Impact of Climate Conditions on Deteriorating Reinforced Concrete Bridges in the US Midwest Region

Abstract

The deterioration of reinforced concrete bridges due to environmental stressors is proven to adversely affect their strength and durability over time. This primarily originates from the penetration of aggressive ions, leading to the corrosion of steel rebars embedded in concrete. A range of factors, such as temperature, humidity, and precipitation, have a direct impact on this process and can greatly influence the corrosion initiation time. In the United States, the Midwest region is known to experience long winters, requiring multiple applications of deicing salts to keep the roadways open. The amount of deicing salts used on an annual basis has witnessed constant growth, while the climate change is believed to have intensified the exposure conditions. To investigate the deterioration of bridges serving the roads in the Midwest region, a computational framework is developed to predict the corrosion initiation time based on regional climate data obtained for the three major cities of Chicago, Minneapolis, and Des Moines. In addition, a rigorous sensitivity analysis is performed to evaluate the contribution of various input parameters based on the Sobol indices. In the absence of any similar studies on the bridges in the Midwest region, this investigation predicts the extent of vulnerability of the region’s bridges to deterioration based on historical climate data, as well as future forecasts. From the simulation results, the impact of climate conditions on the crack width and time duration to reach the durability thresholds has been quantified. With the possibility of an extension to other cold climate regions, the outcome of this study is expected to help transportation agencies optimize their maintenance and repair actions, which will not only improve the condition state of the bridges in service but also reduce the time, effort, and investment needed for the management of a large inventory of bridges.