Influence of chemical additives and wax modifiers on odor emissions of road asphalt

The use of a broad range of asphalt additives is a well-established practice in road pavement engineering for the production of high-performance hot-mix and warm-mix asphalt mixtures. The study aimed to verify and to assess, though an analytical-sensory approach based on artificial olfactory system (AOS), the effects of five different asphalt additives (chemical additives, odor suppressant agent and wax modifiers) on the odorous patterns of asphalt emissions at typical mixing and laying temperatures. The AOS has made possible to identify a specific odor fingerprint of each additive. However, once added to asphalt, these agents did not establish with binder effects of synergy, additivity or antagonism, but appear to be as neutral elements by an odorous point of view. The odorous patterns of emissions generated by heating neat asphalt at various temperatures in laboratory scale tend to coincide with those of asphalt/additive mixtures, underlining how the bituminous binder odor resulted to be hiding or masking compared to that of only-additives.