Air emissions from pavement layers composed of varying rates of reclaimed asphalt

An experimental study of road building and recycling of used pavement has been conducted within the framework of a Life Cycle Analysis. Four equivalent asphalt concretes made with different recycling rates have been investigated during road construction. Airborne emissions, pollutant release over time and odor production related to asphalt laying have all been determined and compared among the various recycling rates. All of the results (VOC, PAH and odors), expressed in terms of concentrations and fluxes, exhibit quite monotonic variations with respect to the recycling rate. These results, however, did not reveal the same trend as a function of the recycling rate (increases or decreases), depending on the selected target parameter (VOC or PAH). Indicators have been proposed for a discussion of results that take into account: (i) raw material emissions with respect to the reference defined in the case of pavement without reclaimed asphalt; and (ii) emissions in each case from all material production sources.