Abstract:
PROBLEM TO BE SOLVED: To provide a cement admixture from which mortar which hardens in an early time after kneading, exhibits high short time strength, and can keep a prescribed flowability during a certain time after kneading, for example, the time required for infiltrating into a crack to be repaired or a void in stratum or the time required for inpouring into a molding flask, that is to say, during working time required until the work is finished can be obtained; and to provide a quick hardening cement composition containing the same. SOLUTION: The cement admixture contains citric acid and an alkali metal salt of tartaric acid. The quick hardening cement composition contains quick hardening cement as a main component and the admixture. COPYRIGHT: (C)2005,JPO&NCIPI
Abstract:
PROBLEM TO BE SOLVED: To provide a fiber reinforced extra quick hardening mortar which has excellent compression strength of a hardened body ranging from the initial stage to a middle-long period after spray and, moreover, has an excellent surface finishing property just after the spray too, its structure and its dry spray method. SOLUTION: The fiber reinforced extra quick hardening mortar comprises an extra quick hardening cement, fine aggregate, inorganic fiber or synthetic fiber, a setting retarder of 0.03-0.1 wt.% to the extra quick hardening cement, and water. COPYRIGHT: (C)2005,JPO&NCIPI
Abstract:
REFERIDO A UNA COMPOSICION CEMENTICIA QUE COMPRENDE: UN ACELERANTE, UNA FUENTE DE SULFATO DE CALCIO, UN CEMENTO FORMADOR DE ETRINGITA QUE CONTIENE UNA MEZCLA DE UN CEMENTO ALTO DE ALUMINA Y SULFATO DE CALCIO, AGUA, ENTRE OTROS. SE REFIERE TAMBIEN A UN METODO DE APLICACION DE LA COMPOSICION CEMENTICIA.
Abstract:
본 발명은 조기강도 발현형 고내구성 콘크리트 조성물에 관한 것으로, 혼화재로서 개질된 플라이애시가 포함되도록 하여 초기강도가 발현됨에 따라 상존할 수 있는 조기경화에 의한 수축 등의 문제를 해결하고 밀실한 페이스트 구조를 제시하여 고내구성이 발현될 수 있도록 하는 콘크리트 조성물에 관한 것이다.
Abstract:
The present invention relates to an admixture including fly ash which is physically and chemically reformed by mixing and pulverizing the fly ash, an activator, and a grinding aid. The initial strength and durability are improved by the reforming, thus a binder capable of improving amount of cement substitution can be provided.
Abstract:
The present invention relates to a polymer-modified cement concrete composition for expressing early strength and to a method for concrete overlay pavement using same. The composition comprises: a cement-based binder of 3-38 wt%; a fine aggregate of 25-70 wt%; a coarse aggregate of 25-70 wt%; water 0.1-20 wt%; and a polymer-based binder of 0.01-20 wt%. The cement-based binder comprises: normal Portland cement of 10-60 wt%; magnesium sulfo-aluminate of 10-60 wt%; plaster of 0.01-10 wt%; blast furnace slag of 0.01-20 wt%; an alumina powder of 0.1-10 wt%; and calcium aluminate of 0.01-10 wt%. The polymer-based binder comprises: styrene of 15-75 wt%; methyl methacrylate of 15-50 wt%; butyl acrylate of 5-40 wt%; itaconic acids of 0.1-20 wt%; and butadiene of 0.1-20 wt%. By means of the present invention, the concrete composition can have improved workability and durability. The concrete composition can especially have improved bending strength, tensile strength, early strength, long-term strength, chloride resistance, and freezing and thawing resistance so that defects in the concrete can be reduced.