摘 要

由于沥青路面具有良好的路用性能，其已经被广泛应用于国内外道路建设。然而，在沥青路面的服役过程中，光、热、氧和水等环境因素的作用会使沥青发生老化现象，严重影响沥青路面的路用性能和使用寿命。不仅造成大量的经济损失，而且严重影响道路交通安全。因此，研究出抗老化性能优良的改性沥青就显得尤为重要了。层状双羟基金属复合氢氧化物（LDHs）是一种具有层状结构的超分子材料，但是LDHs的组成、粒径和晶粒尺寸对紫外线的物理屏蔽和化学吸收有较大影响。利用LDHs的主体结构、晶粒尺寸和形貌合理控制材料的晶粒尺寸可显著提高材料的紫外阻隔能力，能够有效屏蔽和吸收紫外线，将其添加到沥青中，沥青的抗紫外老化性能得到明显改善。

本文选用适宜组成和粒径的LDHs作为沥青抗老化改性剂，制备出LDHs改性沥青，并对改性沥青进行热氧老化试验和紫外老化试验，深入开展不同粒径和组成的LDHs对沥青的物理性能、耐老化性能的影响规律以及作用机理。主要研究结论如下:

（1）不同组成和粒径的均使LDHs使沥青的针入度和延度减小，软化点和粘度增大。并且当LDHs的粒径越大时，这种影响越明显，说明当LDHs的粒子尺寸越大时，其分散在沥青中形成一种-相连续-相分散体系时，在高温下阻碍沥青分子链的运动更加明显。从而使粒径越大的LDHs改性沥青的物理性能变化更加明显。

（2）不同组成的LDHs对沥青的耐紫外老化有明显改善作用上。其中，Mg-AL-Zn-LDHs在提高沥青的耐紫外老化性能上效果优异，这是因为Mg-AL-Zn-LDHs对紫外光的反射能力要比Mg-AL -LDHs的强，说明Mg-AL -LDHs屏蔽紫外光的能力更强，所以表现为改性沥青的抗老化性能更强。

（3）不同粒径的LDHs对沥青耐紫外老化性能有明显的改善作用。与普通沥青相比，LDHs粒径为180nm的LDHs对沥青抗紫外老化性能改善效果最好。这是因为LDHs的层板对紫外光具有很强反射能力，其多层结构可以对紫外光起到物理屏蔽作用，随着LDHs粒径的增大，厚度增加，而其层间距相近，层数增多，故其对紫外线的反射增强。

关键词：沥青，LDHs，物理性能，老化性能

Abstract

As the asphalt pavement has good road performance, it has been widely used in domestic and international road construction. However, in the service of asphalt pavement, the role of environmental factors such as light, heat, oxygen and water will be the phenomenon of asphalt aging, which seriously affects the road performance and service life of asphalt pavement. Not only cause a lot of economic losses, but also seriously affect the road traffic safety. Therefore, it has become particularly important to study modified asphalt with excellent anti-aging properties. Layered bishydroxy metal complex hydroxide (LDHs) is a supramolecular material with a layered structure. LDHs have the ability of reflection, scattering and absorption of ultraviolet light, which can effectively improve the UV aging resistance of asphalt. However, when the types and quantities of LDHs in the LDHs change, the crystal structure will affect the UV blocking ability Change; LDHs of different particle sizes also cause them to have different UV barrier properties.

In this paper, LDHs were prepared by using three kinds of LDHs with different particle size and composition as the modifier. The modified asphalt was prepared by thermal aging test and UV aging test. The LDHs with different particle size and composition Physical properties, anti-aging properties of the law and the mechanism of action. The main conclusions are as follows:

(1) LDHs with different compositions reduce the penetration and ductility of asphalt, increase the softening point and viscosity, increase the hardness of asphalt, improve the high temperature performance, because LDHs are lamellar structure, After mixing, the internal friction of the modified asphalt system is increased to a certain extent, which hinders the extension and movement of the asphalt molecular chain. Which in turn leads to a change in the physical properties of the asphalt. The asphalt aging resistance has a significant improvement in the role, especially in improving the resistance of UV aging resistance. Mg-AL-Zn-LDHs are most effective in improving the aging resistance of asphalt because of the ability of Mg-AL-Zn-LDHs to reflect the UV Than Mg-AL-LDHs slightly stronger, so the performance of modified asphalt anti-aging performance stronger.

(2) LDHs with different particle sizes also reduce the penetration and ductility of asphalt, and the softening point and viscosity increase, because LDHs are lamellar structure, and mixed with asphalt to a certain extent, The internal friction of the asphalt system hinders the extension and movement of the asphalt molecular chain. The asphalt aging resistance has a significant improvement. LDHs have little difference on the anti-thermal aging performance of asphalt, but the anti-UV aging performance of asphalt is quite different. The LDHs with 180nm diameter have the best effect on the anti-UV aging performance of asphalt. This is because the LDHS itself has a strong ability to reflect the UV light, UV can play a multi-layer physical shielding effect, with the LDHs particle size increases, the thickness increases, and its layer spacing is similar, resulting in increased layers , So the reflection of ultraviolet light enhanced, so with the LDHs particle size increases, its anti-UV aging effect is more excellent.

Key Words：asphalt, LDHs, physical properties, aging resistance

目 录

摘 要 I

Abstract II

目 录 IV

第1章 绪 论 1

1.1引言 1

1.2沥青老化与抗老化的研究进展 1

1.3LDHs的研究与应用现状 3

1.4LDHs在沥青抗老化方面的研究进展 4

1.5研究目的及意义 5

1.6主要研究内容 5

第2章 实验部分 7

2.1 实验原料与仪器 7

2.1.1 实验原料 7

2.1.2实验仪器及设备 7

2.3加速老化实验 8

2.4性能测试 8

2.5老化性能评价 8

第3章 结果与讨论 10

3.1LDHs对沥青物理性能的影响 10

3.1.1LDHs的组成对沥青物理性能的影响 10

3.1.2LDHs的粒径对沥青物理性能的影响 13

3.2不同组成和粒径的LDHs对沥青抗热氧老化性能的影响 16

3.2.1LDHs的组成 16

3.2.2LDHs的粒径 18

3.3不同组成和粒径的LDHs对沥青抗紫外老化性能的影响 21

3.3.1LDHs的组成 21

3.3.2LDHs的粒径 24

第4章 结论 28

参考文献 29

致谢 31

第1章 绪 论

1.1引言

沥青是一种表面呈黑褐色的有机凝胶材料，具有粘结、防水和阻尼减震等特点，并且成本低廉、来源广泛和易于维护，一直以来被用作道路建设、建筑和防水材料^[1]。由于沥青路面具有良好的路用性能，因而沥青路面已经逐渐成为国内外的公路路面常见结构形式。截止2016年底，全国高速公路建设总里程达13万公里，位居世界第一^[2]。但是，沥青由于受到光、热和氧等环境因素作用的影响而严重老化，使沥青路面的路用性能下降，还会挥发出有害气体，造成环境污染。伴随着公路交通事业的发展，人们对公路建设材料的性能、寿命等方面的要求，也在日渐提高。