Durability of basalt fibers, glass fibers, and their reinforced polymer composites in artificial seawater

Abstract This study focused on the durability of basalt fibers, glass fibers, basalt‐fiber‐reinforced polymer (BFRP) bars, and glass‐fiber‐reinforced polymer (GFRP) bars in an artificial seawater. The specimens were immersed in the artificial seawater at 20, 40, and 60°C; the specimen immersed in distilled water at a temperature of 60°C was also used as a reference. The tensile strength of the monofilament basalt fibers and glass fibers immersed in the seawater for 90 days at a temperature of 60°C decreases by 61% and 59% respectively, showing the most significant degradation; the brittleness of the fibers also increases due to the decomposition of their sizing agent. The chloride ions in the seawater are beneficial to enhancing the resistance of the composites to moisture absorption. In addition, the tensile strength retention of the fiber‐reinforced polymer (FRP) bars is higher than that of the fibers due to the protection by the epoxy resin. The mechanical properties of the FRP bars immersed in the seawater improve after removing their moisture. The mechanical performance of the BFRP bars is inferior to that of the GFRP bars due to their higher water absorption and weak bonding between the basalt fibers and the polymer matrix.