混凝土表面粗糙度参数下的CFRP-混凝土界面抗冻性研究

为了研究不同混凝土表面粗糙度在盐冻环境下的CFRP-混凝土界面黏结性能退化规律,通过制作具有三面粗糙度的CFRP-混凝土试块,开展了84次CFRP-混凝土界面正拉黏结试验。探讨了混凝土强度、界面粗糙度、盐冻循环次数对CFRP-混凝土梁界面黏结性能的影响,建立了基于粗糙度fi,盐冻循环次数n两参数下的界面剥离承载力回归模型,基于SEM检测技术分析了界面性能退化机理。结果表明:混凝土强度对界面黏结性能影响不大,当混凝土表面粗糙度为0.33时,界面黏结性能最佳;平均单个粗骨料漏出尺寸为整个粗糙度的20%时,界面黏结效果最好;在(-15~8)℃范围内,6次盐冻循环后,界面开始出现劣化,到了12次界面黏结性能降低较为明显。

Analysis on the interfacial frost resistance between CFRP and concrete based on the concrete surface roughness

In order to analysis the different concrete surface roughness in the salt frost environment,and its interfacial bond stress degradation between CFRP and concrete,through the produced CFRP and concrete blocks with three surface roughness.Conducted 42 times pull-out interface tests of CFRP and concrete,discusses the concrete strength,interface roughness,frost cycles which influence on the interface bond performance,proposed interface ultimate load regression model based on roughness fi,frost cycles n,based on the SEM inspection technology to analysis interface performance degradation mechanism.The results show that the concrete strength influences little on the interface bond performance,when the concrete surface roughness is 0.33,the bond performance is best.The appeared average single aggregate size is 20%,the interface bond effect is best.Within(-15~8)℃,after 6 times salt after frozen cycle,interface degradation began to appear,and in 12 times the bond performance degradation is more obvious.