HIGHLY HYDRATED CRYSTALLINE ACTIVE MATERIAL, CEMENT ACCELERATOR AND PROMOTION OF SETTING AND HARDENING OF CEMENT OR MORTAR

摘要

PURPOSE: To promote setting and hardening and to reveal initial strength and long-time strength by adding a highly hydrated crystalline active material obtained by burning a CaO-Al₂O₃-Fe₂O₃-SO₃ composition to mortar and cement. ;CONSTITUTION: This highly hydrated crystalline active material contains 35-58wt.% CaO, 15-55wt.% Al₂O₃, 2-27wt.% Fe₂O₃ and 1-13wt.% SO₃. The material is burned at 1000-1400°C with an appropriate equipment such as an electric furnace. Further, 2-35 pts.wt. of gypsum, expressed in terms of anhydrous gypsum, 5-40 pts.wt. of lime, 5-50 pts.wt. of an alkali metal carbonate and 10-50 pts.wt. of sodium aluminate, in total of 22-200 pts.wt., are mixed with 100 pts.wt. of the active material to obtain a cement accelerator. The accelerator can be added directly to cement or used as the accelerator in spraying or as the quick setting material in the emergency construction work. The accelerator is added to cement preferably by 2-25wt.%.;COPYRIGHT: (C)1996,JPO