Evaluation of Locally Produced Steel Reinforcement Bars Against NIS and BS 4449 Standard Requirements in South East Nigeria

This study evaluates the mechanical and chemical properties of steel reinforcement bars produced by induction furnace steel plants in South East Nigeria against the requirements of NIS 117 and BS 4449:2005 Grade B500B standards. The proliferation of small induction furnace-based rolling mills in the South East zone has raised concerns among structural engineers about product quality consistency, particularly following high-profile building collapse incidents in the region. Rebar samples of 10 mm, 12 mm, 16 mm, and 20 mm diameter are procured from eight producers in Anambra, Imo, and Abia States through market purchases, supplemented by direct mill sampling at three producers. Chemical composition is determined by OES, and mechanical testing including tensile, yield strength, elongation, and bend tests is performed following BS 4449 test procedures. Geometric property compliance is assessed by dimensional measurement. Findings reveal that 35 percent of market-procured samples fail to meet the minimum yield strength of 500 MPa specified by BS 4449 Grade B500B, and 28 percent fail elongation requirements. Geometric non-conformances include undersized rib height in samples from four producers. Traceability marking is absent or incomplete in 60 percent of samples. The study identifies induction furnace scrap chemistry inconsistency as the primary cause of mechanical property variation. Recommendations include mandatory third-party certification of rebar products by accredited testing laboratories in South East Nigeria. Keywords: steel reinforcement bar, BS 4449, mechanical properties, South East Nigeria, quality compliance.