Probabilistic corrosion hazard maps for reinforced concrete infrastructure in coastal regions

Abstract

The development of probabilistic corrosion hazard maps for reinforced concrete infrastructure exposed to airborne chlorides in coastal regions is addressed in the present work, with special attention to bridges. The methodology developed in this study consists of three steps. Initially, spatial distribution, construction year, and main features of the existing infrastructure are examined together with the general characteristics of the study area. The second step deals with the elaboration of relevant environmental data, including the direction and height of sea waves, sea salinity, temperature, relative humidity, rainfall, speed and direction of wind, and chloride deposition rates. Corrosion hazard maps are obtained next, wherein the corrosion current density is selected as an intensity measure. Particularly, they are elaborated for an assigned probability of exceedance given the exposure time window and concrete mixture. The presented methodology is applied to develop probabilistic corrosion hazard maps for reinforced concrete bridges exposed to the marine atmosphere at Oahu Island (Hawaii, United States). For this case-study, it is also discussed the correlation between the actual condition rating of the existing concrete bridges and the estimated corrosion hazard levels.