摘要
研究了白云岩石粉对水泥净浆和砂浆流变性能的影响以及作用机理.结果表明:内掺白云岩石粉后,水泥净浆流动度随着石粉掺量的增加而增大,砂浆扭矩随着石粉掺量的增加而减小,内掺石粉质量分数超过12%后水泥净浆流动度增加更显著;含石粉砂浆的需水量比为93%,相同质量石粉的需水量比水泥小,使得水泥净浆流动度随石粉掺量增加而增大;石粉对减水剂具有吸附作用,能够增大水泥净浆流动度或砂浆流变性能;水泥颗粒和石粉颗粒表面Zeta电位分别为-1.76 mV和-8.94 mV,二者对阴离子型聚羧酸系减水剂的吸附能力不同,聚羧酸系减水剂会优先吸附于水泥颗粒表面上.
The effect of dolomite stone powder content on the rheological behavior of cement-based materials by fluidity of cement paste and the torque parameter of mortar was studied.The action mechanism of stone powder on rheological properties was investigated systematically by testing the water demand,the adsorption behavior and the Zeta potential.The results show that the fluidity of cement paste increases and torque of motar decreases with the increase content of dolomite stone powder,and the fluidity of cement paste increases more significantly when the content of dolomite stone powder exceeds 12%.The water demand ratio of mortar with dolomite stone powder is 93%,which indicates that the water demand of the dolomite stone powder is smaller than that of cement,and it will lead to the better flow properties of cement paste by inclusion of the stone powder.TOC results show that there exists a competitive adsorption of polycarboxylate superplasticizer(PCE)on dolomite stone powder and the cement surface.The adsorption ability of PCE on dolomite stone powder surface is weaker,so the adsorption of dolomite stone powder is also one of the reasons for increasing the rheological properties of cement paste or mortar.The zeta potential value on surface of pure cement particles and stone powder particles is-1.76 mV and-8.94 mV,respectively,which indicate that the cement and stone powder have different adsorption capacity for PCE.PCE will be preferentially adsorbed on the surface of cement particles.
作者
姚燕
高瑞军
吴浩
王玲
YAO Yan;GAO Ruijun;WU Hao;WANG Ling(State Key Laboratory of Green Building Materials,China Building Materials Academy,Beijing 100024,China)
出处
《建筑材料学报》
EI
CAS
CSCD
北大核心
2019年第6期860-865,共6页
Journal of Building Materials
基金
“十三五”国家重点研发计划项目(2017YFB0310100)
关键词
白云岩石粉
水泥净浆
砂浆
流变敏感性
作用机理
dolomite stone powder
cement paste
mortar
rheological sensitivity
action mechanism
