Economic Long Span Concrete Floor Slabs









FOREWORD

This publication was commissioned by the Reinforced

Concrete Council.

The Group was set up in 1988 to promote better

knowledge and understanding of reinforced concrete design

and building technology.

Its members are Co-Steel Sheerness plc and Allied Steel

& Wire, representing the major suppliers of reinforcing steel

in the UK; and the British Cement Association, representing

the major manufacturers of Portland cement in the UK.

The authors of this publication are Peter Matthew, partner

with consulting engineers Powell, Tolner & Associates and

David Bennett, Senior Engineer in the Marketing Division

of the British Cement Association.

ACKNOWLEDGEMENTS

The authors wish to thank the following organizations for

their considerable help in providing the building data for

the survey:



Anthony Hunt/YRM Partnership

Beers

Bison Limited

Bunyan Meyer & Partners

Composite Structures Limited

DGI International plc

Ferguson & McIlveen

Frank Hodgson & Associates

James-Carrington and Partners

Jan Bobrowski and Partners

Ove Arup & Partners

Powell, Tolner & Associates

Skidmore, Owings & Merrill

Waterman Partnership

Thanks are also due to Brian Dyer of Tower Associates

for drafting the floor plans.





INTRODUCTION

Traditional concrete designs for office building have been

associated with either beam and slab or flat slab floors,

typically with 6 to 7.5 m spans. Occasionally, longer-span

floors have been designed using ribbed or waffle

construction. In recent times, changes in the requirements

of end-users and in developers’ specifications have led to

more open-plan offices and larger floors. This has

increased spans from 6 to 9 m, even to 15 m and more.

To verify the competitiveness of concrete long-span

floors, a survey has been conducted of concrete-framed

office buildings, the majority constructed in recent years.

Forty buildings of in situ, precast and composite

construction with long spans have been surveyed. In each

category, examples were found of floors designed in

reinforced and prestressed concrete to carry similar office

floor loadings.

For in situ structures, solid flat slabs and ribbed slab

designs were common, with spans varying from 6 to 15 m.

A number of precast structures with long spans, some

over 20 m, are reported, with composite in situ slabs acting

with precast ribs or other precast members.



Download

*