The National Asphalt Pavement Association (NAPA) has expanded its online Greenhouse Gas Calculator to help quantify the decrease in greenhouse gas emissions that accompany the increased use of recycled materials and warm-mix asphalt technology. The Greenhouse Gas Calculator, which can be accessed at www.asphaltpavement.org/ghgc, complements other environmental life-cycle assessment (LCA) models, and is used by some companies and state departments of transportation to benchmark emissions of carbon dioxide equivalents (CO2e) generated while producing asphalt pavements.
The calculator allows users to compare emissions associated with various fuels used to dry aggregate, plus fuels used by facility equipment, including vehicles. A final category addresses CO2e attributed to electrical use. The calculator also includes emission offset credits for fuels and activities that reduce the amount of CO2e released or that sequester CO2. Credits are calculated for plant-based bio-fuels, recycled fuel oil, and recycled raw materials, such as reclaimed asphalt pavement and recycled asphalt shingles. Credits are also calculated for reducing mix temperatures using warm-mix asphalt technologies.