Abstract:
Basalt Fiber Reinforced Polymer (BFRP) is a new reinforcing material alternative to steel bar in marine engineering, and exhibits good application prospects. Carbon fiber mat anchorage is employed to improve the bond performance between BFRP bars and concrete due to the insufficient bond strength at the interface of BFRP bar-to-concrete, which helps to increase the reinforcing effect of BFRP bar. In this paper, pull-out tests on 20 specimens are carried out, and the influences of carbon fiber anchorage length, anchorage diameter and concrete strength on bond-slip behaviors and failure patterns are investigated. The bond characteristic parameters presented in existing theoretical models are modified based on the experimental data obtained in the paper. The calculation formula of bond strength at the interface of BFRP bar with anchorage end-to-concrete is obtained and a constitutive model is further given. Results indicate that the bond performance between BFRP bar and concrete can be greatly improved by the carbon fiber mat anchorage. The crack propagation of concrete can be effectively prevented and the residual bond strength is also enhanced, and thus the reinforcing effects of BFRP bar can be fully developed. The strength of concrete is the main factor affecting the anchorage performance, and the anchorage performance of carbon fiber mat is enhanced with the increase of anchorage length-to-diameter ratio.