沥青混合料低温临界开裂温度的确定  

Determination of critical thermal cracking temperature of asphalt concrete

作　　者：付国志 曹丹丹[1] 赵延庆[2] ALAE Mohsen FU Guozhi;CAO Dandan;ZHAO Yanqing(School of Civil Engineering,Dalian University of Technology,Dalian 116024,China;School of Transportation Engineering,Dalian University of Technology,Dalian 116024,China)

机构地区：[1]大连理工大学土木工程学院,大连116024 [2]大连理工大学交通运输学院,大连116024

出　　处：《复合材料学报》2019年第4期1001-1007,共7页Acta Materiae Compositae Sinica

基　　金：国家自然科学基金(51678114);辽宁省自然科学基金(2015020238);内蒙古自治区交通运输厅项目(NJ-2014-21)

摘　　要：为了同时考虑沥青混合料在降温过程中温度应力的累积和松弛作用,确定临界开裂温度,对试件进行了线收缩系数试验,并利用间接拉伸试验确定其抗拉强度和蠕变柔量,由蠕变柔量和松弛模量的关系得到松弛模量的Prony系列表达式;由Boltzmann叠加原理,得到温度应力公式,计算出不同降温速率下产生的温度应力,根据低温抗拉强度曲线,确定出沥青混合料的临界开裂温度,并对结果予以验证。结果表明:该方法考虑了应力累积和松弛二者的综合作用,能够较好地反映沥青混合料的低温开裂特性,其计算结果与约束试件温度应力试验结果相近;该方法不仅适用于恒定降温速率,还适用于现场连续变速降温工况;随温度的降低或降温速率的增加沥青混合料内部温度应力累积速度加快,临界开裂温度随降温速率增加而升高。In order to consider both the thermal stress accumulation and relaxation effects of asphalt concrete(AC)during the process of temperature drop,and determine the critical cracking temperature,the low temperature shrinkage coefficient tests were conducted on AC specimens,and the tensile strength and creep compliance were determined from indirect tensile tests.The Prony series representation of relaxation modulus was obtained from the theoretical relationship.The thermal stress was computed according to the Boltzmann superposition principle.Thermal stresses induced at several of temperature drop rates were analyzed and the critical cracking temperatures(CCT)were determined based on the tensile strength curve.The calculation results were verified.The results show that this approach can take both the stress accumulation and relaxation into consideration,and better represent the low temperature cracking characteristic of AC.The calculation results are similar to that obtained from thermal stress restrained specimen test(TSRST).This approach can apply to both uniform temperatures drop and continuous drop in the field.The rate of thermal stress accumulation increases with decreasing temperature or increasing drop rate.The CCT increases with increasing drop rate.

关 键 词：道路工程 临界开裂温度 松弛模量主曲线 沥青混合料 低温开裂 温度应力 

分 类 号：U416.01[交通运输工程—道路与铁道工程]