LOW-ALKALI HYDRAULIC MATERIAL

摘要

PROBLEM TO BE SOLVED: To obtain a hydraulic material capable of maintaining alkalinity for a long period of time. SOLUTION: This hydraulic material is obtained by adding blast furnace water-granulated slag powder and silica fume to a low calcium type cement clinker comprising hauyne (3CaO.3Al2O3.CaSO4), belite (2CaO.SiO2) and ferrite (4CaO.Al2O3.Fe2O3) phase and calcium sulfate as main components. The amount of the total calcium sulfate is 10-50 wt.% calculated as anhydride (CaSO4) based on the total amount of the cement clinker and the blast furnace water- granulated slag. The calcium content based on silicate content is (CaO-2SO3)/ SiO2<1.0 (molar ratio). Water in which a hardened material is immersed has low alkalinity reducing pH with time.