摘要
对电厂收尘原状粉煤灰（超细灰和I级灰）进行扫描电镜（SEM）和激光粒度测试分析,获得其颗粒形态特征,推荐超细粉煤灰粒径分布测试方法,开展其对粉煤灰-水泥浆体流变性能影响研究.结果表明：超细粉煤灰成规则的球状微珠结构,表面光滑,中位径为1.41μm,比表面积达2 151 m^2/kg,无水乙醇介质湿法＋超声制样激光粒度测试与SEM表征符合;随着粉煤灰取代量的增加,I级粉煤灰-水泥浆体流变曲线适用Bingham流变模型,超细粉煤灰-水泥浆体流变曲线先适用Bingham流变模型,在取代量达到60%后宜采用Herschel-Bulkley流变模型;随着粉煤灰取代量的增加,粉煤灰颗粒形态对流变参数的影响显著,且超细粉煤灰对塑性黏度的影响规律与I级粉煤灰相反;超细粉煤灰-水泥浆体的黏度恢复的比例低于I级粉煤灰,利于浆体在拌和或扰动下的流动性改善.
The electron microscope scanning（EMS） and lazer particle size analyzer were used to analyze the particle morphology of two kinds of original fly ash（ultrafine fly ash and grade-I fly ash） collected from a power plant.On this basis,a sample preparation method for particle size distribution test was proposed.Then,the rheological properties of two kinds of fly ash-cement slurry were studied.Results show that the ultrafine fly ash is in the form of regular spherical micro-beads with smooth surface by the wet preparation method plus ultrasonic shaking with anhydrous ethanol as the medium,1.41 μm in median diameter and 2 151 m^2/kg in specific surface area,which is consistent with the morphological characterization obtained by EMS;with the increase of fly ash content,the rheological curve of the grade-I fly ash cement slurry can be represented by the Bingham rheological model,however,although the ultrafine fly ash cement slurry can be firstly described by the Bingham rheological model,the Herschel-Bulkley rheological model is recommended when the fly ash content reaches to 60%;with the increasing of fly ash content,the influence of the particle morphology of the fly ash becomes more significant on the rheological properties,and the influence of ultra-fine fly ash on plastic viscosity of the slurry is opposite to that of grade-I fly ash;the ultrafine fly ash cement slurry contributes better to the fluidity of the slurry under mixing or disturbance as it has lower viscosity recovery ratio than the grade-I fly ash cement slurry.
作者
何小兵
肖翔天
周超
谢培
He Xiaobing;Xiao Xiangtian;Zhou Chao;Xie Pei(School of Civil Engineering;School of Materials Science and Engineering,Chongqing Jiaotong University,Chongqing 400074,China;Luohuang Development Co.Ltd.,Huaneng Group,Chongqing 402283,China)
出处
《华中科技大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2018年第10期34-39,共6页
Journal of Huazhong University of Science and Technology(Natural Science Edition)
基金
中国博士后科学基金资助项目(2015M572641XB)
重庆市教委科学技术研究资助项目(KJ1500512)
山区桥梁与隧道国家重点实验室培育基地开放基金资助项目(CQSLBF-2015-12)
关键词
超细粉煤灰
颗粒形态
流变性能
初始屈服应力
塑性黏度
触变
ultrafine fly ash
particle morphological characteristics
rheological properties
initial yield stress
plastic viscosity
thixotropic
