碳纤维布-混凝土界面剪切性能试验研究

EXPERIMENTAL STUDY OF SHEAR PERFORMANCE OF CFRP REINFORCED CONCRETE INTERFACE

碳纤维布(CFRPS)与混凝土之间的黏结性能是影响碳纤维布加固混凝土结构受力性能的主要因素之一。为了研究影响碳纤维布-混凝土的黏结性能的因素,针对单位面积不同质量的碳纤维布、碳纤维布层数和混凝土强度等级,进行了碳纤维布-混凝土界面黏结性能的双剪试验。在不同碳纤维布、不同碳纤维布层数和不同混凝土强度等级下,分析碳纤维布与混凝土黏结界面的破坏特征,结合其荷载-位移曲线分析碳纤维布-混凝土黏结界面的破坏机理。采用应变叠加法得到黏结应力-滑移曲线,分析不同因素下的滑移量和最大剪应力,得到滑移量及最大剪应力在单一因素下的影响规律。试验结果表明:试件破坏发生均在混凝土表层之间;碳纤维布层数与混凝土强度等级能增加其界面极限承载力和最大剪应力,而不同的碳纤维布对界面极限承载力和最大剪应力影响不大;碳纤维布的相对滑移量随着碳纤维布单位面积质量、碳纤维布层数及混凝土强度等级增加而降低。

The bonding behavior between CFRP and concrete is one of the main factors affecting the mechanical properties of CFRP reinforced concrete structures.In order to study the factors affecting the bonding performance of CFRP-concrete,the double shear tests of CFRP-concrete interface bond properties were carried out according to different CFRP weight per square metre,CFRP layer number and concrete strength grade.Under different CFRP weight per square metre,different CFRP layer number and different concrete strength grade,the failure characteristics of the bond interface between CFRP and concrete were analyzed.Combined with its load-displacement curve,the failure mechanism of CFRP-concrete bonding interface was analyzed.The bond-slip curve was obtained by strain stacking,the slip amount and the maximum shear stress under different factors were analyzed,and the influence law of the slip amount and the maximum shear stress under a single factor were obtained.The test results showed that the failure of the specimens occurred between the concrete surface layer;and the strength grade of the carbon fiber cloth could increase the ultimate bearing capacity and the maximum shear stress of the interface,but different CFRP weight per square metre had little effect on the ultimate bearing capacity and the maximum shear stress of the interface;the relative slip of CFRP decreased with the increase of CFRP mass per unit area,CFRP layers and the strength grade of concrete.