Standard Test Average Test Average ASTM C 97 Absorption (3) 0.03 % Bulk Specific Gravity (3) 2 854 ASTM C 99 Modulus of Rupture Day (3) 4 500 psi ASTM C 170 Compressive Strength Day (5) 29600 psi ASTM C 241 Abrasion Resistance Day (3) 51.9 Ha ASTM C 880 Flexural Strength Day (5) 4 700 psi