ULTIMATE STRENGTH OF R• C. FLAT SLABS

Abstract

The design procedure for reinforced concrete members has been the subject of continuous discussion since the devolopm.nt of reinforced concrete as a material for construction.. These days the method of plastic. design is gaining importance. because of the fact that it gives economy both, in material and in designer's time! It also gives a, true ides of the factor of safety because the behaviour of the rein-forced concrete is not elastic upto failure. The yield line theory is a method for the inelastic analysis of the reinforced concrete slabs. This theory has been applied to the analysis of flat slabs in this volume,. For the yield line analysis various possible crack patterns have been assumed and the pattern which gives the lowest load is considered as a true pattern because the yield line theory gives the upperbound solution of the problem. Empirical design methods are also discussed in this volume. Results of the test of a nine (3 x 3) panel flat slab structure tested to failure are reported and Ore compared with the theoretical results. Test results show the presence of membrane action in • iv the slab before collapse which is neglected in yield line theory. Thus the slab cafl take more load than that predicted by yield line theory. A method has also been given to calculate the deflection at the ultimate load . Theoretical deflections have been compared from the measured deflections.