摘要
选用RHEOLAB QC型旋转黏度计,分别测试了内掺水泥质量分数0. 0%、1. 0%、2. 0%与3. 0%纳米SiO_2的水泥浆体在5℃、20℃、30℃时的稳态流变曲线、静态屈服应力、恒定速率剪切下的表观黏度与剪切应力,系统研究了不同环境温度时纳米SiO_2对新拌水泥浆体流变性能的影响。结果表明:随纳米SiO_2掺量增加,水泥浆体的动态屈服应力与稠度系数均显著增大;随温度升高,掺纳米SiO_2的水泥浆体的稠度系数均增大,纳米SiO_2掺量为0%与1. 0%的水泥浆体的动态屈服应力增大,而纳米SiO_2掺量为2. 0%、3. 0%的水泥浆体的动态屈服应力基本不变;随纳米SiO_2掺量增加,水泥浆体的静态屈服应力与其在10～120 min的增长速率均增大; 20℃、30℃时,随纳米SiO_2掺量增加,水泥浆体的剪切变稀程度增大; 5℃与30℃时,随纳米SiO_2掺量增加,水泥浆体的触变指数增大;当纳米SiO_2掺量为1. 0%时,水泥浆体的活化能低,温度敏感性弱,热稳定性好。
The RHEOLAB QC rotating viscometer was used to measure the steady-state rheological curves,static yield stress and apparent viscosity and shear stress at constant shear rate of fresh cement pastes with nano-SiO2 dosage of0%,1.0%,2.0%and 3.0%at 5,20 and 30℃,the effect of nano-SiO2 on rheological properties of fresh cement pastes were investigated.The results show that:Dynamic yield stress and consistency coefficient increase with the increase of nano-SiO2 dosage;When temperatures rise,consistency coefficients of the pastes increase,the dynamic yield stresses of pastes with nano-SiO2 dosage of 0.0%and 1.0%increase,while the dynamic yield stresses of pastes with nano-SiO2 dosage of 2.0%and 3.0%are basically the same;The static yield stress and the overall growth rate in the period of 10-120 min increase with the incorporation of nano-SiO2;At 20 and 30℃,the degree of shear-thinning of cement pastes increase with the nano-SiO2 dosage;At 5 and 30℃,the thixotropic indexes of cement pastes increase with the nano-SiO2 dosage;When the nano-SiO2 dosage is 1.0%of cement,the activation energy is relatively low,revealing its low temperature sensitivity and good thermal stability.
作者
左胜浩
肖佳
张青
王大富
ZUO Sheng-hao;XIA Jia;ZHANG Qing;WANG Da-fu(School of Civil Engineering,Central South University,Changsha 410075,China)
出处
《硅酸盐通报》
CAS
北大核心
2019年第2期317-322,338,共7页
Bulletin of the Chinese Ceramic Society
基金
国家自然科学基金(51278497)
关键词
纳米SIO2
流变性能
温度
静态屈服应力
活化能
nano-SiO2
rheological property
temperature
static yield stress
activation energy
