Bond Performance of Anti-Corrosion Bar Embedded in Ceramsite Concrete in Freeze–Thaw Cycles and Corrosive Environments

At present, basalt fiber-reinforced polymer (BFRP) bars and epoxy-coated steel reinforcing bars (ECRs) are very promising in ocean engineering. In this study, the bond strength degradation characteristics of BFRP bars, ECR, and ordinary steel bars (OSBs) embedded in ceramsite concrete (CC) were compared in a single-corrosive environment (acid, salt, and alkaline salt, respectively) coupled with freeze–thaw (FT) cycles (0, 15, or 30); a total of 111 specimens were designed. In the three corrosive environments, the BFRP-bar-CC specimens and OSB-CC specimens all failed to pull out, while the ECR-CC specimens showed splitting failure. When corrosive and FT cycles acted together, the failure modes of BFRP-bar-CC specimens and ECR-CC specimens did not change. However, when the FT cycles increased from 15 to 30, the type of failure for the OSB-CC specimens changed from pullout failure to splitting failure. In addition, the bonding strength of the three kinds of bars decayed most rapidly in an acid environment. When 30 FT cycles were applied, the bond strength of ECR-CC specimens and OSB-CC specimens decreased most rapidly in the acid environment, by 9.12% and 18.62%, respectively. However, the bond strength of BFRP-bar-CC decreased most rapidly, by 17.2%, in an alkaline salt environment.