Laboratory method to evaluate dust suppression properties of tall oil pitch used as a stabiliser for unsealed roads in New Zealand

Vehicle movement on unsealed roads, a common pavement type for low-volume roads in New Zealand, produces fugitive dust, resulting in environmental and health concerns associated with both deposition and inhalation. Additionally, dust plumes created by vehicles can significantly impair visibility, posing safety risks to motorists. To evaluate the effectiveness of dust suppressing agents under laboratory conditions, this study established a method and assessment protocol utilising an accelerated pavement surface testing system designed to closely replicate field dust generation caused by pavement-tyre interaction. Initial experiments used tall oil pitch as a dust suppressant and a rolling pneumatic tyre at 25 km h−1. Findings indicated a quantifiable decrease in dust emissions from pavement specimens treated with progressively higher concentrations of tall oil pitch, demonstrating the potential of this method to provide a more realistic approach for the comparative study of dust generation from different materials in a laboratory setting.