基于数字图像处理技术的环保型沥青混合料细观研究

发布时间：2018-05-11 10:22

本文选题：细观结构 + 回收沥青混合料　；参考：《吉林大学》2014年硕士论文

【摘要】：近些年来，沥青混合料的细观结构成为了研究热点，但主要研究的是普通沥青混合料。而随着经济的发展，地球上资源的减少，材料的回收利用引起了人们的重视。在道路工程界，目前研究较多的环保型沥青混合料是多孔性沥青混合料PAC，回收沥青混合料RAC和添加有废旧炉渣的沥青混合料DGAC（BOF）。本文依托台湾成功大学土木所交通组的项目，尝试从细观方面研究环保型沥青混合料PAC，RAC和DGAC（BOF），并建立细观参数与宏观性能之间的关系。本文的主要内容如下： 1.向量幅值Δ与宏观性能的关系研究根据公式=1002n(in=1sin2θi)+(ncos2θi2i=1)计算向量幅值。结果表明，不管是实验室试体还是现地钻心试体，Δ越大，车辙深度越大。因为Δ越大，集料倾向越统一，集料越不均匀。PAC和DGAC（BOF）的抗车辙能力优于普通密级配。RAC（40%）车辙深度虽然大于HMA，，但还是符合规范要求，所以铺筑RAC还是有一定的意义。对于现地钻心试体DGAC（NA）和DGAC（BOF），回弹模量和间接拉伸强度随着Δ的增大而减小。而且在这些方面，DGAC（BOF）的性能都优于普通密级配。 2.集料分布的均匀性研究将实验室三种级配混合料的截面分为上下两部分，通过测量两部分集料粒径在各范围内的频数差来评价实验室三种级配的均匀性，用k表示。结果表明，PAC和HMA分布较均匀，标准差较小，而RAC（40%）由于含有较多小粒径的旧料，标准差较大。 3.空隙分布研究本文主要使用Image-Pro Plus6.0软件进行图像处理，但由于空隙与胶浆灰度比较接近，用软件中的功能提取的不够完整，所以自编程序提取PAC，HMA和RAC（40%）的空隙率。结果表明，三者空隙率随深度的变化趋势都是先变大再变小，都是中部的空隙率较大。 4.图像级配研究根据每档集料等效直径在各范围内的占比，画出级配曲线。引入实际筛分与图像级配的相对误差Di来评价RAC（40%），HMA和PAC。结果表明，用图像级配方法分析密级配混合料与实际筛分曲线最接近，但对于开级配PAC，由于平均误差较大，分析效果不理想。本文意在分析几种环保型沥青混合料PAC，RAC（40%）和DGAC（BOF）的细观结构，希望通过研究细观结构能预测混合料的宏观性能。
[Abstract]:In recent years, the meso-structure of asphalt mixture has become a research hotspot, but the main research is ordinary asphalt mixture. With the development of economy and the decrease of resources on the earth, people pay more attention to the recycling of materials. In the field of road engineering, the environmental friendly asphalt mixture studied at present is porous asphalt mixture (PAC), recycled asphalt mixture (RAC) and asphalt mixture with waste slag (DGA). Based on the project of traffic group of civil engineering institute of Chengcheng University of Taiwan, this paper attempts to study the environmental protection asphalt mixture PACRAC and DGAC / BOF from the view of meso, and to establish the relationship between the meso-parameters and the macroscopic performance. The main contents of this paper are as follows: 1. Study on the relationship between Vector amplitude 螖 and macroscopic performance The amplitude of the vector is calculated according to the formula of 1002ncn ~ (1 sin2 ~ (2 胃) / ncos2 ~ (胃 ~ (2) I ~ (-1). The results show that the greater 螖 is, the greater the rutting depth is. Because the larger 螖 is, the more uniform the aggregate tendency is, and the more uneven the aggregate. PAC and DGACU BOF) have better rutting resistance than the conventional dense gradation. RAC40) rutting depth is higher than HMA, but it still conforms to the specification, so it is of certain significance to lay out RAC. For DGAC NA) and DGAC BOFN, the modulus of springback and the indirect tensile strength decrease with the increase of 螖. Moreover, the performance of DGAC BofF is superior to that of ordinary dense gradation in these aspects. 2. Study on the uniformity of aggregate Distribution The cross section of three kinds of laboratory gradation mixture is divided into two parts, and the uniformity of the three kinds of gradation in laboratory is evaluated by measuring the frequency difference of the particle size of the two parts in each range, expressed in k. The results show that the distribution of HMA and HMA is more uniform, and the standard deviation is smaller, but RAC40) the standard deviation is larger because it contains more used materials with small particle size. 3. Study on void distribution In this paper, Image-Pro Plus6.0 software is mainly used for image processing, but because the void is close to the grayscale of the paste and the function of the software is not completely extracted, the voidage ratio of PACMA-HMA and RAC40) is extracted by a self-programmed program. The results show that the three voids tend to increase first and then decrease with the depth, and the central voidage is larger. 4. Image gradation study The gradation curve is drawn according to the ratio of the equivalent diameter of each aggregate in each range. The relative error (Di) of actual sieving and image gradation is introduced to evaluate the Rac _ (40) HMA and PAC. The results show that the image gradation method is the closest to the actual screening curve, but for open grading PAC, the analysis effect is not ideal because of the large average error. The purpose of this paper is to analyze the meso structure of several kinds of environmental friendly asphalt mixture PACRAC40) and DGACU BOF), and hope that the macroscopic performance of the mixture can be predicted by studying the meso structure.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U414

【参考文献】