基于分维度指标的泡沫沥青冷再生基层路用性能研究

Research of Road Performance of Cold Recycled Pavement Base with Foamed Asphalt Based on Fractal Dimension

针对路用集料非线性特征,采用集料粒径分布范围的体积分形维数、粗集料粒径分布范围的体积分形维数和细集料粒径分布范围的体积分形维数作为描述集料级配分布特征的指标。在此基础上,得出级配分形理论计算式,评价其与混合料性能的相关关系。研究结果表明:2.36 mm档细集料对泡沫沥青冷再生基层混合料物理力学性能有较大的影响;对于连续级配和间断级配,其集料粒径分布的体积分形维数分别表现为一重分形分布和二重分形分布;体积分形维数指标作为评价泡沫沥青冷再生基层集料粒径的分布特征具有很好的适用性;通过建立分维度与冷再生基层混合料物理力学及耐久性指标的回归模型,发现两者存在较好的相关性;集料的体积分形维数是一个富含信息的重要参数,分形特性是集料级配的本质属性。

With the nonlinear characteristics of road mineral material,the fractal dimension of aggregate size distribution including volume fractal dimension of whole aggregate, volume fractal dimension of coarse aggregate and volume fractal dimension of fine aggregate are used as the indexes to describe the distribution characteristics of aggregate gradation. On this basis,the formula of fractal gradation theory is obtained,and its correlation with the performance of the mixture is evaluated. The result shows that（ 1） the fine aggregate of 2. 36 mm size has a great influence on the physical and mechanical properties of the foamed asphalt cold recycling base mixture;（ 2） the volume fractal dimension of aggregate size distribution of continuous-graded aggregate is one-dimensional,while that of gap-graded aggregate is two-dimensional;（ 3） as the evaluation index about cold recycled pavement base with foamed asphalt,the volume fractal dimension has a good applicability;（ 4） after establishing the regression model about the volume fractal dimension,the physical /mechanical and durability indexes about cold recycled pavement base with foamed asphalt,it is found that there is a strong correlation among them;（ 5） the volume fractal dimension of aggregate is an important parameter with rich information because the fractal is an essential character of aggregate.