高性能冷再生沥青混合料关键技术研究

论文总字数：30441字

摘 要

随着我国早期修建的沥青路面里程的增长，越来越多的道路逐渐开始出现各种病害如裂缝、车辙、拥包、推移等等，这些病害将严重影响沥青路面使用性能。因此我们需要检修养护这些达到使用寿命的道路，而在超过路面使用年限，路面铣刨过程后会产生大量的废旧料。沥青路面再生技术可以将这些废料回收利用起来，不仅可以节约资源，还能减少污染保护环境，符合可持续发展战略。而乳化沥青冷再生技术可以最大限度利用旧料再生，并且施工能耗排放更低，施工也无需经受高温炙烤，另一方面乳化沥青冷再生技术也是道路养护的表面处理技术之一，具有重要的现实意义。

本文针对乳化沥青冷再生技术中存在的一些缺点，例如早期强度较低、水稳性能较差，旨在通过加入高性能粉末增强剂，提高乳化沥青冷拌混合料性能。通过对加入增强剂后沥青混合料的各种性能进行实验，来评价增强剂对乳化沥青冷拌料的作用。在查阅各国乳化沥青冷再生的配合比设计方法后，用最大干密度和裹覆状态确定了混合料的最佳含水率，用干湿劈裂强度峰值同时满足尽可能小的空隙率确定了最佳乳化沥青用量。

针对不同掺量增强剂的沥青混合料，通过劈裂实验和浸水马歇尔实验研究了高性能增强剂对乳化沥青混合料早期强度和水稳性的影响，并进一步确定了最佳的增强剂掺量，最后通过车辙试验检验乳化沥青混合料的高温稳定性。

研究表明，增强剂能有效提高乳化沥青混合料的早期强度和水稳定性，但是在养生条件不足、早期强度未形成的情况下高温稳定性较差，不适于用做急需开放交通的沥青路面面层。车辙试验中乳化沥青混合料的动稳定度较低，原因是车辙板对应养生时间不足，早期强度未形成导致的。在相同的养生条件下，欲达到同等程度的早期强度，要求车辙板的养生时间至少为马歇尔击实试件的3倍。在未来的研究中，可以充分考虑养生条件对乳化沥青混合料的早期强度、高温稳定性的影响。

关键词：乳化沥青；冷再生技术；配合比设计；早期强度；水稳定性；高温稳定性

Abstract

With the increase of the mileage of asphalt pavement constructed in China in the early days, more and more roads are beginning to appear various diseases such as cracks, ruts, crowds, and so on. These diseases will have a strong impact on the performance of asphalt pavement. Therefore, we need to overhaul these roads that have reached the end of their service life. After exceeding the service life of the road, a large amount of waste materials will be produced after the road milling process. Asphalt pavement recycling technology can recycle these wastes, not only save resources, but also reduce pollution and protect the environment, in line with sustainable development strategies. The emulsified asphalt cold recycling technology can make the most of the old material regeneration, and the construction energy consumption is lower, and the construction don’t need to be subjected to high temperature. On the other hand, the emulsified asphalt cold regeneration technology is also one of the surface treatment technologies for road maintenance, which is of gerat practical significance.

This text aims at some shortcomings in the cold recycling technology of emulsified asphalt, such as low early strength and poor water stability, aim to improve the performance of emulsified asphalt cold mix by adding high performance powder enhancer. The effect of the reinforcing agent on the emulsified asphalt cold mix was evaluated by experimenting with various properties of the asphalt mixture after the addition of the reinforcing agent. Referring to the emulsified asphalt mix ratio design method in different countries, the best water content of the mixture was determined by the maximum dry density also with the state of the coating, and the optimum emulsified asphalt was determined by the peak of the wet and dry splitting strength while satisfying the smallest possible void ratio.

The survey would do splitting test and water immersion Marshall experiment for asphalt mixture with different dosage enhancers to measure the influence of high performance enhancer on the early strength and water stability of emulsified asphalt mixture, and the best enhancer dosage was further determined. Finally, the high temperature stability of the emulsified asphalt mixture was tested by the rutting test.

Studies have shown that the reinforcing agent can effectively improve the early strength and water stability of the emulsified asphalt mixture, but the high temperature stability is when the conditioned time is not sufficient and the early strength is not formed, and it is not suitable for the asphalt pavement surface layer which is urgently needed for open transportation. The Dynamic stability of the emulsified asphalt mixture in the rutting test is low, because the rutting board has insufficient curing time and the early strength is not formed. Under the same curing conditions, to achieve the same level of early strength, the slab is required to have a cure time of at least 3 times that of Marshall's compacted test piece. In future research, the effects of health conditions on the early strength and high temperature stability of emulsified asphalt mixture should be fully considered.

KEY WORDS: emulsified asphalt; cold recycling technology; mix design; early strength; water stability; high temperature stability

目 录

摘 要

Abstract

第一章 绪论 1

1.1研究背景 1

1.2国内外研究现状 1

1.2.1国外研究现状 1

1.2.2国内研究现状 2

1.3研究目的和意义 3

1.4主要研究内容 4

第二章 冷拌乳化沥青混合料配合比设计 6

2.1原材料 6

2.1.1集料 6

2.1.2乳化沥青 7

2.1.3增强剂 8

2.1.4水 9

2.2配合比设计方法 9

2.2.1修正马歇尔法 9

2.2.2修正Hveem法 9

2.2.3俄勒冈州预估法 9

2.2.4我国规范的设计方法 10

2.3确定最佳乳化沥青含量 10

2.3.1确定最佳含水率 10

2.3.2确定最佳乳化沥青用量 12

2.3.3混合料其他参数的测定 14

第三章 高性能增强剂对冷拌乳化沥青混合料早期强度的影响 17

3.1实验方案设计 17

3.2早期强度测试结果 17

3.3性能结果分析 19

3.3.1增强剂作用机理 19

3.3.2界面状态分析 20

3.4乳液型增强剂早期强度测试 20

第四章 高性能增强剂对冷拌乳化沥青混合料水稳定性的影响 22

4.1实验方案设计 22

4.2水稳定性测试结果 22

第五章 高性能增强剂对冷拌乳化沥青混合料高温稳定性的影响 25

5.1实验方案设计 25

5.2车辙试验结果 27

第六章 结论与展望 29

6.1主要结论 29

6.2不足与展望 29

参考文献 30

致谢 33

第一章 绪论

1.1研究背景

为了追上发达国家的脚步，改革开放后，在国家的大力支持下，我国公路建设蓬勃发展，其中高速公路的发展尤为突出。尤其是自二十一世纪以来，我国高速公路建设速度逐渐追上世界前列。据统计，去年我国新建9.6万公里的公路，其中高速公路占六千公里，新修建和改建了两万公里国省干线级公路。至此到2018年结束，我国高速公路总里程已经超过14万公里，而沥青路面占这些高速公路的比例超过九成。目前，一般沥青路面设计使用年限为12-15年，因此许多曾经修建的高速公路如今会产生各种各样的病害如裂缝、车辙、拥包、脱落等等，当这些病害积累到一定程度时，会影响公路的路用性能。为了减小这些病害对公路的影响，路面的养护维修就变得重要。

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