Bond‐Slip Behavior Between GFRP Bars and Mortar Based on Pull‐Out Tests

Bond performance is important in glass fiber reinforcement polymer (GFRP) bar reinforced mortar structure. To study bond behavior between GFRP bars and mortar, pull‐out tests were conducted on nine cylinder specimens with reinforced carbon sheets. The loading mode included monotonic loading and cyclic loading. Bond strength, slip, bond stiffness, and residual bond properties were investigated and fitted to bond‐slip curves of classical models. The results show that monotonic loading, cyclic constant loading, and cyclic variable loading have little effect on the ultimate bond strength between a GFRP bar and mortar. The bond‐slip curves have the same change laws. Under cyclic constant loading, bond stiffness increases with cycles loading times and is basically stable after 10 times, and the bond‐slip curves show the same characteristics. Under cyclic variable loading, bond stress–strain has a linear characteristic, bond stiffness presents a hardening tendency, and bond‐slip curve is similar and stable in each loading–unloading process. The ascending stage and descending stage of the bond‐slip curve match the modified Eligehausen, Popov, and Bertero (mBPE) model, no horizontal line is observed in the peak load stage, the descending stage curve is approximately linear, and the residual stage curve exhibits a fluctuating decreasing tendency. Based on the test results, a Gaussian function and its parameters are proposed for the expression of the residual stage. POLYM. COMPOS., 40:2840–2849, 2019. © 2018 Society of Plastics Engineers