【作者】 张清平；

【导师】 周志刚；

【作者基本信息】 长沙理工大学 ， 道路与铁道工程， 2011， 博士

【摘要】 在我国交通事业快速发展、高等级公路进入大规模维修期,沥青路面再生技术的研究是我国公路建设中面临的重要任务。与普通沥青相比,改性沥青具有更优良的路用性能,得到了广泛应用。由于改性沥青的大规模使用历史相对较短,目前的再生利用技术主要针对基质沥青,并且改性沥青老化性状难预测、再生设计较复杂等因素,关于旧改性沥青的再生应用研究,国际上尚处于起步阶段。因此,本文结合海南东线高速府城至琼海段左幅大修工程热再生路段施工,针对普通沥青与PE改性沥青两类旧沥青路面现场热再生技术展开研究,为该技术的应用与推广打下良好基础,也为沥青路面再生利用成套技术的研究提供有价值的参考。现场热再生技术具有一定的使用条件,因此在应用之前首先在旧路历史信息、原路面技术状况、交通量等方面展开了详细的调查和检测,对旧沥青路面使用性能进行评价,特别是路面结构承载能力,为现场热再生技术方案的选择和再生路段的划分提供依据。通过旧路面材料性能的试验检测,确定和评估了再生路段路面结构的使用现状,并在此基础上分析了旧路面病害及其成因。旧沥青混凝土材料老化程度的评价是其能否再生利用的前提。首先研究改进了旧沥青抽提回收试验方法。对所抽取的旧普通沥青和改性沥青分别进行傅里叶红外光谱、四组分、三大指标、布洛克菲尔德(Brookfield)粘度和动态剪切流变(DSR)等系列试验,确定了旧沥青相关性能指标,评价其老化程度,分析了其老化机理。并通过试验进行了旧集料的集料性能、级配分布及其变异性研究。总结提出了再生剂的技术要求及其类型,据此研制开发并选取了富含旧沥青中所缺失组分的再生剂。分别对旧改性沥青和普通沥青掺配不同掺量的不同种类再生剂得到再生沥青,进行了四组分试验、三大指标试验、布洛克菲尔德(Brookfield)粘度试验和动态剪切流变(DSR)等系列试验,研究有关指标的变化规律,对比分析了再生剂的再生效果,从而推荐了适合依托工程要求的再生剂及其掺量范围,并应用SHRP方法进行了再生沥青性能检验。在此基础上总结了再生沥青设计的主要流程,提出了再生控制指标与再生剂掺量的关系模型,确定再生剂的设计掺量。再生沥青混合料性能不仅是再生沥青混合料设计的关键,也是其使用寿命和质量的主要决定因素。因此,首先分析选择了现场热再生沥青混合料设计方法,提出了再生沥青混合料不同设计方案。然后开展了再生沥青混合料的常规力学性能、温度稳定性、水稳定性、疲劳性能等系统的试验,回归分析了再生沥青混合料高温稳定性、低温稳定性、水稳定性等随新旧料掺配比例的变化规律,指出了加铺再生和复拌再生两种再生工艺均能有效改善旧沥青混合料的老化性能,提高其高低温稳定、水稳定性。证明了通过选择合适的再生剂及其掺量、新旧料的掺配比例能使再生沥青混合料性能满足规范要求,总结提出了再生沥青混合料性能有关指标的控制范围。通过进行间接拉伸疲劳试验,研究旧料、不同再生沥青混合料的疲劳性能,得出结论:再生沥青混合料比旧料的疲劳特性参数K值大很多,说明其疲劳寿命有显著提高;疲劳特性参数n值的变化范围不大,说明旧沥青混合料和再生沥青混合料的疲劳寿命对应力水平的敏感性下降;在同样的应力下,再生料的疲劳寿命明显高于旧料。通过APA试验,对比分析了旧沥青路面、常规大修工程沥青路面、再生沥青路面的疲劳寿命,证明了再生沥青路面具有较高的疲劳寿命,与间接拉伸疲劳试验结果一致。通过红外线热像仪、小型气象站等现场检测对比研究了施工气象条件和旧沥青路面材料状况对现场热再生加热效果的影响,通过室内外试验对比研究了不同施工环节的再生温度、再生沥青混合料拌和时间等再生工艺参数对再生效果的影响,提出了相应的现场加热工艺和再生工艺要求。同时,提出了一种用同标号原样基质沥青进行室内短期及长期模拟老化至现场热再生施工加热再次老化后的现场热再生沥青老化模拟方法。在上述研究的基础上,结合现场施工与跟踪监测,进一步综合评价了依托工程现场热再生技术的适应性。更多还原

