Seismic strengthening of infilled reinforced concrete frames by CFRP

The objective of the presented research was to investigate seismic strengthening of non-structural brittle masonry infill walls of reinforced concrete (RC) frames by Carbon Fiber Reinforced Polymers (CFRP). The contribution of CFRP strengthening to the overall behaviour in terms of lateral strength and stiffness, effects of different application techniques and connection details were investigated experimentally and analytically. Experimental work consisted of two parts. The first part included diagonal tension tests of 26 masonry wall panel specimens. These tests were conducted to observe the effects of different CFRP types and applications over the initial stiffness, shear strength and failure modes. In the second part, five one story-one bay RC frames were tested under cyclic in-plane lateral loads. Lateral load-top displacement hysteresis curves and failure modes were obtained. Initial stiffness, peak-to-peak stiffness, equivalent displacement ductility, strength reduction factors, energy dissipation and hysteretic damping values of specimens were evaluated comparatively. A damage table was built for strengthened specimens using experimental observations. In the analytical part, structural models of the CFRP strengthened one story-one bay RC frames were established in order to achieve the generalization of a number of test results. Experimental results and observations were also utilized in this process. Analytical results complied well with the experimental results in terms of lateral load capacity and initial stiffness.