FIELD AND LABORATORY STUDIES ON THE DURABILITY PROPERTIES OF NEW AND REPAIRED COASTAL STRUCTURES

Reinforced concrete structures are widely constructed in the Persian Gulf region for infrastructures of ports and oil industries. But these structures are increasingly beingdeteriorated, mainly due to the chloride-induced corrosion of the embedded bars. Consequently, hundreds of million dollars are spent for repair and rehabilitation every year. In marine structures, piles are often subjected to the most severe corrosion due to the permanent wet and dry cycles. In the majority of previous studies, Fick’s 2nd low is often used to predict chloride transport in terms of diffusion [1], because of its convenient and easy calculation with constant values of the apparent diffusioncoefficient (Dapp) and surface chloride content (Cs), which are in fact dependent on concrete mix proportion, production method and degree of contact to severeconditions (e.g. submerged, tidal, splash and atmospheric zones in a marine environment)[2,3]. However these models need to be calibrated with experimental results and surveys of real structures for different climates and exposure conditions all over the world and especially severe conditions like Persian Gulf [4].