Marine Durability of 23-Year-Old Reinforced Concrete Beams

This paper gives findings of marine durability tests of 23-yr-old reinforced concrete beams exposed to marine tidal and atmospheric environments. The study mainly focused on corrosion of steel bars with respect to orientation in concrete, carbonation and chloride-ion induced corrosion of steel bars, quantitative evaluation of corrosion based on the electrochemical data, and the influence of stirrups on macrocell formation. Experimental work covered electrochemical investigations, chloride ion profile and carbonation depth measurements, microscopic steel concrete interfaces, and visual observation of steel bar corrosion. The study found that chloride-ion induced corrosion is significantly influenced by the orientation of steel bars in concrete. Cracks and interfacial gaps between steel and concrete must be accounted for in order to predict corrosion of steel bars in concrete.