FROM TRADE-OFFS TO EQUIVALENT SOLUTIONS: A LIFE CYCLE THINKING INFORMED APPROACH TO DESIGN DECISION MAKING

As the infrastructure industry moves towards adopting Environmental Product Declarations (EPDs), as instruments for communicating the environmental impacts from pavements, there is a growing need to develop methods that support the informed use of mid-point impact indicators such as Global Warming Potential (GWP) in the design decision-making process. This research presents an equivalent solutions framework that will aid decision-makers to inform the design of pavement systems by explicitly accounting for performance requirements, costs and mid-point environmental impact indicators as reported through instruments such as EPDs. A limited illustration of the framework is provided for the case of Hot-Mix Asphalt (HMA) mixtures containing Reclaimed Asphalt Pavement (RAP). A trade-off between each distress and GWP are identified through Lagrange multipliers. The outcomes of the analysis provide decision-makers with guidelines on margins of tolerance and indicate the possibility of identifying equivalent functionalities (for GWP and TC) across designs with varying RAP content