Mechanical and Chemical Properties of Reinforcement Bars Manufactured in Nigeria

Abstract

Reinforcement bars, or REBAR for short, are mainly produced from metal scrap or iron ore, or a combination of both. Their manufacturing process has a significant effect on their properties, so also are the percentage concentration of various constituent elements and the cooling rate in the production process. This research work aims to study the physical and chemical properties of rebars manufactured in Nigeria vis-à-vis their suitability for construction purposes. The effect of chemical composition in rebar on steel stresses was studied. Rebar samples were collected at various points in Abuja and its environs and tested for their mechanical and chemical properties. The results show some tolerable and intolerable deviations from provisions of BS 4449 B500B 2005 indicating that some of the rebars are satisfactory for use in reinforced concrete works while others are not. Tests conducted on the rebars include Tensile Strength, Relative Rib Area, Percentage Elongation, Bend and Rebend, and Spectrometer tests, among other physical examinations. In some rebars, results showed moderate to vast deviation from minimum acceptable standard values as specified in BS 4449 B500B 2005 for yield stress, elongation, bar diameter, mass per kilogram, carbon equivalent, while there is satisfactoriness for other tested samples.