高掺量粉煤灰水泥浆体长期水化碱环境的变化

Variation of Alkalinity in Cement Paste with High Volume Fly Ash During Long-Term Hydration

通过测试2组水胶比和5种粉煤灰掺量水泥浆体不同龄期的粉煤灰水化反应程度、Ca(OH)2含量、孔隙液的pH值和碱金属离子的变化,探讨了高掺量粉煤灰水泥浆体长期水化碱环境的稳定性.结果显示:粉煤灰长龄期的水化反应程度较低,其掺量(质量分数)小于60%时,不能完全消耗水泥水化所产生的Ca(OH)2,而Ca(OH)2对水泥浆体孔隙液碱度起维持作用,在整个碱环境稳定时,水泥浆体中未溶解的Ca(OH)2对碱环境无直接影响.

A series of experiments were carried out to investigate the stability of alkaline environment in cement paste with high volume fly ash on the degree of reaction of fly ash,Ca（OH）2 content in paste,pH and alkali metal ion in pore solution of pastes at different age.The results indicate that the degree of reaction of fly ash is low in all groups at long-term and Ca（OH）2 in paste will not be entirely consumed if fly ash content is less than 60%（by mass）;Alkaline environment of paste is guaranteed stabilizing by Ca（OH）2 content in paste,but it is not directly affected by insoluble Ca（OH）2 content.