SMA沥青混合料的冻断温度及其影响因素研究  

Study on freezing fracture temperature of SMA asphalt mixture and its influencing factors

作　　者：丁灿 沈菊男 Ding Can;Shen Junan(Provincial Center for Ecological Road Technology Industrialization,Civil Engineering College,Suzhou University of Science and Technology,Suzhou 215009,China)

机构地区：[1]苏州科技大学土木工程学院省生态道路技术产业化中心,浙江苏州215009

出　　处：《山西建筑》2022年第21期1-6,共6页Shanxi Architecture

基　　金：国家科学自然基金(51378328);苏州市科技计划项目(SS202026)。

摘　　要：冻断温度作为约束试件温度应力试验的主要指标,能够准确评价沥青混合料的低温性能,研究其影响因素是更好控制或减少沥青路面低温收缩裂缝的重要课题。基于约束试件温度应力试验、弯曲梁流变试验、沥青混合料的体积参数和小梁弯曲试验,分析了沥青及SMA混合料指标对冻断温度的影响规律。结果表明,同一试验条件下,冻断应力提高70.9%,冻断温度降低10.6℃,二者呈负相关。冻断温度与沥青流变性相联系,沥青劲度模量越大,蠕变速率越小,冻断温度越高。沥青混合料的空隙率主要影响最佳沥青用量,进而影响冻断温度,空隙率降低0.32,沥青用量提高0.8%,冻断温度降低10.6℃。同一试验条件下,沥青混合料弯拉应变和弯曲劲度模量分别降低5.3%和5.8%,冻断温度也会降低33.7%,二者呈正相关。As the main index to thermal strength restrained specimen Test,the freezing fracture temperature can accurately evaluate the low temperature performance of asphalt mixture,and study of its influencing factors is an important topic to better control or reduce the low temperature shrinkage crack of asphalt pavement.In this paper,the influence of asphalt and SMA mixture indexes on freezing fracture temperature is analyzed based on thermal strength Restrained Specimen Test,rheological test of bending beam,volume parameter of asphalt mixture and bending beam test.The results show that:under the same test conditions,the freezing fracture strength increases by 70.9%,and freezing fracture temperature decreases by 10.6 ℃,and the two are negatively correlated.The freezing fracture temperature is related to the rheological properties of asphalt.The higher the stiffness modulus of asphalt,the smaller the creep rate and the higher the freezing fracture temperature.The void fraction of asphalt mixture mainly affects the optimal asphalt content,and then affects the freezing fracture temperature.The void fraction decreases by 0.32,the asphalt content increases by 0.8%,and the freezing fracture temperature decreases by 10.6 ℃.Under the same test conditions,bending tensile strains and bending stiffness of asphalt mixture decrease by 5.3% and 5.8% respectively,and the freezing fracture temperature also decreases by 33.7%,showing a positive correlation.

关 键 词：冻断温度 沥青混合料 冻断应力 劲度模量 

分 类 号：TU502[建筑科学—建筑技术科学]