摘要
采用水泥净浆流动度来评价抗泥剂(JJA-KNJ)对加蒙脱土水泥中聚羧酸超塑化剂(PCE)分散性能的改善效果,并结合有机碳含量(TOC),热重(TG),X射线衍射(XRD),扫描电镜(SEM)分析,研究了JJA-KNJ与蒙脱土之间的作用机理.结果表明:抗泥剂JJA-KNJ可改善PCE对加蒙脱土水泥的初始分散能力,显著改善PCE对加蒙脱土水泥的经时分散能力,提高其保坍性能;当PCE与JJA-KNJ同时存在时,JJA-KNJ能降低蒙脱土对PCE的吸附量,使得蒙脱土表面变得更加光滑,且空隙更小;JJA-KNJ溶于水后,吸附在蒙脱土颗粒的表面上,形成一层有机阳离子聚合物保护膜,阻止PCE的侧链进入蒙脱土的层间;JJA-KNJ在水泥水化的碱性条件下对蒙脱土颗粒具有明显的稳定效果,而且这一效果不会随着时间的延长出现明显衰减.
Through fluidity of cement paste the improvement of dispersion property of polycarboxylate superplasticizer（PCE）after adding montmorillonite by anti-clay agent（JJA-KNJ）can be evaluated,and its mechanism can be elucidated by TOC,TG,XRD and SEM.The results show that anti-clay agents（JJAKNJ）can improve the dispersion of PCE after adding montmorillonite and significantly increase the dispersion of PCE with time and enhance the slump retention performance.When JJA-KNJ and PCE coexist in the synthetic cement pore solution,JJA-KNJ decreases with the adsorption of PCE on montmorillonite.Montmorillonite surface becomes smoother and forms smaller pores after anti-clay agents JJA-KNJ;cationic polar terminal of JJA-KNJ dissolves in water and adsorbes on the surface of the montmorillonite particles,thus forming a layer of organic cationic polymer protective film to prevent the side chain of PCE onto montmorillonite interlayer.JJA-KNJ has a significant stabilizing effect under alkaline conditions of hydration of cement,stabilizing effect will not be significant attenuation with the extension of time.
出处
《建筑材料学报》
EI
CAS
CSCD
北大核心
2017年第4期556-562,共7页
Journal of Building Materials
关键词
聚羧酸减水剂
蒙脱土
净浆
抗泥剂
机理
polycarboxylate superplasticizer
montmorillonite（MMT）
paste
anti-clay agent
mechanism
