侵蚀环境下GFRP筋力学性能退化试验
Experiment on Mechanical Properties Degradation of GFRP Bars in Eroded Environment

为了研究侵蚀环境下玻璃纤维增强复合材料(GFRP)筋的力学性能退化机理，对3种不同直径的GFRP筋进行了为期半年的溶液浸泡试验。试验采用了清水、碱溶液以及盐溶液3种侵蚀环境，在浸泡不同时间后分别对筋材进行了外观检测和力学性能试验。结果表明：不同侵蚀环境下，GFRP筋的抗拉强度在碱环境中下降最多，平均为11.44%，其次是盐环境，平均为4.59%，下降最少是清水环境，平均为4.30%；GFRP筋的剪切强度在清水、盐、碱环境中分别平均下降了23.03%，18.69%，28.28%，说明侵蚀环境对其力学性能有明显的影响；在盐环境下，直径为8，12，16 mm的试样抗拉强度分别下降了3.53%，9.42%，0.82%，说明GFRP筋力学性能退化具有一定的尺寸效应；GFRP筋的剪切强度退化随浸泡时间的增加而增大，在前36 d下降较快，36 d后下降则趋于平缓。
In order to study the mechanical properties degradation mechanism of glass fiber reinforced polymer (GFRP) bars under eroded environment, three kinds of GFRP bars with different diameters were tested in solution immersion for six months. In the experiment, three kinds of eroded environments, such as clear water, alkali solution and salt solution, were used to test the appearance and mechanical properties of the reinforcement materials after soaking different time. The results show that in different eroded environment, the tensile strength of GFRP bars decreases mostly in alkaline environment, the average is 11.44%, in the salt environment, the average is 4.59%, in the water environment, the average is 4.30%, and the shear strenghs decrease 23.03%, 18.69%, 28.28% in water, salt and alkali environments respectively, which indicates that the eroded environment has a significant effect on mechanical properties. In the salt environment, the tensile strengths of 8, 12 and 16 mm specimens decrease by 3.53%, 9.42% and 0.82% respectively, which indicates that the mechanical properties of the samples have a certain size effect. The shear strength degradations of GFRP bars increase with the increase of immersion time, and decrease rapidly in previous 36 d and slowly after 36 d