掺膨胀剂及矿粉对水工混凝土抗硫酸盐侵蚀性能的影响研究

Study on Influence of Expansion Agent and Mineral Powder on Sulfate Resistance of Hydraulic Concrete

文章利用质量变化率、膨胀率和抗蚀系数等指标分析了水工混凝土抗硫酸盐侵蚀性能,并应用MIP压汞测孔技术初步分析了膨胀剂及大掺量磨细矿渣改善抗硫酸盐侵蚀性能的作用机理。试验表明,膨胀剂及大掺量磨细矿渣的加入可以明显增强混凝土抗硫酸盐侵蚀能力,其作用机理是增大硬化浆体中的小孔所占比例,减小大、中孔所占比例;采用膨胀剂和磨细矿渣等量替代水泥后改善了混凝土侵蚀后期质量急剧损失状况,有利于减小砂浆膨胀率以及提高其抗蚀系数。

In this paper,the sulfate resistance of hydraulic concrete is analyzed by using mass change rate,expansion rate and corrosion resistance coefficient,and MIP mercury porosimetry technique is used to preliminarily analyze the mechanism of improving sulfate resistance of expansive agent and fine slag with large dosage.The results show that the addition of expansive agent and large amount of ground slag can significantly enhance the sulfate resistance of concrete,and its mechanism is to increase the proportion of small pores in hardened slurry and reduce the proportion of large medium pores.After replacing cement with expansive agent and ground slag in equal quantities,the rapid mass loss of concrete in late erosion period is improved,which is beneficial to reduce the expansion rate of mortar and improve its corrosion resistance coefficient.