碱激发材料修补普通混凝土的黏结面性能研究

Bonding Properties of Interface in Ordinary Concrete Repaired by Alkali-Activated Material

本工作研究了用碱激发矿渣-粉煤灰材料修补普通混凝土对黏结面力学性能与抗氯离子渗透性能的影响。对比分析了用普通混凝土直接修补(方式C)、分别刷水泥净浆界面剂及碱激发矿渣-粉煤灰净浆界面剂后再用普通混凝土修补(方式J)、用碱激发矿渣-粉煤灰混凝土直接修补(方式S)三种方式修补后的黏结面的劈裂抗拉强度和氯离子扩散系数。结果表明:三种修补方式中,碱激发矿渣-粉煤灰混凝土直接修补(方式S)的效果最好,此时碱激发剂模数的合理取值为1.3。用方式S修补后的黏结面的劈裂抗拉强度与氯离子抗渗透性能的相关性较好,均随矿渣掺量的增加先增强后减弱,矿渣、粉煤灰掺量各50%时二者达到最强。用碱激发材料修补后,在碱激发剂作用下,碱激发矿渣-粉煤灰与老混凝土的部分组分发生水化反应,提升了黏结面的力学性能与抗氯离子渗透性能。

In this work, the effect of alkali-activated slag fly ash(AASFA) on the mechanical properties and chloride penetration resistance of concrete bonding surface was studied. The splitting tensile strength and the chloride ion diffusion coefficient of the bonding surface repaired through three methods are compared and analyzed, which are direct repairing with ordinary concrete(the method C), brushing the interface agent using cement or AASFA paste before repairing with ordinary concrete(the method J) and direct repairing with AASFA concrete(the method S). The results show that AASFA repairing concrete(the method S) with alkali activator modulus of 1.3 has the best effect among the three methods. There is a good correlation between the splitting tensile strength and the chloride penetration resistance of the bonding surface repaired through method S. The two properties are first enhanced, then weakened with the increase of slag content, and reach the strongest when the contents of slag and fly ash account for 50% respectively. After repairing with alkali activated material, under the action of alkali activator, the hydration pro-ducts of slag fly ash and old concrete cement influence each other to promote the reaction, and the generated material improves the mechanical properties and chloride ion penetration resistance of the bonding surface.