同济大学学报（自然科学版）2017，Vol.45Issue(2)：230-234,5.DOI:10.11908/j.issn.0253-374x.2017.02.011
硫酸盐对聚羧酸减水剂吸附-分散性能的影响
Effects of sulfates on the Adsorption and Dispersing Properties of Polycarboxylate Superplasticizer
摘要
Abstract
The effects of sulfates on the adsorption and dispersing properties of cement paste of polycarboxylate (PCE) superplasticizer were studied.The effects of sulfates on the hydration process of cement paste were systematically investigated through isothermal calorimetry as well as scanning electron microscope (SEM).The results show that the addition of sulfates reduces the adsorption of PCE on cement particles and hence impairs the dispersing capability of PCE.Among the sulfates,alkali sulfates (Na2SO4 and K2SO4) most significantly influence the dispersing capability of PCE,while the poorly soluble CaSO4 · 2H2O slightly influences the dispersing capability of PCE.A small amount of sulfates retards induction period,promotes the maximum hydration rate,and increases the heat evolution rate due to the transformation from ettringite (AFt) to mono calcium aluminate (AFm).A high amount of sulfates significantly advances the maximum hydration rate peak at acceleration period,promotes the formation of AFt,and impairs the formation of hydrated calcium aluminate (CAH).Among the sulfates,the addition of MgSO4 greatly retards the hydration heat peak at acceleration period and significantly promotes the transformation from AFt to AFm.After cement paste is hardened,a large number of filamentous hydrated sulphoaluminate phases are present due to the addition of MgSO4,because MgSO4 greatly retards the hydration process and slows the nucleation and precipitation of hydration products.关键词
硫酸盐/水泥/聚羧酸减水剂/分散性能/水化性能Key words
sulfates/cement/polycarboxylate superplasticizer/dispersing properties/hydration properties分类
建筑与水利引用本文复制引用
何燕,张雄,张永娟,洪万领..硫酸盐对聚羧酸减水剂吸附-分散性能的影响[J].同济大学学报（自然科学版）,2017,45(2):230-234,5.基金项目
国家自然科学基金(No.51378391) （No.51378391）
“十三五”国家重点研发计划(2016YFC0700800) （2016YFC0700800）
