge forms . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 Top reinforcement and in-situ concrete . . . . . . . . . . . . . . . . . . 20 Ceiling finish. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

9.0 9.1 9.2 9.3 9.4

Transfloor bridge decking . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Design details . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Load distribution - panel to panel connection. . . . . . . . . . . . . . 23 Bearing of bridge deck panels. . . . . . . . . . . . . . . . . . . . . . . . . 24 Construction practice for bridge decks . . . . . . . . . . . . . . . . . . 25

10.0

References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

11.0

Appendices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 Appendix A - Typical construction details for multi-level building . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 Appendix B Design Examples Estimate Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 Detailed Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 Appendix C Transpan™ Transfloor™ design software output . . 44 Appendix D Construction practice . . . . . . . . . . . . . . . . . . . . . . 54 Appendix E Quotation checklist. . . . . . . . . . . . . . . . . . . . . . . . 56

Further Information For further technical information regarding Transfloor™, contact our sales Engineers or technical representatives at Smorgon ARC. For contact details, refer to back cover. Transfloor™ Precast Flooring System

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 suspended 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.

ADJUST NUMBER AND TYPE OF TRUSSES TO SUIT CONSTRUCTION LOADS. 5 TRUSSES IS THE PRACTICAL MINIMUM FOR 2500 WIDE PANEL. FOR SLABS WITHOUT VOIDS ABOUT 18 TRUSSES ARE POSSIBLE. USE MAXIMUM 8 TRUSSES IN VOIDED SLABS.

MAX. PANEL WIDTH - 2500 (TRANSPORT LIMITATION). LESSER WIDTHS AS REQUIRED TO FIT JOB DIMENSIONS, BUT MAXIMISE THE NUMBER OF FULL WIDTH PANELS TO SECURE BEST ECONOMY.

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 ANY LENGTH PANEL CAN BE SUPPLIED. MAXIMUM 12M FOR EASE OF TRANSPORT.

120 MINIMUM RIB AT INTERNAL TRUSS. FILLED WITH IN-SITU CONCRETE. 180 MINIMUM RIB AT EDGE TRUSSES

LENGTH OF VOID ADJUSTED TO SATISFY END SHEAR REQUIREMENTS. PANEL CONCRETE THICKNESS 50 MINIMUM. VARY THICKNESS TO SUIT (EG. EXTRA COVER, DIAMETER BARS ETC.)

PANEL FABRIC RF62 MINIMUM. HEAVIER IF REQUIRED BY DESIGN.

POLYSTYRENE VOID FORMERS (OF ANY CROSS-SECTION) 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 Activity

Labour

Transfloor™ System Day/s

Hours

Activity

Labour

Day/s

Hours

Erect & prop wall panels

2 Dogman 2 Labourers

1 1

16 16

Erect and prop wall panels

2 Dogman 2 Labourers

1 1

16 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 2 Labourers

3 3

96 48

Place Transfloor™ panels

2 Dogman 2 Carpenters

1 1

16 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 Scaffolders

2 2

64 32

Remove propping frames

2 Scaffolders

1

16

Total Cycle (approximate hours) Typical Cycle

464 0.62 hrs/m

2

Total Cycle (approximate hours) Typical Cycle

216 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 Figure 4: Column penetration in Transfloor™ panel

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

Figure 5: Transfloor™ on load bearing block walls

4. After approval has been obtained for dimensional accuracy and engineering integrity, the panels are produced and delivered to site at a time 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 satisfactory 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

Generic Truss Reference

Truss specifications

Smorgon ARC Product Code

Top Chord Diameter

Height (H) (mm)

Mass (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
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