| 摘要 |
PURPOSE:To obtain a fiber cement board having uniform composition and free from asbestos without causing environmental pollution by forming a specific mixture composed of silica, pulp fiber, cement and aggregate using a dry-roll forming process and curing the product under specific condition. CONSTITUTION:A formed raw material is produced by mixing 5-10wt.% of silica having a Blaine value of 18,000cm<3>/g and 5-10wt.% of pulp fiber having a water content of 50-150%, mixing the obtained mixture with 35-45wt.% of cement and 25-35wt.% of aggregate and forming the mixture by dry-roll forming process. The formed raw material is subjected to spontaneous curing and then autoclave curing to obtain the objective fiber cement. The water content of the pulp fiber is restricted to 50-150% in order to facilitate the adhesion of dried fine powder of silica by the moisture on the surface of the pulp fiber, to promote the reaction with the subsequently added cement by the attached powder and to improve the bonding strength to cement matrix. |
