采用CFRP加固钢结构研究已经引起工程界的广泛重视并取得一定进展。针对CFRP-钢结构黏结试件在荷载和腐蚀环境下的黏结耐久性问题进行试验研究,试验中采用带有转动钢铰的工字钢梁-CFRP组合试件,影响因素包括维持荷载的等级、盐水环境下干湿交替循环的次数等。维持荷载系统采用螺栓加载,荷载控制通过自制的压力传感器进行。加载等级为试件极限承载力的15%和25%,干湿交替环境考虑15、30、60、90、120次盐水环境下的干湿循环。试验分析了荷载和干湿交替环境共同作用下CFRP-钢界面破坏特征、极限荷载影响和破坏机理。结果表明:荷载和干湿交替环境共同作用下,CFRP-钢结构界面破坏特征与对比试件相比发生明显变化,侵蚀介质渗透到黏结界面上,试件的极限承载力有显著降低。并且,极限承载力随腐蚀时间增加有进一步降低的趋势。
This study is concerned with the bond durability of the interface of steel beams and CFRP under loading and aggressive environments. A specimen of CFRP and I steel with rotated hinge is adopted in an experiment with loading and wet-dry cycling in salt solution. A bolt loading set is employed and the loading level is controlled by pressure sensors at 15% and 25% of the ultimate bear capacity of the specimens, and there involve, respectively, 15, 30, 60, 90 and 120 times of wet-dry cycles in salt solution. The ultimate bear capacity, the failure characteristics of the CFRP and steel interface are studied after long term loading and dry-wet cycling. The test results indicate an obvious difference in failure characteristics and a significant decrease in the ultimate bear capacity of the specimen after long term loading and dry-wet cycling exposure, and the ultimate bear capacity decreases further with the exnosure time.