摘要
为研究高速分散速率与时长等参数对水泥基浆体流变行为的影响,采用涡流式高速分散设备,设计不同速率与时长,分别对不同水胶比、不同硅灰掺量的水泥基浆体进行分散,再通过流变仪测试浆体的流变性能。试验结果表明:分散速率对于较低水胶比水泥浆体屈服应力、触变性的影响大于较高水胶比浆体;不同水胶比水泥浆体样品的塑性黏度均随分散速率的提高迅速降低后趋于稳定,塑性黏度变化的转折点大致出现在分散速率为1 000~1 500 rpm处。硅灰的掺入显著提高了各浆体的屈服应力、塑性黏度与触变性,但当采用较高的速率进行分散时,浆体间流变参数的差异总体上呈缩小趋势。掺硅灰等超细粉体的水泥基浆体的高速分散时长建议控制在2 min左右。
In order to study the influence of parameters such as high-speed dispersion rate and time length on the rheological behavior of cement-based paste,eddy current high-speed dispersion equipment was used to get different rates and time lengths.Cement-based paste with different water-binder ratios and different silica fume contents were dispersed respectively,and the rheological properties of the paste were tested by rheometer.The results showed that the influence of dispersion velocity on the yield stress and thixotropy of paste with lower water-binder ratio was greater than that of paste with higher water-binder ratio.The plastic viscosity of cement paste samples with different water-binder ratios decreased rapidly with the increase of dispersion velocity,and then tended to be stable.The turning point of plastic vis-cosity change occured roughly at the dispersion rate from 1000 rpm to 1500 rpm.The addition of silica fume significantly increased the yield stress,plastic viscosity and thixotropy of each paste,but the difference of rheological parameters between the samples tended to de-crease when the paste was dispersed at a higher rate.It was suggested that the dispersion time of cement-based paste mixed with ultrafine powder such as silica fume should be controlled at about 2 min.
作者
蒋睿
王月华
刘子科
何龙
翁智财
胡建伟
李康
成卫辉
JIANG Rui;WANG Yuehua;LIU Zike;HE Long;WENG Zhicai;HU Jianwei;LI Kang;CHENG Weihui(Institute of Railway Construction,China Academy of Railway Sciences Co.,Ltd.,Beijing 100081,China;State Key Laboratory of High Speed Railway Track Technology,Beijing 100081,China)
出处
《混凝土》
CAS
北大核心
2024年第4期94-102,共9页
Concrete
基金
国家重点研发计划(2021YFB3703700)
中国铁道科学研究院基金(2020YJ139)。
关键词
水泥基浆体
分散速率
分散时长
屈服应力
塑性黏度
cement-based paste
dispersion rate
dispersion time
yield stress
plastic viscosity
