碱硫比对硅酸盐水泥流变性能的影响

Influence of Alkali to Sulfate Ratio on the Rheological Property of Portland Cement

选取三种碱含量有差异的熟料,通过外加碱金属硫酸盐和石膏来调节水泥的碱硫比(R/S=Na_2O_e/SO_3,摩尔比),测定和分析水泥浆的黏度、流动度、早期强度和水化产物的变化,以反映不同碱硫比对水泥流变性能的影响。结果表明,碱含量为0. 10%的低碱水泥熟料,黏度随碱硫比的增加先减小后增大;对于碱含量为0. 64%水泥熟料,水泥黏度随碱硫比增加而减小;而碱含量为0. 34%的水泥熟料,水泥黏度随碱硫比增大黏度变化趋势较为缓和,也呈现增大的趋势;流动度变化也呈现同样规律;强度则随着碱硫比的增大而有所下降。可以认为,碱硫比在一定范围内明显影响水泥的流变性能,或者水泥实际应用时可通过调整碱硫比来改善流动性。

Three kinds of clinker with different alkali content were used in the experiments.To reveal the influence of alkali to sulfate ratio on the rheological property of cement,the alkali to sulfate ratio(R/S=Na2Oe/SO3,molar ratio)of cement was adjusted by addition of alkali sulfates and gypsum.The viscosity,fluidity,strength development and hydration products were performed.Results show that with the alkali to sulfate ratio increases,the viscosity of cement pastes made with low-alkali clinker(alkali content of 0.10%)decreases first and then increases;the viscosity of cement made by the clinker with 0.64% alkali content decreases;and as for the cement made by the clinker with 0.34% alkali content,the viscosity increases slightly.Moreover,with the alkali to sulfate ratio increases,changes of the fluidity present similar to the viscosity,while the strength decreases a lot.It can be concluded that the alkali to sulfate ratio could affect the rheological properties of the cement pastes significantly.In the other word,the fluidity of cement pastes can be improved by adjusting alkali to sulfate ratio in practical applications.