| 요약2 |
To estimate possibility and problem of blast furnace slag cement and concrete, in the filed application of the blast furnace slag cement and concrete, the blast furnace slag concrete that is alternated by S/P 40% applied to bottom slab of a parking place of apartment underground and mass member of a laboratory and it measured compressive strength, length change and heat of hydration by a curing method. 1) In case of S/C, the early development rate of compressive strength appeared relatively lower than it of OPC, but, since age 14 day, the development rate of compressive strength of the S/C appeared almost analogously with it of the OPC. 2) The drying shrinkage of S/C is happened 70% of whole drying shrinkage in early 12 hours. 3) Until about 80 hours within after placing, heat of hydration of OPC was higher about 10℃(17%) than that of S/C. And for maximum peak hour of heat of hydration, OPC appeared at about age 25 hours before and after. However S/C appeared at 68 hours before and after. 4) Drying shrinkage change in the horizontal axis of cast in place concrete, the same as mass member, the S/C showed bigger length change than it of the OPC. And length change happened within 8～10 hours after placing, and after that time, a length change was no longer happened. Drying shrinkage about the axis of ordinates of concrete is smaller than dry shrinkage of the horizontal axis. And drying shrinkage about the axis of ordinates too is happened bigger in S/C similarly with the horizontal axis. 5) After cast-in place concrete placing, the heat of hydration did not increase since the after this while rise steadily for about 16 hours since early age. |