沥青混凝土结构表征与参数构建

为研究沥青混凝土的结构,丰富表征沥青混凝土结构的参数,首先对常见的体积参数进行总结,分析沥青混凝土组成成分和结构特点. 然后,从不同角度出发构建新的体积参数,并对参数进行分类和分析. 最后,在AC-16级配范围内通过改变细集料的比重得到了5个不同级配,同时设置4.2%、4.7%、5.2%（沥青占混合料的质量比）3种不同沥青用量,研究沥青用量对参数的影响,根据现行沥青混合料试验规程要求制作标准马歇尔试件,并进行体积指标的测定,通过计算得到构建的参数,并分析参数随级配及沥青用量的变化规律. 结果表明:体积参数随着沥青混合料的级配、沥青用量的改变有着明显的变化. 其中,沥青类参数VA、VM、d_b与混合料中的沥青用量有明显的线性关系,同时VM还与V_f有关；空隙类参数VMA、V_K、VV随V_f的增加先减小后增大. 只改变沥青用量时,VMA、V_K、VV隨沥青用量的增加而减小；集料类参数G、V_c、V_f、Vf /(1-c)、F_BV、F₁、F₂、V_c/f与混合料中粗细集料以及矿粉的比例有关.

Characterization and parameter construction of asphalt concrete structure

To study the structure of asphalt concrete and enrich the characterization of asphalt concrete structure parameters, common volume parameters were summarized to analyze the composition and structural characteristics ofz asphalt concrete. Then, new volume parameters were constructed from different angles, and the parameters were classified and analyzed. Finally, within the scope of the AC-16 grading, five different gradations were obtained by changing the proportion of fine aggregate. Meanwhile, three different dosages of asphalt: 4.2%, 4.7%, and 5.2% (the percentage of asphalt by mass in asphalt mixture) were set to investigate the influence of asphalt content on parameters. Standard Marshall specimens were made according to the existing asphalt mixture production test code requirements, and the volume index was determined. The constructed parameters were obtained by calculation, and the variation of the parameters with gradation and asphalt content was analyzed. Results show that the volume parameters changed obviously with the gradation of asphalt mixture and the change of asphalt content. The asphalt parameters VA, VM, and d_b had obvious linear relationship with the amount of asphalt in the mixture, and VM was related to V_f. The void parameters VMA, V_K, and VV decreased first and then increased with the increase of V_f. When only changed the asphalt content, parameters VMA, V_K, and VV decreased with the increase of the asphalt content. The aggregate parameters G, V_c, V_f, Vf /(1-c), F_BV, F₁, F₂, and V_c/f were related to the proportion of coarse and fine aggregate and mineral powder in the mixture.