Bond between Glass Fiber Reinforced Plastic Reinforcing Bars and Concrete - Experimental Analysis

In this paper results of an experimental investigation on bond between a glass fiber reinforced plastic (GFRP) rebar and concrete are presented and discussed. Rebars used in tests are the FRP C-Bar™ produced by Marshall Industries Composites, Inc. Bond tests were carried out by using a test machine obtained from a modification of the standard scheme of the beam-test and were conducted on prismatic concrete specimens within which a #4 Grade B E-Glass C-Bar was embedded: the embedment length was ranging from 5 to 30 times the bar diameter, thus obtaining different test arrangements. Bond-slip relationships were obtained and bond mechanisms discussed. Furthermore, values of elastic modulus and tensile strength of rebar were evaluated. Finally, a bond-slip constitutive law obtained by means of a system identification procedure is presented. Numerical simulations of bond tests have been performed by using such bond-slip relationship and the obtained bond-slip curves have been compared with the experimental ones.