磨细石灰石粉对减水剂-水泥适应性的影响

Influence of Limestone Powder on the Adaptability of Cement and Superplasticizer

采用化学分析、热分析、Zeta电位分析等手段研究聚羧酸和萘系减水剂在磨细石灰石粉存在下与水泥的适应性。结果表明:在磨细石灰石粉存在下,聚羧酸减水剂促进水泥水化初期钙矾石和单碳型水化硫铝酸钙的生成,降低水泥对减水剂的吸附;而萘系减水剂的吸附量大,石灰石粉加速了水泥颗粒表面的减水剂被生成的水化产物覆盖的过程,导致流动度损失加快。因此,在石灰石粉存在下,聚羧酸减水剂的适应性较萘系减水剂更佳。

Adaptability of polycarboxylate superplasticizer and naphthalene superplasticizer in cement in the presence of limestone powder was studied by chemical analysis, thermal analysis and zeta potential analysis. The ex- perimental results show that in the presence of limestone powder, more ettringite and calcium monocarhoaluminate are formed in the system with polycarboxylate superplastieizer even at initial period of hydration, which resuhs in a lower amount of polycarboxylate superplasticizer adsorbed by cement particles. However, as the adsorption amount of naph- thalene superplasticizer is higher, limestone powder accelerates the process that cement particles adsorbing snperplas- ticizer molecules being covered by hydration product, which leads to a rapid flow loss. So the adaptability of polycar- boxylate superplastieizer with cement ＇is much better than that of naphthalene superplasticizer in the presence of lime- stone powder.