| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a method for producing a cement composition by easily using, as a raw material, gypsum recovered from waste gypsum boards in a large amount without employing a special facility or process. <P>SOLUTION: In the production of a cement composition containing a cement clinker component, gypsum recovered from waste gypsum boards and containing a surfactant, and a defoaming agent, when the cement clinker component is crushed, the defoaming agent is added, and then mixing and crushing are carried out. Thereby, a foaming action due to the surfactant contained in the recovered gypsum is depressed, and it becomes possible to prevent the strength of mortar or concrete from lowering. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
