Abstract: With the continuous advancement of China's “Polar Silk Road”, research on polar infrastructure has become one of the key development directions in the field of civil engineering. In this paper, considering the characteristics of the polar construction environment, four typical working conditions (room temperature seawater immersion, low-temperature air freezing, low-temperature seawater salt freezing, and low-temperature seawater freeze-thaw cycle) were selected to simulate the polar marine environment. The tensile strength, interlayer shear strength, and failure modes of glass fiber reinforced polymer (GFRP) under different erosion conditions were systematically investigated, and changes in chemical composition and microstructure of GFRP after erosion were analyzed. The results show that GFRP maintains a dense structure at low temperatures, but increased brittleness leads to more severe damage. Under both low-temperature air freezing and low-temperature seawater salt freezing conditions, the tensile strength of GFRP increases significantly by 10% to 20%, and the interlayer shear strength improves by 5% to 15%. XRD analysis indicates that the low-temperature environment effectively inhibits resin hydrolysis, thereby considerably slowing down the penetration of chloride ions into the fiber interior and significantly reducing the extent of chloride-induced erosion of GFRP.

Key words: GFRP bar, polar environment, tensile property, shear performance, microstructure, chemical composition