Specifications: 1) Density: 1,200 - 1,400kg/m3 2) Bending strength: over 9MPa (GB/T7019-1997) 3) Water absorption rate: less 0.25% (GB/T7019-1997) 4) Water penetration rate: 0% 5) Water content: less10% 6) Radioactivity: standard (GB6566-2000) 7) Characteristic: nonflammability A grade (GB-8624-1997)