密级配沥青混合料集料分形分维与路用性能的关系

Relationship between fractal dimension and road performance of dense-gradation asphalt mixture

从集料结构本身出发,利用分形几何的基本理论,建立沥青混合料集料的粒径分布分形模型、集料体积分形模型和集料孔隙分形模型。集料的体积分形维数是一个饱含丰富信息的重要参数,其与沥青混合料的空隙率存在强相关性,建立AC-16密级配沥青混合料集料体积分形维数与沥青混合料空隙率的回归模型。通过大量路用性能试验,得到AC-16密级配沥青混合料集料的体积分形维数与路用性能指标之间的相关变化规律。集料的体积分形维数增大,沥青混合料的高温性能、抗滑性能呈下降趋势,水稳定性、低温抗裂性呈上升趋势。根据密级配沥青混合料集料体积分形维数与各项路用性能的关系,可对具有不同集料体积分形维数的沥青混合料的路用性能进行预估。

The fractal models of grain size distribution, aggregate volume and aggregate pore are deduced from the composition of aggregation by using the theory of fractal geometry. The fractal dimension of aggregate volume is an important parameter with rich information content. There is a strong correlation between the fractal dimension of aggregate volume and the air void of asphalt mixtures. A regression model for the fraetal dimension of aggregate volume and air void of AC-16 is derived. The correlations between road performance and the fractal dimension of aggregate volume of AC-16 are obtained from road tests. With the fraetal dimension of volume being increased, the high temperature stability performance and anti-skidding performance of asphalt mixtures are weakened, whereas the moisture susceptibility and the low temperature anti-split performance are improved. The road performances of asphalt mixtures with different fractal dimensions of aggregate volume can be estimated accordingly.