Comparison of laboratory-generated and field-obtained HMA VOCs with odour potential

Abstract

Previous research developed a gas chromatography (GC) methodology for simulating and evaluating hot mix asphalt (HMA) volatile organic compounds (VOCs). The objectives of this research were to determine if (1) the VOCs produced and measured in the laboratory method represented the relative ranking of VOCs measured during the production of HMA, and (2) the odour reducer had a quantifiable influence on the VOCs during HMA production. Three HMA plants were run using asphalt binders with and without a commonly used commercial additive used for reducing odour complaints from neighbouring communities. Air samples were obtained over 4 h of continuous operation of each plant for each asphalt binder (i.e. one with and one without odour reducer). Two locations at each plant were concurrently sampled: at the drag slat (i.e. where the HMA moves from the drum to the storage and/or loading area, and from the head space in the storage tank. Good correlations were found between the laboratory and field measurements; the laboratory GC method provides a good relative ranking of concentrations for the VOC compounds monitored in this study. The odour reducer used in this study significantly reduced VOCs at both sampling locations.