Practical service life assessment and rehabilitation strategy development for hyperbolic shell natural draft cooling towers

Years of service in industrial plant operating environments can cause varying types and degrees concrete deterioration on reinforced hyperbolic shell natural draft cooling towers. Exposure to water potentially result material erosion corrosion embedded reinforcing steel associated delamination spalling over time. Such affect the integrity structure degree that repair programs are required reliably maintain towers for their life. Condition assessment is challenging due massive size, geometry, operational considerations (i.e. schedule, risk cost). A case history presented illustrating a rational targeted investigation approach included combination field condition survey, laboratory materials testing, consideration constraints, probabilistic-based life modeling, structural analysis. Existing degradation as well predicted conditions from modeling informed analyses were performed identify risk-based limit states The multi-faceted provided information critical understand mechanisms, characterize health, develop prioritized strategies obtain desired extension.