Experimental investigation of seismic strengthening of reinforced concrete short columns using externally bonded reinforcement,near surface mounted,and hybrid techniques

Abstract

Nowadays, the existence of short columns is a major factor in the failure and collapse of structures during the earthquake. In this article, 10 reinforced concrete short columns are prepared and experimentally investigated under cyclic lateral displacements. Since failure in short columns under earthquake was in the form of diagonal cracks and shear rupture, two new techniques are proposed to strengthen short columns against seismic loads. These techniques include externally bonded reinforcement with carbon fiber-reinforced polymer sheets and near surface mounted with glass fiber-reinforced polymer bars in the form of transverse, diagonal, and hybrid strengthening techniques. The experimental results demonstrated that the above-mentioned strengthening techniques in short columns lead to a change in the type of failure from shear to flexural, and the change of crack patterns and columns failure. The mentioned strengthening methods lead to an increase of ductility, increase of load carrying capacity and increase of dissipated energy.