Investigation of corrosion damage and repair system in a concrete jetty structure

This paper presents the diagnostic investigation of a reinforced concrete jetty after 15 years of service. The main cause of the deterioration was reinforcement corrosion, which initiated within few years after the completion of the jetty structure. The structure underwent major corrosion rehabilitation after 7 years of service. Despite the use of high-strength concrete in the construction of the jetty structure, inadequate cover thickness for reinforced concrete elements intensified corrosion rate and caused early age corrosion problems to reappear. Other contributing factors included high salinity of the seawater by simultaneous action of climatic factors such as exposure to high relative humidity and air temperature. After the initial repair work, a new investigative procedure was carried out to reevaluate the repaired and surrounding unrepaired areas. Results indicate that the deterioration progressed even in concrete elements that were undamaged during the first step of the investigation. No sign of steel corrosion appeared on repaired areas; but shrinkage cracking and incipient corrosion around repaired areas were indications of dimensional and electrochemical incompatibility between repair concrete and substrate. The repair strategy was reevaluated through the repair index method proposed by Andrade and Izquierdo. The results showed that the patching repair method was more suitable and feasible in comparison with other techniques.