A Review on Degradation Mechanism and Life Estimation of Civil Structures

Reinforced concrete (RC) is widely used in civil construction since it is the most versatile, economical and durable construction material of all times. Reinforcement corrosion has been widely reported to be one of the major durability problems, mainly when the rebar in the concrete is exposed to the chlorides, either contributed from the concrete ingredients or penetrated from the surrounding chloride-bearing environment. Carbonation of concrete or penetration of acidic gases into the concrete causes reinforcement corrosion. Besides these, factors related to the concrete quality, such as water/cement (w/c) ratio, cement content, impurities in the concrete ingredients, presence of surface cracks, etc. and those related to external environment, such as moisture, oxygen, humidity, temperature, bacterial attack, stray currents, etc., affect reinforcement corrosion. In this paper, a review is presented on the mechanisms of degradation of concrete, techniques used to monitor reinforcement corrosion, and empirical models and experimental methods to predict the remaining service life of structures.