PREVENTION OF OCCURRENCE OF EFFLORESCENCE IN PRODUCTION OF CEMENT PRODUCT

摘要

PURPOSE:To prevent efflorescence by sticking fast a sheet having mold release characteristics to the surface of molded article simultaneously with molding, right after molding or right after surface processing and hardening the molded article in the state. CONSTITUTION:A cement such as Portland cement is blended with given amounts an aggregate such as sand or pebble and additives such as an expanding agent, a coagulant, a waterproofing agent and then a necessary amount of water to give an intimate mixture. The intimate mixture is molded into a given shape, the molded article is subjected to surface processing simultaneously with the molding, immediately after the molding or immediately after the molding and forming a decorative layer on the molded article and a sheet of given thickness such as polyethylene terephthalate, silicone resin or polytetrafluoroethylene is stuck fast to the surface of the molded article. Then the molded article is cured with steam at a high temperature, hardened and the sheet is removed to give a cement product not observed to cause efflorescence.