Experimental and Numerical Investigation on The Punching Behavior of High Strength R.C Flat Slab Under Repeated Load

Abstract

In this paper, the punching behavior of square simply supported reinforced concrete flat slabs was experimentally and numerically investigated. Four models of reinforced concrete flat slabs were constructed and tested. The test variables were type of concrete and load (four models): High Strength Concrete flat slabs under monotonicload or repeated load (two models) and Normal Strength Concreteflat slabs under monotonicload or repeatedload (two models). The results showed that the punching shear strength of flat slabmodels increased up to 60% with the use of HSC. While, repeated load reduces the punching shear strength of flat slabmodels by about (34.4%-10%); it depends on the level of loading, number of cycles and type of concrete. Three-dimensional (3D) nonlinear finite element (NFE) analysis has been carried out to conduct the numerical investigation of the general behavior of HSC and NSC flat slab models. The ABAQUS model succeeded to an acceptable degree in predicting the structural behavior of the analyzed flat slabswith average of differences of about 5% between the predicted and experimental ultimate load.