ASSESSMENT OF COAL MINE OVERBURDEN SAND FOR USE IN CONCRETE MAKING AS FINE AGGREGATE

This paper presents a study carried out to assess the suitability of sand recovered from a coal mine overburden as an alternate to river sand. The overburden consists of weathered sandstone sludge. The sand particles were recovered by washing the overburden and separating sand particles by sedimentation and decantation method. To assess the suitability of the sand for making concrete, tests as recommended in Indian standard code IS:383 - 2016 were carried out. The recovered sand named CMOB sand was found suitable for making concrete. The recovered sand was fine grained having fineness modulus of 2.24 and falls in zone III. Saturated and surface dry loose and compacted bulk density was found to be 1499.44 kg/m3 and 1696.67 kg/m3 respectively. The specific gravity was found to be 2.6 and water absorption 1.2%. The chief constituents in CMOB sand were SiO2 about 90.00% and Al2O3 about 4.00%. No deleterious material was found beyond the limit prescribed in the IS code.