水泥稳定砂类土冷再生基层试验研究及应用

Experimental Study and Application on Cold-recycled Base with Cementstabilized Sandy Soil

研究目的:为推广冷再生技术在道路维修改造中的应用,完善冷再生材料设计指标及施工技术标准,本文就冷再生水泥稳定砂类土基层材料的试验展开研究,对比分析原道路旧料与冷再生材料的性能变化特征,进行冷再生基层材料的设计,并提出冷再生基层的施工质量控制要点。研究结论:(1)试验表明:冷再生基层添加剂的类型和剂量可通过击实试验和无侧限抗压强度试验及工程特点来综合确定,原道路材料颗粒级配、强度和稳定性较差,而5%的水泥稳定砂类土再生材料施工最佳含水量为12.1%,强度和稳定性较好,满足路面基层使用要求;(2)建立道路改造前详细工程评价项目,主要包括现状评价、结构承载力评价及旧料的性能评价等;(3)通过工程应用,指出就地冷再生基层施工水泥和水的添加方法,并提出冷再生铣刨-压实一体化作业方法;(4)经检测,冷再生水泥稳定基层的各项指标均满足使用要求,再生效果好,可为类似冷再生基层设计与施工提供参考。

Research purposes： The experimental study aims to promote the application of cold recycling technology in road reconstruction and improve design indexes of cold recycled mixture and construction standards. Comparative analysis about the performance of existing pavement mixture and cold recycled mixture, and design of cold recycled base material are carried out. Finally this paper puts forward the quality control points in construction about cold recycling technology. Research conclusions： （ 1 ） The result of the tests shows that types and dose of additive are determined through compaction test, unconfined compression test and engineering characteristics;grain composition, strength and stability of old road mixture are compared with cement - stabilized recycled mixture. And optimum water content on 5% cement - stabilized sandy soil mixture was respectively 12. 1% which shows that intensity and stability of cementstabilized recycled mixture is better, and can meet the requirement on pavement base. （2） Engineering evaluation projects is established in detail. It mainly includes present situation, structural bearing capacity and the performance of old mixture, etc. （3） Through engineering practice, it points out the method of equipment matching on cold in - place recycling units and adding method of cement and water, and integrative operation method of milling - planing and compacting in cold in - place recycling technology is proposed. （4） Detection results of cold - recycled base show that various indexes of base can meet pavement operating requirements, and regeneration effect is good, which is provided for references to the design and construction of similar cold regenerative base.