环氧沥青混合料疲劳衰变特性试验  

Experiment on Fatigue Damage Characteristics of Epoxy Asphalt Mixture

作　　者：罗桑[1] 钱振东[1] HARVEY J 

机构地区：[1]东南大学智能运输系统研究中心,江苏南京210096 [2]加利福尼亚大学伯克利分校路面研究中心,加利福尼亚伯克利ca94804

出　　处：《中国公路学报》2013年第2期20-25,共6页China Journal of Highway and Transport

基　　金："十一五"国家科技支撑计划项目(2009BAG15B03);国家自然科学基金项目(50878053);教育部高等学校博士学科点专项科研基金项目(20110092120062)

摘　　要：为获取钢桥面铺装环氧沥青混合料的疲劳衰变特性,首先基于正交异性桥面板-铺装层组成的复合结构模型,计算出标准胎压、超载50%以及超载100%胎压作用下铺装层的最大拉应变,作为疲劳试验应变水平的选取标准;然后,采用小梁四点弯曲疲劳试验对3组不同温度和不同应变条件下的环氧沥青混合料疲劳性能进行测试;最后,利用威布尔公式对不同温度与应变条件下的环氧沥青混合料疲劳寿命与疲劳裂纹扩展时的作用次数进行预测。结果表明:环氧沥青混合料初始模量大小仅与温度相关,与应变水平无关;在10℃和20℃时,1.38 MPa以下胎压以及30℃时0.7MPa胎压作用500万次均不发生疲劳破坏;30℃时,1.1 MPa和1.38 MPa胎压分别作用66 833次和35 480次出现疲劳损坏现象;相同应变作用下,试验温度越低,小梁疲劳破坏越快;环氧沥青混合料疲劳曲线可明显分为试验设备稳定、疲劳裂缝启裂、疲劳裂缝扩展3个阶段。研究结果可为环氧沥青混合料铺装疲劳寿命预估以及预防性养护提供理论依据。To obtain fatigue characteristics of epoxy asphalt mixture paved on steel deck bridges, the tensile strain of pavement was calculated firstly under standard tire pressure, 50~ and 100~ overload respectively, with composite structure model of orthotropic steel deck and concrete pavement. Secondly, four-point bending fatigue tests were conducted under three different temperatures and three strain levels under each temperature. Finally, fatigue lives and load cycles at crack propagating were predicted with Weibull formula. The results show that initial modulus of epoxy asphalt mixture is determined by temperature but not by strain level; epoxy asphalt mixture is in good condition at five million load cycles when the tire pressure is less than 1.38 MPaat 10 ~C and 20 ~C, and 0.7 MPa at 30 ~C; fatigue damage happens at 66 833 and 35 480 cycles under 1.1 and 1.38 MPa tire pressure at 30 ~C respectively; under the same strain level, fatigue life of epoxy asphalt mixture decreases with temperature decreasing; fatigue curves ofepoxy asphalt mixture can be divided into equipment warm-up, initial cracking and crack propagating stage. The findings provide theory foundation for fatigue predication and preventive maintenance of epoxy asphalt mixture pavement.

关 键 词：道路工程 环氧沥青混合料 四点弯曲疲劳试验 疲劳衰变 威布尔公式 

分 类 号：U414.1[交通运输工程—道路与铁道工程]