Durability of concrete structures in marine environment

In India, construction is the biggest industry and concrete worth Rs.20,000 crores is being used annually, a major port in aggressive marine environment along the vast coast line and hence the loss to the economy due to premature deterioration of the structures is enormous. When tire structures are situated in marine environment with possible high chloride diffusion, the reinforcement becomes active when carbonation front reaches reinforcement. Carbonation time to reach reinforcement can be enhanced either by increasing cover thickness or by decreasing the carbonation constant. In this paper, structures in marine environment were analysed for quality of concrete, depth of carbonation, carbonation constant, alkalinity of concrete, depth of chloride penetration and chloride-hydroxide ratio. Attempts were made to correlate the effect of quality of concrete and cover thickness on the enhancement of service life of the structures, The paper also highlights the importance of preventive measures at the stage of design and construction like increase in concrete cover, quality of concrete and coatings to reinforcement.