Case Study: Cradle-to-Laid Life Cycle Assessment of a Concrete Pavement Reconstruction Project in Colorado

This study presents a cradle-to-laid Life Cycle Assessment (LCA) of the Global Warming Potential (GWP) impact of 1 lane mile of a concrete pavement for a highway construction project in Colorado. For this study, cradle-to-laid includes the A1-A3 modules of the production stage and the A4-A5 modules of the construction stage according to the ISO LCA methodology. Quantity takeoffs of materials were calculated from the project's construction drawings, pavement design report, general contractor's production metrics, and Colorado Department of Transportation (CDOT) project-specific mix design data. The GWP impact values for concrete production were obtained from a facility-specific concrete cradle-to-gate LCA, with values sourced from project estimated quantities, LCI data from the National Ready Mix Concrete Association (NRMCA) Rocky-Mountains regional concrete benchmark, and LCI data from FHWA's LCA Pave tool. For production of aggregate base course, installation of dowel bars and tie bars, and transportation and construction of all pavement materials, GWP impact values were extracted from the FHWA's LCA Pave tool software. The results presented in this paper could be used by agencies or practitioners as a case study for LCA of the construction of a concrete highway pavement.