Evaluation of Old Netim Basement Rocks (South-Eastern Nigeria) for Construction Aggregates

Abstract

The physico-chemical and engineering properties of the basement rocks from Old Netim, southeastern Nigeria were determined to ascertain their suitability for civil construction purposes. The results indicate that specific gravity (SG) ranges from 1.55 (overburden) to 2.73 (fresh granite gneiss), hardness (H) 1.0 (weathered soft rock) to 6.0 (fresh strong gneiss), compressive strength (?) 19.31 to 77.37 MN/m² and the moisture content (W%) 0.11 to 10.12.The moderately high strength of the rocks as well as the low values of water absorption capacity are consistent with the chemical composition of the Oban granite gneiss. The results also indicate that moisture content (W%) decreases with increasing hardness (H), specific gravity (SG) and compressive strength (?) except where rock weathering and underground water cause some adverse effects on the rock quality. The relationship between moisture content (W%), specific gravity (SG) and compressive strength (?) indicates that the fresh basement rocks from Old Netim quarry are capable of withstanding heavy traffic, foundation loads and generally suitable for most civil construction works.