【Abstract】 With the rapid development of highway construction in China, the high-class highway has entered the period of large-scale maintenance. The research on recycling technology of asphalt pavement is an important task for the highway construction. Compared with ordinary asphalt, the modified asphalt has been widely used for its better performance. As the modified asphalt has been used on a large scale only for a short time and the current recycling technology focuses on substrate asphalt, with some facters such as unpretictable aging properties and comparatively complicated recycling design involved, the applied research on the recycling of modified asphalt is still in the infant stage in the world. On the practice basis of the construction of hot in-place recycling section of left-panel large-scale expansion project of the east highway of Hainan from Fucheng to Qionghai, this paper will conduct the research on hot in-place recycling technology of ordinary asphalt pavement and PE modified asphalt pavement, which will lay a good foundation for its application and promotion, and also provide a valuable reference for the research on sets of recycling technology of asphalt pavement.Hot in-place recycling technology has certain conditions of use, therefore, first of all,a detailed investigation and testing which is done about historical information on the old road, the original technical condition of the road, traffic and other aspects before the application, old asphalt pavement performance is evaluated. Especially bearing capacity of pavement structure provided basis for selection of hot in-place recycling technology program and the division of regeneration section. Through the test of the old road material properties, the materials used in Existing pavement structure and current situation are determined and evaluated. Diseases and causes of the old road are analyzed on the basis of it.Whether reuse of old asphalt mixture is related to evaluation of aging. First of all, test methods for recycling and extraction of old asphalt which is improved is studied, Fourier transform infrared spectroscopy, four components, three indicators, Brookfield viscosity and DSR, and other tests are carried out for the old ordinary asphalt which is extracted and modified asphalt, performance indicators of the old asphalt are determined, aging is evaluate, aging mechanism is analyzed. Aggregate performance, grading distribution and variability of the old aggregate is studied. Technical requirements and types of recycling agent are proposed. Recycling agent including components which is the absence of the old asphalt is selected. The old modified asphalt and ordinary asphalt blending with different contents of different types of recycling agent is recycled asphalt. Four components, three indicators, Brookfield viscosity and DSR, and other tests are carried out. Variation of The indicators is studied, the regeneration of recycling agent is comparative analyzed, Thus recycling agent and their dosage range based on engineering requirements is recommended, and performance test of recycled asphalt is done with the method of SHRP. The main flow of recycled asphalt design is summarized on the basis of it, the relational model of recycling control targets and regenerated content to determine the design content of recycling agent.The performance of recycled asphalt mixture is not only the key of the success of regeneration design, but also the main determinant of using life and quality of recycled asphalt pavement. Therefore, first of all, design method of hot in-place recycling asphalt mixture is selected, different designs of recycled mixture are proposed. Then test is carried out for the conventional mechanical properties, temperature stability, water stability, fatigue performance of recycled asphalt mixture. Change rule of the high low temperature stability and water stability of recycled asphalt mixture blended with the old and the new material dosage proportion. Remixing regeneration and repaving regeneration all can obviously improve aging properties of the old asphalt mixture, make its high/low temperature performance, water stability improved. Selecting appropriate regenerative agent and dosage, blending ratio of new old material can make recycled asphalt mixture performance reaching requirements specification is proved. Meanwhile, proposed control range and methods of the recycling asphalt mixture performance index is proposed.Through indirect tensile fatigue tests, this article studies the fatigue properties of different recycled asphalt mixtures and the old materials. The results shows that compared with the old materials, the fatigue characteristic parameter‘k’of recycled mixtures increases significantly, which indicates that the fatigue life resistance has been improved greatly. The range of variation of the fatigue characteristic parameter‘n’is not large, which implies that the sensitivity to stress of the fatigue life of the aging asphalt and recycled asphalt mixtures decreases. Under the same stress, the fatigue life of the recycled asphalt is apparently longer than that of the old materials. With APA round-return wheel load simulation structural tests, the essay further compares and analyzes the fatigue life of the recycled asphalt pavements, the conventional asphalt pavements and the old asphalt pavements in different recycling projects. The results show that the recycled asphalt pavements have longer fatigue life, which is consistent to the results of the indirect tensile fatigue tests.Through on-site tests, such as infrared thermal imager, small-size weather station, the article studies the effects of the weather conditions during construction and the status of the old asphalt pavement materials to on-site regenerative heating. By indoor and outdoor tests, it comparatively studies the effects of renewable technological parameters, such as regeneration temperature, regeneration asphalt mixing time, to regeneration results. Thus, it puts forward the corresponding on-site heating process and regeneration requirements.Based on these studies, combined with the on-site tracking and monitoring, the study further evaluates the adaptability of on-site heat regeneration technology.更多还原