Abstract: Accelerated aging test under seawater, alkaline solution and alkaline+seawater solution(solution mixed with seawater and alkaline) at 60 ℃ was carried out to investigate the mechanical performance of GFRP bars under marine environment. Solution mixed with seawater and alkaline was selected in dry/wet and stress/corrosion conditions. Tensile tests and SEM method were used to study the durability and corrosion mechanism of GFRP bars under different conditions. The test results show that alkali ion has the largest influence to the durability of GFRP, because the chemical reaction between silicon-oxygen bond of fiber and water molecule or hydroxide ion lead to silicon-oxygen bond rupture,and promote the formation of hydration product. But in accelerated aging test, the degradation of tensile strength of GFRP bars immersed in alkaline+seawater solution for 6 months is nearly 30%, and the degradation of elasticity modulus is 12%. GFRP bars show good anti-corrosion performance under dry/wet and stress/corrosion conditions, the tensile strength and elasticity modulus retention is both nearly 90% under the two conditions.

Key words: GFRP bars, corrosion, dry/wet, stress/corrosion