An expanding agent a self-stressing cement mixed with an expanding agent and a method for allowing self-stress to cement

摘要

PURPOSE: A cement admixture is provided by mixing aluminum- and sulfate-based materials with lime- or calcium sulfo aluminate-based materials and polyethylene oxide without sintering. Also, self stressing cement and a method for offering self stress to cement, concrete or mortar are provided by using cement admixture. CONSTITUTION: The high efficiency cement admixture is prepared by mixing the following components without sintering. The components comprise 25-70wt.% of aluminum-based materials such as fly ash, slag alumina cement; 25-70wt.% of sulfate-based materials such as anhydrous gypsum, gypsum hydrate and gypsum titanate; 5-15wt.% of lime-based materials such as unslaked lime and slaked lime or calcium sulfo aluminate(CSA)-based materials; 0.01-0.05pts.wt. of polyethylene oxide(PEO). The prepared admixture offers self stressing, shrinkage decrease, viscosity and fluidity to cement, concrete or mortar by mixing 5-15wt.% of prepared admixture with 85-95wt.% of conventional cement like Portland cement.