Evaluation of Concrete Work Practices in Residential Building Construction Sites in Kano Metropolis, Nigeria

Prompted by the increasing frequency of building collapses in the region, the research assesses the processes of concrete mixing, handling, placement, and curing across 100 active construction sites. This study examines concrete work practices in residential building construction within Kano Metropolis, Nigeria, with a specific focus on compliance with Section 10.3.9.3 of the Nigerian National Building Code (NNBC). Data were collected using structured observational checklists and site photographs. The findings indicate widespread non-compliance with key standards, including batching accuracy (20% compliance), use of approved mix designs (2%), and implementation of quality control testing (2–4%). Although materials such as cement and water generally meet quality specifications, issues such as poor storage conditions, reliance on manual mixing, inadequate compaction, insufficient curing, and lack of proper documentation undermine concrete integrity. These deficiencies are largely attributed to inadequate technical expertise, limited supervision, and weak enforcement of regulatory frameworks. As a result, concrete strength is often compromised, increasing the risk of structural failure. The study emphasizes the need for targeted capacity-building initiatives, stricter regulatory enforcement, and widespread adoption of standardized practices. Key recommendations include mandatory training for site personnel, improved supervisory mechanisms, and the use of certified mix designs to enhance structural performance and safety. Overall, the study contributes to efforts aimed at improving construction quality and promoting sustainable urban development in Kano and comparable urban centres.