Investigating Deterioration Mechanisms of Outdoor Concrete Staircases Constructed at the Okanagan Campus of UBC

The concrete characteristics of eight deteriorated outdoor staircases at the University of British Columbia (UBC)’s Okanagan campus, constructed between 1992 and 2012, were comprehensively evaluated. This study focused on the investigation of reinforced staircases that showed substantial distress at their early ages, much before their design service life ends, requiring continuous intervention for safe operation. Hence, this study aimed to identify the root causes of such deterioration. The evaluation involved visual inspections and measurements of distressed reinforced concrete staircases for compressive strength, chloride ion permeability, permeable pores, absorption rate, and detailed microstructural analysis. Concrete staircase elements in cold climates, prone to ice abrasion, cracking, spalling, and frost erosion, are further threatened by climate change. Extreme weather events, rising temperatures, fluctuating freeze–thaw cycles, and precipitation rates are expected to accelerate concrete degradation, which necessitates a better understanding of their long-term effects on structural durability. Despite evident signs of severe damage, some concrete staircases exhibited reasonable strength values, allowing for an extension of their service life. The study underscores the imperative for ongoing repairs due to the diverse modes of deterioration impacting concrete quality across all in situ sites.