| 摘要 |
PURPOSE:To obtain the title material giving high strength even in a long gelling time, also outstanding in long-term binding strength, by blending, as part of the components, water-glass and powdered hard-to-dissolve calcium compound, and furthermore by providing specific requirements. CONSTITUTION:The objective binder containing water-glass and powdered hard- to-dissolve calcium compound, also provided with the following requirements (1)-(4): (1) molar ratio: SiO2/Na2O=0.5-2.5, (2) molar ratio: CaO/SiO2>=0.2, (3) content of SiO2: >=0.07mol. per 100cc of the final binder, (4) content of said powdered hard-to-dissolve calcium compound: >=1g per 100cc of the final binder. Said hard-to-dissolve calcium compound is e.g. naturally-occurring calcium compound powder such as line (CaO), Ca(OH)2 or dolomite, or the synthetic calcium compound powder from one of these substances or dominant substances therein. |
