柔性基层在高寒地区沥青路面结构中的应用研究

Study on Applicability of Flexible Base of Asphalt Pavement in High-cold Area

为了研究半刚性基层、沥青稳定碎石柔性基层、级配碎石柔性基层和应力吸收夹层在减缓高寒地区沥青路面的半刚性材料层反射裂缝方面的不同效果,采用断裂力学理论和有限元技术,对半刚性材料层已有裂缝的4种路面结构进行了在车辆荷载和高寒地区的骤然降温综合作用下的热-力耦合分析。从应力强度因子和疲劳寿命两方面,开展了上述4种路面结构对反射裂缝在沥青面层中的扩展行为影响的对比研究。结果表明,在沥青混凝土路面的面层和半刚性材料层之间设置的柔性基层和应力吸收夹层可大幅度减缓反射裂缝的扩展速度,从而延长路面使用寿命,并按照沥青稳定碎石柔性基层、级配碎石柔性基层、应力吸收夹层、半刚性基层的顺序依次递减。

In order to study the different performances of semi-rigid base, asphalt-treated permeable flexible base, graded gravel flexible base and stress absorbing interlayer in decreasing the extending velocity of reflective cracks in semi-rigid material course of pavement surface in high-cold area, thermal-stress couple analysis was conducted in four kinds of pavement structures which included cracks through their semi-rigid material courses with vehicle load and the sharp temperature decline. The fracture mechanical theory and finite element （FE） program were employed on stress intensity factor （SIF） and fatigue life to conduct comparative studies on the different performances of abovementioned four kinds of material courses in decreasing the reflective cracks in pavement surface. The conclusion can be drawn that （1） the asphalt-treated permeable flexible base, graded gravel flexible base and stress absorbing interlayer between the semi-rigid material course and the pavement surface can decelerate the extending velocity of reflective cracks in pavement surface to increase the pavement life; （2） the fatigue lives of these pavement structures are in descending sequence.