earticle

영어

The objective of the study is to investigate the effect of impregnation of alkali activator on the strength enhancement of hardened high volume fly ash mortar. Sodium hydroxide (12 mol) is adopted for alkali activator of hardened mortar in this study. Four different contents of fly ash(FA) are chosen ranged from 30~90 % by cement weight. Alkali activator was applied on the surface of hardened specimen at 3 days. Curing temperatures ranged from 40~80℃ are varied. Mortars with 40 % of Water to binder ratio were fabricated. Test results indicated that the specimen impregnated with sodium hydroxide subjected to high curing temperature exhibited higher strength enhancement than that without sodium hydroxide by as much as 100~300 % due to accelerated pozzolanic reaction by sodium hydroxide. For the curing temperature effect, water curing at 40℃ of the specimen with 60 % of FA for 24 hours resulted in an highest enhancement of the strength regardless of age among other conditions, while the specimen with 90% of FA showed remarkable increase of strength at 60℃ of the curing temperature.