摘 要

沥青混合料在路面铺筑上使用十分广泛，作为粘弹性材料中的一种，具有较强的温度敏感性，因此温度是影响沥青混合料性能的一个重要因素。沥青混凝土路面在不同温度下会表现不同破坏方式，其中高温的车辙损害尤为严重。有关研究表明，我国所有的沥青路面维护原因中，车辙占了80%以上。因此研究如何有效防止车辙损害对我国道路建设来说显得十分有意义。以往传统的解决车辙问题的措施是通过提高沥青混合料的高温稳定性，或者优化沥青混合料的集料级配，但这些方法从本质来说都是“被动”的接受高温，难以从根本上解决车辙问题。沥青路面温度场与沥青混合料导热有关，因此本文考虑将沥青路面设计成一个有导热梯度的结构，即上面层阻热，中下面层导热。将沥青路面作为一个整体来研究温度场的分布，并不能从本质上解释沥青混凝土中各组分的热物性能对沥青路面温度场分布的影响。因此本文从沥青胶浆的角度出发，研究导热、阻热无机粉体对沥青胶浆热物性能的影响，这对沥青路面温度场的研究具有重要的意义。

本文运用Hot Disk热常数分析仪研究掺加导热和阻热粉体沥青胶浆的热物性能，并运用ANSYS有限元分析模拟胶浆内部温度场和相对热流密度的分布情况，得出主要结论如下：（1）通过TPS瞬态平面热源法测量出基质沥青、沥青胶浆的热导率、热扩散系数和比热容，主要采用热导率指标评价无机粉体对沥青胶浆热物性能的影响。基质沥青本身热导率较低，加入石墨能明显提高沥青胶浆热导率；而在在一定范围内添加漂珠，可以一定程度上减小沥青胶浆热导率，但是掺量过多则会产生堆积效应，反而增大胶浆热导率。这里必须注意到，漂珠由二氧化硅(热导率0.27 W/mK)和三氧化二铝(热导率10 W/mK)组成，两种成分热导率都比沥青胶浆大，所以少量添加漂珠，使漂珠在沥青胶浆中分散，可以起到明显的隔热作用，但是漂珠添加量过多，且在胶浆中互相接触时，热量可能会沿着漂珠壁传递，隔热的漂珠反而起到了导热作用。漂珠的添加能够增加沥青胶浆的比热容而石墨的添加会减小沥青胶浆的比热容。（2）通过ANSYS有限元模拟出漂珠沥青胶浆和石墨沥青胶浆的温度场和热流分布图，得出结论，对于添加了漂珠的沥青胶浆，大部分热量从沥青传递且热量流经漂珠时，发生发生“沿界迁移”效应。对于掺加了石墨的沥青胶浆大部分热量选择通过石墨内部传递，发生“越界迁移”效应。

关键词：热物性能，沥青胶浆，漂珠，石墨，有限元

Abstract

Asphalt mixture is widely used in pavement construction, and is a typical viscoelastic material, with obvious temperature sensitivity, so the temperature of asphalt mixture performance is an important factor. At different temperatures, the damage of asphalt pavement is different, such as the rutting damage under repeated action of high strength load at high temperature. Related research shows that the cause of the maintenance of asphalt pavement in our country, the rutting accounted for more than 80%. Therefore, it is very meaningful to study how to effectively prevent the damage of the track to the road construction in our country. Traditional solve the rutting problem measures is by improving the high-temperature stability of asphalt mixture, or to optimize the aggregate gradation of asphalt mixture, but these methods essentially are "passive" subjected to high temperature, it is difficult to fundamentally solve the problem of rut. The temperature field of asphalt pavement is related to the heat conduction. Therefore, this paper considers the design of asphalt pavement as a thermal conductivity gradient structure, that is, the heat resistance of the upper layer and the heat conduction in the middle and lower layer. Present researches focused the internal temperature distribution in the whole asphalt pavement. It was hard to fundamentally explain the influence of each component in asphalt mixture on the thermal properties of pavement. So in this paper, starting from the angle of asphalt mortar, effect on thermal conductivity, resistance of inorganic heat powder on asphalt mortar thermophysical properties, which research on asphalt pavement temperature field has important significance. In the research, Hot-disk thermal analyser were used to evaluate the thermal properties of asphalt mastic; ANSYS finite element was used to study the internal changes of the temperature field and the distribution of heat flow. Some conclusions can be drawn as:

(1) through TPS Transient plane source method for measuring the matrix asphalt, the asphalt mortar thermal conductivity, thermal diffusivity and specific heat capacity, mainly using thermal conductivity rate effects of index evaluation of inorganic powder on asphalt mortar thermophysical properties. The asphalt itself had low thermal conductivity, adding graphite can improve the thermal conductivity of asphalt mastic; In adding floating beads in a certain range, can to some extent reduce asphalt mortar thermal conductivity, but floating beads content too much can produce the accumulation effect, instead increased mortar thermal conductivity. Here we must pay attention to, cenosphere is composed of silicon dioxide and aluminum oxide, two components thermal conductivity than asphalt mortar is large, so the addition of a small amount of floating beads ,and making it dispersed in asphalt mastic, can play a obvious thermal insulation effect, but floating beads add too much and touching each other in the mortar, heat may be transferred along the wall of the cenospheres, instead insulated floating beads conduct heat. Add floating beads can increase the specific heat capacity of asphalt mortar,by contrast Graphite will reduce the specific heat capacity of asphalt mortar. (2) Through ANSYS finite element simulation ,it was found that to add floating beads in asphalt mortar, most of the heat transfer from the asphalt, and when the heat flows through the bead, the occurrence of "along the boundary migration effect; When the asphalt mortar added graphite, most of the heat transfer from graphite inside,the occurrence of "Cross-border Migration" effect.

Key Words: thermal properties, asphalt mastic, cenosphere, graphite, finite element

目 录

中文摘要 I

Abstract II

第一章 绪论 1

1.1 研究的背景和意义 1

1.2 国内外研究进展 3

1.2.1 沥青路面温度场的研究进展 3

1.2.2 沥青胶浆的国内外研究进展 5

1.3 本课题的研究内容和方法 5

第二章 原材料与实验方案 7

2.1 原材料 7

2.1.1 导热和阻热无机粉体的选择 7

2.1.2 基质沥青 9

2.2 实验仪器 10

2.3 实验方案 10

2.3.1 制备沥青胶浆 10

2.3.2 沥青胶浆的热物性能测试 11

第三章 无机粉体对沥青胶浆热物性能的影响 12

3.1 导热理论的基本概述 12

3.1.1 热传导 12

3.1.2 热对流 12

3.1.3 热辐射 13

3.1.4 Fourier定律 13

3.2 沥青胶浆热物理参数 13

3.2.1 热导率λ 13

3.2.2 热扩散系数 14

3.2.3 比热容 14

3.3 试样的测试与参数的选择 15

3.3.1 瞬态平板热源法测量原理 15

3.3.2 沥青胶浆试样的制备与测试 15

3.4 测试结果及数据分析 17

3.4.1 不同掺量粉体对沥青热导率的影响 17

3.4.2不同掺量粉体对沥青比热容的影响 18

第四章 基于ANSYS的沥青胶浆热物性能模拟 20

4.1 有限元方法的概述 20