Analyzing Hot Mix Asphalt Emissions in Paving Placement and In-Service Temperature Conditions

The paving industry significantly contributes to elevated emissions of air pollutants, thereby contributing to a decline in air quality. Current research mostly centers on hot mix asphalt (HMA) production’s emissions and worker health impacts. However, characterizing asphalt emissions under operational conditions remains an underexplored aspect in scientific literature. This study analyzes asphalt emissions in two stages: (i) during real-world placement and (ii) after compaction and cooling. For the first phase, passive methods were used for NO2 and SO2 measurements, while the second involves automated collection of NO2 and total volatile organic compounds (TVOCs) in the laboratory. Results suggest that HMA emissions in-use temperatures may be a relevant and continuous source of air pollution. NO2 emission rate measured in the lab had presented the same order of magnitude of pollutant concentration collected using passive sampling during the field campaign. The TVOCs emission showed a close relation in-between different temperature cycles. It could contribute to emission inventories, aiding the comprehension and depiction of factors that impact urban air quality.