CORROSION-INDUCED CRACK PERFORMANCE PREDICTION OF RC BRIDGE UNDER CHLORIDE ATTACK CONSIDERING EFFECT OF GLOBAL WARMING

Using the atmospheric climate change data, the present study modifies chloride-induced corrosion initiation model and corrosion current density model, and analyzes how greenhouse warming changes (CO₂ and temperature) and its effects on corrosion-induced crack performance to RC bridges under chloride attacking. Due to the randomness of corrosive parameters such as climate change, chloride concentration, temperature, humidity and performance deterioration, this paper develops time-dependent reliability-based method to predict the probability of corrosion initiation and mean proportion of corrosion-induced cracking for RC bridges in service time of 100 years. It is found that atmospheric greenhouse warming increases effect of corrosion damage and should be considered for prediction of corrosion damage. For sea-spray region (Zone 1) the mean proportion of corrosion-induced cracking is 127% and 140% higher than that predicted for offshore atmospheric region (Zone 2). When structures are located 1 km way from coastline, the mean proportion of corrosion-induced cracking is reduced to be 1%. For a cover of 20mm and a w/cof 0.55, probability of corrosion-induced cracking is up to 0.893 over next 100 years. This indicates corrosion damage for many concrete structures and therefore lots of maintenance and repair actions are needed. This work can provide information on the effects of greenhouse effect and chloride ion attack on civil engineering for decision makers to decide mitigation methods.