Commercial Odor-Reducing Agents for Minimizing the Odor Potential of Asphalt Binders

Odors arising from hot mix asphalt (HMA) production and application are a serious problem due to the proximity of HMA production to human habitation. One possible solution to this problem is the use of odor-reducing agents, which are intended to suppress the production of malodorous compounds. In this study, the ability of seven odor-reducing agents to reduce the odor compounds produced by 22 different HMA binders was quantified. Some odor-reducing agents produced only modest reductions in odors and were inconsistent in performance. Results indicate that terpine and essential oil based odor reducing agents did not appear to be effective in reducing odors. The aldehyde based agents attained the highest degree of odor reduction and appeared to be the most consistent performer over the spectrum of asphalt binders tested. Aldehydes produced reductions in odor potential that consistently exceeded 50% in odor-related volatile organic compounds. The odor reduction seen with the aldehydes is similar to those obtained with a nitrogen purge, leading to the hypothesis that these type of agents act as an oxygen scavenger.