PRODUCTION OF BLAST FURNACE SLAG POWDER HAVING LOW SEPARABILITY AND PRODUCTION OF CONCRETE HAVING LOW SEPARABILITY

摘要

PURPOSE:To decrease an amount of a separation-reducing agent used in obtaining a compaction-free concrete. CONSTITUTION:In a method for producing a concrete by kneading cement with blast furnace slag powder, an aggregate and a water-reducing admixture and water, blast slag powder having low separability obtained by mixing a blast furnace slag with a separation-reducing agent and crushing the mixture is used as the blast furnace slag powder. The separation-reducing agent is previously mixed with the blast furnace slag and the mixture is crushed and added to the concrete. Thereby, the separation-reducing agent can effectively be dispersed into concrete as blast furnace slag powder having low separability and sufficient separation-reducing effect can be obtained by using a small amount of the separation-reducing agent. Since the separating and reducing agent is used in a small amount, catching of air in kneading is reduced, a defoaming agent is made unnecessary and production is made inexpensive.