In the field of reinforced-concrete (RC) structures, the use of fiber reinforced plastic rebars (FRP rebars) as an alternative to the steel reinforcements appears very promising, especially if such structures are exposed to corrosive environments. However, a better understanding of the mechanical behavior of FRP reinforcements—in particular bond behavior—is needed in order to use them for practical purposes. For this reason, in the last few years a number of tests on several types of FRP rebars has been conducted in order to evaluate the interaction phenomena between FRP rebars and the concrete matrix and to evidence behavioral differences with respect to the deformed steel rods. In this paper a state-of-the-art report on the bond of FRP bars to concrete is presented. Numerous tests are analyzed to better understand bond mechanisms and the influence of type of fiber, outer surface (shape and type of matrix), and other significant parameters (i.e., confining pressure, bar diameter, compressive concrete str...

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.