公路半刚性基层再生利用关键技术研究

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3.0 侯斌 2025-01-09 5 4 4.43MB 78 页 15积分
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采用水泥作为稳定剂,通过再生设备对旧半刚性基层材料进行现场再生利用
是一项近年来较常用的道路维修技术,本文围绕工程实践中存在的若干关键技术
问题,开展了室内试验和工程应用研究。
首先选取不同来源的旧半刚性基层材料对其各项性能及其水泥再生后的强
度进行系统的试验分析,并与新骨料和公路沥青路面再生技术规范标准进行比较,
评价其再生可能性及适用性,发现旧半刚性基层材料经铣刨后,由于部分粗骨料
破碎,使得集料级配更加连续,且满足传统悬浮密实型级配范围的要求。虽然经
化学分析发现基层结合料残留的活性已基本丧失且旧料中骨料的吸水
率高于新骨料,但铣刨料中的粗骨料压碎值仍满足规范要求,且旧半刚性基层材
料水泥再生后混合料无侧限抗压强度满足规范中各等级公路底基层的强度要
求。
其次从旧沥青混凝土掺量和混合料级配对水泥再生混合料关键路用性能的
影响进行了分析评价。一方面,基于旧沥青混凝土掺量和老化程度的不同,水泥
再生混合料表现出以下规律:当沥青老化不严重时,掺入较高含量的旧沥青混凝
土会降低再生材料各龄期的抗压强度、劈裂强度、回弹模量和水稳定性;相反,
掺入较高含量的旧沥青混凝土会适当改善再生材料的干缩性能。另一方面,基于
混合料级配的不同,水泥再生混合料表现出以下规律:旧半刚性基层材料级配通
过添加碎石后,级配得到了改善,形成骨架密实型结构,会增大材料的整体密实
度,降低最佳含水量,显著增加混合料的抗压强度、劈裂强度和抗压回弹模量,
改善混合料的水稳定性和抗干缩性能。最后依据再生材料组成的不同,首次提出
了水泥再生半刚性基层材料的应用条件与场合。
根据前文的室内试验研究和以往工程经验,结合就地冷再生技术和厂拌冷再
生技术的特点,提出了水泥再生混合料的设计方法,强调了旧路面材料的具体取
样方法、原材料分析、级配设计和成型方法。最后根据水泥再生半刚性基层技术
依托工程中的具体应用,介绍了水泥就地及厂拌冷再生技术的工程应用情况,
归纳了水泥就地及厂拌冷再生技术合理的施工技术方法。
关键词:旧半刚性基层材料 水泥再生混合料 旧沥青混凝土 级配
地冷再生 厂拌冷再生 工程应用
Abstract
Using cement as stabilized agent, the method which the old semi-rigid base
materials are recycled with the in-place recycler is a frequently-used technology in
recent years. Laboratory tests and application researchs are developed in order to solve
some key technical problems exist during the engineering practice in this paper.
Firstly, old semi-rigid base materials extracted from different sources are selected
to make a systematic analysis of raw material performances and the strength of recycled
materials through test, and compare with the natural gravel and normative
standards(Technical specification of highway asphalt pavement regeneration) to
evaluate the possibility and applicability of recycling. Result shows the old semi-rigid
material after milling, parts of the coarse aggregates have been broken, the aggregate
gradation is continuous and meets the requirements of the traditional suspension dense
gradation range. Although, residual activity of aggregate in base milling material has
been basically lost and the aggregate bibulous rate of old material is higher than the new
aggregate bibulous rate. But the crushing value of milling material still meets the
regulatory requirements and the strength of recycled materials meets the specifications
of each grade highway subbase strength requirements.
Secondly, analysing and evaluating the influence on the key performance of
cement recycled mixture from admixture content of the old asphalt concrete and mixture
graduation. Based on the different content and the aging degree of old asphalt concrete,
the following rules are found. When the asphalt is not aged seriously, the mix with
higher concentration of old asphalt concrete can lower the compressive strength,
indirect tensile strength, modulus of resilience and water stabilization of recycled
material in each curing period. On the contrary, drying plastic shrinkage of recycled
material is improved appropriately as well. Based on the differences of the mixture
gradation, the folloing rules are found. It shows that adding coarse aggregates to the old
semi-rigid base materials, the gradation can be improved and the type of dense skeleton
can be formed, overall the density is increased, the best moisture content is reduced, the
compressive strength, indirect tensile strength, and compressive modulus of resilience
of the mix are increased significantly, besides, the water stabilization and drying plastic
shrinkage can also be improved. Then, the application conditions and situations are
proposed according to the different composition of recycled materials.
