海水干湿循环作用下 CFRP-高强混凝土黏结性能研究

摘要

In coastal areas,one of the major factors to restrict the application of CFRP (carbon fiber reinforced polymer or plastic ) in strengthening concrete structures is seawater wet-dry cycles. Considering structure load and seawater wet-dry cycles,the 5% NaCl solution was used to simulate seawater,the self-designed loading device was used to apply sustained load,and the double-sided shear test was used to study the bond behaviors of high-strength concrete with CFRP. The experimental results indicate that the bond behavior has significant degradation under seawater wet-dry cycles,and ultimate load,peel load,ultimate slip and fracture energy are all reduced.The degradation of bond behavior is more serious under the sustained load and wet-dry cycles,and the parameters of bond behavior are further reduced.So the interfacial bond behavior of high-strength concrete with CFRP under wet-dry cycles will be overestimated without consideration of the sustained load in the study of durability of CFRP-high-strength concrete interface.%在沿海地区，海水干湿循环成为限制 CFRP(碳纤维增强复合材料)在加固混凝土结构应用中的主要因素之一。考虑结构自身荷载和海水干湿循环作用，用5% NaCl 溶液模拟海水，利用发明的持载装置施加持续荷载，采用双面剪切试验方法对 CFRP 与高强混凝土的界面黏结性能进行了研究。结果表明：海水干湿循环作用下界面黏结性能发生显著的退化，极限荷载、剥离荷载、端部滑移、断裂能等界面参数均显著降低；而持续荷载和干湿循环耦合作用下界面黏结性能退化更加严重，黏结界面参数进一步降低。因此未考虑持续荷载作用而对CFRP-高强混凝土界面耐久性的研究将会过高地估算界面的黏结性能。