Paving Asphalts: Environmental and Flammabiuty Considerations

Abstract

Abstract The evaluation of petroleum-based paving asphalts as a possible source of heavy metal pollution in soils and water, as well as the determination of combustion parameters—smoke mass and particle size distribution, and sulfur dioxide and oxides of nitrogen during controlled burning—represented the main goals of this study. Special consideration was given to the changes in combustion behavior, smoke components, and heavy metal content introduced by the addition of tire rubber to the paving asphalt samples. The different analytical techniques applied were conducted on samples of pure asphalt cement (including different brands and grades), samples of asphalt rubber (with concentrations of 4%, 10%, and 18% of tire rubber), and samples of asphalt concrete taken from two different locations in the city of College Station, Texas. Instrumental neutron activation analysis (INAA) was used to identify and quantify the heavy metals present in the asphalts. Zinc, manganese, and vanadium were the most prevalent ...