PARAMETRIC STUDY OF WEB BONDED CFRP SHEAR REINFORCEMENT ON INTERNAL STEEL STRESSES

摘要

A four-point Iosipescu shear test is used to evaluate the effects of CFRP reinforcement on crack width development and the corresponding stress of the internal steel reinforcement. The test program indicates that the steel reinforcement yields following cracking in a concrete beam test specimen containing a No. 10 (No. 3) 71 mm2 (0.11 in~2)-420 MPa (60 ksi) yield strength reinforcing bar in most cases; however, some CFRP reinforced specimens have a steel strain as low as 45 percent of the yield strain prior to the failure between the CFRP and the concrete surface. The research conducted a parametric study and provides a correlation between CFRP shear reinforcement ratios, crack width, and internal steel reinforcement stress. The results are found by testing several shear friction type specimens where the CFRP varies in size while the internal steel reinforcement is held constant.