无机防腐剂抗硫酸盐侵蚀机理研究

Study on sulfate resistance mechanism of inorganic preservatives

以机械活化超细矿渣粉为主要原料、以石膏和硫铝酸盐水泥熟料(SAC)为辅料,制备海洋环境混凝土用无机防腐剂,利用三元云分析、SEM、XRD研究方法研究其防腐性能和防腐机理.研究结果表明:该多元复合无机防腐剂凝结时间、膨胀率、耐蚀系数等指标均满足标准要求;掺入该无机防腐剂的普通混凝土在硫酸盐侵蚀150次循环后,耐蚀系数仍高于75%,达到KS150级;防腐剂的加入有助于水化初期钙矾石(AFt)的生成,并抑制其在水化后期向低硫型钙矾石(AFm)的转化,同时消耗腐蚀原料,并生成多种凝胶体填充晶体骨架的空隙,增加了混凝土微结构的致密性,进而提高混凝土的耐蚀性能,从微观角度为矿渣粉在抗硫酸盐腐蚀中的应用提供理论参考.

The paper,inorganic preservatives for marine environmental concrete are prepared by using the activated ultrafine slag powder as the main raw material,gypsum and sulphur aluminate cement(SAC)as supplementary materials.The corrosion resistance and mechanism of inorganic preservatives are studied by means of ternary cloud analysis,SEM and XRD.The results show that the setting time,expansion rate and corrosion resistance coefficient of the composite inorganic preservative are consistent with the standard requirements.The corrosion resistance coefficient of ordinary concrete mixed with the inorganic preservative is higher than 75%after 150 cycles of sulfate corrosion.The addition of preservatives is helpful to the formation of calcium vanadium stone in the early stage of hydration and inhibits the late conversion to low sulfur calcium vanadium.At the same time,the corrosion raw materials are consumed and the various of gels are generated to fill the voids of cement paste,increasing compactness of the concrete microstructure.In addition,the research results provide a theoretical reference for the application of slag powder in sulfate corrosion resistance at the microscopic level.