| 摘要 |
PURPOSE:To provide a lightweight hardened compact of gypsum excellent in bending strength, surface hardness, smoothness, processability, etc., by preparing a construction in which a cellular gypsum layer is sandwiched between fiber-containing dense gypsum layers of a specific thickness through a prescribed amount of fiber bundles placed therebetween. CONSTITUTION:A fiber-containing hemihydrate gypsum slurry for the first layer is cast into a frame mold and the first fiber bundles are then oriented in the longitudinal direction. A cellular hemihydrate gypsum slurry for the second layer is subsequently cast and the second fiber bundles are then oriented in the longitudinal direction. A fiber-containing hemihydrate gypsum slurry for the third layer is subsequently cast and demolding is carried out after hardening the whole layers. The hardened compact is then dried. Thereby, the objective lightweight gypsum hardened compact containing the second layer, composed of the cellular gypsum layer containing fiber or without containing the fiber through the first and second fiber bundles interposed in an amount of 0.1-5wt.% based on the total weight of the lightweight gypsum hardened compact and sandwiched between the first and the third layers composed of fiber-containing dense gypsum layers having the total thickness of 10-50% based on the whole layer thickness from both sides is produced. |
