Author : Rizgar Amin Agha

This paper treats the punching shear capacity for Critical Shear Crack Theory (CSCT) and EC2 equation considering connection between supporting columns and slabs without shear reinforcement. It shows the effects of individual parameters as found from CSCT calculations with the corresponding results from EC2, to demonstrate the differences between the two methods. It treats the conditions simulated in most tests where a load or reaction acts through a column or plate at the centre of the slab and is balanced by reactions or loads near the edges of the slab. In general, the predictions by EC2 are more conservative compared to those by CSCT. The increasing of compressive strength causes in increasing of punching shear capacity in both methods and the rate of increasing in shear capacity is decreases with increasing the compressive strength. The providing of flexural reinforcement in the perimeter area around the support enhanced the punching shear capacity and it increased with increasing of the reinforcement ratio. the stiffness of the slab where investigated and shows that the stiffer slab produces lesser rotation and then higher shear resistance. It was found that the CSCT approach is a complex method to be used in a design practice; however the overestimations in cases of smaller size aggregate and lower stiffness in EC2 can justify can justify the need for a new and more complex equation to consider these parameters.

Keywords: Punching shear strength, size factor, aggregate size, flexural reinforcement, concrete strength, steel strength, slab rotation and slenderness

Article published in International Journal of Current Engineering and Technology, Vol.4, No.5 (Oct-2014)