Fourth Edition GROUND FLOORS

1 34 CONCRETE INDUSTRIAL GROUND FLOORSA guide to design and constructionTechnical Report 34 Fourth EditionTechnical Report 34 Fourth Edition Concrete Industrial GROUND FloorsThe Concrete Society TR 34: Concrete Industrial GROUND FLOORS - Fourth EditionPublished by The Concrete SocietyISBN 978-1-904482-77-2 The Concrete SocietyFirst published August 2013, Reprinted June 2014 and March 2016 (with amendments and an additional Appendix).The Concrete SocietyRiverside House, 4 Meadows Business Park, Station Approach, Blackwater, Camberley, Surrey GU17 9AB Tel: +44 (0)1276 607140 Fax: +44 (0)1276 607141 publications in this series are available from the Concrete Bookshop at: Te l : +44 (0)7004 607777 All rights reserved. Except as permitted under current legislation no part of this work may be photocopied, stored in a retrieval system, published, performed in public, adapted, broadcast, transmitted, recorded or reproduced in any form or by any means, without the prior permission of the copyright owner.

2 Enquiries should be addressed to The Concrete The Concrete Society does its best to ensure that any advice, recommendations or information it may give either in this publication or elsewhere is accurate, no liability or responsibility of any kind (including liability for negligence) howsoever and from whatsoever cause arising, is accepted in this respect by the Group, its servants or should note that publications are subject to revision from time to time and should therefore ensure that they are in possession of the latest by Short Run Press Ltd, revised guidance document was prepared by a Concrete Society Project Steering Committee and Design sub-group, consisting of: Project Steering CommitteeK Louch Stanford Industrial Concrete Flooring (chair)R Day The Concrete Society (secretariat)T Hulett Face ConsultantsN Woods GHA Livigunn Consulting EngineersD Eddy Flat Floor ConsultingD Simpson The Concrete SocietyR Butler Winvic ConstructionD Horton McLaren ConstructionP Shaw formerly RPS Consulting EngineersJ Clayton RPS Consulting EngineersM Dalton ProLogis J West ProLogisM Jeffs GazeleyL Pettit Bericote PropertiesDesign sub-groupT Hulett Face Consultants (chair)R Day The Concrete Society (secretariat)K Louch Stanford Industrial Concrete Flooring LtdN Woods GHA LivigunnP Shaw formerly RPS Consulting EngineersJ Clayton RPS Consulting EngineersC Sketchley Sketchley AssociatesK Bent Sprigg Little PartnershipM Graham HydrockP Ridge FairhurstThe Concrete Society recognises the initial contribution from John Clarke (Concrete Society, retired), Stuart Alexander (formerly of WSP Group)

3 To the Discussion Document published as part of this projects development and Ryan Griffiths (Eastwood Partnership, formerly of Face Consultants) for his input to the Design sub-group. Also Kevin Dare (CoGri Group) for his analysis and proposed revisions to floor surface Concrete Society acknowledges the significant time in kind given by all those numerous individuals and companies involved in bringing the Fourth Edition to Concrete Society wishes to thank the Association of Concrete Industrial Flooring Contractors (ACIFC) for their assistance and the following companies who sponsored this revision and contributed financial support from the outset of the Brymar FloorsCoGri GroupFace ConsultantsFairhurstGHA Livigunn Consulting EngineersLafarge TarmacMalin Industrial Concrete FloorsPeikko GroupPermabanSnowden-Seamless FloorsSomero EnterprisesStanford Industrial Concrete FlooringTw i nte c 34 CONCRETE INDUSTRIAL GROUND FLOORSA guide to design and constructionTechnical Report 34 Fourth Edition iiConcrete Industrial GROUND FLOORS 4th IFCP reface ivGlossary of terms and abbreviations vUnits and symbols vii1 Introduction Scope Changes in Fourth Edition Design Maintenance Design and specification 22 Floor surfaces Abrasion resistance Chemical resistance Slip resistance

4 Colour and appearance Cracking Crazing Curling Delamination Surface aggregate Surface fibres 53 Surface regularity Departure from datum Free and defined-movement Surface regularity in free-movement areas Choosing the free-movement floor classification Properties measured Surveying Surface regularity in defined-movement areas Choosing the defined-movement floor classification Survey practice for all floor types Change of floor flatness with time 104 Warehouse equipment and floor loadings Load type Warehouse equipment static loads Mobile pallet racking Live storage systems Drive-in racking Push-back racking systems Cantilever racks Mezzanines Clad rack structures Warehouse equipment dynamic loads Pallet trucks Counterbalance trucks Reach trucks Front and lateral stackers (VNA trucks) Articulated counterbalance trucks Stacker cranes 155 Soils and support structures Soil investigation Subgrade Sub-base Membranes Slabs on insulation Design model for a GROUND -supported slab Design model for a pile-supported floor Pile head construction 186 Design structural properties Concrete Flexural tensile strength Reinforcement Steel fibres and macro- synthetic fibres Micro- synthetic fibres Moment capacity Fabric-reinforced concrete Steel and macro- synthetic fibre-reinforced concrete Calculation of residual moment capacity from notched beam tests Moment capacity calculation methods Punching shear Shear at the face of the loaded area Shear on the critical perimeter Dowel capacities Conventional bar dowels and fabric Plate dowels Bursting forces Effect of steel and

