Technical evaluation of iron ore fines in making concrete for industrial floors.

Abstract

Iron and its products, especially the various forms of steel, have been and still are a vital material in many sectors of life. It is utilized in many industrial activities ranging from production of heav- duty mechanical equipment to light electrical appliances and home appliances. With the world’s iron ore consumption estimated to stand at 1.3 billion tonnes by 2025, exploitation of any existing natural deposits is of increasing importance to meet the demands of the expanding world economy. Uganda is enriched with iron ore which is being extracted and exploited in areas like Kyanyamuzinda, Kamena, Rushekye, Nyamiyaga, Butale and Kasenyi which make the Muko deposit in Kabale and Kisoro districts. Others in Sukulu in Tororo, Bukusu in Mbale and Wambogwe resources of Sukulu. These iron ores are being extracted and processed to overcome the persevering situation of increasing demand for iron and steel products. However, this comes with challenges like generation of unwanted iron ore fines, particulates and dust. These iron ore fines are poorly disposed yet they are capable of playing a vital role in the construction sector. Industries constructed also face frequent cracking of industrial floors by continuous movement and vibration of machines used. Sand used as aggregate has a low density and offers low strength. The increasing generation of iron ore fines which are a by-product of iron ore processing are disposed every year in landfills, quarries, rivers, lakes among others thereby posing environmental problems. The aim of this study was to evaluate iron ore fines as replacement for fine sand aggregate in concrete and compare with the result of conventional concrete. Characterization of the iron ore fines was done using BS sieve analysis to determine the physical composition. Concrete mixtures containing 25%, 50%, 75% and 100% iron ore fines as sand replacement were prepared with water-to-cement ratio ranging between 0.25-0.40. Tensile, compressive strengths and flexural strength were determined and compared. Compressive strength increased by 22.5%, flexural by 14.6% and tensile strength increased by 21%. The water absorption test showed a decreasing tendency with increased addition of iron ore fines. Finally, the overall research proved that iron ore fines can be used as partial replacement of sand to improve the strength of concrete.