摘要
为了解决刚性基层沥青路面存在的沥青面层反射裂缝问题,提出了采用开级配大粒径沥青碎石混合料(OLSM)作为裂缝缓解层的方法,以国内外OLSM参考级配为基础,结合试验段修筑情况,采用离散元方法,运用二维颗粒流程序,建立设置OLSM-25裂缝缓解层的沥青路面离散元模型,对其细观结构与抗裂性能进行离散元数值分析,从细观角度阐释了OLSM-25裂缝缓解层的抗裂机理。研究结果表明:在车辆荷载偏载作用下,当裂缝缓解层厚度相同时,OLSM-25裂缝缓解层底部A点颗粒的竖向接触力、竖向运动速度及竖向位移量均小于普通AC-25裂缝缓解层的对应值,OLSM-25裂缝缓解层的抗裂效果优于普通AC-25裂缝缓解层;在实际工程应用中,综合考虑应力缓解效果及变形能力两大因素,选择材料组成相对偏粗、空隙率适中的2#级配OLSM-25作为裂缝缓解层较为合适。
In order to solve the problem of the reflective cracking in the rigid base asphalt pavement, with a method of using open-graded large stone asphalt mixes （OLSM） as the cracking relief layer, the discrete element model of asphalt pavement with OLSM-25 cracking relief layer was established by employing the discrete element method and the two-dimensional particle flow code according to the reference gradation of OLSM both at home and abroad and the condition of construction in the test roads. After numerical analying on mesostructure and anti-cracking performance of asphalt pavement with OLSM-25 cracking relief layer, the anti-crack mechanism of OLSM-25 cracking relief layer was demonstrated from the microscopic view. The results show that under the action of the asymmetric traffic load, the vertical contact force, the speed of the vertical movement and the vertical displacement of A point particle at the bottom of OLSM-25 cracking relief layer are less than the corresponding values of the ordinary AC-25 cracking relief layer with the same thickness, and the anti-cracking effect of OLSM-25 cracking relief layer is better than that of ordinary AC-25 cracking relief layer. In the practical engineering applications, it is more appropriate to take No. 2 gradation OLSM-25 composed of more coarse aggregates and medium porosity as the cracking relief layer by considering two factors-stress relief effect and the deformation ability. 3 tabs, 6 figs, 14 refs.
出处
《长安大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2015年第3期34-39,52,共7页
Journal of Chang’an University(Natural Science Edition)
基金
交通运输部西部交通建设科技项目(2008 318 812 10)
中央高校基本科研业务费专项资金项目(CHD 2010JC011)
陕西省教育厅专项科研计划项目(14JK1067)
关键词
道路工程
开级配大粒径沥青碎石
二维离散元
细观结构
数值分析
抗裂机理
裂缝缓解层
road engineering
OLSM
two-dimensional discrete element
mesostructure
numerical analysis
anti-cracking mechanism
cracking relief layer
