硫铝酸盐水泥-硅酸盐水泥-石膏三元复合材料的护筋性能研究

Rebar-protecting Property of Sulphoaluminate Cement-Portland Cement-Gypsum Ternary Composites

通过测定水泥石碱度和孔隙率、砂浆电极的极化电位、混凝土的氯离子扩散系数和钢筋混凝土电极电化学加速锈蚀的开裂时间,从多个不同角度研究了硫铝酸盐水泥-硅酸盐水泥-石膏三元复合材料体系的护筋性能。结果表明,三元体系的碱度比硅酸盐水泥低,pH值在10～11之间,难以在钢筋表面形成钝化膜保护;水泥石孔隙率和混凝土氯离子扩散系数均明显高于硅酸盐水泥,密实性和抗渗性较差。

By measuring the alkalinity and porosity of cement paste, the formation of passivation film of mortar electrode, the chloride diffusion coefficient of concrete and the cracking time of reinforced concrete electrode after electrochemical accelerated corrosion, the rebar-protecting property of ternary system was studied from different aspects. The results show that the alkalinity of the ternary system is lower than that of Portland cement. The pH value in the system ranges from 10 to 11, so that the passivation film cannot be formed on the surface of the steel bar. With the porosity and the chloride diffusion coefficient of ternary system being obviously higher than those of Portland cement, the ternary system’s density and permeability is poorer.