Performance of concrete structures in the marine environment of Karnataka, India

Well-made concrete often survives better than might otherwise be expected, simply because of its impermeability and its ability to withstand the ingress of corrosive materials. The less the surplus voids the greater is the resistance to deterioration. Corrosion of steel is a multibillion-dollar problem worldwide. However, there are many structures, which show early deterioration, namely those exposed to aggressive environments. In the past and even at present times, too much emphasis is placed on concrete compressive strength rather than on environmental factors, which are known to affect concrete durability. This is one of the main reasons for serious deterioration of concrete structures that is prevalent today. The long-term behaviour of concrete structures has shown that their main cause of distress is reinforcement corrosion. One of the most aggressive exposure conditions for concrete is the marine environment In these condition chloride penetration and chloride induced reinforcement corrosion rates can be very high, often leading to a reduced service life. This paper describes a series of case studies of different types of concrete structures, subjected to marine environment in the West-Coast of Karnataka (INDIA), that have suffered extensive deterioration due to corrosion.