干湿循环下预应力CFRP加固高强混凝土的耐久性

Durability of High Strength Concrete Strengthened with Prestressed CFRP Under Wet-Dry Cycles

通过四点弯曲试验,研究了干湿循环作用下预应力CFRP(碳纤维复合材料)加固高强混凝土的界面耐久性.试验中设置了3种预应力等级,预应力分别为CFRP抗拉强度标准值的0%、15%和30%.通过分析干湿循环次数和预应力等级对加固试件承载性能及剥离破坏形态的影响,研究了界面劣化规律.结果表明:干湿循环120次后试件承载力降低,预应力等级越高,承载力降低越显著;随着干湿循环次数的增加,试件由混凝土层剥离破坏逐渐转化为树脂胶层剥离破坏.

The effects of the wet-dry cycles on the interace durability of the with prestressed CFRP(Carbon Fiber-Reinforced Polymer)wem investigated by a four-point bending test.Three prestress levels,namely,0%,1 5%and 3 0%of the standard value tensile strength of the CFRP sheet,were imposed in the test.Then,the interace degradation lawwas demonstrated by analyzing the influence of the wet-dry cycles and the prestress levels on the carrying capacity and thedebonding failure model of specimens.reveal that the cairying capacity of the specimens decreases after 120 cycles,and higher prestress canying capacity load to decrease faster,and that,with the increase of the wet-dry cycles,the failure model of the specimens transfonns from the peeling of the protective layer of the concrete to the debonding of the resin layer.