Jacobs Journal of Civil Engineering

Behavior of Slab Column Connection with Pyramid Shaped Drop Panel

*Ahmed I
Department Of Civil Engineering, Mist Higher Institute Of Engineering And Technology, Egypt

*Corresponding Author:
Ahmed I
Department Of Civil Engineering, Mist Higher Institute Of Engineering And Technology, Egypt
Email:ahmedfroty16@gmail.com

Published on: 2019-06-25

Abstract

Both experimental and FEA are used to study punching shear strength of RC interior slab-column connection made with pyramid shaped drop panel subjected to vertical and horizontal loads. Experimental study included construction and testing of six half-scale interior slab-column connection with same geometry and reinforcement ratios. One specimen has no drops used to predict vertical punching shear at failure, another identical specimen has been subjected to 50% of ultimate vertical load and horizontal load up to failure to be considered as a reference. Four specimens varied between rectangular and pyramid drop panels of same dimensions with variable thicknesses of 40 mm and 30 mm respectively, are constructed to compare punching strength between specimens have rectangular and pyramid drop panels with same thickness at column face to each other. FEM using the CDP model offered in (ABAQUS 2016) are used for RC specimens, and the validation of FEA has been verified through comparison with available experimental data obtained. It has been shown that the load vs. deflection diagrams and ultimate load capacities obtained from FEA closely agree with the experimental results. Following the establishment of the validity and reliability of the FEM scheme, a parametric study has been carried out to investigate capacities of 5 specimens at different values of vertical and horizontal loads. The results of the study demonstrated that the pyramid shaped drop panels are able to improve the punching shear capacity and enhance the ductility of the flat slab column connections compared to rectangular shaped drop panels.

Keywords

Punching shear capacity; Slab column connection; Drop panel; Pyramid shaped drop panel

Introduction

Slab-column framed systems are widely used and preferred by engineers due to its numerous benefits, however, the behavior of slab-column systems is worrying for structural due to the possibility of punching shear failure which is sudden yet brittle and could lead to catastrophic structural collapse. Present design rules for punching shear failure of reinforced concrete slabs, given in various codes of practice, are largely based on studies of the behavior and strength of simply-supported, conventional specimens extending to the nominal line of contra flexure. The code provisions rely mostly on empirical methods derived from the test results on conventional and thin slab specimens.