基于普氏击实试验的冷再生混合料设计优化

Design optimization of cold recycled mixes based on Proctor hammer compaction

路面再生利用技术是修复老旧沥青路面的重要手段,将废弃沥青路面作为骨料生产冷再生混合料,可以有效降低运输成本、能源消耗和温室气体排放。然而现有规范中尚未明确不同压实方法对冷再生混合料设计的影响,采用改进的Proctor测试程序进行沥青混合料击实试验,对不同乳化沥青和水泥掺量的冷再生混合料的力学行为进行评价,通过分析不同的养护温度和养护时间,提出了一种快速、实用的实验室冷再生沥青混合料配合比设计方法。力学试验表明,相对于传统的沥青混合料击实方法,改进的Proctor击实成型的试件能更好地控制材料变化的影响,此外,60℃的养护温度与较短的养护时间有利于提升沥青混合料的力学性能,达到优化设计的目的。

Recycling techniques are important tools for rehabilitation of old and deteriorated asphalt pavements.The production of co ld recycled mixes using reclaimed asphalt pavement as aggregates provides economic benefits as it decreases transportation costs,energy consumption,and gas emissions.Despite that,there is no methodology to design this type of mix.The present research evaluated the design of cold recycled mixes through different compaction methods and varying asphalt emulsion and cement contents.Different curing temperatures and periods were analyzed to propose a faster and more practical method for mix design in the laboratory.Mechanical tests performed indicated that specimens compacted by the Marshall hammer provide similar results when varying asphalt emulsion and cement contents,while the Proctor hammer compaction was able to better capture the influence of these materials.The temperature of 60℃associated with shorter curing time is believed to be good for design purposes.