In this study, it was evaluated air content properties of concrete using air-entraining agents for modified flyash.

In this study, it was evaluated the carbonation properties of concrete by replacement of the flyash after it was ground by vibration mill and was modified chemically. Also, it was compared to 1day, 3day, 7day, 28day and 56day-strength of the concrete, respectively.

In this study, it was evaluated the early-strength of mock-up concrete by replacement of the flyash after it was ground by vibration mill and was modified chemically. Also, the early-strength of the specimens for maintaining structure was evaluated on the first, second, third day separately.

This paper is to investigate the effect of heat curing method on strength development of concrete subjected to -10℃ by preparing mock up specimen, which had slab, wall and column. As expected, the application of heat curing methods had larger strength than non heat curing specimen because of higher maturity. And within 7 days of heat curing, minimum strength to protect from early frost damage was achieved.