5 Macro- synthetic fibres on bursting forces 267 Structural design of GROUND -supported slabs Introduction Partial safety factors for loads Fatigue effects of heavy dynamic loads Reinforcement requirements Radius of relative stiffness Bending moments for internal point loads Load locations Point loads Closely spaced point loads Design equations for single point loads Design equations for multiple point loads Load transfer at joints Load transfer by aggregate interlock Load transfer by dowels or bars Punching shear capacity and GROUND support GROUND support Line loads Uniformly distributed loads 338 Structural design of pile-supported slabs Introduction Partial safety factors for loads Fatigue effects of heavy dynamic loads Reinforcement requirements Pile heads and effective spans Design for flexure Folded plate - UDL Folded plate concentrated line load Punching shear Curtailment 38 iiiConcrete Industrial GROUND FLOORS 4th Design load conditions Construction joints Serviceability checks Deflection and cracking 429 Concrete specification Specification considerations Strength and related characteristics Concrete in cold store FLOORS Shrinkage and movement Drying shrinkage Early thermal contraction Plastic shrinkage Mix design for placing and finishing Consistence and finish Abrasion resistance Chemical resistance 4510 Concrete materials Cement Aggregate Mechanical performance Drying shrinkage Water-reducing admixtures Dry-shake toppings The importance of curing 4711 Construction and joints Construction methods Large area construction Long strip construction Wide bay construction Overlay construction Two-layer construction In-floor heating systems Post-tensioned

6 FLOORS Joints Joint types Free-movement joints Sawn free-movement joints Restrained-movement joints Sawn restrained-movement joints Formed restrained-movement joints Tied joints Isolation joints Performance of sawn and formed joints Formed joints Armouring of joints Installation Joint layout Wire guidance systems Joint sealants Properties Joint sealants in new FLOORS Sealant application Joints in cold stores 5412 Design and construction best practice Preconstruction planning Construction Protection of a new floor Post-construction 5613 Maintenance Introduction Cleaning Cleaning frequency Cleaning materials Spillages Tyre marks Surface wear and damage Joints Joint inspection Joint sealant Joint deterioration Cracks Inspection and action schedule Applied coatings Textured surface Repair General tips and advice 59 References 60 Appendix A: Model design brief for concrete industrial GROUND - FLOORS 62 Appendix B: Chemical attack 64B1.

7 Introduction 64B2. Sulfates 64B3. Chlorides 64B4. Physical salt weathering 64B5. Acids and alkalis 64B6. Other substances 64 Appendix C: Rigorous assessment of moment capacity of fibre-reinforced section, with and without supplementary fabric or bar reinforcement 66 Appendix D: Derivation of dowel load transfer equations 68D1. Round dowel bars 68D2. Plate dowels of constant cross-section 68 Appendix E: Fatigue design check for MHE load repetitions on GROUND -supported FLOORS 69 Appendix F: Derivation of punching shear load reduction equation (by GROUND support) 71F1. To calculate radius b 71F2. To calculate GROUND pressure within critical perimeter 71F3. Additional reduction if load applied through a stiff bearing 72 Appendix G: Derivation of serviceability limit state equation for hmin in pile-supported slabs 73 Appendix H: Optimised Pile Layouts for Pile Supported FLOORS 75 Appendix I: Daily work activity check sheet 78 Advertisements 80 ivConcrete Industrial GROUND FLOORS 4th This is the Fourth Edition of Concrete Society Technical Report 34 Concrete industrial GROUND FLOORS .

8 TR34 is recognised globally as a leading publication giving guidance on many of the key aspects of concrete industrial GROUND FLOORS . Guidance on the design and construction of GROUND -supported concrete FLOORS was originally developed and published by the Cement and Concrete Association in the 1970s and 1980s. The first Edition of Technical Report 34 was published in 1988 and took account of the rapid development of new construction techniques and gave guidance on thickness design. The second (1994) Edition [1] and third Edition (2003)[2] continued to update this guidance to reflect current knowledge and practice. As with previous editions, this Fourth Edition is the result of a thorough review of all aspects of floor design and construction. Experience since 2003 suggests that GROUND -supported FLOORS constructed in accordance with TR34 have provided good performance. This experience has been based largely on steel fabric FLOORS with sawn joints and on jointless steel-fibre-reinforced GROUND -supported FLOORS .

9 Significantly, the design guidance in this Edition has been expanded to include comprehensive guidance on the design of pile-supported FLOORS . The Society acknowledges the support and assistance of its members and of the concrete flooring industry who have contributed to the preparation of this report, and also the help and comments provided by many individuals and companies, both in the UK and overseas. vConcrete Industrial GROUND FLOORS 4th of terms and abbreviationsKey terms and abbreviations are defined below. A list of the symbols and units used in the report Wearing of the concrete surface by rubbing, rolling, sliding, cutting or impact forces. Abrasion resistance The ability of the floor surface to withstand the abrasion produced by long-term use of the interlock Mechanism that transfers load across a crack in concrete by means of interlocking between irregular aggregate and cement paste surfaces on each side of the crack.

10 Armoured joint Steel protection to joint arrises. Bay Area of concrete defined by stacking Unit loads, typically pallet loads, paper reels or similar goods, stacked directly on a floor, usually one on top of another. Client The party who commissions the building and employs a principal contractor to build Change of length caused by shrinkage, temperature variation Pattern of fine, shallow random cracks on the surface of concrete. Curing Procedure to significantly reduce the early loss of moisture from the slab The tendency of slab edges to lift, caused by differential drying shrinkage with depth. Datum A reference point taken for surveying. Defect A feature causing obvious serviceability or structural issues that directly prevents safe and efficient use of the floor. Defined-movement area Narrow aisles in warehouses where materials handling equipment is move only in defined Elastic or creep deformation of the slab or its support under Debonding of a thin layer of surface joint A joint that opens wider than adjacent (typically dormant) joints in a sawn-jointed joint Sawn joint that does not open, usually because of failure of crack to form below the saw cut; generally associated with a dominant joint.