According to the former indoor experimental research and previous engineering
experience, combing the characteristics of cold in-place recycling technology and cold
in-plant recycling technology, the design method of cold recycled mixture with cement
is put forward. The specific sampling methods, analysis of raw materials, grading
design and forming method for the old pavement material are emphasized. In
accordance with the application of the semi-rigid base cold recycled with cement in
supported project, introducing the engineering applications of cold in-place recycling
and cold in-plant recycling technology, the reasonable construction technology for
applying cold in-place recycling technology and cold in-plant recycling is summarized.
Keywords: old semi-rigid base materials, cement recycled mixtureold
asphalt concrete, gradation, cold in-place recycling, cold in-plant
recycling, engineering application
中文摘要
ABSTRACT
第一章 ................................................................................................................ 1
1.1 研究背景 ............................................................................................................... 1
1.2 国内外研究现状 ................................................................................................... 2
1.2.1 国外研究现状 ................................................................................................. 2
1.2.2 国内研究现状 ................................................................................................. 2
1.3 水泥再生技术在浙江省国省道干线公路适应性分析 ....................................... 4
1.4 主要研究内容 ........................................................................................................ 4
第二章 旧半刚性基层材料性能研究 ............................................................................ 6
2.1 旧半刚性基层材料表观分析 ............................................................................... 6
2.2 旧半刚性基层材料级配特性 ............................................................................... 6
2.3 旧半刚性基层材料活性 ....................................................................................... 8
2.4 旧半刚性基层材料骨料强度 ............................................................................... 9
2.5 旧半刚性基层材料吸水率 ................................................................................... 9
2.6 旧半刚性基层材料再生后适用性评价 ............................................................. 10
2.6.1 确定最佳含水量及最大干密度 ................................................................... 10
2.6.2 适用性评价 ................................................................................................... 11
2.7 本章小结 ........................................................................................................... 11
第三章 水泥再生混合料性能特性的试验研究 .......................................................... 13
3.1 旧沥青面层材料的掺入对水泥再生混合料性能影响研究 ............................. 13
3.1.1 原材料 ........................................................................................................... 13
3.1.2 材料组合方案 ............................................................................................... 15
3.1.3 抗压强度 ....................................................................................................... 16
3.1.4 劈裂强度(间接弯拉强度) ....................................................................... 19
3.1.5 刚度(抗压回弹模量) ............................................................................... 20
3.1.6 水稳定性能 ................................................................................................... 22
3.1.7 抗干燥收缩性能 ........................................................................................... 24
3.2 水泥再生旧半刚性基层材料性能研究 ............................................................. 25
3.2.1 原材料 ........................................................................................................... 25
3.2.2 材料组合方案 ............................................................................................... 27
3.2.3 最佳含水量和最大干密度 ........................................................................... 28
3.2.4 抗压强度 ....................................................................................................... 29
3.2.5 劈裂强度(间接弯拉强度) ....................................................................... 31
3.2.6 刚度(抗压回弹模量) ............................................................................... 32
3.2.7 水稳定性能 ................................................................................................... 33
3.2.8 抗干燥收缩性能 ........................................................................................... 34
3.3 应用条件与场合 ................................................................................................. 36
3.4 本章小结 ............................................................................................................. 37
第四章 水泥再生混合料设计方法研究 ...................................................................... 39
4.1 原材料 ................................................................................................................. 39
4.1.1 旧路面材料 ................................................................................................... 39
4.1.2 水泥 ............................................................................................................... 40
4.1.3 新集料 ........................................................................................................... 40
4.1.4 ................................................................................................................... 41
4.2 级配设计 ............................................................................................................. 41
