聚羧酸减水剂与不同新鲜度水泥的相容性

为研究聚羧酸减水剂与水泥相容性的影响因素,采用净浆流动度法测试不同新鲜度、不同温度、不同湿度的水泥与聚羧酸减水剂的相容性,采用Zeta电位仪测试表面电荷、激光粒度仪测试平均粒径、X射线衍射仪测试物相成分.研究结果表明:新鲜度较低、温度较低、湿度较高将导致水泥与聚羧酸减水剂饱和掺量点更低、流动度更高,即相容性更好;新鲜度较高的水泥相对于新鲜度低的水泥Zeta电位高出1.86 mV,平均粒径高出2.63 μm,且对聚羧酸减水剂吸附较多的C3A、C4AF含量较高.可初步推断,导致相容性出现差异的因素主要包括水泥温度、湿度、水泥组分、Zeta电位. 

Compatibility of Polycarboxylate Superplasticizer with Cements of Different Freshness

In order to study the factors influencing the compatibility of polycarboxylate superplasticizer with cements, cement paste fluidity methods were used to evaluate the compatibility between the superplasticizer and cements with different freshness at different temperatures and moistures. The Zeta potential of cements was measured by Zeta potential analyzer, the mean particle sizes were measured by laser particle analyzer, and the cement clinker phases were investigated by X-ray diffraction. The results show that lower cement freshness, lower temperature and higher moisture would lead to lower saturation point of polycarboxylate superplasticizer in cement, higher initial fluidity and lower flow loss, namely, higher compatibility. Compared with the stale cement, the fresh cement was 1.86 mV higher in Zeta potential, 2.63 μm larger in particle size, and higher content of C3A and C4AF that would absorb more superplasticizer. It can be concluded that the possible factors that influence the compatibility of cements with the superplasticizer include temperature, moisture, Zeta potential and the clinker phases of cement.