水泥与减水剂相容性的流变学研究

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.

RESERCH ON THE RHEOLOGICAL COMPATIBILITY OF CEMENTS PASTE DOPTED WITH SUPERPLASTICIZERS

Through checking the influence of factors, such as water cement ratio, superplasticizer type and cement manufactured by different factory, on compatibility and rheological property of the cement paste, this article focus on the research of the relationship between compatibility and rheological property. The rheological principle of compatibility was defined firstly and the rheological foundation of the Marsh Cone method for testing compatibility was validated and deepened It is showed that The rheological characteristic of the cement paste added with admixture accords with normal Bingham model or Newtonian model, yield stress and viscosity coefficient drop fast as increasing of chemical admixture dosage. The Marsh cone fluidity synthetically reflects the combination of both yield stress and viscosity coefficient..Yield stress and viscosity coefficient keep almost unchanged when the dosage of admixture has exceeded the saturation point of Marsh cone test. But they increase with time and their increments have good correlation with the loss of Marsh fluidity. Marsh fluidity at the saturation point represents the down limit of yield stress and viscosity coefficient of paste.