石膏对硅酸盐水泥与萘系减水剂相容性的影响

采用Marsh筒法研究了石膏的种类及掺量对硅酸盐水泥与萘系减水剂相容性的影响。研究结果表明：①水泥中掺加石膏的种类对萘系减水剂的饱和掺量点影响不大。②掺加脱硫石膏的水泥浆体的初始Marsh时间要小于掺加二水石膏的水泥浆体。当减水剂掺量较小时，掺加脱硫石膏时水泥浆体的60minMarsh时间要小于掺加二水石膏的；而当减水剂掺量在2．1％以上时，情况则反之：达到饱和掺量点后，掺有二水石膏的水泥浆体的Marsh时间经时损失率要小于掺有脱硫石膏的水泥浆体。⑨在萘系减水剂的掺量较小时，随着水泥中石膏掺量的增加，水泥浆体的Marsh时间呈减小趋势；当萘系减水剂掺量增加到一定程度时，随着水泥中石膏掺量的增加，这种趋势不再明显。④对于初始Marsh时间来说，随着石膏掺量的增加，减水剂的饱和掺量点明显下降。而对于60minMarsh时间来说，随着石膏掺量的增加，减水剂的饱和掺量点则保持不变。

Effect of gypsum on compatibility between cement and sulphonated naphthalene based superplasticizers

The compatibility of the type and conent of gypsum on the compatibility between cement and sulphonated naphthalene based superplasticizers was researched. The results showed that： （1）The type of gypsum in cement had little effect on the saturation dosage point of sulphonated naphthalene based superplasticizers. （2）The initial Marsh time of cement pastes that mixed with dehydrategypsum was shorter than that mixed with gypusm. The 60min Marsh time of cement pastes with gypsum was larger that with dehydrategypsum when the dosage of sulphonated naphthalene based superplasticizers was lower, while the situation would converse for the dosage of sulphonated naphthalene based superqeasticizers was larger than 2.1%. The loss rate of Marsh time of cement pastes with gypsum was less than that with desulphogypsum after the dosage of superplasticizers reached saturation point. （3）When the dosage of sulphonated naphthalene based superplasticizers was low, the Marsh time of cement pastes decreased with the increase of gypsum content. When the dosage of sulphonated naphthalene based superplasticizers increased to a certain point, the Marsh time of cement pastes changed little with the increase of gypsum content. ~For initial Marsh time, the saturation dosage point of superplasticizers reduced significantly when the content of gypsum increased; For 60min Marsh time, the saturation dosage point of superplasticizers kept steady with the content of gypsum increased.