Physical Properties Brand GG-0.7a GG-0.7b GG-0.6 GG-0.5a GG-0.5b GG-0.4 Index Bulk Density 0.7 0.7 0.6 0.5 0.5 0.4 Compressive Strength Mpa 2.45 1.18 0.78 0.78 0.59 0.78 Permanent Line Chang 900 Conductivity Coefficient 0.2 0.21 0.17 0.15 0.16 0.13