同类变级配沥青混合料矿料间隙率模型及分析

Model and Analysis of Voids in the Mineral Aggregate for the Same Type of Hot Mix Asphalt at Different Gradations

关键词:  同类变级配沥青混合料  矿料间隙率  粗集料间隙率  物理模型  分界筛孔通过率

Key words:  same type of hot mix asphalt （HMA） at different gradation  voids in the mineral aggregate （VMA）  voids of coarse aggregate of HMA （VCA_mix）  physical model  pass rate of boundary sieve mesh

摘要:

为揭示同类变级配沥青混合料矿料间隙率（VMA）的变化规律与机制，将粗细集料分界筛孔尺寸及其筛孔通过率x用于整体级配矿料划分与分析；同时基于确定配比沥青混合料的VMA与粗集料间隙率（VCA_mix）的计算公式，推导出VMA与VCA_mix之间的物理关系式，在此基础上建立了同类变级配沥青混合料的VMA物理模型，并对模型进行了深入分析和试验验证.结果表明：同类变级配沥青混合料中细集料对VCA_mix的增大作用性质及x是影响VMA的2个决定性因素，当x对VCA_mix起线性函数增大作用时，随着x的增大，VMA或呈凸形曲线下降或呈凹形曲线上升；当x对VCA_mix起指数函数的增大作用时，随着x的增大，VMA可能呈凹形曲线下降、凸形曲线下降、凹形曲线上升及类似开口向上2次抛物线等多种变化趋势.

Abstract:

In order to reveal the variation rule and mechanism of the voids in the mineral aggregate （VMA） of the same type of hot mix asphalt （HMA） at different gradations， the boundary particle size between coarse and fine aggregate and pass rate of the sieve holes x were used for the classification and analysis of the overall mineral aggregate to be graded. Based on the calculation formula of VMA and voids of coarse aggregate （VCA_mix） of HMA in which the proportion was determined， the physical relation between VMA and VCA_mix of the same type of HMA at different gradations was established through derivation. On this basis， the physical model of VMA was studied theoretically and verified by experiments. The results show that the increasing function of fine aggregate on VCA_mix in HMA and x are the two decisive factors affecting the VMA size. When x linearly increases VCA_mix， the VMA will either decrease in a convex curve or rise in a concave curve with the increase of x. When x exponentially increases VCA_mix， with the increasing of x the changing trends of VMA may be one of concave curve descending， convex curve descending， concave curve ascending， and complete concave curve similar to quadratic parabola with the opening upward.