大粒径沥青混合料防裂机理耦合数值分析  

Coupled Numerical Analysis of Anti-crack Mechanism of Large Stone Asphalt Mixture

作　　者：资建民[1] 路庆昌[1] 王海军 黄求喜[3] 万伟[1] 

机构地区：[1]华中科技大学土木工程与力学学院,湖北武汉430074 [2]长春市政工程设计研究院宁波分院,浙江宁波315040 [3]西华大学建筑与土木工程学院,四川成都610039

出　　处：《公路交通科技》2009年第5期40-44,共5页Journal of Highway and Transportation Research and Development

基　　金：湖北省交通厅科技攻关项目(2005361)

摘　　要：采用有限元方法分析LSAM-30基层沥青路面结构的最不利荷位在行车荷载、温度荷载以及两者耦合应力作用下的应力状态,同时与设置相同厚度的ATPB-30、AC-30I基层的应力计算结果进行对比分析,结果表明LSAM-30、ATPB-30基层比AC-30I基层有较好的缓解反射裂缝的能力。LSAM-30粗骨料多,公称粒径大,因而导热系数大,温缩系数小,回弹模量小,可有效减小结构层层间温度梯度,进而减小层间温度应力,同时其表现出的足够的柔性也可以充分地吸收裂缝处的应变能,因而具有较强的防裂能力。通过工程实例对比分析了LSAM-30、ATPB-30、AC-30I,3种基层的防裂性能。通过长期实际使用情况表明,铺设LSMA基层的路面使用状况良好、未发现裂缝生长迹象,而铺设其他2种基层的路面则出现了不同程度的裂缝,结果表明LSMA基层具有明显的防裂性能。Stresses of pavement with flexible base of LSAM-30, ATPB-30 and AC-30I at the most adverse point under the function of traffic load and temperature load as well as the coupling of them were calculated and compared by finite element method. The result indicates that flexible bases of LSAM-30 and ATPB-30 and more effective in the prevention of reflection crack. Because of the great volume of coarse aggregate and large maximum nominal particle- size, the LSAM-30 thermal conductivity is greater, and the temperature shrinking coefficient is lower as well as the modulus of resilience, which could reduce the temperature gradient among the structure layers effectively and then minish the thermal stress. At the same time, the adequate flexibility performance of the LSAM may also absorb strain energy at the crack of the semi-rigid subbase sufficiently. As a result, it presented preferable reflection crack resistance. A case study was conducted to do comparative analysis of anti-cracking performance of LSAM-30, ATPB -30 and AC-30I flexible bases. A long-term follow-up observation of test roads with the three bases shows that the pavement with LSMA base is in good condition and no sign of crack found while pavements with ATPB-30 and AC- 30I flexible bases have varying degrees of crack. LSMA flexible base has an obvious performance of anti-crack.

关 键 词：道路工程 防裂机理 数值分析 大粒径沥青混合料 反射裂缝 

分 类 号：U416.01[交通运输工程—道路与铁道工程]