就地热再生沥青混合料配合比设计及性能评价

Mix Proportion Design and Performance Evaluation of Hot Recycling Asphalt Mixture

摘要: 针对就地热再生沥青混合料级配变异性大、不确定因素多等特点，论文基于室内试验对就地热再生沥青混合料的再生剂合理掺量、配合比设计方法、路用性能评价等进行系统研究，以完善就地热再生沥青混合料的配合比设计及性能评价体系。研究表明当再生剂掺量为8%时，回收沥青关键技术指标能够恢复到原有性能；根据就地热再生沥青混合料的材料特性，提出应将新集料与沥青预拌再与铣刨料拌和的方式，通过析漏指标控制预拌料的沥青用量为2.5%，基于马歇尔试验法确定再生沥青混合料外掺沥青用量为0.6%；基于室内试验表明，就地热再生沥青混合料具有良好的高温性能和水稳定性，但其低温抗裂性能较差；依托试验路的铺筑对现场再生沥青混合料进行汉堡车辙试验，研究表明混合料剥落点大于10,000次，碾压20,000次的最大变形量均小于7 mm，具有良好的水敏感性和高温抗车辙性能。

Abstract: In view of the characteristics of in-situ geothermal recycled asphalt mixture, such as large variability of gradation and many uncertain factors, based on indoor test, this paper systematically studies the reasonable amount of recycled agent, mix proportion design method and road performance evaluation of in situ geothermal recycled asphalt mixture, so as to improve the mixture ratio design and performance evaluation system of in situ geothermal recycled asphalt mixture. The research shows that when the content of recycling agent is 8%, the key technical indexes of recycled asphalt can be restored to the original performance; according to the material characteristics of geothermal recycled asphalt mixture, the new aggregate and asphalt premixed and milled material should be mixed, and the asphalt content of the ready mixed material should be controlled to 2.5% through the leakage index. Based on the Marshall test method, the asphalt consumption of recycled asphalt mixture is determined. Based on the indoor test, it is found that the in-situ recycled asphalt mixture has good high-temperature performance and water stability, but its low-temperature crack resistance is poor; relying on the paving of the test road, the Hamburg rutting test is carried out on the recycled asphalt mixture on site, and the research shows that the maximum deformation of the mixture after 20,000 times of rolling is less than 7 mm and the stripping point of the mixture is more than 10,000 times, and the maximum deformation is less than 7 mm after 20,000 times of rolling and high temperature rutting resistance.