Performance Benchmark of Greenhouse Gas Emissions from Asphalt Pavement in the United States

Hot mix asphalt (HMA), used extensively in road construction, has the highest greenhouse gas (GHG) emission intensity among construction subsectors. In the absence of an authorized performance benchmark in the pavement industry, current prevailing practices of HMA form an institutional resistance to change, and emission mitigation efforts are unable to be quantified and rewarded. The objective of this paper is to develop a performance benchmark for sustainable asphalt production based on GHG emission performance. The baseline configuration is the use of conventional HMA. System boundary, functional unit, and calculation method are standardized to support the consistency of the benchmark. A sampling survey of hot mix facilities and placement projects has formed the data pool to conduct the statistics analysis. Results show that the performance benchmark is 115kgCO₂e/MT HMA. It represents an emission level that 80% of existing HMA producers are unable to reach, which reasonably avoids the occurrence of free-riders. Under the carbon trading mechanism with an assumed price of $15/MT carbon, expected benefits from producing a foam stabilized base (FSB), a less carbon-intensive asphalt material, can be $0.7/MT asphalt using CCPR process and $4.2/MT asphalt using CIR process. With the aid of a predetermined performance benchmark, rapidly evolving carbon trading markets may increase the competitive advantages of "green" production in terms of investment offset through carbon trading.