Laboratory Study of Dust Palliative Effectiveness

Three different aggregate types were treated with water and two commercially available dust palliatives and tested in the laboratory to quantify their resistance to erosion by wind and traffic. Treated and untreated specimens were subjected to a simulated wind velocity of 32 km/h in a wind tunnel to examine resistance to wind erosion. In a second test, different specimens were subjected to up to 1,500 simulated traffic applications to measure resistance to traffic erosion. Material and environmental variables considered in the testing program include curing temperature, curing period, palliative concentration, and application rate. Results obtained confirm that dust palliatives can significantly reduce erosion of low-volume unpaved roads and that the effectiveness of a particular palliative depends on soil type, traffic loads, and environmental conditions. A parametric study was also conducted to establish palliative selection criteria. The laboratory testing program developed and the selection criteria identified can be used as a decision-making tool to select an effective dust palliative for a particular soil type and environment.