ULTRAHIGH-STRENGTH FIBER-REINFORCED CEMENT COMPOSITION, ULTRAHIGH-STRENGTH FIBER-REINFORCED MORTAR OR CONCRETE, AND ULTRAHIGH-STRENGTH CEMENT ADMIXTURE

摘要

An ultrahigh-strength fiber-reinforced mortar or concrete which can attain a high flexural strength even with a smaller amount of metal fibers and which can contain fine aggregates for use in ordinary fresh concrete and is highly suitable for general-purpose use. Flowability (workability) is improved, and a mortar containing no metal fibers is made to have an increased absolute value of compressive strength and a heightened proportion of flexural strength to compressive strength, whereby the mortar or concrete is provided. Also provided is an ultrahigh-strength fiber-reinforced cement composition which is characterized in that it comprises cement, silica fume, coal gasification fly ash, plaster, and metal fibers and that the proportion of the silica fume to the coal gasification fly ash is (95-50):(5-50) by mass. The ultrahigh-strength fiber-reinforced mortar or concrete comprises this cement composition and fine aggregates incorporated therein. Furthermore provided is an admixture for ultrahigh-strength cement which is characterized in that it comprises silica fume, coal gasification fly ash, and plaster as major components and that the proportion of the silica fume to the coal gasification fly ash is (95-50):(5-50) by mass.