Development of a Framework for Assessing Global Warming Potential Across the Concrete Pavement Life Cycle

Abstract

The objective of this work is to develop a framework for performing life cycle assessments (LCAs) of a concrete pavement. Current concrete LCAs focus primarily on stages A1 through A3, as communicated through concrete environmental product declarations (EPDs), accounting for only the concrete mixture design and constituents. Because of current EPD limitations, concrete mixtures are evaluated based on a declared unit of material rather than a functional unit. Concrete pavement LCAs that tend towards beyond the gate stages focus on the excessive tailpipe emissions due to pavement vehicle interactions, highlighting the importance of pavement performance and demonstrating the need for functional units. However, the pavement industry desires a pavement LCA to incorporate the life cycle stages beyond the gate and beyond tailpipe emissions, including construction, repair, maintenance, rehabilitation, and end of life. Incorporating a more holistic approach allows for improved decision-making and consideration of material choices that may have a higher upfront global warming potential (GWP) but result in longer life, thus lowering overall emissions. The framework developed in this study considers the embodied emissions associated with the entire pavement life cycle, including repair, maintenance, rehabilitation, and end of life. The framework does not include the tailpipe emissions or use phase of the pavement in which the sole source of emissions arises from vehicles. Developing this framework offers not only a holistic solution of concrete pavement life cycle to the industry, but also transitions concrete LCAs from a declared unit to a functional unit.