Preventing Corrosion of Reinforcing Steel in Seawater Cooling Tower and Basins

摘要

Cathodic prevention is a proven technique for preventing corrosion of reinforcing steel in new reinforced concrete structures exposed to chloride containing environments. Premature deterioration and failure of seawater reinforced concrete structures due to chloride-induced corrosion of the reinforcing steel has been a serious concern in industrial plants in Arabian Gulf countries which uses seawater as cooling system for removing exothermic heat generated during process. In a new petrochemical plant, reinforced concrete seawater cooling tower and associated basins were constructed with built-in cathodic prevention (CP) systems to prevent corrosion of the steel reinforcement from day one. The CP system design and installation details are described. The anode system consisted of mixed metal oxide (MMO) coated titanium mesh anode ribbon and titanium conductor bar. The CP systems have now been in operation for 5 years and their performance in meeting the specified criteria and their design objectives is described and discussed. A remote monitoring system with unique features has been designed and installed for CP system monitoring, assessment and adjustment remotely.