粉煤灰对砂岩碱硅酸反应的抑制及机理研究  

Effect of Fly Ash on Inhibiting Alkali-silica Reaction of Sandstone and Its Mechanism

作　　者：李北星[1] 文梓芸[2] 李双艳[3] 

机构地区：[1]武汉理工大学硅酸盐材料工程教育部重点实验室,武汉430070 [2]华南理工大学材料科学与工程学院,广州510641 [3]中南勘测设计研究院,长沙410014

出　　处：《武汉理工大学学报》2006年第5期40-44,共5页Journal of Wuhan University of Technology

摘　　要：以砂浆棒快速法和混凝土棱柱体法为基础,研究了粉煤灰对砂岩骨料碱硅酸反应(ASR)膨胀的抑制作用,采用扫描电镜(SEM)和能谱仪(EDAX)分析了砂岩的ASR反应及粉煤灰抑制机理,通过混凝土强度和抗冻性测定讨论了粉煤灰对砂岩ASR抑制的可靠性问题。结果表明:粉煤灰能有效地抑制砂岩的ASR膨胀,抑制原因在于:碱与粉煤灰发生强烈的反应而使碱得到了“耗散”,且碱与粉煤灰生成的碱硅铝凝胶不具备膨胀能力。经受加速ASR的混凝土试件,掺粉煤灰越多,强度越低,抗冻等级越低。The effects of fly ash on inhibiting alkali-silica reaction （ASR） expansion occurred in sandstone were studied respectively based on accelerated mortar bar test and concrete prism test. The ASR of sandstone and inhibiting mechanism of fly ash were analysed with SEM and EDXA. Moreover, the reliability of fly ash in inhibiting ASR of sandstone was discussed by concrete strength and freezing and thawing tests. Results indicated that the effect of fly ash on inhibiting ASR expansion was fine. The reason why fly ash can inhibit the alkali reactivity for the sandstone was that the strong reaction between alkali and fly ash dissipated the alkali, and the products of alkali-silica-alumina gels was non expansible. For the concrete specimens suffered from accelerated ASR, their strength and freeze-thaw resistance were decreased with increasing the content of fly ash.

关 键 词：砂岩骨料 粉煤灰 碱硅酸反应 抑制 机理 

分 类 号：TU528.041[建筑科学—建筑技术科学]