基于细观结构的沥青碎石封层路面力学行为分析
Mechanical Behavior Analysis of Asphalt Chip Seals Based on the Microstructure
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摘要: 为了认识沥青碎石封层的力学行为与破坏机理,采用有限元软件建立沥青碎石封层细观结构二维有限元模型,分析在竖向荷载作用下封层内部细观结构应力、应变和位移的力学行为特性. 分析结果显示:轮迹内侧边缘碎石竖向位移最大,偏转角度最小;相反,轮迹外边缘碎石偏转角度最大,并向两侧逐渐递减. 沥青层内的水平应变主要为压应变,轮迹外侧沥青和胶浆层接触面上剪应变最大. 黏结层的水平变形、剪切变形均不同程度大于沥青层,黏结层与胶浆层交界处具有最大等效Mises应力,易发生剪切破坏. 胶浆层的中心主要为受压变形,胶浆层两侧边缘处主要表现为较高剪切变形.Abstract: Based on the microstructure, a two-dimensional finite element model for asphalt chip seals was built to analyze the mechanical behavior under vertical loads. The results show that the vertical displacement of stones in chip seals at the inner edge of the wheel is the maximum and the rotation angle is the minimum. On the contrary, the rotation angle of the stones at outer edge of the wheel path is the largest, and gradually decreases from the outer edge to two sides. The horizontal strain in asphalt binder is mainly compressive strain. The maximum shear strains at the outer edge of wheel path exist at the interface between asphalt and asphalt mastic. The horizontal deformation and shear deformation at the aggregate-asphalt interface are higher than in asphalt binder. The maximum Mises stress is on the interface at the stone-asphalt and the greater shear deformation is in asphalt mastic under the stones, which easily lead to shear failure on the asphalt chip seals.