Punching shear capacity of expanded polystyrene (EPS) lightweight concrete flat slabs without shear reinforcement

This work presents an experimental and theoretical study on the punching shear behavior of Lightweight Concrete Slabs. Lightweight obtained using Expanded polystyrene (EPS) beads as partial coarse aggregate's replacement, without adding supplementary bonding additives, to reduce concrete density from 2400 to 1800 kg/m3. The EPS content, concrete strength and column aspect ratio were test parameters. Five groups of concrete prepared by partially replacing natural coarse aggregate with 0%, 10%, 20%, 30% and 40% (by volume) of EPS balls. Ten reinforced concrete slabs without shear reinforcement with a monolithic column were tested under concentric loading. The study aimed to examine the effect of the EPS on the density and compressive strength of concrete and eventually on the flat slabs punching capacity. Five series of mixtures identified and compared with conventional normal weight concrete. Results showed that with increasing EPS content, rate of reduction in concrete strength is faster than the reduction in concrete density. Also, showed that the failure base area increased while the concrete density decreased, this yielded a higher punching capacity compared to rate of decrease in the concrete strength. International standards models showed overestimation of punching shear capacity and didnot reflect the reduced concrete strength action of lightweight concrete.