矿物掺合料对混凝土抗干湿循环–硫酸盐腐蚀性能影响研究

Study on the Influence of Mineral Admixture on the Anti-Dry-Wet Cycle-Sulfate Corrosion Resistance of Concrete

摘要: 为了研究矿物掺合料对盐湖地区混凝土抗硫酸盐腐蚀性能影响，设置了同水胶比下两种矿物掺合料、三种硅灰掺量的及无矿物掺合料对照组的五组试验，分析了混凝土试件在干湿循环–硫酸盐腐蚀条件下破坏情况。结果表明：两种矿物掺和料均能提高混凝土内部密实度、降低孔隙率，使混凝土受硫酸盐侵蚀劣化过程变得缓慢，显著提高混凝土抗硫酸盐腐蚀能力。硅灰对混凝土抗干湿循环–硫酸盐腐蚀影响强于粉煤灰。粉煤灰掺合料会造成混凝土在硫酸盐侵蚀前期初始强度下降。在5%~9%硅灰掺量的影响下，混凝土抗干湿循环–硫酸盐腐蚀性能随掺量提高而增强。

Abstract: In order to study the influence of mineral admixtures on the sulfate corrosion resistance of concrete in the salt lake area, six sets of tests were set up with two mineral admixtures, three silica fume admixtures and a control group without mineral admixtures under the same water-binder ratio, analyzing the damage of concrete specimens under the conditions of dry-wet cycle-sulfate corrosion. The results show that both mineral admixtures can increase the internal density of concrete, reduce porosity, slow down the deterioration of concrete by sulfate erosion, and significantly improve the ability of concrete to resist sulfate corrosion. Silica fume has a stronger effect on the resistance of concrete to dry-wet cycle-sulfate corrosion than fly ash. Fly ash admixture will cause the initial strength of concrete to decrease in the early stage of sulfate attack. Under the influence of 5%~9% silica fume content, the concrete anti-dry and wet cycle-sulfate corrosion performance will increase with the increase of the content.