OLSM缓解层沥青路面热-荷载耦合应力数值分析

Numerical Analysis of the Temperature- load Coupling Stress for Open- graded Large Stone Asphalt Mixtures

针对半刚性基层沥青路面和刚性基层沥青路面结构中普遍存在的反射裂缝问题，提出了采用开级配大粒径沥青碎石混合料作为裂缝缓解层的方法，采用三维有限元法，对设置普通沥青混凝土与开级配大粒径沥青碎石2种类型裂缝缓解层的贫混凝土基层沥青路面结构进行热一荷载耦合应力对比分析可知，后者的耦合应力明显小于前者的应力。试验路观测与理论计算分析表明，开级配大粒径沥青碎石混合料中大粒径矿料多、沥青含量少及空隙率大的结构特点有利于消散及吸收裂缝处路面应力，可有效地防止或减缓贫混凝土基层沥青路面的反射裂缝，是一种可以缓解反射裂缝的有效材料。

Aiming at the problem of the reflective cracking in semi-rigid base asphalt pavement and rigid base asphalt pavement structures, a method of using Open-graded Large Stone asphalt Mixes （OLSM） as the crack alle- viating layer is proposed, the 3-D finite element method is used to analyze the temperature-load coupling stress for the crack alleviating layer of ordinary asphalt concrete and OLSM, the result indicates that the temperature-load coupling stress of the latter are less than that of the former. The investigation of testing road and result of theoretical calculation indicate that, large mineral aggregate, low asphalt content and a great percentage of voids in OLSM are helpful to dissipate or absorb stress and strain around the crack, and OLSM can prevent lean concrete base asphalt pavement from the reflective cracking effectively, OLSM is an effective material to alleviate the reflective cracking.