4.3 确定最大干密度和最佳含水量 ......................................................................... 42
4.4 成型方法 ............................................................................................................. 42
4.5 养生与无侧限抗压强度试验方法 ..................................................................... 43
4.6 控制指标与水泥用量的确定 ............................................................................. 43
4.7 干缩、劈裂强度 ................................................................................................. 43
4.8 浙江省部分工程水泥再生混合料配合比设计结果 ......................................... 44
4.9 本章小结 ............................................................................................................. 44
第五章 水泥再生工程应用研究 .................................................................................. 46
5.1 水泥就地冷再生半刚性基层技术在 G330 国道建德段的应用 ....................... 46
5.1.1 工程慨况 ....................................................................................................... 46
5.1.2 老路状况 ....................................................................................................... 46
5.1.3 维修方案 ....................................................................................................... 47
5.1.4 施工准备 ....................................................................................................... 48
5.1.5 试验路段 ....................................................................................................... 48
5.1.6 施工情况 ....................................................................................................... 50
5.1.7 观测和分析 ................................................................................................... 52
5.1.8 项目的经济和社会效益分析 ....................................................................... 53
5.2 2013 年缙云县 S219 路面大中修工程应用简况 ............................................ 55
5.2.1 路面结构 ....................................................................................................... 55
5.2.2 工程总结 ....................................................................................................... 55
5.3 2013 S229(龙后线)公路路面大中修工程应用简况 ............................. 56
5.3.1 工程概述 ....................................................................................................... 56
5.3.2 就地冷再生基层方案 ................................................................................... 56
5.3.3 工程总结 ....................................................................................................... 57
5.4 水泥厂拌冷再生半刚性基层技术在甬余线江北段的应用 ............................. 57
5.4.1 工程慨况 ....................................................................................................... 57
5.4.2 老路状况 ....................................................................................................... 58
5.4.3 维修方案 ....................................................................................................... 58
5.4.4 施工准备 ....................................................................................................... 58
5.4.5 试验路段 ....................................................................................................... 59
5.4.6 施工情况 ....................................................................................................... 60
5.4.7 项目的经济和社会效益分析 ....................................................................... 62
5.5 本章小结 ............................................................................................................. 64
第六章 结论与展望 ...................................................................................................... 66
6.1 主要结论 ............................................................................................................. 66
6.2 进一步研究建议 ................................................................................................. 67
附录 ................................................................................................................................ 68
参考文献 ........................................................................................................................ 69
在读期间公开发表的论文和承担科研项目及取得成果 ............................................ 72
致谢 ................................................................................................................................ 73
第一章 绪论
1
第一章
1.1 研究背景
随着我国公路交通的快速发展,国、省干线公路网逐步形成,新建公路的比
例逐年下降,改建、养护维修工程比重不断增加。如采用传统方式继续对沥青路
面进行改造和维修,不仅会增加重修路面所需的沥青和砂石材料,而且容易破坏
周围的环境,造成环境污染。同时,我国路面结构基本上都采用半刚性基层,在
重载作用下基层很多已出现了开裂、破碎等破坏,在路面维修、改造时需要一并
处理。目前浙江省对于沥青面层材料已经开展了就地热再生、厂拌热再生、泡沫
沥青就地冷再生、泡沫沥青厂拌冷再生等多种再生方式,并取得了巨大的社会和
经济效益。但对于相当比重的大修路段,由于标高限制、基层大面积损坏等因素
往往需要对基层甚至底基层进行挖除,从而产生比沥青面层多出 35倍的基层材
料,挖除的这些半刚性基层材料数量十分巨大。以浙江省 46167 公里等级公路为
例,每年约有 8%的沥青路面需要进行大中修改造,其中 40%采用翻修施工工艺[1]
如果路面宽度取 12m则挖除基层厚度为 20cm那么每年由于挖除产生的基层铣
刨材料大约有 815 万吨,这些材料如果不加以合理利用,既污染了环境,又浪费
了宝贵的资源。从土木建筑的实质上来讲,基层损坏主要是结构层的破坏,而石
料本身损坏较少,完全可以加以再生利用。如不合理利用,既造成大量砂石料的
浪费,又污染了环境,因此探究采用科学合理的方法对这些半刚性材料的再生利
用处理已变成目前面临的突出问题。
目前国内一些省份对于基层或底基层材料(主要是半刚性材料)主要采用就
地冷再生技术及厂拌冷再生技术,即将沥青面层和基层(或部分基层)旧料一并
铣刨后就地或运至拌和场与水泥拌和加以再生利用,施工速度快,造价也相对较
低。由于沥青面层和基层(或部分基层)一体化再生利用过程中,其原材料性能
与新砂石料存在差异,而且不同道路所用无机结合料不同、其稳定的粒料或土质
不同,使得回收得到的半刚性基层材料性能也大相径庭。因此,若对回收的旧半
刚性基层材料性能不加区分,而是简单套用水泥稳定碎石基层材料设计方法来设
计水泥再生混合料,显然不能充分有效利用旧基层材料。本文将选用常见的几种
旧半刚性基层材料,通过对它们的材料性能和水泥再生混合料性能的试验研究,
结合不同旧路再生后的结构力学性能要求,对旧半刚性基层水泥再生混合料的设
计方法进行优化研究,结合依托工程提出水泥就地及厂拌冷再生技术的基本施工
工艺,达到既能充分利用旧基层材料,又能改善和提升旧路面基层的路用性能,
使其达到新路面使用性能要求的目的,同时降低工程造价,获得良好的经济和社
公路半刚性基层再生利用关键技术研究.pdf

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作者:侯斌 分类:高等教育资料 价格:15积分 属性:78 页 大小:4.43MB 格式:PDF 时间:2025-01-09

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