Quantifying the Greenhouse Gas Emission Reductions Associated with Recycling Hot Mix Asphalt

Market based policies to reduce greenhouse gas emissions have become increasingly popular in the last decade. These policies provide economic incentives for reducing greenhouse gas emissions. A life-cycle inventory model was developed to evaluate three alternatives for the management of waste hot mix asphalt (HMA) including, (1) recycling as new aggregate, (2) recycling as new HMA, and (3) disposal in a landfill. Global warming potential, environmental emissions, and total energy use were quantified for each management alternative. The recycling of used asphalt into new HMA results in a reduction of 16 kg CO2e compared to landfilling. Recycling used HMA as aggregate reduced GHG emissions by 9 kg CO2e A Monte Carlo analysis on the alternatives showed that the range of reduction for recycling as HMA was 12 to 26 kg CO2e and for recycling as aggregate 6 to 11 kg CO2e.