沥青混合料蠕变模型的改进及其参数确定  

Modification of Creep Model of Asphalt Mixture and Parameters Determination

作　　者：张久鹏[1] 徐丽[2] 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,西安710064 [2]中交第一公路勘察设计研究院有限公司,西安710075

出　　处：《武汉理工大学学报（交通科学与工程版）》2010年第4期699-702,706,共5页Journal of Wuhan University of Technology（Transportation Science & Engineering）

基　　金：国家自然科学基金项目(批准号:50608006);西部交通建设科技项目(批准号:2006318812112)资助

摘　　要：现有力学模型不能全面描述沥青混合料的蠕变,因此根据沥青混合料三阶段的蠕变特性,对Burgers模型中表征粘性流动的外部粘壶进行改进,认为其粘滞系数先增大后减小.推导了改进模型的本构方程,得到了蠕变应变、蠕变速率和蠕变加速度的解析表达式;运用最小二乘原理,建立了模型参数的确定方法;通过两个实例验证了改进模型的正确性.研究表明改进模型拟合曲线与实测应变吻合较好,相关性系数高,而且计算得到的流变时间与实测流变时间误差较小,说明该力学模型能够反映下沥青混合料第三阶段的蠕变,而流变时间Ft可作为研究沥青混合料蠕变性能的一个重要指标.The existing mechanics model can not describe the overall creep of asphalt mixture,so based on the three-phase creep character of asphalt mixture,the dashpot of Burgers model was modified and its viscosity coefficient first increased then decreased.Then,constitutive relationship of the improved model was deduced,and the expressions of creep strain,creep rate and creep acceleration were also given.Meantime,creep rupture time was defined as the creep stability criterion by analyzing the stability of the modified model and parameters determination method was established by the principle of least square.Finally,the proposed model was verified through two experimental studies.It is indicated that the modified model can clearly describe the three-phase creep,especially the accelerating creep stage,and creep rupture time can also be used as a important index to research the creep character of asphalt mixture.The research puts forward a new thought for studying the creep character of asphalt mixture.

关 键 词：沥青混合料 蠕变模型 改进 流变参数 

分 类 号：U416.2[交通运输工程—道路与铁道工程]