Evaluation of the UK and USA codes of practice for reinforced concrete slab design

After an introductory Chapter on slabs, the broad design provisions of the British and American Codes of Practice are set out A historical review of elastic and ultimate load methods of slab design together with examples is then followed by a discussion on loads, load factors, material factors, patterns of loading and the division of slabs into various strips. Three extensive chapters with examples on the use of the Codes of Practice examine and discuss the provisions and behaviour of slabs on rigid and semi-rigid supports and flat slabs supported by columns. The results of an extensive elastic finite element investigation are compared with the various methods available for the design of the three types of slabs under both serviceability and ultimate conditions. In Chapter 5 on rigidly supported slabs it is concluded that for the British Code the ultimate load recommendations are satisfactory but that in general the moment coefficients recommended require considerable negative moment redistribution and in some cases by considering the finite element results the steel must almost be yielding under the serviceability loads. With one exception the American code is better from the serviceability condition aspect but the simply supported slab bending moment coefficients would cause premature failure. Chapter 6 on slabs on semi-rigidly supported slabs indicates the British code is sadly deficient on design information for this type of slab while the American code gives proposals which give answers which are broadly in agreement with the finite element analysis. Chapter 7 on flat slabs shows that both the British and American codes are reasonably satisfactory both from the serviceability and ultimate conditions. The final Chapter highlights areas which need attention and make some suggestions for further study.