CEMENT ADMIXTURE CONTAINING SILICA FUME SELECTED BY CHARACTERISTIC EVALUATION METHOD, CEMENT COMPOSITION, CEMENT CONCRETE AND THEIR MANUFACTURING METHODS

摘要

PPROBLEM TO BE SOLVED: To provide a cement admixture containing silica fume selected by a characteristic evaluation method where fluidity can be judged whether it is good or bad when mixed in cement concrete and to provide high strength cement concrete using a cement composition, being excellent in fluidity, not causing working defects and being excellent in durability. PSOLUTION: It is characterized by that the quantity of a supernatant liquid which is centrifugally separated from a cement paste containing silica fume at a rotating speed of 7,500 rpm or more is measured and then the quantity of free water is determined and that silica fume whose content of free water selected by the characteristic evaluation method of silica fume is 8% or more is used in a method for manufacturing the cement admixture containing silica fume and being used with a water reducing agent. It is characterized by that the silica fume is used in the manufacturing methods of the cement composition and the cement concrete and that the cement admixture, the cement composition and the cement concrete are manufactured by their manufacturing methods. PCOPYRIGHT: (C)2009,JPO&INPIT