The concrete and production manner null of the high intensity concrete compact which uses

摘要

PURPOSE: To obtain a concrete excellent in operating efficiency and strength of a molding by blending a raw material for the concrete having a specified unit amount of cement, etc., with a specific natural anhydrous gypsum and a polycarboxylic acid-based cement dispersing agent in prescribed amounts. ;CONSTITUTION: This concrete is produced by blending (A) a raw material for the concrete having 400-600kg/m³ unit amount of cement at ≤35wt.% water- cement ratio with (B) a natural anhydrous gypsum capable of providing 0.15-1.5wt.% SO₄ ionic concentration of a 0.05wt.% aqueous solution of Na₂HP₄ at 20°C temperature when 100g aqueous solution is brought into contact with 1g thereof in an amount of 5-20wt.% based on the unit amount of the cement and (C) a polycarboxylic acid-based cement dispersing agent in an amount of 0.1-2wt.% based on the unit amount of the cement. The resultant concrete is good in operating efficiency due to no occurrence of false setting and a high-strength concrete molding can be obtained by molding the concrete.;COPYRIGHT: (C)1995,JPO