可溶碱对水泥/氨基磺酸盐减水剂相容性的影响

Influence of Soluble Alkali on the Compatibility of Cement and Aminosulphonate Based Superplasticizer

测定了水泥浆体中的总碱含量和可溶碱含量.通过掺加K2CO3溶液(改变水泥浆体中可溶碱的含量),同时调整氨基磺酸盐高效减水剂掺量,观察水泥浆体的流动度和流动度经时损失变化,以确定水泥浆体中可溶碱含量对水泥/氨基磺酸盐高效减水剂相容性的影响.研究结果表明:氨基磺酸盐高效减水剂掺量和水泥中的可溶碱含量共同决定了水泥浆体的流动度.水泥中所含可溶碱含量低于最佳可溶碱含量.当氨基磺酸盐高效减水剂掺量小于其饱和掺量时,掺加适量的可溶碱有助于提高水泥浆体的流动度,减小水泥浆体流动度经时损失;当氨基磺酸盐高效减水剂掺量大于其饱和掺量时,则基本上可以不考虑可溶碱含量对水泥浆体流动度的影响.

The total alkali content and soluble alkali content in cement paste were determined. The change of fluidity and its time-depended lose of cement paste were investigated with the modifications of the content of soluble alkali in cement paste and the dosage of aminosulphonate based superplasticizer. The influence of the content of soluble alkali in cement paste on the compatibility of cement and aminosulphonate based superplasticizer was discussed. The researching results show that the fluidity of cement paste is obviously affected by the content of soluble alkali in cement paste and the dosage of aminosulphonate based superplasticizer together. The content of soluble alkali in cement paste is lower than the optimal one, Addition of adequate quantity of soluble alkali benefits increase of the fluidity and decrease of its time-depended lose of cement paste when the dosage of aminosulphonate based superplasticizer is lower than its saturated amount. There is little effect for the soluble alkali content in cement paste when the dosage of aminosulphonate based superplasticizer is greater than its saturated amount.