Mechanical Properties of Concrete Using All-in Aggregates from Small-Scale Mining Sites

Abstract

Concrete is vital in building construction industries; however, it significantly contributes to the depletion of natural resources (aggregates), leading to global CO2 emissions. To reduce concrete-related CO2 emissions, the integration of wastes and by-products as components in concrete production is a promising strategy. One of such by- products is the residue from small-scale mining (galamsey) sites, which causes environmental pollution and is a source of soil contamination. This work sought to assess the properties of concrete made with all-in-aggregates sourced from small-scale mining (galamsey) sites (galamsey aggregate). Conventional gravel and sand were completely replaced with all-in-aggregates from mining (galamsey) sites for concrete and tested for workability, density, compressive, tensile strength and water absorption. The result indicated that the density, compressive strength, tensile strength and water absorption level of the concrete increased as the curing days increased. The result showed that the density, compressive, tensile strength and water absorption level of the control was 2385.83kg/m3, 33.41N/mm2, 3.30N/mm2 and 2.60% respectively while the mining sites (galamsey aggregate) concrete recorded density of  2359.22kg/m³, compressive 32.56N/mm2, tensile strength 3.21N/mm2 and water absorption level of 2.67%. The study revealed that the all-in-aggregates from the small-scale mining (galamsey) site gave good workability with a slump (workability) value of 59mm and 35.67mm for mining site (galamsey) aggregate and granite, respectively. The study concluded that the workability, density, compressive, tensile and water absorption of the mining site (galamsey) aggregates are within the acceptable standard requirement for concrete application.