沥青路面高掺量厂拌热再生技术研究

发布时间：2018-03-21 12:12

本文选题：高掺量　切入点：厂拌热再生　出处：《东南大学》2015年硕士论文　论文类型：学位论文

【摘要】：随着我国高速公路沥青路面相继进入养护维修阶段,路面每年的翻修铣刨过程会产生大量的沥青路面材料,具有较大的社会经济价值,从资源节约和环境保护出发,实现高速公路路面旧料的高掺量、大比例回收利用是路面养护发展的必然趋势。但目前国内外厂拌热再生混合料RAP的掺配比例普遍较低,本文针对高掺量厂拌热再生混合料的应用技术展开研究。通过室内实验研究再生剂、SBR胶乳等添加剂对SBS老化沥青性能的改善及对RAP掺量的提升效果,在此基础上研究高掺量厂拌热再生混合料的生产工艺、配合比设计方法、以及路用性能评价,从而推动高RAP掺量厂拌热再生技术在高速公路的应用。首先,分析了改性沥青老化性能,基于老化沥青性能恢复为基础的沥青再生理论对老化改性沥青分别加入不同比例的再生剂、SBR胶乳进行再生,对其针入度、延度、软化点、粘度等常规性能指标进行检测分析,通过综合考虑确定再生剂掺量为旧沥青质量的2%,胶乳掺量为旧沥青质量的4%。同时加入新沥青进行调和再生,新沥青的加入进一步改善了再生沥青的各项性能,最终表明仅从旧沥青性能恢复上来讲,通过添加剂和新沥青综合作用,RAP的掺配比例可以达到50%。其次,对厂拌热再生生产过程中拌合温度、材料添加顺序、拌合时间等关键工艺参数进行分析探讨。通过室内拌合试验确定了添加温拌剂的再生混合料的最佳出料温度、RAP和新集料的拌合合理温度；同时室内研究不同材料添加顺序、拌合时间等再生工艺对再生混合料性能的影响,基于灰色关联度理论对再生混合料路用性能进行多指标评价,最终确定了最佳的生产工艺组合。进而,对再生混合料配合比设计中关键控制参数矿料间隙率、最大理论密度进行分析,重点确定了最大理论密度的修正计算公式；在此基础上,采用马歇尔设计方法确定了30%、40%和50%RAP掺量下再生沥青混合料的级配组成、最佳沥青用量等,并采用Superpave设计方法对依据马歇尔理论设计的再生混合料配合比进行验证分析,各项性能指标均能满足高速公路新拌沥青混合料的设计标准,进一步证明了配合比设计的合理性。最后,通过动态蠕变试验、半圆低温弯曲试验、冻融劈裂试验、半圆疲劳试验等,分析了不同高RAP掺量再生混合料的路用性能,并与普通热拌沥青混合料进行对比,并在试验结果基础上探讨采用添加纤维来进一步改善高掺量再生混合料的路用性能。最终实现RAP掺量高达50%的再生沥青混合料满足我国高速公路沥青路面的技术要求,从而使得高掺量RAP厂拌热再生技术能够应用于高等级公路的建设与维修。
[Abstract]:As the asphalt pavement of expressway in our country has entered the maintenance and repair stage one after another, a large number of asphalt pavement materials will be produced in the course of pavement renovation and planing every year, which is of great social and economic value, starting from the conservation of resources and environmental protection. It is an inevitable trend of pavement maintenance and development to realize high content of used materials and large proportion of recycled materials in expressway pavement. However, the proportion of RAP mixed with hot recycled mixture is generally low at home and abroad. In this paper, the application technology of high content hot mix mixture was studied. The improvement of the performance of SBS aging asphalt and the improvement of RAP content were studied by laboratory experiments. On the basis of this, the production process, mix ratio design method and road performance evaluation of high content hot mix mixture are studied, so as to promote the application of high RAP mix heat recycling technology in expressway. The aging property of modified asphalt was analyzed. Based on the theory of asphalt regeneration based on the recovery of aging asphalt performance, the asphalt latex was regenerated by adding different proportion of recycled agent SBR latex, and the penetration, ductility and softening point of the modified asphalt were analyzed. The viscosity and other conventional performance indexes are tested and analyzed. Through comprehensive consideration, it is determined that the amount of recycled agent is 2% of the mass of old asphalt, and the amount of latex is 4% of the mass of old asphalt. At the same time, new asphalt is added to mix and regenerate. The addition of new asphalt further improves the performance of recycled asphalt, and finally shows that only from the performance recovery of old asphalt, the blending ratio of additive and new asphalt can reach 50%. Secondly, The mixing temperature and adding order of materials in the production process of hot regeneration of factory mixing are studied. The key process parameters such as mixing time and so on are analyzed and discussed. The optimum discharge temperature of recycled mixture with warm mixing agent and the reasonable mixing temperature of new aggregate are determined by indoor mixing test, and the order of adding different materials is also studied in laboratory. The influence of mixing time and other regeneration technology on the performance of recycled mixture is studied. Based on the grey correlation degree theory, the road performance of recycled mixture is evaluated with multiple indexes, and the best production process combination is finally determined. Based on the analysis of the key control parameters in the mix ratio design of recycled mixture, the maximum theoretical density, the modified formula of the maximum theoretical density is determined. Marshall design method is used to determine the gradation composition and optimum asphalt content of recycled asphalt mixture with 30% and 50 rap content, and the Superpave design method is used to verify and analyze the mix ratio of recycled mixture designed according to Marshall's theory. Each performance index can meet the design standard of expressway fresh asphalt mixture, which further proves the rationality of mix ratio design. Finally, through dynamic creep test, semi-circular low-temperature bending test, freeze-thaw splitting test, In this paper, the pavement performance of recycled mixture with different high RAP content is analyzed and compared with that of common hot mix asphalt mixture, such as semicircle fatigue test, etc. On the basis of the test results, it is discussed that adding fiber is used to further improve the road performance of high volume recycled mixture. Finally, the recycled asphalt mixture with RAP content up to 50% meets the technical requirements of highway asphalt pavement in China. So that the high-volume RAP plant-mix heat regeneration technology can be used in the construction and maintenance of high-grade highways.
【学位授予单位】：东南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U414

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