Study on bond performance between FRP bars and seawater coral aggregate concrete

Application of FRP (fiber reinforced polymer) and SCAC (seawater coral aggregate concrete) in island construction can overcome the shortcomings in conventional steel and concrete. This paper is concerned with the bond performance between FRP bars and SCAC by pullout tests. The effect of fiber type, diameter and bond length of FRP bar and curing condition on the bond behavior is analyzed. It is found that the maximum average bond stress decreases with the increasing of the bond length and the bar diameter. The bond strength is slightly reduced for the specimens immersed in seawater compared to those cured in standard condition for FRP bars bonded to SCAC. Moreover, a four-linear model for local bond stress-slip relationship is proposed with four characteristic parameters, and an analytical approach is then presented to predict the maximum pullout load based on the model. The analytical results show good agreement with the experimental ones, and the proposed four-linear model with four characteristic parameters proves to be reasonable in the present study.