Life Cycle Assessment of Pavements under a Changing Climate

Each of pavements’ life cycle phases such as material extraction, transportation, construction, operation, rehabilitation, and end-of-life emits greenhouse gases. Such emissions can be influenced by climate change via changes in the rates of pavement deterioration and thus intensity and frequency of maintenance and rehabilitation. However, climate change has not been given full considerations in previous pavement life cycle assessments (LCA). This research introduced a methodology to integrate the effects of climate change within pavement LCA. A case study was performed to calculate the life cycle global warming potential (GWP) and costs of several typical interstate pavements due to climate change, using downscaled climate data obtained from the CoupledModel Intercomparison Project Phase 5 (CMIP5). Pavement performance (roughness) was determined using the Pavement ME system. Rehabilitaiton alternatives were also assessed according to predefined pavement roughness triggers. Whereby, roughness triggers were alternatives assessed using LCA. Use of Reclaimed Asphalt Pavement (RAP) was evaluated as an alternative of local virgin materials. SimaPro and PaLATE were used to convert material and energy consumptions into GWP values and equations from HDM4 model were used for determining operational GWP impacts and costs. Asphalt mix production costs were used on the basis of values obtained from local asphalt contractor. For each of the case study scenario, LCA was conducted using historic climatic data, as the current state of practice in field of pavement LCA, as well as future climatic projections. The results of this research demonstrate the importance of considering future climate change in pavement LCAs. This study also presents a generalizable framework for climate change informed pavement LCAs.