Concrete Overlay Strategies for Improving Pavement Resilience

Increases in flooding events and rising groundwater levels caused by climate change threaten to weaken pavement foundations, which can have a major impact on flexible pavement service life. Rigid pavements are not as sensitive to the strength of underlying layers, so one potential method to improve the resilience of existing asphalt pavements is to construct concrete overlays. In this analysis, typical asphalt pavement sections on collector and arterial streets under Iowa climatic and soil conditions are identified and evaluated under a variety of theoretical flooding scenarios to determine the impact of inundation on service life. Three types of concrete overlay designs are developed for these typical asphalt pavement sections under the same conditions. A life cycle cost analysis (LCCA) is performed to compare the costs and performance of the concrete overlay strategies to a conventional flexible pavement rehabilitation strategy under the theoretical flooding scenarios. The results of the LCCA indicate that a variety of concrete overlay designs can provide more cost-effective performance when pavement foundation layers become inundated, depending on the roadway functional class and frequency of flooding. These findings indicate that concrete overlays can be a useful method for improving resilience of existing flexible pavements and mitigating the costs of flood damage.