earticle

영어

In constructing a concrete structure, one of the most important things to be considered is the construction period, because delay in the construction period makes construction costs more expensive. This paper investigated the effects of the kinds and replacement ratio of mineral admixtures as fine aggregate on the early strength properties of mortar and concrete mixtures. For this purpose, fly ash(FA) and blast furnace slag powder(BS) which are broadly used as mineral admixtures in concrete were selected in this investigation. In addition, another mineral admixtures such as meta kaolin(MK), zeolite(ZL) and diatomite(DM), which have an improvement effect of strength were used. The mineral admixtures were used to replace fine aggregate at replacement ratios of 0%, 2% and 4% by volume. The compressive strength of mortar and concrete were determined at various early ages. In addition, the batcher plant(B/P) test was performed for optimum mixture selected through previous tests. Test results indicated that the dosage of high-range water reducing agent of the mixture using the mineral admixture as fine aggregate increased relatively, in particular, the dosage of the mixture using DM as fine aggregate increased significantly about 4 to 6 times than other mixtures. The early-age compressive strength of mortar and concrete mixtures with mineral admixture as fine aggregate was higher than that of base mixtures. In addition, the compressive strength of concrete with BS showed higher early strength value than other mixtures. For B/P test results, the time for deforming of early-strength development concrete(ESC) which ranged from 20 to 38 hours, was shorter than the Plain mixture ranging from 30 to 72 hours.