摘要
在胶凝材料中掺入不同类型的硫酸盐,采用净浆流动度、总有机碳(TOC)及ζ电位等试验,研究了硫酸盐种类及其掺量对不同结构聚羧酸减水剂分散性能的影响,探讨了硫酸盐影响聚羧酸减水剂分散性能的机理,并提出改善措施.结果表明:二水硫酸钙掺量达到胶凝材料质量的3.6%以上时,对不同结构聚羧酸减水剂的减水效果均有所降低.硫酸钠掺量对质量不同结构聚羧酸减水剂的净浆流动度均有很大影响,当其掺量为胶凝材料质量的1%时,相应浆体基本失去流动性;硫酸钠掺量为胶凝材料质量的3%时,溶液中有机碳的含量降低了23%;硝酸钡的加入能使溶液中的有机碳含量基本恢复到未掺硫酸钠时的程度,流动度得到改善.电泳试验表明:硫酸钠的加入对浆体ζ电位有很大影响,其掺量越高,ζ电位绝对值愈小,分散性愈差;当加入硝酸钡后,浆体ζ电位绝对值有较大提高.
Influence of varieties of sulfate and its use level on dispersing properties of different kinds of polycarboxylate superplasticizer was investigated, the dispersion mechanism of sulphate for polycarboxylate superplasticizer was explored and the improvement measures was recommended through determination of fluidity of cement paste,total organic carbon（TOC） and ~ potential with different types of sulphate add- ed in cementitious materials. The results show that dehydrate calcium sulphate would decrease the water reduction ratio that different kinds of polycarboxylate superplasticizer can achieve when the use level of cal- cium dihydrate sulphate reached above 3.6% of the total mass of cementitious materials; the use level of Na2 SO4 have significant impact to the fluidity of the cement paste with these three different kinds of polycarboxylate superplasticizer added; the cement paste loses its fluidity when the use level reaches 1% of the total mass of cementitious materials. When the use level of Na2SO4 reaches 3% of gelled materials, TOC of the solution decreases by 23%. The addition of Ba2NO3 could make TOC content recovered to the extent when the solution is not mixed with Na2 SO4, and the fluidity also would get improved. The electrophoresis experiments indicate that the addition of sodium sulphate has great influence on the ζ potential, the more the use level, the smaller the absolute value of ζ potential and the poorer the dispersity. When Ba2NO3 is added, the absolute value of ζ＂ potential would be raised a lot.
出处
《建筑材料学报》
EI
CAS
CSCD
北大核心
2013年第3期410-415,共6页
Journal of Building Materials
基金
北京市教育委员会科技成果转化和产业化项目(PXM2013-014210-000082)
关键词
硫酸盐
聚羧酸减水剂
竞争吸附
总有机碳
Ζ电位
sulfate
polycarboxylic series of water reducer
competitive adsorption
total organic carbon （TOC）
ζ potential
