| abstract |
An invention for a cement board is disclosed. The cement board of the present invention comprises: 35-55% by weight of cement, 10-20% by weight of silica sand, 20-35% by weight of bottom ash, 2-5% by weight of silica fume, 1-6% by weight of anhydrous gypsum, 0.1 to 1 wt% of a water reducing agent, 0.01 to 1 wt% of a thickening agent and 0.02 to 1.2 wt% of a fluidizing agent are mixed to prepare a mixture, and the mixture is compression molded. |