沥青混合料高温蠕变变形行为及机理  

High-Temperature Creep Deformation Behavior and Its Mechanism of Asphalt Mixture

作　　者：栗培龙[1] 张争奇[1] 王秉纲[1] 

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

出　　处：《建筑材料学报》2012年第3期422-426,共5页Journal of Building Materials

基　　金：国家自然科学基金资助项目(51008031);高等学校博士学科点专项科研基金资助项目(20100205120001);中央高校基本科研业务费专项资金资助项目(CHD2012JC028)

摘　　要：采用3种级配沥青混合料,在不同温度条件和应力水平下进行静态蠕变试验,根据应力应变关系得到了稳态蠕变速率,讨论了温度和荷载应力对沥青混合料稳态蠕变速率的影响,并通过稳态蠕变速率与温度、应力水平的量化关系获得了应力指数和蠕变激活能,并分析了沥青混合料的蠕变行为与机理.研究表明:虽然3种沥青混合料的稳态蠕变速率均随温度和应力水平的提高而逐渐增大,但它们的应力指数相差不大,均小于3,属于矿料界面位错机理控制的扩散蠕变;沥青混合料蠕变激活能与车辙动稳定度相关性较好,可以反映该混合料的高温稳定性,其中中型级配AC-16沥青混合料的蠕变激活能最高;公称粒径大小不是影响沥青混合料高温性能的决定性因素.Static creep tests were conducted on three kinds of asphalt mixtures under different temperatures and stress levels. The property of creep deformation was analyzed. The mechanical parameter k （creep rate, that is, the second phase slope） was obtained according to the stress-strain relations. The effects of temperature and stress on creep rate of asphalt mixture were discussed. Form the relation of creep rate with temperature stress, stress exponent and creep activation energy were calculated to analyze the creep mechanism of asphalt mixture. The results show that k increases gradually with temperature and almost linearly with increasing load stress. The stress exponents of three mixtures have no significant difference, and they are all diffusion creep controlled by the mechanism of mineral aggregate interface. The creep acti-vation energy has close relation with dynamic stability, which reflects high temperature performance of as-phalt mixture.

关 键 词：沥青混合料 蠕变行为 力学参数 应力指数 蠕变激活能 

分 类 号：U414[交通运输工程—道路与铁道工程]