高温下CFRP-混凝土界面受剪性能试验研析.pdfVIP

第六届全国土木工程研究生学术论坛 清华大学 2008 高温下 CFRP-混凝土界面受剪性能试验研究 胡克旭，卢凡，蔡正华 （同济大学结构工程与防灾研究所，上海 200092 ） 摘 要: CFRP 加固构件的耐火性能不理想的一个重要原因是粘结 CFPR 和混凝土的胶粘剂胶体在高温下会软化直至变为 流态既而蒸发，导致胶层失效。针对目前对高温下 CFRP 和混凝土两种材料共同工作的界面性能研究较少，本文开展了高温下 CFRP-混凝土界面受剪性能的研究，分别在 4 ℃、40 ℃、60℃、80℃、100℃、120℃、140℃、160℃、180℃下进行高温下双面剪 切试验。试验中记录其荷载-位移试验曲线，研究了各温度下界面破坏形式、高温对胶体及 CFRP 的影响，以及粘结强度随温度 的变化规律。试验发现高温下界面破坏沿胶层发展，胶体会随温度升高软化甚至蒸发，CFRP 会出现高温氧化现象。对试验数据 的分析表明，40 ℃时的界面粘结强度高于 4 ℃，40 ℃后粘结强度随温度升高降低，在 100℃后又趋于稳定，结果表明该规律主要 与胶层在高温下的形态有关。 关键词： 高温；CFRP-混凝土界面；双面剪切试验；界面粘结强度 Researches on Mechanical Property of CFRP-Concrete Interface Under Elevated Temperatures HU Kexu, LU Fan, CAI Zhenghua (Research Institute of Structural Engineering and Disaster Reduction, Tongji University, Shanghai 200092, China) Abstract: The main reason that the fire-resistance of the CFRP reinforced components is unsatisfactory is that the adhesive between CFRP and concrete softens and becomes flow pattern even evaporates under elevated temperature, causing the glue layer failure. For the research on the performance of the CFRP-concrete interface is less, the double-slap shear test under elevated temperature was designed, and the test was executed under 4℃、40 ℃、60℃、80℃、100℃、120℃、140℃、160℃ and 180 ℃. During the test, the research of the changing regulation of the interface strength with temperature has been done, and the failure type, influence of the temperature on the glue and CFRP were studied. The test result shows that the failure interface was along with the glue layer, the adhesive softened even evaporated with the temperature increasing, and CFRP was oxidated at high temperature. The analysis of the test data shows, the interface bond strength under 40 ℃ was higher than which under 4 ℃, but after