泡沫沥青冷再生混合料性能与合理路面结构研究

发布时间：2018-01-05 22:00

本文关键词：泡沫沥青冷再生混合料性能与合理路面结构研究　出处：《重庆交通大学》2015年硕士论文　论文类型：学位论文

【摘要】：基于节约能源、保护生态环境和沥青路面废旧材料再生利用的可持续发展战略方针,泡沫沥青冷再生技术作为新兴“绿色”的道路维修养护方法,近些年越来越受到国内外公路建设养护部门的重视。泡沫沥青冷再生技术主要应用于大修改造路面结构基层或底基层中,无论是对节能环保、降低道路维修成本,还是对路面使用性能都具有重要价值。本文依托G318线重庆市万州区落凼至分水段路面改造工程项目,从混合料性能与合理路面结构设计的角度对泡沫沥青冷再生技术进行分析,力求形成完善的理论体系,为实际工程项目的应用提供指导意义。首先,本文对泡沫沥青的发泡机理、破灭机理和发泡效果的评价指标体系进行了分析。通过室内沥青发泡特性试验,研究沥青的发泡效果与其影响因素之间的相关性。沥青的发泡效果采用膨胀比和半衰期两个指标综合评价。结果表明:沥青种类、沥青温度、发泡用水量对沥青的发泡效果均产生显著影响。基于泡沫沥青冷再生混合料的强度形成机理,提出其混合料的配合比设计流程。考虑到不同地区经济水平、技术力量及施工限制,针对粉料目标通过率无法达到设计标准的实际工程现状,设计了一组粉料较少的级配。通过土工重型击实试验,确定了不同级配混合料的最佳拌和用水量;以间接抗拉强度为控制指标,确定了最佳泡沫沥青用量;详细评价了再生混合料的物理特性和路用性能,主要包括混合料的密度、空隙率、水稳定性、高温稳定性、无侧限抗压强度、疲劳特性。结果表明:粉料对混合料性能有显著的影响,但是3%的0.075mm以下粉料通过率的混合料性能也较好,满足再生技术规范要求,可用于指导实际的工程应用。其次,通过试验探讨了沥青种类及用量、拌和用水量、养生条件、水泥掺量等关键因素对泡沫沥青冷再生混合料性能的影响程度。发泡效果理想的沥青在混合料中的分散性良好,能形成强粘结力的沥青胶浆。合理的拌和用水量不仅充当着润滑剂,而且能改善泡沫沥青在混合料中的分散性。按规范标准,养生3d后的试件中含水量极少,水泥已完全水化,形成足够强度。水泥能改善泡沫沥青在混合料中的分散效果,且水泥作为“刚性”的次级结合料,能提高混合料的强度。最后,本文根据路面结构的损坏与结构内部应力应变力学特性有着密切联系,建立有限元模型。基于路面结构基层的模量和厚度变化,分析泡沫沥青冷再生基层路面结构的受力影响,并拟定不同的路面结构组合进行力学特性对比,对指导泡沫沥青半柔性冷再生基层路面合理结构的设计有着重要意义。
[Abstract]:Based on the sustainable development strategy of saving energy, protecting ecological environment and recycling used asphalt pavement waste materials, the cold recycling technology of foamed asphalt is used as a new "green" road maintenance and maintenance method. In recent years, more and more attention has been paid by the maintenance departments of highway construction at home and abroad. The cold recycling technology of foamed asphalt is mainly used in the basic course of pavement structure or the base course of the pavement, whether it is energy saving or environmental protection. Reducing the cost of road maintenance is still of great value to the pavement performance. This paper relies on the G318 line of Chongqing Wanzhou District Luodang to water section of pavement reconstruction project. From the point of view of mixture performance and reasonable pavement structure design, the cold recycling technology of foamed asphalt is analyzed in order to form a perfect theoretical system and provide guidance for the application of practical engineering projects. In this paper, the foaming mechanism, the burst mechanism and the evaluation index system of foaming effect of foamed asphalt are analyzed, and the foaming characteristics of indoor asphalt are tested. This paper studies the correlation between the foaming effect of asphalt and its influencing factors. The foaming effect of asphalt is evaluated by expansion ratio and half-life. The results show that the kind of asphalt, the temperature of asphalt. Based on the strength formation mechanism of cold recycled asphalt mixture, the mixture ratio design process is put forward, taking into account the economic level of different regions. In view of the actual engineering situation that the passing rate of powder target can not reach the design standard, a group of powder gradation with less gradation is designed, and the heavy compaction test is carried out through geotechnical heavy compaction test. The optimum mixing water consumption of different gradation mixture is determined. Taking the indirect tensile strength as the control index, the optimum amount of foamed asphalt was determined. The physical properties and road performance of recycled mixture are evaluated in detail, including density, void ratio, water stability, high temperature stability and unconfined compressive strength. Fatigue characteristics. The results show that: powder has a significant impact on the performance of the mixture, but the mixture of less than 0.075mm of 3% has better performance, which meets the requirements of the technical specifications for recycling. It can be used to guide practical engineering application. Secondly, the types and dosage of asphalt, mixing water consumption and health condition are discussed through experiments. The degree of influence of cement content on the performance of foamed asphalt cold recycled mixture. The asphalt with ideal foaming effect has good dispersity in the mixture. Reasonable mixing water not only acts as lubricant but also can improve the dispersion of foamed asphalt in mixture. According to the standard, the moisture content of the sample after 3 days of health preservation is very little. Cement has been completely hydrated to form sufficient strength. Cement can improve the dispersion effect of foamed asphalt in the mixture, and as a "rigid" secondary binder, cement can improve the strength of the mixture. Finally. In this paper, according to the damage of pavement structure and the stress and strain characteristics of the structure, a finite element model is established based on the change of the modulus and thickness of the base course of the pavement structure. This paper analyzes the mechanical effect of froth asphalt cold recycled base pavement structure, and draws up different pavement structure combinations to compare the mechanical characteristics. It is of great significance to guide the design of reasonable pavement structure of semi-flexible cold regenerated base course of foamed asphalt.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U414

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