Identifying the Effect of CFRP Application Type on Behavior of CFRP-Strengthened Beams by Acoustic Emission

Abstract

Strengthening structures using CFRP (Carbon Fiber Reinforced Polymer) strips is a widely used method because of superior mechanical properties of CFRP. Along with the overall impact of the FRP strengthening, FRP application type is one such important parameter that directly affects the strengthened beam behavior. FRP can be applied in a number of different ways. FRP sheets, either full wraps or strips are the mostly preferred methods for strengthening in recent years. These methods have more or less advantages according to each other. In other words, CFRP application influences the strengthened beam behavior since application type has a direct impact on the failure mechanism. In this study, it was aimed to identify the effect of CFRP application type on behavior of reinforced concrete (RC) beams. For this purpose, CFRP-strengthened RC beams, which were strengthened by different application types such as side-bonded and U-jacketed CFRP sheets, were tested under cyclic loading and monitored by Acoustic Emission (AE) technique. AE data obtained from the tests were processed by parameter and SiGMA analyses. Crack locations, types and orientations were determined and were compared with mechanical results. Thus, failure mechanisms of the specimens were evaluated and effects and discrimination of CFRP application type on the fracture mechanism were revealed.