硫酸盐对聚羧酸减水剂吸附-分散性能的影响

发布时间：2018-04-02 12:39

本文选题：硫酸盐　切入点：水泥　出处：《同济大学学报(自然科学版)》2017年02期

【摘要】：系统研究了硫酸盐对掺聚羧酸减水剂水泥浆体流变性及水化性能的影响.结果表明:硫酸盐降低了聚羧酸减水剂在水泥颗粒表面的吸附量,削弱了聚羧酸减水剂对水泥浆体的分散作用.随着硫酸盐掺量的增加,聚羧酸减水剂分散性能下降.少量硫酸盐延缓了水化加速期最大水化放热速率峰的出现,并且提高了最大水化放热速率.而大量硫酸盐则使得水泥水化诱导期缩短,最大水化速率峰显著提前.大量硫酸盐的加入促进了水泥浆体中钙矾石(AFt)的生成,削弱了水化铝酸钙(CAH)的生成.MgSO4对于水泥浆体中水化产物生成的促进作用最明显.掺加MgSO4的水泥水化产物中含有大量细丝状水化硫铝酸盐产物.MgSO4对水泥水化具有显著延缓作用,水化产物结晶成核作用较缓慢,从而使得水化产物生成及分布更加均匀,形状更加细小.
[Abstract]:The effects of sulfate on rheological and hydration properties of polycarboxylic acid superplasticizer cement paste were studied systematically.The results show that sulfate reduces the adsorption of polycarboxylic acid superplasticizer on the surface of cement particles and weakens the dispersion of polycarboxylic acid water reducer to cement paste.With the increase of sulfate content, the dispersion of polycarboxylic acid superplasticizer decreases.A small amount of sulfate delayed the emergence of the maximum hydration heat release rate peak and increased the maximum hydration heat release rate in the accelerated hydration period.However, the hydration induction period of cement was shortened and the maximum hydration rate peak was significantly advanced by a large amount of sulphate.The addition of a large amount of sulfate promoted the formation of ettringite in cement paste and weakened the formation of calcium aluminate hydrate. MgSO4 promoted the formation of hydration products in cement paste most obviously.The hydration products of cement mixed with MgSO4 contain a large number of filamentous hydrated sulphoaluminate products. MgSO4 has a significant effect on the hydration of cement, and the crystallization nucleation of hydration products is slow, which makes the formation and distribution of hydration products more uniform.The shape is smaller.
【作者单位】：同济大学材料科学与工程学院;同济大学先进土木工程材料教育部重点实验室;
【基金】：国家自然科学基金(No.51378391) “十三五”国家重点研发计划(2016YFC0700800)
【分类号】：TU528.042.2

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