摘要
自密实混凝土是CRTSⅢ型板式轨道充填层结构的关键材料,其施工性能的稳定对无砟轨道运行期间性能的稳定有重要影响.由于自密实混凝土材料组成的特点,其对环境温度的敏感性较普通混凝土更显著,主要体现在环境温度高时容易出现扩展度损失,造成灌板失败,环境温度低时容易出现扩展度返大,造成混凝土离析,这些均造成了充填层自密实混凝土施工过程的不稳定.本文主要介绍了由于环境温度变化对自密实混凝土施工稳定性的影响及其带来的主要施工质量缺陷,并结合实践经验提出了降低自密实混凝土温度敏感性的针对性技术措施,以期为无砟轨道充填层自密实混凝土现场施工稳定性的控制提供相应技术措施.
Self-compacting concrete ( SCC) is the key material in CRTS DI slab ballastless track structure, and construction stability of SCC plays an important role in ballastless track during operation. Due to characteristics of material composition of SCC, its sensitivity to environmental temperature is more obvious than that of ordinary concrete, which is mainly reflected in the slump flow increases when environmental temperature is high, leading to pouring failure, but slump flow decreases when environmental temperature is low, leading to concrete segregation, all of which result in unstable construction process of filling layer SCC. In this paper, the author introduced the influence on concrete construction stability changing with environmental temperature change as well as the main quality defects resulting from unstable construction of SCC. Combined with practice experience, the targeted measures of decreasing temperature sensitivity of SCC were put forward, hoping to provide corresponding technical measures for keeping site construction stability of SCC.
作者
于连山
谢清泉
周官强
马昆林
Yu Lianshan;Xie Qingquan;Zhou Guanqiang;Ma Kunlin(China Railway 21^st Bureau Group 6^th Engineering Co. Ltd., Beijing 101111, China;School of Civil Engineering, Central South University, Changsha Hunan 410075 , China)
出处
《铁道建筑技术》
2019年第6期59-62,67,共5页
Railway Construction Technology
基金
国家自然科学基金资助项目(51678569)
中铁二十一局科研项目(18A-1)
关键词
无砟轨道
自密实混凝土
温度敏感性
施工稳定性
ballastless track
self-compacting concrete
temperature sensitivity
construction stability
