摘要
半刚性水稳基层是高等级路面结构的主要形式,具有优良承载力与工程经济效益。针对骨架密实型水泥稳定碎石结构施工过程的离析、难以碾压密实、钻芯完整性差的问题,以紫惠高速路面工程为依托,通过跟踪基层试验路段铺筑各个环节,开展骨架密实型水稳碎石的设计与施工关键技术研究。使用分级掺配法设计具有优良骨架与密实性的目标矿料级配,并基于振动成型法确认最佳水泥剂量下的混合料最大干密度与最佳含水率指标,最终通过不同时间下的抗压强度试验确定合理的施工窗口期。施工过程中,针对骨架型水稳混合料特性,对混合料搅拌、运输、摊铺、碾压、养生等环节的关键技术要点进行总结归纳。最后,重点研究不同碾压工艺对混合料压实度、芯样质量的影响。试验结果显示,提前使用胶轮进行搓揉碾压,有助于提高路面压实度与结构层的完整性,减少后期开放交通后产生的表层碎石过度跑散问题,同时增强水稳结构的抗冲刷性能。
Semi-rigid cement-stabilized base is the main form of highway pavement structure,which has excellent bearing capacity and economic benefits.In order to solve the problems of segregation,difficulty in rolling compaction,and poor integrity of drilling core during the construction process,the key technology research on the design and construction of skeleton dense cement-stabilized base was carried out by tracking each link of the base test section in Zihui expressway.The gradation admixture method was used to design the gradation of the aggregate gradation with excellent skeleton and compactness.The maximum dry density and the optimal water content index of the mixture under the optimal cement dose were confirmed based on the vibration forming method.The reasonable construction window period was finally determined through the compressive strength test under different time.In the process of construction,the key technical points of mixing,transportation,paving,rolling and curing were summarized according to the characteristics of cement stabilized crushed stone.Finally,focuses on the impact of different rolling processes on the compaction of the mixture and the quality of the core sample.The test results show that the use of rubber wheels for rubbing and rolling in advance can help to improve the compactness of the base and the integrity of the structural layer,which can reduce excessive runaway of surface gravel caused by vehicle load in the later period,and enhance the anti-scouring performance at the same time.
作者
丁蓬勃
陈搏
DING Peng-bo;CHEN Bo(Guangdong Zihui Expressway Co.,Ltd.,Huizhou Guangdong 516251,China;Guangzhou Xiaoning Institute of Roadway Engineering,Guangzhou 510641,China)
出处
《科技和产业》
2021年第5期311-317,共7页
Science Technology and Industry
关键词
骨架密实型
水泥稳定碎石
级配设计
施工控制
碾压工艺
skeleton dense
cement stabilized crushed stone
gradation design
construction control
rolling process
