The Properties of Hardened Slag by Alkali and Curing Method

알칼리 첨가 및 양생방법에 따른 슬래그 경화체의 특성

In this research influences of type and concentration of alkali activator and curing condition on the hydration, and properties of alkali activated blast furnace slag(AAS) concrete were investigated. Sodium carbonate and sulfate were used as alkali activators and their concentration were 4~10 weight percent with Na$_2$O equivalent to binder. The curing conditions were standard curing using 23$^{\circ}C$ water and activated curing chamber at $65^{\circ}C$. Results show that in case of sodium carbonate addition high early strengths were gained by activation of early hydration, but later strength gained was slight. On the other side sodium sulfate strengths were continuously increased with adding amount and ages. Steam curing activated early hydration so that early strengths were improved but later strengths were similar to standard curing. The strength reduction of AAS mortar with sodium sulfate was less than OPC mortar in 5% sulfuric acid solution so that AAS concrete can be useful for acid-resistance concrete.