Yield Line and Membrane Action Of Slabs

Abstract

The objective of this research is to study the validity of the assumption in the yield line theory and reintroduce practical designers to use of yield line design. This work is intended to cover an investigation of two – way slabs .The support condition of these slabs were simply supported and fixed end, the reinforcement arrangement used is isotropic and orthotropic reinforcement. The yield line theory was used as the method of solution to obtain the ultimate load. To verify the analytical results experimentally, four rectangular twoway slabs subjected to concentrated load at the centre were tested. Data of the experimental work including deflection readings, and yield line patterns are presented. Experimental results are discussed and comparisons are made between the theoretical and experimental results. Finally conclusions are drawn and recommendations are presented. It is concluded that the difference between the experimental and theoretical failure load were small and mainly on the conservative side , a significant increase in load carrying capacity of fixed supported slabs (isotropic and orthotropic reinforcement) is due to compressive membrane action imposed by horizontal restraints. also similar yield line patterns for theoretical and experimental cases were observed