湿热耦合环境下碳纤维布加固混凝土界面耐久性能

为研究碳纤维补强聚合物加固混凝土结构在湿热环境下的耐久性能,通过对不同湿热耦合作用下36个CFRP-混凝土试件进行试验研究,分别进行5 d、10 d、15 d的加速湿热老化,并对其进行双剪试验,分析了不同温度、湿度的耦合作用下CFRP-混凝土界面的破坏形态、极限承载力、应变分布及相对位移等力学参数,进而分析湿热耦合环境对界面力学性能及黏结耐久性能的影响。结果表明:湿热老化作用后,CFRP-混凝土界面的界面力学性能有所退化;高温高湿耦合作用对界面的力学性能影响较大,15 d湿热腐蚀后,极限荷载、极限位移、CFRP应变较室温组试件分别下降26. 11%、25. 77%、40. 33%;湿热腐蚀介质渗入黏结界面,引起应变传递及位移发展更为迅速,对加固结构耐久性造成了损伤。

Bond Behavior Study on Interface between CFRP and Concrete under Hydrothermal Environment

In order to explore the bonding behavior of concrete structures strengthened by CFRP under hydrothermal environment, there were 36 specimens carried out for CFRP-concrete under different hydrothermal environment. And accelerated hydrothermal aging were respectively conducted in 5 days, 10 days and 15 days. Then the double- shear test was performed to obtain the failure mode, ultimate bearing capacity, strain distribution and relative displacement on CFRP-concrete interface under the coupling action of different temperature and humidity. After long term temperature and humidity coupling, interface mechanical properties and bond durability were studied. Results showed that: the mechanical properties of CFRP-concrete interface were degraded after hydrothermal aging. The coupling action of high temperature and high humidity had an influence on the mechanical properties. After 15 days hydrothermal corrosion, limit load, ultimate displacement and CFRP strain were decreased by 26.11%, 25.77% and 40.33% respectively, compared with the specimens at room temperature. The penetration of hydrothermal corrosion medium into bonding interface, leading to the development of strain transfer and displacement more rapidly, caused damage to the durability of reinforced structures.