水泥稳定碎石半刚性基层再生应用研究

发布时间：2018-08-11 11:29

【摘要】：近年来，广西地区大多数沥青路面都进入了大中修阶段，这些路面在开挖的过程中，必然会产生大量的废弃路面材料，旧水泥稳定碎石基层材料是一种具有较高的强度和刚度，抗冻性和水稳定性都良好，但是抗开裂性能比较差，如何对这种材料的再生利用，成为了道路科研人员和工程人员必须解决的问题。本文主要研究了水泥、乳化沥青、水泥乳化沥青、水泥粉煤灰四种再生方法再生旧水泥稳定碎石基层材料，通过对旧料的筛分确定了新料掺配比例为20%左右，通过旋转击实实验确定再生混合料的最大干密度和最佳含水率，研究了在最佳含水量和最大干密度下各种再生方法的再生混合料的无侧限抗压强度、劈裂强度、冻融劈裂强度等力学性能，研究发现水泥再生混合料中水泥最佳掺量为5%，乳化沥青再生混合料中乳化沥青最佳掺量为7.5%，并分析其强度随龄期、水泥掺量或乳化沥青掺量的变化规律，通过对水泥乳化沥青再生混合料进行了正交实验，发现水泥乳化沥青再生混合料的强度主要是由水泥这部分决定的，乳化沥青的掺入对再生混合料强度影响不大，但可以增加再生混合料的柔性，，减少收缩开裂。同时研究了在水泥掺量为4%条件下水泥粉煤灰再生混合料的最佳配合比为4:10:86，发现了一定量的粉煤灰可以提高再生混合料的强度，通过SEM分析了各种再生方法的强度形成机理，对这几种再生方法效果综合评价，认为水泥粉煤灰与水泥乳化沥青再生方法在改善旧水泥稳定碎石基层材料性能中效果比较好，可以在工程中采用。最后，本文研究了再生旧水泥稳定碎石混合料基层施工方法包括厂拌再生利用、就地再生利用以及多锤头就地破碎再生利用，以及它们的适用范围、施工工艺与质量控制，通过对广西地区沥青路面的交通量、路面材料使用情况、结构形式进行调查，总结出了原沥青路面五种基本结构，针对这五种沥青路面基本结构进行半刚性基层再生并使用软件HPDS2006计算每种沥青路面结构层厚度，得出了不同沥青路面半刚性基层再生典型结构，为以后半刚性基层再生利用的施工技术提供了一定的参考价值。
[Abstract]:In recent years, most asphalt pavements in Guangxi have entered the stage of major and medium repair. During the excavation of these pavements, a large number of abandoned pavement materials will inevitably be produced. The old cement stabilized macadam base material is a kind of high strength and stiffness. The frost resistance and water stability are good, but the cracking resistance is poor. How to recycle this material has become a problem that road researchers and engineers must solve. In this paper, four regenerative methods of cement, emulsified asphalt and cement fly ash are studied to regenerate the old cement stabilized macadam base materials. The proportion of new materials is about 20% by screening the old materials. The maximum dry density and optimum moisture content of recycled mixture were determined by rotating compaction test. The unconfined compressive strength and splitting strength of recycled mixture were studied under the optimum moisture content and maximum dry density. The mechanical properties such as freezing and thawing splitting strength are studied. It is found that the optimum content of cement in cement recycled mixture is 5, and the optimum amount of emulsified asphalt in emulsified asphalt recycled mixture is 7.5. The strength of recycled mixture is analyzed with age. Through orthogonal experiment of cement emulsified asphalt recycled mixture, it is found that the strength of cement emulsified asphalt recycled mixture is mainly determined by cement. The mixing of emulsified asphalt has little effect on the strength of recycled mixture, but it can increase the flexibility of recycled mixture and reduce shrinkage cracking. At the same time, the optimum mix ratio of cement fly ash recycled mixture is 4: 10: 86 under the condition of cement content of 4%. It is found that a certain amount of fly ash can improve the strength of recycled mixture, and the strength forming mechanism of various regeneration methods is analyzed by SEM. According to the comprehensive evaluation of the effects of these regeneration methods, it is considered that the regeneration method of cement fly ash and cement emulsified asphalt is better in improving the properties of the old cement stabilized macadam base material, and can be used in engineering. Finally, this paper studies the construction methods of recycled old cement stabilized macadam mixture base, including reclaimed utilization of factory mix, in-situ recycling and local crushing and recycling of multi-hammer head, as well as their applicable scope, construction technology and quality control. Through the investigation of the traffic volume, the use of pavement materials and the structure form of asphalt pavement in Guangxi, five basic structures of the original asphalt pavement are summarized. According to the five kinds of asphalt pavement basic structure, the semi-rigid base course is regenerated, and the thickness of each asphalt pavement structure layer is calculated by using the software HPDS2006, and the typical regenerative structure of different asphalt pavement semi-rigid base course is obtained. It provides a certain reference value for the construction technology of regeneration and utilization of semi-rigid base.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U416.2

【参考文献】