Comparative sustainability assessment of warm-mix asphalts: A thermodynamic based hybrid life cycle analysis

Warm-mix asphalt (WMA) has received considerable attention in the past few years as a potential solution for the reduction of energy consumption and emissions during production and construction of asphalt mixtures. However, many concerns and questions are still unanswered regarding its environmental benefits. Although several studies have been conducted to quantify the atmospheric emissions of WMA pavements, the direct and indirect role of ecological resource consumption was generally excluded in these studies. In this study, a thermodynamic based hybrid life cycle assessment model was developed to evaluate the environmental impacts of different types of WMA pavements and compare it to that of a conventional hot mix asphalt (HMA) one. The impacts on the ecosystem were calculated in terms of cumulative mass, energy, industrial exergy, and ecological exergy. Monte Carlo simulation was also conducted to analyze the variability of critical input parameters. The results of this study showed that although the mixing phase is important, it should not be the only phase to evaluate the decreased amount of atmospheric emissions of WMA pavements.

► A thermodynamic based hybrid life cycle assessment model was developed to evaluate the environmental impacts of different types of WMA pavements.
► The impacts on the ecosystem were calculated in terms of cumulative mass, energy, industrial exergy, and ecological exergy.
► Monte Carlo simulation was conducted to analyze the uncertainty of critical input parameters.