Post-Fire Structural Condition Assessment and Remediation Strategy for a Seven-Storied Reinforced Concrete Industrial Building: A Case Study from the Ready-Made Garment Sector in Bangladesh

Abstract

Post-fire assessment of existing reinforced concrete (RC) structures is frequently carried out using a single assessment technique, most commonly visual inspection, in isolation, an approach that risks two opposite failure modes: unnecessary demolition of members whose fire exposure did not compromise structural capacity, and continued occupation of members whose internal damage is not visible at the surface. Existing codes and guidance establish individual test methods but offer limited practical guidance on how visual, non-destructive and destructive evidence should be combined into a single, consistent, evidence-based decision on member-level remediation. This study addresses that gap by developing and demonstrating an integrated, tiered assessment framework that combines visual crack survey, phenolphthalein carbonation testing, ultrasonic pulse velocity (UPV) testing and cylindrical concrete core extraction with compressive-strength testing, cross-checked against a structural capacity verification, to classify fire-affected members and select a matched remediation strategy. The framework’s central methodological contribution is a clear decision rule: a member is classified as core-damaged, and assigned to concrete removal, epoxy-injection and jacketing, only where the combined carbonation and UPV/crack evidence shows damage penetrating beyond the reinforcement clear cover; members with distress confined to the cover concrete are instead assigned a lower-cost plaster or wire-mesh reinstatement. The framework is demonstrated on a seven-storied RC industrial building in Bangladesh following a third-floor fire, where it distinguished core-damaged from surface-damaged columns, beams and a flat-plate slab, and was cross-validated by an independent punching-shear capacity check of the fire-affected slab-column connections. Beyond the specific case, the framework is presented as a generalizable, replicable protocol for practising structural engineers undertaking post-fire condition assessment and rehabilitation planning of existing RC buildings, particularly in ready-made garment and other industrial facilities where rapid, defensible return-to-service decisions are operationally critical.