| abstract |
The present invention is an improved one of the U.S. Pat. Application Ser. No. 211,307 now U.S. Pat. No. 3,782,992 and relates to a process for regulating setting time of hydraulic cement which comprises clinker containing 5 - 60 % by weight of 11CaO.7Al2O3.CaX2, more than 5 % by weight of 3CaO. SiO2, and further 2CaO.SiO2 solid solution and 4CaO.Al2O3.Fe2O3; anhydrite with or without hemihydrate; at least one selected from the group consisting of sugars, sodium hydrogen carbonate, water-soluble phosphates, carboxylic acids, silicofluorides, sodium silicates, ligninsulfonate, sulfuric esters of higher alcohol and alkylsulfonates, whereby the anhydrite is contained in an amount that Al2O3/SO3 weight ratio of Al2O3 in the clinker and SO3 in the anhydrite is 0.7 - 1.8 and hemihydrate is contained less than 5 % by weight based on SO3. |