| It is estimated that a vehicle making a single pass on one mile of untreated, unpaved road every day can generate one ton of dust per year. This dust constitutes fine materials which act as a binder to the larger coarse aggregates within surface gravel. As these fines are removed, the surface deteriorates and expensive aggregate ends up along the roadside in ditches and culverts. The surface continually deteriorates until the road must be reconstructed. Furthermore, airborne dust presents serious safety concerns to traveling motorists and health concerns associated with respiratory illnesses. At the West Virginia Division of Highway's current funding levels it is anticipated that less hot-mix asphalt will be used to pave roadways for the purpose of dust control. If the road is treated with a chemical dust suppressant, however, it can retain a percentage of fines that would otherwise be expelled as dust.;The purpose of this thesis was to evaluate the effectiveness of five commercially available chemical dust palliatives for use on public gravel secondary roads in West Virginia. Dust control products included in this study are a petroleum emulsion with polymer, synthetic organic fluid, calcium chloride, bituminous resin pitch, and lignin sulfonate. Three methods of field testing were used which included a mobile dust sampling device, soil silt fractions, and moisture analyses. Results of field testing indicated that calcium chloride was the most cost-effective material for providing dust control throughout the evaluation period. All but one product provided some measurable degree of dust control at the end of the three-month evaluation period when compared to the four untreated control sections. |
