Life Cycle Assessment of Continuously Reinforced Concrete Pavement Overlay on Concrete Road Rehabilitation: Insights from Two Case Studies

In the realm of rehabilitating existing jointed plain concrete pavement (JPCP) or continuous reinforced concrete pavement (CRCP), the conventional choice is asphalt concrete (AC) overlays due to the cost-effectiveness of their initial construction and rapid traffic accessibility. However, AC overlays tend to deteriorate more quickly in structural performance and surface smoothness compared to the original JPCP or CRCP, necessitating more frequent post-overlay maintenance or rehabilitation. Recently, CRCP overlays have gained attention for outperforming AC overlays in terms of durability and ride quality. Despite their superior performance and lower use-phase cost, concerns linger regarding the overall environmental impact of CRCP overlays. To bridge the gap, this paper examines the sustainability of CRCP overlays through pavement life-cycle assessment (LCA). We conducted two case studies to evaluate the life-cycle environmental impacts, including both embodied and use-stage emissions of CRCP overlays for concrete pavement rehabilitation. We leveraged Pavement ME software for the prediction of pavement performance after rehabilitation and employed a streamlined pavement LCA framework to evaluate the life-cycle greenhouse gas (GHG) emissions of CRCP overlays. The results reveal that CRCP overlays tend to have higher embodied emissions, but much lower total GHG emission for a life-cycle perspective as compared to AC overlays. For the two case studies employed in this paper, the life-cycle GHG emissions for CRCP overlays can be as low as 15% of that of AC overlays for the rehabilitation of existing concrete pavements.