The construction industry has significant impacts on ecological systems, and alternative ways to mitigate environmental impacts associated with construction activities have generated tremendous interest in the United States. Although quantifying and analyzing the cumulative ecological resource consumption of the construction industry is of great importance, it has not been studied sufficiently. Several studies have been conducted to quantify the energy and resource consumptions, as well as air emissions of different construction sectors and pavement designs. However, the direct and indirect role of the ecosystem goods and services were generally excluded in these studies.
Current study aims to fill this research gap in life cycle assessment literature by accounting for the total ecological resource consumption of the construction sectors and several pavement designs, including their supply chains. To achieve this objective, a thermodynamic based hybrid life cycle assessment model has been developed. This developed model has complemented previous life cycle assessment studies on resource consumption of U.S. construction sectors and different pavement structures by evaluating them not only from emissions and energy consumption standpoints, but also from ecological resource accounting perspective. The economic output values of each U.S. construction sector were obtained from Department of Commerce Input-Output Table. The impacts on the ecosystem were calculated based on the economic data in terms of cumulative mass, energy, industrial exergy, and ecological exergy.
In this study, 13 different U.S. construction sectors and various pavement technologies, including Continuously Reinforced Concrete Pavement (CRCP), Hot-mix Asphalt (HMA), and Warm-mix Asphalt (WMA) additives such as Sasobit®, EvothermTM, and Aspha-min® are holistically evaluated by using several sustainability metrics such as resource and emissions intensity, efficiency, renewability, and loading ratio.