Comparative Study of the Mechanical and Chemical Properties of Locally Produced Low-Carbon Steel Rebars on the Ghanaian Market

Abstract

Low-carbon steel reinforcement bars (rebars) are widely used in reinforced concrete construction in Ghana due to their relatively low cost and acceptable mechanical properties. However, most locally produced rebars are manufactured from recycled scrap metals, and limited data exist on their mechanical and chemical performance. This study investigates rebars produced by four leading Ghanaian manufacturers coded as AS, BS, CS, and DS, and compares them with Ghana Standards Authority (GSA) and British Standards (BS 4449). Tensile tests and spectrometer analysis were conducted to determine mechanical and chemical properties, respectively. Results showed that all rebars exceeded the GSA minimum yield strength (≥300 N/mm²) and ultimate tensile strength (≥400 N/mm²), with recorded values ranging from 380.02–499.69 N/mm² (yield) and 574.66–718.94 N/mm² (ultimate). Only BS rebars (Yield: 499.69 N/mm²; Ultimate: 718.94 N/mm²) fully satisfied the stricter BS 4449 thresholds (≥460 N/mm² yield; ≥600 N/mm² ultimate), while AS (452.7/667.1 N/mm²) and CS (432.16/604.95 N/mm²) were marginal, and DS (380.02/574.66 N/mm²) fell short. Elongation values (19.55–27.69%) exceeded the 14% requirement in both standards, confirming adequate ductility. Actual diameters were consistently lower than nominal, with 12 mm rebars measuring between 10.48 mm (CS) and 11.59 mm (BS). Chemical composition confirmed low-carbon steel (0.299–0.349% C), though phosphorus (0.049–0.054%) and sulfur (0.035–0.047%) levels in some samples approached the 0.05% limit. The findings provide essential data for engineers, designers, and regulators, underscoring the need for stricter quality control to ensure compliance with international benchmarks while supporting sustainable scrap-based steel production.