CEMENT COMPOSITION AND HARDENED CEMENT ARTICLE

摘要

PROBLEM TO BE SOLVED: To obtain a cement composition containing a reduced amount of cure accelerator and exhibiting practical curing speed even by the inclusion of a cure-inhibiting and retarding substance by compounding cement with a specific amount of one or more kinds of inorganic powder having a specific BET surface area and selected from zeolite, zonotlite, magnesium oxysulfate and basic magnesium carbonate. SOLUTION: The objective composition can be produced by compounding 100 pts.wt. of a cement with 1-30 pts.wt. of inorganic fine powder capable of absorbing organic material and having high specific surface area such as zeolite having a BET specific surface area of 10-700 m<2> /g. Zeolite is especially effective for promoting the curing of the cement because it has ion-exchanging capability and releases a cement curing reaction promoting ion such as Na or K in addition to the adsorption of a cure-inhibiting substance. The inorganic fine powder preferably has an average particle diameter of 1-500μm. The cement curing inhibiting substance is e.g. oxycarboxylic acids and sugar alcohols. The action of the inorganic fine powder gives especially good effect in the production of a cement product containing a woody reinforcing material exuding the above cure-inhibiting substances.