Punching shear failure of slab with lightweight aggregate concrete (LWAC) and low reinforcement ratio

• Full scale lightweight aggregate concrete (LWAC) slabs were constructed and tested.
• Effects of LWAC on the punching shear resisting capacity of slabs were evaluated.
• Failure mechanism of LWAC slabs was evaluated by using the results of test and FEM.
• A modified design equation for LWAC slabs was proposed and successfully verified.

This paper presented the punching shear resisting capacity of lightweight aggregate concrete (LWAC) slabs having low reinforcement ratio. Five full scale slabs were constructed using normal concrete and four different types of LWAC. The experimental study was then performed to study the effect of LWAC on the punching shear resisting capacity of slabs. The nonlinear finite element analysis was also conducted for each slab specimen to analyze the failure mechanism of LWAC slabs with low reinforcement ratio, by demonstrating the cracks formation and propagation. Finally, from the test results of this study and previous researches, a simple design equation to predict the punching shear resisting capacity of LWAC slabs was proposed considering the reinforcement ratio of the slab. The proposed equations provided good prediction of the punching shear resisting capacity of LWAC slabs with different reinforcement ratios.