动态疲劳荷载作用下路面混凝土力学性能研究  

Mechanical Property of Pavement Cement Concrete Under Dynamic Fatigue Load

作　　者：郭寅川[1,2] 申爱琴[1] 田丰[1] 周胜波[1] GUO Yin-chuan SHEN Ai-qin TIAN Feng ZHOU Sheng-bo(Key Laboratory of Highway Engineering in Special Region of Ministry of Education, Chang＇an University, Xi＇an 710064, Shaanxi, China Louisiana Transportation Research Center, Louisiana State University, Baton Rouge LA 70803, Louisiana, USA)

机构地区：[1]长安大学特殊地区公路工程教育部重点实验室,陕西西安710064 [2]路易斯安那州立大学路易斯安那州交通研究中心,路易斯安那巴吞鲁日la70803

出　　处：《中国公路学报》2017年第7期18-24,共7页China Journal of Highway and Transport

基　　金：国家自然科学基金项目(51608047;51278059)

摘　　要：为了探究经历车辆动态疲劳荷载作用后路面水泥混凝土力学性能的衰减规律,基于正交试验设计了力学性能、耐久性及工作性最佳的路面混凝土配比;选取了30%、50%、80%三个荷载应力水平,设计了4种不同的疲劳加载方案对路面混凝土进行疲劳试验。利用MTS测定了不同疲劳加载方案下路面混凝土的剩余强度和应力-应变曲线变化规律,并借助经典的断裂能理论对动态疲劳荷载作用下路面混凝土力学性能进行研究。结果表明:应力水平为80%的动态疲劳荷载作用下路面混凝土的剩余弯拉强度呈现衰减趋势,加载4h后其剩余弯拉强度较基准降低了20%;当荷载应力水平为30%、50%时,动态疲劳荷载作用前期混凝土剩余弯拉强度出现负衰减,疲劳加载3h后其剩余弯拉强度较基准分别提高7.9%、3.1%;动态疲劳荷载造成路面混凝土脆性增加,其变形呈现"弹性-塑性-类似弹性"的三阶段衰减规律;路面混凝土的断裂能随着加载时间及荷载应力水平的增加逐渐降低,应力水平大于50%时疲劳荷载对混凝土的断裂能劣化显著;当应力水平为30%、50%和80%时,加载4h后断裂能较基准分别降低24%、57%和66%。In order to explore the attenuation law of mechanical properties of pavement cement concrete under vehicle dynamic fatigue load,pavement cement concrete ratios with optimum mechanical property,durability and workability were proposed based on the orthogonal test.Three stress levels（i.e.30%,50% and 80%）were selected to design four different fatigue load schemes for the fatigue test.The residual strength and the change law of stress-strain curves of pavement cement concrete under different fatigue load schemes were measured by MTS and the classical theory of fracture energy was used to analyze the mechanical property of pavement cement concrete under dynamic fatigue load.The Results show that the residual strength ofpavement cement concrete decreases under dynamic fatigue load with stress level of 80%,and the residual strength decreases by 20% after 4hours＇ loading.When loading stress levels are 30% and 50% respectively,there is a negative attenuation of residual strength in the initial period of dynamic fatigue load and the residual strength increases by 7.9% and 3.1% respectively,after 3hours＇ loading.The brittleness of pavement cement concrete increases,resulting from the dynamic fatigue load.The attenuation law of deformation is characterized by three stages,namely,elasticity,plasticity,and quasi-elasticity.With the increase of loading time and stress level,the fracture energy of pavement cement concrete gradually decreases.When the stress level is greater than 50%,the fracture energy deteriorates significantly under the fatigue load.When the stress levels are 30%,50% and 80% respectively,the fracture energy of pavement cement concrete decreases by 24%,57% and 66% respectively after 4hours＇ loading,compared with the control specimen.

关 键 词：道路工程 水泥混凝土 力学性能试验 动态疲劳荷载 断裂能 

分 类 号：U416.1[交通运输工程—道路与铁道工程]