Experimental Investigation of CFRP Strengthened RC Beams under Monotonic and Fatigue Loadings

The aim of this research is to investigate the effect of Carbon Fiber Reinforced Polymer (CFRP) composite fabric on monotonic and fatigue behaviors of reinforced concrete beams. To control the failure occurrence, a small notch was induced at the middle span in bottom surface for all of the studied RC specimens. Totally 12 beams were tested from which 6 beams tested under monotonic and 6 other tested under fatigue cyclic loading. Every 6 tested beams consisted of 3 intact and 3 CFRP retrofitted RC beams. The specimens were 150×150×1000 mm in dimensions and a 150 mm-deep notch was cut at the center. The experimental examination was conducted to study stress distribution throughout the critical cracked regions in CFRP strengthened RC beams. Results from monotonic and fatigue tests were compared to each other. In the monotonic test stiffness measurements were carried out until the failure of specimens. In the fatigue test, the ceiling of applied load was considered at the level of design service load for bridges. Load–deflection curves, strain responses and propagation of tension cracks would provide an insight on the performance of the CFRP strengthened beams subjected to different cycles of fatigue loading.