Mechanical and Microstructural Properties of Steel Reinforcing Bars Produced from Different Manufacturing Industries as Available in Nigeria Market

The performance of reinforced concrete infrastructure depends strongly on the properties and quality control of its constituent materials, particularly steel reinforcement. This study evaluates the geometric, mechanical, and microstructural properties of steel reinforcing bars produced by major Nigerian steel manufacturers and compares them with imported bars available in the same market. Tests conducted include dimensional checks (size consistency and relative rib area), Vickers hardness, tensile properties, and microstructural/chemical characterization using XRF and SEM/EDS. Results show that imported bars have more consistent dimensions and rib areas (0.55% ≤ COV ≤ 0.94%) than locally produced bars (0.80% ≤ COV ≤ 1.91%), while PRISM rebars exhibit hardness values 18.5% above recommended limits. Eurotherm bars are more elastic but have lower strength compared to other brands, and microstructural examination reveals fewer inclusions in STAR and TOP bars, in contrast to PRISM and DUST bars, where inclusions promote brittle fracture. Overall, PSL steel bars demonstrated superior performance in reinforced concrete relative to PRISM and TMT bars.