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为研究矿料性状与级配对矿料间隙率的影响规律与作用机制,发展沥青混合料矿料级配设计理论,首先采用数学建模方法,基于一定假设,分别建立了骨架空隙、骨架密实和悬浮密实型级配的未加沥青的矿料间隙率(V_(MAa))物理模型;根据模型,建立了一种矿料间隙率(VMA)排序的早期诊断技术,并提出了一种骨架密实型级配设计新方法。其次,通过沥青混合料制件试验,对模型揭示的规律性进行检验。研究结果表明:未加沥青矿料的矿料间隙率等于普遍意义上的粗料间隙率和细料间隙率的乘积;所建模型联合揭示了V_(MAa)的变化规律,即随着粗细分界粒径通过率的增大,V_(MAa)先减小(骨架空隙级配),当减小到一定程度(骨架密实级配)后开始增大(悬浮密实级配),呈现两边不对称的V形趋势,试验验证效果较好;粗、细料的间隙率,密度及细料用量等参数对V_(MAa)分别有不同的方向性影响,与级配类型有关;级配曲线设计应分为粗料和细料两段进行,在级配设计的初始阶段,无需制件,仅根据拟定级配的粗、细料间隙率、密度及粗、细分界粒径通过率等数据信息就能预估VMA的排序;路面中常用的沥青混合料如AC-25可设计成骨架密实级配。
In order to study the rule and mechanism of the effect of aggregate characteristics and gradation on the porosity of mineral aggregate and to develop the gradation design theory of asphalt mixture, the mathematical modeling method is firstly used to establish the framework voids, According to the model, an early diagnosis technique of VMA ranking was put forward and a new method was proposed for the determination of void fraction (V MAA) Type grading design new method. Secondly, the regularity revealed by the model was tested by asphalt mixture workpiece test. The results show that the void fraction of mineral material without bitumen ore is equal to the product of coarse material void fraction and fine fractional void fraction in the general sense. The established model jointly reveals the variation of V MAA, As the particle size increases, V MAa decreases first (skeleton gap gradation), and then decreases when it reaches a certain degree (skeleton dense gradation) and then begins to increase (suspension dense gradation) V-shaped trend, the experimental verification better; coarse, fine material gap, density and the amount of fine material and other parameters on the V MAA have different directional effects, and the type of grading; grading curve design should be divided For the coarse and fine materials two sections, in the initial stage of grading design, no parts, only based on the proposed grading coarse, fine material porosity, density and coarse, subdivided grain size through the data rate and other information VMA can predict the order; Common asphalt pavement, such as AC-25 can be designed into the skeleton dense grading.