Assessment and enhancement of the behavior of lightly RC wall elements subjected to pure shear

Abstract

Observed damage from the past earthquakes has indicated that several structural walls before the 1970s are non-seismically designed and performed poorly, exhibiting unexpected failure modes such as shear failure due to inadequate detailing and/or poor confinement of concrete core. The shear behavior alone is complex, because it influenced by a host of parameters often interdependent. This paper aims to assess and enhance the non-linear behavior of lightly reinforced concrete wall or panel elements subjected to pure shear. The existing softened membrane model was chosen as a basic model to evaluate the structural behavior and the work strategy was given as follows: first, identification of the range in which reinforced concrete panels were considered as lightly reinforced elements, based on the non-ductile behavior, Experimental data of reinforced concrete panel element A1 conducted by Pang and Hsu and the recommendation of Euro code 2. Next, the influence of the following design parameters on the shear behavior of lightly reinforced panel elements was investigated: the steel grid orientation; the diameter of longitudinal reinforcement, the type of reinforcement, and the crack angle; Finally, to enhance the shear performance, one case that reinforced with ribbed bars exhibited a non-ductile behavior has been selected to strengthen it with one, two, or three layers of fiber-reinforced polymer as an alternative to the traditional methods, using the so-called “softened membrane model-FRP”.