集料分布对沥青混合料劈裂强度影响数值分析

Numerical analysis of effect of aggregate distribution on splitting strength of asphalt mixtures

基于数字图像处理,研究沥青混合料集料分布状态.采用有限元法建立基于沥青混合料二维截面的劈裂试验模型,数值分析集料分布状态对虚拟劈裂试验力学性能的影响,并通过室内劈裂试验进行验证.研究结果表明:基于数字图像处理,通过集料分布状态指标可以评价沥青混合料集料分布状态;集料公称最大粒径增大,沥青混合料集料分布状态变差;集料分布状态与沥青混合料虚拟劈裂试验力学性能变异性存在明显的相关性,集料分布状态越差,通过沥青混合料虚拟劈裂试验计算得到的压头反力均值的变异系数越大.

The aggregate distribution in asphalt mixtures was analyzed based on digital image processing. The splitting test model based on two-dimensional cross sections of asphalt mixtures was established by the finite element method. The effect of aggregate distribution on the mechanical properties of asphalt mix- tures was numerically analyzed and verified by the laboratory splitting test. Results show that the aggre- gate distribution in asphalt mixtures can be assessed by the index of aggregate distribution based on digital image processing. The aggregate distribution in asphalt mixtures deteriorates with an increase in the nomi- nal maximum aggregate size. There is an obvious relationship between aggregate distribution and varia- tions in the mechanical properties of the virtual splitting test of asphalt mixtures. The worse the aggregate distribution is, the greater the variation coefficient of the average pressure head reaction forces is.