CEMENT MIXTURE OF LOW SELFCONTRACTILITY AND METHOD FOR LOWERING SELF-CONTRACTILITY OF SET CEMENT

摘要

PROBLEM TO BE SOLVED: To provide a method lowering self-contractility, inhibiting craze, improving durability of a set cement by coexisting dihydrate gypsum and contractility lowering agent to cement mixture such as cement paste, mortal, concrete, etc., before setting. ;SOLUTION: The alcohol based contractility lowering agent, such as lower alcohol alkylene oxide adduct, glycol-ether.aminoalcohol derivatives, etc., low molecular weight alkylene oxide copolymer, copolymer of allyl-ether and maleic anhydride, polyoxyalkylene derivatives are utilized as the contractility lowering agent. The dihydrate gypsum is compounded in amount of 2.5-7.0 wt.%, or 2.0-4.0 wt.% converted to SO₃, the total polyoxyalkylene derivatives in amount of 2-4 wt. based on the whole binders manifesting adhesivity existing in the non adhesive particles contained in the cement adulterant, is preferred to effectively lower the contractility.;COPYRIGHT: (C)1999,JPO