Abstract
<title>Abstract</title> <p>Reinforced concrete (RC) roofs in coastal marine environments are vulnerable to accelerated deterioration due to the combined effects of high humidity, airborne chlorides, wet–dry cycles, thermal fluctuations, and inappropriate rehabilitation practices. This study investigates the deterioration of the RC roof system of the Central Bank of Yemen – Aden building, with particular focus on the structural consequences of unplanned roof rehabilitation involving excessive superimposed layers added for slope correction and drainage. Field inspections, exploratory openings, photographic documentation, and structural load assessment were used to evaluate the relationship between roof dead load accumulation and observed distress in the supporting structural system. The investigation revealed that the roof build-up reached approximately 53 cm in thickness before rehabilitation, resulting in a cumulative dead load of 9.759 kN/m². For Column C20, the corresponding load contribution from the roof layers was estimated at 375.53 kN, equivalent to approximately 38.28 tons. Although the original design capacity could not be verified due to the absence of archival structural drawings and calculations, field observations documented vertical cracking, delamination, efflorescence, and reinforcement corrosion in the affected structural elements. The rehabilitation strategy involved removing excessive superimposed layers, reducing the thickness of slope-forming materials, improving drainage configuration, applying waterproofing measures, and repairing localized deteriorated reinforced concrete elements. These interventions reduced the cumulative roof dead load from 9.759 kN/m² to 4.003 kN/m². The load transferred to Column C20 decreased from 375.53 kN to 154.10 kN, corresponding to a reduction of approximately 58.96%. The findings demonstrate that roof rehabilitation in coastal RC buildings must be treated as a structural and durability-sensitive engineering process rather than a surface-level waterproofing intervention. The study provides a practical case-based framework for assessing rehabilitation-induced dead loads, integrating field investigation with load quantification, and guiding sustainable rehabilitation strategies for RC roof systems exposed to aggressive marine environments.</p>