Large scale assessment of reinforcement steel quality in a developing construction market: evidence from 12,161 tests in Sudan

Abstract This study evaluates the quality of steel reinforcement in Sudan using a large dataset of over 12,000 tests, supported by independent laboratory verification and a stakeholder survey. The results show that while larger diameter bars (20–32 mm) generally comply with Grade 460 requirements, the smaller and more commonly used bars (8–16 mm) exhibit significant deficiencies in both strength and diameter under-sizing. The findings indicate that current market conditions are more consistent with lower strength levels than those typically assumed in design. Temporal analysis further shows that previous regulatory interventions had only short-term impact, with compliance declining in subsequent years. Laboratory verification confirms systematic diameter under-sizing and variability in mechanical properties, while survey responses highlight weak quality control practices across the sector. A simplified structural assessment indicates that diameter under-sizing alone can reduce flexural capacity by more than 15% for typical bar sizes, with combined effects of reduced strength and increased safety factors leading to total capacity reductions approaching 30%. Overall, the study underscores the need for sustained regulatory enforcement, improved testing practices, and more reliable material control to ensure structural safety.