Experimental and analytical evaluation of bond properties of GFRP bars

A better understanding of the bond behavior, which is one of the main behavioral aspects: of reinforced concrete structures, is needed for fiber-reinforced plastic reinforcing bars, because tests have shown that the bond is different from that of steel reinforcing bars and varies with the type of reinforcing bar as well. In this paper results from bond tests performed on commercially available glass fiber-reinforced plastic (GFRP) reinforcing bars are presented and discussed. The experimental bond-slip curves have been obtained and some information about bond mechanisms have been derived. Furthermore, values of the elastic modulus and the tensile strength of the reinforcing bars have been measured. Finally, a numerical procedure for the identification of the constitutive bond stress-slip relationship, based on the experimental results, is presented.