Quality control test for carbon fiber reinforced polymer (CFRP) anchors for rehabilitation
Different strategies can be used to repair, rehabilitate and strengthen existing structures. Techniques based on Fiber Reinforced Polymer (FRP) materials appear to be innovative alternatives to traditional solutions because of their high tensile strength, light, weight, and ease of installation. One of the most common and useful FRPs is Carbon Fiber Reinforced Polymer (CFRP) used in sheets and anchors attached on the concrete surface to strengthen the section through addition of tensile capacity. The purpose of this study was develop a technique for assesses the strength of anchors for quality control purpose. However, to transfer tensile capacity to a concrete surface, the sheets are bonded to the surface with epoxy adhesive. As tension increase, CFRP sheets lose adherence of the epoxy from the concrete surface and finally debond. To avoid this failure, CFRP anchors are applied in addition at the epoxy. The CFRP anchors allow the CFRP sheets to utilize their full tensile capacity and maximize the material efficiency of the CFRP retrofit. The number and size of anchors play a critical role. However the capacity of CFRP anchors has not been investigated extendedly. A methodology for assessing the quality of CFRP anchors was developed using plain concrete beams and reinforced externally with CFRP sheets attached with epoxy and CFRP anchors. Applying load to the beam, allowed the development a tensile force in the CFRP sheets and a shear force on the CFRP anchors. The shear forces in the CFRP anchors were defined by the load applied to the beam and compared with forces based on measured stress in CFRP sheets.