Study On Steel Bridge Coating Maintenance Evaluation Model Based On Life-Cycle Costs

Steel bridge has been more widely used for the advantages of good ability of spanning capacity, construction. However, steel bridges are subject to be corroded, which reduces the durability and safety of the steel bridge. The corrosion protection has become the key to the steel bridge maintenance, how to maintain steel bridgemore economically and reasonablly has become an important issue.This paper introduces the mechanism of corrosion, the type of corrosion. And describe the coating maintenance policies based on summing up maintenance policies at home and abroad, which include corrective maintenance, preventative maintenance and predictive maintenance. As well as propose the coating maintenance projects,1.Inspect steel bridges, according to rust rate, the coating condition of a structure may be divided into three categories: minor damage, fair damage and severe damage.2. According to the rust rate, The various coating maintenance strategies are divided into touch-up painting, overcoating, recoating or the "do-nothing", and on this basis, the steel bridge coating maintenance evaluation model based on life-cycle costs is introduced, where the cost of each maintenance strategy or cash flows in the life-cycle is discounted to their present value and summed, then select the minimum cost to achieve the maximum benefit strategy. The model which includes (1) Overall bridge condition rating, using deterministic input values.(2)Bridge component condition rating, using deterministic input values.(3)Overall bridge condition rating, using probabilistic input values. (4)Bridge component condition rating, using probabilistic input values. This model can provide a better strategy for decision-makers and can give some guidance on the future maintenance of steel bridges.