There is growing interest for state departments of transportation to identify practices that reduce the embodied carbon of infrastructure. To achieve this, there is a need to understand the embodied carbon related to current pavement construction practices. Despite significant progress in standardizing how the environmental impacts of our pavement’s construction materials (A1–A3) are quantified and communicated, similar standards are needed to quantify the embodied carbon of infrastructure construction beyond the gate (A4-A5).
To address this gap, Alabama, Louisiana, Mississippi, and Virginia have joined a collaborative effort through the Federal Highway Administration’s (FHWA’s) Climate Challenge to conduct several case studies on the implementation of Life Cycle Assessment (LCA) for various pavement construction projects. This paper summarizes preliminary results from the various case studies. To encourage collaboration and harmonization amongst the state participants and beyond, OpenLCA was used to conduct the LCAs using the recommended public background datasets from the American Center for Life Cycle Assessment Open Standard, Federal LCA Commons, and the FHWA LCA Pave tool. The scope of the LCAs were cradle-to-construction (A1–A5). Construction practices included in the study are full depth reclamation with cement stabilization, hot mix asphalt with highly polymer modified binder, high recycled asphalt pavement with recycling agents and recycled plastics, and warm mix asphalt with lower mixing and compaction temperatures. Environment Product Declarations, where available, were collected from material manufacturers, while construction process data collected included water, fuel, materials used, transportation distances, and wastes or recycled materials hauled off-site.
