BFRP 和 CFRP 加固受弯混凝土界面疲劳性能试验

摘要

以纤维增强复合材料（FRP）片材外贴混凝土受弯构件为研究对象，探讨玄武岩纤维（BFRP）和碳纤维增强复合材料（CFRP）加固混凝土界面疲劳性能。通过实施四点弯曲加载试验，研究了BFRP和CFRP加固混凝土界面疲劳破坏模式、界面疲劳裂缝扩展规律以及构件跨中挠度和FRP应变随加载循环次数的变化规律，并对BFRP和CFRP加固混凝土界面的静载剥离承载力和疲劳寿命进行了分析，给出了BFRP和CFRP加固混凝土界面的疲劳强度。研究结果表明：与BFRP‐混凝土界面相比，CFRP‐混凝土界面的静载剥离承载力提高了约50％，其疲劳寿命也明显提高；既有疲劳历程对BFRP和CFRP加固混凝土界面的静载剥离承载力影响不大。%Taking the flexurally strengthened concrete members with fiber reinforced polymer (FRP) as the research object ,the fatigue behaviors of the concrete interface strengthened with basalt fiber reinforced polymer (BFRP ) and carbon fiber reinforced polymer (CFRP ) were investigated .Based on a series of four‐point bending loading tests ,the fatigue failure modes and the propagation law of interface crack strengthened with BFRP and CFRP , as well as the evolution of mid‐span deflection and FRP strain change rule with loading cycle numbers were studied .Moreover , the debonding load‐carrying capacity and the fatigue life of the BFRP‐concrete and CFRP‐concrete interface were analyzed ,and the fatigue strength of the concrete interface flexurally strengthened with BFRP and CFRP was proposed .The study results show that compared with the concrete members strengthened with BFRP ,the debonding load‐carrying capacity of those with CFRP increases about 50% ,and the fatigue life of those with CFRP is significantly longer .The effects of pre‐fatigue damage are slight on the debonding load‐carrying capacity of BFRP‐concrete and CFRP‐concrete interface .