RESEARCH ON DURABILITY OF CONCRETE FOR EXISTING BRIDGE

After a fixed number of years of operation an existing reinforced concrete bridge would be deteriorated due to natural aging, the ambient effects, increasing of the vehicle loading and deficiency of maintenance, such as corrosion of concrete, corrosion of reinforcing steel, crack development protective concrete spalling off and so on. Thus certainly this will lead to reduction of carrying capacity and durability, and then affects its normal useful function. Therefore, it is very important to evaluate the working condition of an existing bridge. In this present paper, carbonation and chloride penetration are analyzed quantitatively for the girders of Zhenhua Crossroad which has been gone in use for 15 years in Qingdao. Probability of corrosion of reinforcement is also analyzed. Based on test results, states of durability for this bridge are evaluated. Then some suggestions to upgrading of the durability of concrete suffering from serious carbonation are offered.