STRENGTHENING OF FLAT SLABS IN PUNCHING SHEAR USING STEEL SHEAR BOLTS

Abstract

In this study, an easy to install and economical strengthening technique for increasing the punching shear strength of flat slabs at interior column by using vertically applied steel shear bolts was developed. To study the behavior of strengthened flat slabs at interior column connection, the study divided into three phases. The first phase is the experimental phase, the second phase is generation of finite element model using ANSYS program and verify its results with the experimental results, and the third and last phase is the parametric study, which used to develop a design equation and design guidelines. In the experimental phase, nine half-scale specimens were tested. The effect of shear bolts arrangement, spacing between shear bolts, and column aspect ratio on the punching shear behavior of the specimens were investigated. The contribution of strengthening method to the punching load capacity, displacement, and failure mechanisms of the specimens were studied. In the second phase, three dimensional nonlinear finite element model was generated using ANSYS program to investigate the punching shear failure mechanism of test specimens. The validity of the generated finite element models were compared with the experimental results of this study. The discussions regarding to the punching load capacity, longitudinal reinforcement strain, shear bolts strain, and failure mechanism are presented.