STRENGTHENING OF LIGHTWEIGHT REINFORCED CONCRETE BEAMS USING CARBON FIBER REINFORCED POLYMERS (CFRP)

Abstract

This research aimed to investigate the effect of utilizing “Fiber Reinforced Polymer” (FRP) on the light weight concrete beams. The main hypothesis is that such utilization of the FRP will lead to strengthened lightweight beams. The research that has been done on this relationship is somewhat broad in the scope and have mostly focused on the normal-weight concrete. However, only few studies that have considered the light weight concrete. Eight Beams were tested in this research under four point bending test. Two beams were taken as a control beams without any external bonding of Carbon Fiber Reinforced polymer. Another two beams strengthened with external CFRP sheet bonded with epoxy only. Next two beams strengthened same as the previous two but anchored to the concrete by Mechanical Fixation which is anchor bolt. Two of the beams strengthened with CFRP sheet at tension face on the bottom and CFRP sheet as U-wrap at the ends to increase the anchorage to the concrete. The theoretical value for the strengthened beam was calculated according to ACI 440 and compared to the experimental value from the test. Four point flexural load test was considered in this research. Test result showed an increase in the strength of the strengthened beam compared to the control beam, while the deflections for strengthened beams were decreased. Strengthened with CFRP sheet using u-wrap anchor was the most effective system for strength enhancement which was 12% with respect to control beam. However the ductility of the beam was reduced significantly.