ON THE TYPE A PORTLAND BLAST-FURNACE SLAG CEMENT CONCRETE DUE TO BLENDED ORDINARY PORTLAND CEMENT AND TYPE B PORTLAND BLAST-FURNACE SLAG CEMENT

The climatic change such as the global warming is one of the important international problem. On the field of construction materials, environmental-conscious concrete which are CO2 reduction from the concrete materials advance development and practical application. Mostly of these techniques use equivalent for the type C blended cement that are used a large amount of mineral admixtures as the substitution of cement. However, these concrete are used only underground structures of buildings due to properties of strength development, durability and construction performance. Moreover, the load for ready-mixed concrete plant is large on the manufacturing.This research studied on the environmental-conscious concrete to use general purpose including above-ground structures. Type A portland blast-furnace slag cement is the blended cement which has the equality properties with ordinary portland cement. Nevertheless, Type A portland blast-furnace slag cement does not have production and distribution. Therefore, equivalent for the type A portland blast-furnace slag cement is made to blend the ordinary portland cement and the type B portland blast-furnace slag cement, and experimented on the indoor and the actual site.On the indoor experiment, fresh concrete properties, strength development and durability were tested on 47 types concrete which were due to influenced mixing rate of blast-furnace slag, water-cement ratio and variability in qualities of the type B portland blast-furnace slag cement. As the result, concrete properties of blended the ordinary portland cement and the type B portland blast-furnace slag cement were similar to concrete adding granulated blast-furnace slag into ordinary portland cement. On 20% or less rate of blast-furnace slag, furthermore, compressive strength of since 28 days, setting times and carbonation resistance were equality with ordinary portland cement concrete.On the actual experiment, time dependent change of fresh concrete, strength development of various curing conditions and model members, and construction performances were tested concrete which was made in ready-mixed concrete plant. As the results, method of mixture proportion design, quality control and curing showed can treat same with ordinary portland cement concrete.In this matter, the type A portland blast-furnace slag cement equivalent which blend the ordinary portland cement and the type B portland blast-furnace slag cement has similar concrete characters with ordinary