Decision-Making Tool for Incorporating Cradle-to-Gate Sustainability Measures into Pavement Design

Abstract

Pavements consume large amounts of energy, materials, and a significant portion of maintenance funds, which cause a substantial strain on the environment and the economy. Hence, a sound framework for designing and constructing a sustainable pavement is needed. To measure sustainability in a pavement, various tools were developed and adopted. Among these approaches, life cycle assessment (LCA) is a widely used quantitative method for measuring the environmental impacts of pavement alternatives. However, application of LCA in pavement is challenging, as it requires substantial time and resources to collect the required data for the analysis. An alternative sustainability tool, environment product declaration (EPD), addresses some of the limitations of LCA. This study presents a cradle-to-gate framework for selection of a pavement design, based on optimization of the pavement mix design/products for structural, environmental, and economic performances. The developed framework allows one to compare different design/product alternatives that balance engineering goals against environmental and economic performances and combines the two into an overall performance score, which identifies a cost-effective and environmentally preferred pavement. This approach is inclusive of (1) an EPD analysis, which quantifies the environmental impacts from raw materials extraction to manufacturing; (2) a transportation analysis, which quantifies the impact of transporting mixes from a plant location to the construction site; and (3) an economic analysis, which evaluates the economic value of an alternative. Developed modules and databases were incorporated into a simple decision-making tool, a Windows-based software, which was developed for the selection of a design/product with a balance that extends across engineering, environmental, and economic performance criteria. The developed methodology is demonstrated in a number of case studies.