SUBSTANCE HAVING HIGH HYDRATION ACTIVITY, ACCELERATOR FOR CEMENT AND METHOD FOR PROMOTING SETTING AND HARDENING OF CONCRETE OR MORTAR

摘要

PURPOSE: To obtain an accelerator for cement having excellent initial and long- term strength development by adding ZnO or BaO to a CaO-Al₂O₃ system to obtain a composition having a specific composition imparted with calcium aluminate hydration activity. ;CONSTITUTION: This accelerator for cement is a highly hydrating substance obtained by melting and quenching a CaO-ZnO-Al₂O₃ composition, containing 10-79wt.% of CaO, 1-30wt.% of ZnO and 20-60wt.% of Al₂O₃ based on the sum of CaO, ZnO and Al₂O₃ and containing 40-80wt.% of CaO and ZnO in total. BaO may be used as a substitute for ZnO. The highly hydrating substance may be incorporated with one or more kinds of substances selected from 5-35wt.% of gypsum, 5-40wt.% of lime, 5-50wt.% of an alkali metal carbonate, 10-50wt.% of sodium aluminate and ≤25wt.% of aluminum hydroxide.;COPYRIGHT: (C)1995,JPO