Ⅱ级粉煤灰改善混凝土抗硫酸盐侵蚀性能的研究

A Study on Effect of Ⅱ Fly Ash on the Concrete in Sodium Sulfate Solutions

配制甘肃黑河西流水水电站大坝面板高性能混凝土,拟采用永昌电厂生产的Ⅱ级粉煤灰作掺合料。对掺此粉煤灰的水泥基胶凝材料进行了抗硫酸盐化学侵蚀的试验研究。实验结果表明,掺粉煤灰试件其抗侵能力优于不掺粉煤灰试件,在本次实验其抗侵能力提高2倍以上。粉煤灰生成有利于抗硫酸盐侵蚀的低Ca/Si比CSH。试件对SO42-的吸收与试件自身CaO析出量同浸泡时间有良好的相关性。

To compound the high performance concrete （HPC） for face rockfill dam project of hydroelectric station in Heihe River, Ganshu province, the Ⅱ fly ash producted by Yongchang power station is selected as raw material. In order to further understand the property of this kind of Ⅱ fly ash, which improves concrete resistance to sulfate attack, the study on performance of sulfate erosion resistance of concret that compounded by Ⅱ fly ash has been conducted. The study shows that the sample added with Ⅱ fly ash is superior to the sample without Ⅱ fly ash in sulfate attack resistance, and its ability of sulfate attack resistance is two times as much as the one without Ⅱ fly ash. The Ⅱ fly ash is helpful to produce low Ca/ Si CSH . The absorption weight of SO4^2- and release weight of CaO are associated with the time when the sample is immersed in Na2SO4 solution.