摘要 我国沥青路面在建设的同时，进入了一个持续的大规模养护维修期。在维修过程中直接对沥青路面铣刨弃用不仅会造成巨大的经济损失，同时会引发环境污染，因此研究沥青路面的再生问题就显得尤为重要。在目前国内常用的四种沥青再生技术中，厂拌热再生技术的应用最为广泛、旧料发挥的经济效益最高，但是旧料掺量较少的问题仍然限制了厂拌热再生技术的应用，因此研究高旧料掺量的厂拌热再生工艺就显得尤为重要。论文在分析了众多沥青温拌技术之后，选择硫磺改性为基础的温拌技术作为与厂拌热再生工艺的结合点，重点针对高旧料掺量的硫磺改性厂拌温再生技术进行研究，以期为沥青再生应用的拓展和推广增加新的途径。
作为厂拌温再生技术研究的前提，论文对硫磺改性沥青的微观机理和混合料能影响规律进行了研究：首先利用差示扫描量热仪和光学显微镜进行微观分析，探宄了不同的硫磺掺量情况下硫磺改性剂在沥青胶结料和沥青混合料中的微观存在状态；其次对不同硫磺掺量清况下沥青胶结料的感温性能的变化规律进行了试验研究；接着分析不同硫磺改性剂掺量对于混合料粘弹特性和基本力学性能的影响；最后分析了厂拌温再生关键工艺对于混合料性能的影响。从以上试验规律中找出硫磺改性剂与高旧料掺量的厂拌温再生工艺的切入点和结合点。 论文打破沥青热再生研究的传统思路，从“取长补短”的角度来研究沥青再生问题。利用硫磺改性剂的特性，不仅实现再生过程的温拌施工，而且跳过旧沥青性能的再生研究工作，直接从宏观的沥青混合料再生利用层面进行探讨。论文首先分析了国内外典型的连续级配混合料设计方法的特点，然后将高旧料掺量的厂拌温再生技术的特点进行适应性分析，最终选择法国高模量设计方法作为高旧料掺量的厂拌温再生技术的指导思想，确定了高旧料掺量的厂拌温再生的配合比设计方法、步骤和计算公式，最后利用国内常用试验设备，进行厂拌温再生沥青混合料两个等级的性能检验。
基于前述厂拌温再生混合料的性能检测结果，指导了两个工程项目的顺利施工，并总结工程的成功经验，最终确定厂拌温再生工程的具体控制措施、技术要求和施工技术指南。论文以昆禄公路大修结构形式作为我国干线公路大修的典型结构，将下面层结构采用硫磺改性厂拌温再生混合料与采用厂拌冷再生混合料和常规厂拌热再生混合料的三种路面结构进行对比研究：分析了三种路面结构在准轴载和超载作用下，路面结构内部的应力应变指标的变化情况和趋势进行对比研究。通过理论的力学分析，进一步明确了硫磺改性厂拌温再生混合料作为下面层结构的技术优势。
论文根据实体工程的数据，将高旧料掺量的硫磺改性厂拌温再生技术与常规热拌沥青混合料技术的社会经济效益进行了对比研究：不仅进行了资源节约相关的经济效益分析，还利用产品寿命周期评价理论的分析方法，对能耗节约和二氧化碳减排进行了社会效益的评价。
关键词：沥青路面，厂拌温再生，硫磺改性，温拌，咼旧料掺量，咼模量，微观分析，施工工艺，配合比设计 ABSTRACT While Chinese new asphalt pavements are still in the rapid construction, existing asphalt pavements have already entered into a sustained period of large-scale maintenance．Milling and abandoning old pavement during maintenance can cause enormous economic loss and serious environmental pollution. Therefore，the research of recycling of aged pavement is become particularly important. In the current domestic asphalt recycling techniques，hot in-plant recycling technology IS the most widely used and most cost-effective one. When we analyze Chinese two typical maintenance works, the hot In-plant recycling technology is also the best choice，But the fewer RAP dosage problem still limit the application of hot In-plant recycling technology. Thus the study of high RAP dosage of hot in-plant recycling technology is very important．After many mix asphalt technologies were analyzed，sulfur modification warm mix technology was chosen to combine with hot In-plant recycling technology to achieve high RAP dosage recycling.
As the premise of research on warm m plant recycling technology, the microscopic mechanism and mixture performance impact of sulfur modification were investigated. First, DSC and optical microscope were used in micro analysis，and the microscopic state of sulfur existence in the bitumen binder and asphalt mixture with different sulfur dosage were explored; Second, the law of different sulfur dosage on temperature sensitivity were studied; Third, the law of different sulfur dos age on viscoelastic performance and mechanics performance of the mixture were studied. At last, the pivotal process conditions of warm in-plant recycling were investigated about its influence to the mixture ． The integration point of sulfur modification and high RAP dosage warm in-plant recycling technology can be found from above test results. The traditional idea of research on hot in-plant recycling was broken in this thesis, and "complementary perspective" was used to study the problem of asphalt recycling. Using characteristics of sulfur modification，not only the recycling construction process can achieve warm mix, but also the binder recycling study was skipped and macro asphalt mixture recycling law was directly explored. Three typical continuous gradation material design methods were analyzed, and applicability analysis were evaluated with high RAP dosage warm in-plant recycling technology. Thus the French high modulus design method was chosen as the mixture design guidance of high RAP dosage in-plant recycling technology. Then the mixture design method, procedures and formulas of high RAP dosage warm in-plant recycling technology were determined. At last, two levels mixture performances of high RAP dosage warm in-plant recycling were evaluated by domestic existing equipments.
Based on foregoing warm recycling mixture performance data, the two trial sections were smoothly paved and the final construction control process, technical requirement and technical manual were confirmed through the experiences summarization of the two trials. Using Kunlu highway rebuilding project as domestic second class highway typical major overhaul structure, the sulfur modification warm in-plant recycling mixture was used in the base layer comparing with cold in-plant recycling mixture and hot in-plant mixture. Under the standard axle load and the overload, the trends of stress and strain of three pavement structures were studied. Through the theoretical mechanical analysis, the technical advantages of using sulfur modification warm in-plant recycling mixture as base layer could be further confirmed.
High RAP dosage sulfur modification warm in-plant recycling technology and conventional hot mix asphalt technology were compared together about social and economic benefits according with the project data. Firstly the economic benefit about resource conservation was analyzed. Then social benefits about energy saving and CO2 emission reduction were evaluated through Life Cycle Assessment method.
Key Words: asphalt pavement, warm in-plant recycling, sulfur modification, warm mix, High RAP dosage, high modulus, microanalysis, construction technology, mix design |
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