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For high strength concrete of 40∼60 MPa, the effects on the early strength and concrete dry shrinkage properties replacing 60∼80% of Ordinary Portland Cement with Blast Furnace Slag Powder and using the Alkali Activator (Modified Alkali Sulfate type) are considered in this study. 1% Alkali Activator to the binder, cumulative heat of hydration for 72 hours was increased approximately 45%, indicating that heat of hydration contributes to the early strength of concrete, and the slump flow of concrete decreased slightly by 3.7∼6.6%, and the 3-and 7-strength was increased by 8∼12%, which that the Alkali Activator (Modified Alkali Sulfate type) is effective for ensuring the early strength when manufacturing High Strength Concrete (60%) of Blast Furnace Slag Powder. Furthermore, the dry shrinkage test, both 40 MPa and 60 MPa specimens had level of length changes in order of BS40 > BS60 > BS60A > BS80A, and the use of the Alkali Activator somewhat improved resistance to dry shrinkage.

김세환 1) ‧ 전현규 2) ‧ 황인동 3) ‧ 서치호 1) ‧ 김상헌 4)*

In this research, as a measure of reducing energy lost through external wall, we used Glass Hollow Micro Sphere (HMS) to improve insulation performance to structural concrete. The following is a result of experimenting concrete using HMS.As usage of HMS, decrease in slump arose and it is judged as a need of using superplasticizer. Replacement ratio increasing more and more, amount of air showed tendency to decrease and compressive strength decreased for interfacial adhesion had not been formed. as replacement ratio and unit volume decreased. It appears that thermal conductivity decreased about 30.0~46.5 percent as compared with normal weight concrete.