乳化沥青冷再生混合料强度提升措施研究进展  

Research progress on strength enhancement measures of emulsified asphalt cold recycled mixtures

作　　者：汪海年[1] 焦虎 徐宁 陈玉[1] 李元乐 WANG Hai-nian;JIAO Hu;XU Ning;CHEN Yu;LI Yuan-le(School of Highway,Chang'an University,Xi'an 710064,Shaanxi,China)

机构地区：[1]长安大学公路学院,陕西西安710064

出　　处：《交通运输工程学报》2024年第3期48-68,共21页Journal of Traffic and Transportation Engineering

基　　金：国家重点研发计划(2021YFB2601000);国家自然科学基金项目(52078048)。

摘　　要：分析了乳化沥青冷再生混合料的强度形成过程与构成机理,从外掺剂添加、结合料优化、设计方法和施工工艺改进以及再生沥青混合料回收料(RAP)预处理4个方面总结了乳化沥青冷再生沥青混合料强度的提升措施,分析对比了各种措施的提升机理和改善效果;根据各种措施存在的问题及特点,提出了相应的应用建议,并展望了未来的研究方向。研究结果表明:添加外掺剂来增强强度的研究相对较多,其次是优化结合料,改善混合料设计方法和施工工艺以及RAP预处理的研究较少,但这几个方面对于混合料强度的增加均有广阔的应用前景;外掺剂中,水泥最为常用,研究也最为系统,其增强效果要优于石灰,但掺量过高会导致低温抗裂性不足;火山灰质材料同样存在此问题,且杂质较多;纤维改善效果较为均衡,但受种类、掺量、添加顺序等因素影响;再生剂能够提高耐久性,但对早期强度不利;关于结合料,乳化沥青的慢裂性质有助于整体强度,高黏快凝有利于早期强度,掺量应适中,推荐3.5%~4.0%;改性乳化沥青应根据具体气候环境条件进行选择;改善混合料设计方法和施工工艺主要是从级配、含水率、结构层厚度、拌和顺序、压实养护方法等方面进行,强度增强效果相对较小,可作为附加改善条件;使用大掺量RAP的趋势使得RAP预处理技术变得更为重要,目前主要集中于降低结团率、级配分档、严控RAP储存条件和RAP表面化学改性4个方面。未来的研究应从以下几个方面进行:进一步明确火山灰质材料与乳化沥青之前的相互作用机理,以确定最佳掺量及剔除其中的杂质;探索不同外掺剂以及不同改性剂在提高混合料强度方面的复配应用;根据强度构成机理,探究多个提升措施的改善效果,以得到一个均衡的强度提升措施体系;重点关注RAP的预处理手段,探索RAP表面物理特性预处理对乳化沥�The strength formation process and composition mechanism of emulsified asphalt cold recycled mixtures were analyzed.The measures to improve the strength of emulsified asphalt cold recycled mixtures were summarized from four aspects,including addition of additives,optimization of binding materials,improvement of design methods and construction processes,and reclaimed asphalt pavement(RAP) pretreatment.The enhancement mechanism and improvement effect of various measures were analyzed and compared.According to the problems and characteristics of various measures,corresponding application suggestions were put forward,and future research directions were foreseen.Analysis results show that the addition of additives to enhance the strength has been relatively well studied,followed by the optimization of binding materials,and less research has been done to improve mixture design methods and construction processes,as well as RAP pretreatment,however,these aspects have promising applications for increasing the strength of the mixture.Among the additives,cement is the most commonly used and systematically studied,and its enhancement effect is better than that of lime,but too high cement content will lead to insufficient crack resistance at low temperatures.Volcanic ash material also suffers from this problem and has more impurities.Fiber has a more balanced improvement effect,but is affected by the type,doping amount,adding order,and other factors.Regenerating agent can improve durability,but is not favorable for early strength.In terms of binding material,the slow cracking nature of emulsified asphalt contributes to the overall strength,high viscosity and fast setting are beneficial to early strength,and the doping amount should be moderate and recommended at 3.5%-4.0%.Modified emulsified asphalt should be selected according to specific climatic and environmental conditions.The mixture design methods and construction processes are mainly improved in terms of the aggregate,moisture content,structural layer thickness,mixing

关 键 词：道路工程 乳化沥青冷再生混合料 强度提升措施 RAP预处理 表面物理特性 早期强度 耐久性 

分 类 号：U416[交通运输工程—道路与铁道工程]