Effect of Dry-Wet Cycles on BFRP Bars and Modified Ceramsite Concrete in Marine Environments

Abstract

This study investigates the bonding behavior of modified ceramsite concrete (MLC) and basalt fiber-reinforced polymer (BFRP) bars exposed to dry-wet (D-W) cycles of simulated seawater using pull-out tests. Two types of concrete strengths—MLC25 and MLC35—were examined under different environmental exposure periods (0, 10, 30, and 50 cycles) using a total of 54 specimens. Compared with the specimens that were only immersed in artificial seawater (ASW, without D-W cycles), the D-W cycles had no significant effect on the failure mode, which remained as pull-out and splitting failures. However, the ultimate bond strength and slippage varied significantly, and the ultimate bond strength decayed between 5% and 35%, while the slippage increased from approximately 4% to 60%. The bond strength of LC35 decreased by 33.65%, and the slippage increased significantly (by 55%) after 50 D-W cycles (using one-time concentrated ASW). Moreover, the mechanical properties under this unconditional environment showed that the splitting tensile strength decreased by 3.67% and the compressive strength decreased by 5.47%.