水泥与减水剂相容性的流变学研究

Rheological Investigation into Compatibility of Cement and Superplasticizers

通过考察水灰比、减水剂类型、水泥等因素对水泥与减水剂相容性及净浆流变性能的影响,研究相容性与浆体流变性能的关系,阐述了相容性的流变学含义.研究结果表明:掺减水剂的水泥净浆的流变特征符合一般宾汉姆流型或牛顿流型.Marsh筒法检测的流速是浆体屈服应力和黏度系数的综合反映;饱和点掺量与饱和点Marsh时间分别代表了浆体屈服应力和黏度系数降低至最小恒定值时对应的减水剂最小掺量,以及最小黏度系数的大小.

By investigating the influences of the water-to-cement ratio, the superplasticizer type and the cements manufactured by different factories on the compatibility of cement and superplasticizer and on the rheological properties of cement paste, the relationship between the compatibility and the rheological properties is revealed, and the rheological principle of compatibility is defined. The results show that the rheological characteristics of the cement paste adding superplasticizer accord with the normal Bingham model or the Newtonian model, that the Marsh cone fluidity synthetically reflects both the yield stress and the viscosity coefficient of the paste, and that the superplasticizer dosage and the Marsh time at the saturation point represent the smallest dosage of superplasticizer at the down limits of yield stress and viscosity coefficient, and the smallest viscosity coefficient, respectively.