Systematic approaches toward minimum maintenance risk management methods for weathering steel infrastructures

Since the revised Japanese Specification for Highway Bridges clearly states that degradation of bridge members to occur in a prolonged period of time must be taken into account as a risk, wide scope of discussion has been carried out in Japan. The final goal of these activities is to realize the ultra long term durability of steel infrastructures with a minimized maintenance cost. To reduce risks for anomalous rusting to occur on weathering steel structures, a computerized corrosion prediction system, visual as well as instrumental rust monitoring methods, repairing or retrofitting methods in case of contingency, etc. have been developed. Unlike organic or inorganic materials, weathering steels do not deteriorate internally. Therefore, all corrosion risks can be monitored by the inspection of steel member surfaces. The present work proposes a systematic management method for Risk Based Minimum Maintenance (RBMM) of weathering steel bridges.