钢桥面与环氧沥青铺装界面剪切特性

Shear Characteristics of Interface Between Steel Bridge Deck and Epoxy Asphalt Pavement

为了给钢桥面铺装设计提供参考,针对钢桥面铺装工程中普遍采用的环氧沥青混凝土铺装结构,考虑了温度、法向应力等影响因素,进行了钢桥面与环氧沥青混凝土铺装界面剪切特性的试验研究。采用钢-混凝土界面剪切试验装置(Steel-Concrete Interface Shear,SCIS),在25℃、60℃两种温度和0,0.2,0.5,0.7 MPa四级法向应力水平下测试了钢桥面与环氧沥青混凝土铺装界面的剪切性能,获得了界面剪切破坏形态、抗剪强度、残余抗剪强度、剪应力-剪切变形曲线等试验结果,分析了温度、法向应力对界面抗剪强度的影响规律以及界面的黏结-滑移机理。基于摩尔-库仑强度理论建立了钢桥面与环氧沥青混凝土铺装界面在25℃和60℃两种温度条件下的抗剪强度包络线。研究结果表明:在仅考虑温度和压、剪应力的条件下,钢桥面与环氧沥青混凝土铺装界面破坏产生于防腐涂装与防水黏结层的界面区;界面抗剪强度随温度降低和法向应力水平增加而增大;残余抗剪强度受温度影响较小,主要随法向应力增加而增大;界面剪应力-剪切变形曲线具有韧性破坏特征且呈四阶段发展规律;钢桥面与铺装界面的抗剪强度包络线可采用摩尔-库仑强度理论进行建立。

In order to provide a reference for the design of asphalt pavements on steel bridges,shear characteristics of the interface between the steel bridge deck and the epoxy asphalt pavement which has been widely applied in projects were experimentally investigated.Factors affecting the interface characteristics,including temperatures and normal stress levels,were taken into consideration.The shear tests were performed at the steel-asphalt interface at two temperatures of 25 ℃ and 60 ℃ and four normal stress levels of 0,0.2,0.4,and 0.7 MPa for each temperature by steel-concrete interface shear（SCIS）test apparatus.The failure patterns,shear strengths,residual shear strengths,curves of shear stress-displacement were obtained from the tests.Influences of temperatures and normal stress levels on the shear strength and Bond-slip mechanism of the interface were analyzed.Finally,the shear strength envelopes of the interface at 25 ℃ and 60 ℃ were established in terms of the Mohr-Coulomb failure law.The results show that the interface between the steel bridge deck and the epoxy asphalt pavement failsat the primer-tack coat interface,only taken temperature,compressive and shear stress into consideration.The shear strengths significantly increase with decreasing temperatures and more valuable normal stress levels.The residual shear strengths are less influenced by temperatures,markedly increasing with the increase of normal stress levels.The shear stress-displacement curves present ductile failure characteristics and can be divided into four phases.The shear strength envelopes of the interface between the steel bridge deck and the epoxy asphalt pavement can be established based on the Mohr-Coulomb failure law.