Licentiatavhandling Stockholm : Kungliga tekniska högskolan, 2007

One of the most significant problems associated with gravel roads is traffic-generated dust which facilitates the deterioration of the road surface and acts as a major source of particulate matter in the air, thus affecting traffic safety, public economics, and environmental quality. This work describes different programs for evaluating the effectiveness of different dust suppressants and the results obtained from completion of these experiments. In chapter one, a general introduction into this project and its objective will be offered. The next chapter gives insight into the basic concepts of gravel roads. In the third chapter the existing literature concerning dust control of gravel roads is briefly retold. The fourth chapter gives an account of the research methodology. A field evaluation of different dust suppressants will be described in the fifth chapter. Chapter six describes methods for analysing dust suppressant residual concentration of samples taken from the different test road sections included in the above mentioned field evaluation. The objective is to investigate the longevity of these dust suppressants. Results from the analyses of the horizontal diffusion of gravel road generated dust are presented in chapter eight. The ninth chapter offers a description and evaluation of the objective method used for quantitative dust emission measurements by means of a visual method. In chapter ten dust emissions are correlated to other general deformation processes on the gravel road. Chapter eleven defines laboratory trials concerning the leaching of dust suppressants from gravel wearing course material when subjected to water. Concentrations of dust suppressant as well as size distribution of gravel material were factors examined in this context. In chapter twelve, laboratory examinations of the drying rate for different combinations of aggregate gradations and chloride compounds will be presented. The thirteenth chapter gives a description of a developed laboratory equipment for evaluating dust suppressant effectiveness, while chapter fourteen offers a conclusive summary.