摘要
为合理评价沥青混合料的低温抗裂性能,通过小梁低温弯曲、中梁线收缩系数和法国梯形梁动态模量3种试验方法,分别对RIOHTrack所用9种AC-25下面层沥青混合料进行了低温性能测试,分析了-10℃下最大弯拉应变、应变能密度、线收缩系数、复模量和相位角5个评价指标之间的相关性,并对比评价了各下面层混合料的低温性能。结果表明:不同试验指标的低温性能评价结果存在一定的差异,小梁低温弯曲试验的最大弯拉应变和应变能密度及M2F动态模量试验的复模量和相位角与沥青混合料的低温蠕变性能呈现良好的一致性,而线收缩系数虽可表征混合料本身的低温收缩性能,但不能合理评价各混合料低温抗裂性能的优劣;相同试验不同指标之间及小梁低温弯曲与M2F动态模量试验结果之间的相关性显著,最大弯拉应变和复模量分别为这2种试验方法的最优指标,其中最大弯拉应变与其他试验指标之间的综合相关性最为显著,故优选其作为最佳评价指标。据此评价可知:橡胶混合料的低温性能最优,SBS改性混合料次之,普通混合料最差,说明沥青结合料类型对混合料低温性能有显著影响,橡胶和SBS改性沥青及高标号石油沥青能有效改善沥青混合料的低温性能,粗集料含量较高的混合料及再生混合料也能达到良好的低温性能。
In order to reasonably evaluate the low temperature crack resistance of asphalt mixture, the low temperature performance of 9 AC-25 asphalt mixtures in the bottom surface layer of RIOHTrack are tested by the methods of testing small beam low temperature bending, linear shrinkage coefficient of middle beam and dynamic modulus of French trapezoidal beam respectively. The correlations among 5 evaluation indicators including maximum flexural-tensile strain, strain energy density, linear shrinkage coefficient, complex modulus and phase angle at-10 ℃ are analyzed, and the low temperature performances of all bottom surface layer mixtures are compared and evaluated. The result shows that(1) There are some differences in the evaluation results of different test indicatores in low temperature performance, the maximum flexural-tensile strain and strain energy density of small beam low temperature bending test and the complex modulus and phase angle obtained by M2 F dynamic modulus test show good consistency with the low temperature creep performance of asphalt mixture. However, the linear shrinkage coefficient can characterize the low temperature shrinkage performance of mixture itself, but it cannot reasonably evaluate the advantages and disadvantages of low temperature crack resistance of the mixtures.(2) There are significant correlations among different indicatores in the same test and between the test results of the small beam low temperature bending and the M2 F dynamic modulus, the maximum flexural-tensile strain and the complex modulus are the optimum indicators for these 2 test methods respectively. Among them, the comprehensive correlation of the maximum flexural-tensile strain with other test indicators is the most significant, so it is preferred as the best evaluation indicator. It can be seen from this evaluation that the low temperature performance of rubber mixture is the best, that of SBS modified mixture is the second, and that of ordinary mixture is the worst, indicating that the type of asphalt binder has significant influence on the low temperature performance of mixture. Rubber, SBS modified asphalt and high grade petroleum asphalt can effectively improve the low temperature performance of asphalt mixture. The mixture with higher content of coarse aggregate and the recycled mixture can also achieve good low temperature performance.
作者
查旭东
李聪
邹博
王旭东
潘勤学
ZHA Xu-dong;LI Cong;ZOU Bo;WANG Xu-dong;PAN Qin-xue(School of Traffic and Transportation Engineering,Changsha University of Science and Technology,Changsha Hunan 410114,China;Research Institute of Highway,Ministry of Transport,Beijing 100088,China)
出处
《公路交通科技》
CAS
CSCD
北大核心
2022年第6期1-8,共8页
Journal of Highway and Transportation Research and Development
基金
国家自然科学基金项目(51878077)
湖南省自然科学基金委青年基金项目(2020JJ5579)
安徽省交通运输科技进步计划项目(201720)
中铁五局集团有限公司科技项目(2020[12])。
关键词
道路工程
评价指标
低温性能试验
沥青混合料
相关性分析
road engineering
evaluation indicator
low temperature performance test
asphalt mixture
correlation analysis
