| 摘要 |
PURPOSE:To prevent the release of a basic magnesium carbonate layer from the surface of a steel material and the generation of a crack by producing a refractory building material wherein the basic magnesium carbonate layer is provided on the surface of the steel material through a buffer layer by extrusion molding. CONSTITUTION:A raw material consisting of 15-25 pts.wt. of magnesium carbonate, 18-32 pts.wt. of lightweight aggregate, 35-50 pts.wt. of a polymer, 3-5 pts.wt. of an alkali-resistant glass fiber, 5-8 pts.wt. of pulp and 2 pts.wt. or more of a thickening material is cured. A buffer layer is subjected to steam ageing at 35-45 deg.C for 4-12 hr and subsequently subjected to steam ageing at 75-85 deg.C for 4-12hr to be cured. By adding a predetermined amount or more of the polymer and a predetermined amount or more of the lightweight aggregate, Young's modulus can be extremely reduced. |
