高比例RAP厂拌热再生沥青混合料微观机理与性能试验研究

发布时间：2018-08-11 17:15

【摘要】：近年来，随着我国公路事业的大力发展，我国的公路维修改造工程逐渐增多。每年就公路维修铣刨产生的RAP就有1.6亿吨。将其废弃将会占用土地、污染环境、破坏生态、浪费资源等，如将其全部再生利用，可节省将近200亿元的直接材料费。研究RAP的再生具有经济、社会及环境效益。热再生沥青混合料中的新旧沥青混合状态目前还是黑箱问题，高比例RAP再生沥青混合料的新旧沥青混合状态对再生沥青混合料的水稳性、低温抗裂性、疲劳耐久性有显著影响。为改善再生沥青混合料的性能，提高RAP的使用比例，，本文采取微观试验及性能试验方法探索再生沥青胶浆。由于新旧沥青辨别的复杂性，寻找一种可靠的示踪剂标记新沥青加入到再生沥青混合料中，由此区分再生沥青混合料中的旧沥青。首先，初选几种示踪剂纳米ZnO、三聚氰胺及Sb2O3。对初选的几种示踪剂进行SEM试验及示踪剂/沥青的物理性能试验，确定了示踪剂类型和掺量（5%掺量的三聚氰胺和4%掺量的2#纳米ZnO）、搅拌方法（胶体磨和高速剪切法）、制样方法（厚玻片）及观察方法（断面）等。将制备的5%掺量三聚氰胺/沥青胶浆作为新沥青加入再生沥青混合料中，采用SEM对再生沥青混合料中集料表面沥青胶浆的三聚氰胺进行探测，通过对比纯RAP、普通沥青混合料的沥青胶浆确定了三聚氰胺的出现范围。所测试样的初步试验结果显示，加入到再生沥青混合料中的新沥青与RAP表面旧沥青发生混合的有效深度范围为56.54%~78.12%。再生沥青混合料的性能试验是假设有效沥青比为60%、70%、80%、90%、100%时，对两个RAP比例40%、60%进行AC-13的再生沥青混合料的配比设计，其路用性能试验结果显示按有效沥青比为70%~90%中经试验确定的一比例时，其马歇尔性能、高温稳定性、低温抗裂性、水稳性及弯拉变形性能较好。以广惠（广州→惠州）高速公路为依托工程，逐步将厂拌热再生技术应用于高速公路主、超车道的下、中、上面层，提高RAP的掺配比例，广泛应用于实体工程，提高路面施工经济效益。通车3年的再生试验段检测结果显示：各指标符合质量及相关技术要求，性能较好，为进一步提高RAP的掺配比例建立基础。
[Abstract]:In recent years, with the development of highway in our country, the highway maintenance and reconstruction project is increasing gradually. There are 160 million tons of RAP produced each year for road maintenance milling and planing. It will occupy the land, pollute the environment, destroy the ecology and waste the resources. If the waste is completely recycled, the direct material cost of nearly 20 billion yuan can be saved. The study of RAP regeneration has economic, social and environmental benefits. The mixing state of new and old asphalt in hot recycled asphalt mixture is still a black box problem at present. The new and old asphalt mixing state of high ratio RAP recycled asphalt mixture has a significant effect on the water stability, low temperature crack resistance and fatigue durability of recycled asphalt mixture. In order to improve the performance of recycled asphalt mixture and increase the use ratio of RAP, this paper adopts microscopic test and performance test method to explore the recycled asphalt mortar. Due to the complexity of distinguishing old and new bitumen, a reliable tracer marking new asphalt is found to be added to the recycled asphalt mixture to distinguish the old asphalt from the recycled asphalt mixture. First, several tracer nanocrystalline ZnO, melamine and SB _ 2O _ 3. SEM test and physical property test of tracer / asphalt were carried out on several tracers in primary election. The types and amounts of tracer (5% melamine and 4%) nanocrystalline ZnO), agitation (colloid mill and high speed shear), sample preparation (thick glass) and observation method (section) were determined. Melamine on the aggregate surface of recycled asphalt mixture was detected by SEM by adding 5% melamine / asphalt slurry as new asphalt into recycled asphalt mixture. By comparing pure Rapp, the asphalt slurry of ordinary asphalt mixture determines the scope of melamine. The preliminary test results show that the effective depth range of mixing the new asphalt and the old asphalt on the RAP surface is 56.54 and 78.12. The performance test of recycled asphalt mixture is based on the assumption that the effective asphalt ratio is 60% and 80%. When the ratio of two RAP is 40% or 60%, the proportion design of recycled asphalt mixture with AC-13 is carried out. The road performance test results show that the Marshall performance, high temperature stability, low temperature crack resistance, water stability and bending and tensile deformation properties are better when the effective asphalt ratio is 70%. Based on the project of Guanghui (Guangzhou Huizhou) Expressway, the plant mix heat regeneration technology has been gradually applied to the lower, middle and upper layers of the main and overtaking freeway, to increase the blending ratio of RAP, and to be widely used in physical engineering. Improve the economic benefit of pavement construction. The test results of regenerative test section for 3 years show that each index meets the requirements of quality and related technology, and the performance is good, which establishes the foundation for further increasing the proportion of RAP mixed.
【学位授予单位】：华南理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U414

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