Experimental Study of Reinforced Concrete Slabs Strengthened by CFRP Subjected to Impact Loads

Abstract

This paper shows a progression of experimental studies to investigate the response of reinforced concrete slabs when subjected to high-mass low-velocity impact loads. The researcher has confirmed that FRP composites are effective for strengthening a wide variety of concrete structural members. To date, very little published research has been performed on the behavior of strengthened two-way slabs under impact loads. The purpose of this study is to investigate experimentally on behavior slabs strengthening with CFRP. A total of seven reinforced concrete slabs were tested under the effect of impact load by a drop-weight facility. Measurements involved a load cell, accelerometer, strain gauges in the reinforcement steel and concrete, and using (a laser sensor, LVDT) to measure deflection in the center and quarter of the slabs. These experimental variables included in this study were focused mainly on the formation and dimension of carbon fiber under impact loads. The test results showed that the adding carbon fibers were active in increasing slab capacity and mitigating local damage under the impact, as the strengthening of slabs by CFRP, the increased in an impact force of the slabs about (11.9-19.5%) and the maximum deflection at the central slabs decreased by (6.5-22%). It can be observed that the increase in the area of the CFRP layer under the impact region led to more decrease of the deflection. With regard to acceleration, it is evident that the distribution of forces acting on the plate also varies over the course of the event and that the evolution of the inertial force resulted in load distributions that are significantly different from those developed in static test conditions. The evolution of inertial forces in impact loading conditions resulted in observed responses then failure patterns governed by shear.