活性复合掺合料对水泥胶砂抗侵蚀性能影响

Effect of Active Composite Admixture on Erosion Resistance of Cement Mortar

以防腐阻锈成分、粉煤灰、矿渣粉等量取代部分水泥,研究单掺防腐阻锈成分、双掺粉煤灰和矿渣粉以及复掺三者时对水泥胶砂抗蚀系数、电极电位的影响,并利用扫描电子显微镜(SEM)对不同复合掺合料水化产物和表面特征进行分析。试验结果表明:单掺FZJ的水泥胶砂,当掺量为6%时,其初始抗蚀系数比未掺的基准水泥胶砂高20%;双掺粉煤灰与矿渣粉的水泥胶砂,当两者掺量为65%时,100次循环后抗蚀系数远高于基准水泥胶砂,抗蚀效果显著;三者复掺最佳替代水泥量为71%时,56 d电极电位曲线趋向钝化,水泥胶砂的抗氯盐锈蚀效果最显著。电镜分析表明:防腐阻锈成分对粉煤灰、矿渣粉实现了碱改性,增加其二次水化活性,使三者复合掺合料的砂浆试块抗侵蚀性能随养护龄期的增长更加显著,为在氯盐、硫酸盐环境下矿物掺合料砂浆或混凝土耐久性研究提供应用技术。

The effect of corrosion resistance and electrode potential of the autogenous cement mortar was studied by the addition of a single additive,a mixture of coal ash and slag powder,and a triple mixing composite,and analyzed the hydration products and surface characteristics of different composite admixtures by SEM.Experiments show:when the single additive is 6%,the anticorrosion coefficient of cement mortar is 20%higher than that of the benchmark cement mortar;When the mixing of coal ash and slag powder is 65%,the corrosion resistance coefficient of the 100 cycles is much higher than that of the benchmark cement mortar;When the optimal replacement cement quantity is 11%,the 56 d electrode potential curve tends to be passivated,and the corrosion resistance of the cement mortar is the most significant.The analysis of SEM shows that the corrosion resistance of the components to fly ash,the slag powder realizes alkali modification and increases its two hydration activity,so that the anti erosion performance of the mortar specimens with three composite admixtures is more significant with the growth of curing age,which provides the application technology for the study of the durability of mineral admixture mortar or concrete in the environment of chlorine salt and sulfate.