摘要
将水泥净浆试件在5％Na2SO2溶液中长期浸泡,用试件强度随浸泡时间的变化和试件中物相的XRD分析,研究了硅灰对水泥净浆抗硫酸盐侵蚀性能的影响。在Na2SO4溶液侵蚀下,普通硅酸盐水泥净浆试件强度随浸泡时间先增长。然后急剧降低;外观和XRD相分析表明,其原因是由于形成了膨胀性钙矾石,造成试件开裂破坏;加入硅灰的水泥净浆试件强度损失明显减小,尤其是抗折强度没有降低,其抵抗强度下降系数还略有增加;原因是由于硅灰的稀释作用和火山灰效应减少了水泥净浆中Ca(OH)2的量,从而降低了水泥净浆试件在硫酸盐溶液侵蚀下形成的膨胀性钙矾石的量。因而,硅灰对水泥混凝土抗硫酸盐侵蚀性能有改善作用。
The behavior of silica fume cement paste against sulfate attack has been studied. The experimental method used is long immersed tests, in which the hardened cement paste specimens are immersed in the 5% Na2SO4 solution. The strength change of the specimens with the time has been measured and phases of the specimens have been analyzed by XRD. Results indicate that the strength of the OPC paste specimens increases at an early stage and then decreases greatly following sulfate attack. The appearance and XRD analysis have indicated that the cause of their deterioration is the expansion of ettringite and the obvious reduction of strength loss in silica fume cement paste specimens. The bending strength does not reduce, while the decrease coefficient of strength increases a little. The factor is that the Ca(OH)2 in the cement paste is reduced and the formation of expansive ettringite against sulfate attack is decreased yet by the dilute effect and the pozzolanic reaction of silica fume. Therefore, the silica fume may be mixed into cement concrete to improve their anti-sulfate attack.
出处
《西南石油学院学报》
CSCD
北大核心
2006年第3期103-105,共3页
Journal of Southwest Petroleum Institute
基金
国家自然科学基金项目(编号:50378092)。
关键词
水泥净浆
硫酸盐侵蚀
硅灰
钙矾石
cement paste
sulfate attack
silica fume
ettringite
