Durability and Service Life of Concrete Structures

Degradation and deterioration of structures caused by physical and chemical damage results in decrease in performance with time, physical damage occurs due to fire, abrasion or expansion and contraction stresses while chemical damage occurs due to harsh environment. Lack of durability of concrete or initiation of cracking is caused mainly due to volume change in concrete caused by corrosion of reinforcement. A case study on structures situated around city of Bhopal has been presented here. Numerous deteriorated structures of different age groups have been surveyed and around hundred RC structures of age group ranging from newly constructed to as old as sixty years situated in different locations of the city of Bhopal are identified and selected for in-situ condition survey. These structures have been numbered in order of their age. Field survey of selected structures have been performed and performance indicators/ parameters measured are concrete cover in mm, carbonation depth in mm, chloride content at rebar level as percentage of weight of concrete, Half cell potential in mV, Compressive strength of concrete in Mega-Pascal (MPa) along with survey of age of structures in years.