纤维对GFRP筋与混凝土粘结及锚固性能的影响

摘要

为了研究结构型纤维对GFRP筋与混凝土粘结性能的影响,对36个中心拉拔试件进行试验,主要变化参数为纤维掺量和粘结长度. 考虑结构型纤维对GFRP筋与混凝土基体粘结性能的改善作用,改进了ACI 440.1R-06中GFRP筋与混凝土之间锚固长度的计算公式. 研究结果表明:掺加2~6 kg/m3的结构型合成纤维,可使GFRP筋与混凝土基体的极限粘结应力提高12%~35%;纤维掺量相同的情况下,极限粘结应力随粘结长度的增加而降低. 将改进公式与不同规范中GFRP筋锚固长度公式的计算结果进行对比,建议的公式能够较为合理地反映结构型纤维对GFRP筋与混凝土粘结性能的影响.%The effect of structural fibers on the bond behavior between glass fiber reinforced polymer ( GFRP ) rebars and a concrete matrix was studied by conducting 36 put-out tests. The main test parameters were fiber contents and embedment lengths. Considering the improvement effect of structural fibers on the bond behaviour between GFRP rebars and the concrete matrix, a modified calculation formula of anchorage length between GFRP rebars and concrete in ACI 440.1R-06 was proposed. The results show that, with the addition of 2~6 kg/m3 synthesized structural fibers in the concrete matrix, the ultimate bond stress between GFRP rebars and the concrete matrix increases by 12%~35% compared with a plain concrete ( PC) matrix. In the case of the same fiber content, the ultimate bond stress between GFRP rebars and concrete decreases with the increasing of embedment length. Compared with the calculation results of the GFRP rebar anchorage length formula in dif-ferent specification formulas, the results show that the proposed formula can better reflect the effect of structur-al fiber on the bond behavior between GFRP rebars and concrete matrix.