Hydration Behavior of Blast Furnace Slag Activated by Na₂SO₄ and Fineness of Slag

抄録

The effect of alkali activator and fineness of slag on the physical properties of blast furnace slag cement was investigated. Na₂SO₄ was used as an alkali activator in this study. Blast furnace slag cement was prepared from mixture of blast furnace slag, ordinary Portland cement, and anhydride gypsum. The fluidity and the compressive strength according to each mixture ratio of them were analyzed by using statistical analysis in order to discover the parameters influencing the fluidity and compressive strength. The results showed that the hydration of blast furnace slag took place by addition of Na₂SO₄, and ettringite with column-crystalline was created as main hydration product of blast furnace slag. And it is found that the compressive strength of blast furnace slag cement tends to increase as ordinary Portland cement content is higher until 3 days. However, it is also known that the compressive strength tends to increase with the increase of higher blast furnace slag content, along with increase in the OPC on 28 days. As a result of this analysis, it is considered that the ordinary Portland cement content influences the initial compressive strength of blast furnace slag cement, and that in later days is greatly influenced by slag content.