Life cycle energy consumption and GHG emission from pavement rehabilitation with different rolling resistance

摘要

This paper describes a pavement life cycle assessment (LCA) model developed to evaluate energy use and greenhouse gas (GHG) emissions from pavement rehabilitation strategies. The LCA model analyzes the energy and GHG emissions associated with material production, construction and pavement use, which includes the effects of pavement rolling resistance on vehicle operation. The model was used to evaluate a set of case studies of pavement rehabilitation for both asphalt and concrete surfaces with different rolling resistances and traffic levels. The primary goal of the case studies is to evaluate the effect of rolling resistance on the life cycle performance of pavements, not to compare asphalt and concrete pavements. Energy and GHG emission savings from pavement rehabilitation are compared with an alternative where no rehabilitation occurs, only routine maintenance of damaged pavement. The results of the case studies show that for highway sections with high traffic volumes the energy and GHG savings accrued during the use phase due to reduced rolling resistance can be significantly larger than the energy use and GHG emissions from material production and construction, with the extent of the benefit dependent on constructed smoothness. These savings can be larger than those from other strategies to reduce highway transportation energy use and emissions, such as projected improvements in vehicle fuel economy. For low traffic volume highways, the smoothness obtained by the contractor and materials used have a more significant effect on the performance of the rehabilitation, and may result in a net increase in energy use and GHG emissions if low traffic volumes and poor construction quality occur together.