Hollow Block 25 Our products Hollow Block 10 Hollow Block 12 Hollow Block 15 Hollow Block 20 Length 40 cm Width 25 cm Height 20 cm Average weight 20 kg/piece Average density 950 kg/m3 Compressive Strength (Net Area) Not less than 4.14 N mm² (average) (not less than 3.45 N mm²) per block Average absorption 6% Materials used Dolomite cement – Portland cement Colors used inorganic oxides