Degradability of unpaved roads submitted to traffic and environmental solicitations: Laboratory scale
Abstract
Dust emission generated during earthwork induces security nuisances for workers, residents and other activities around the site. At present, dust abatement is mainly done by water spraying. Since water spraying is not environmentally friendly, it becomes an economic and ecological challenge for companies. To enhance water saving, analysis of the mechanism of dust production is fundamental. This study aims to analyse the combined effects of traffic cycles and hydromechanical stresses on surface erosion and the modification of the microstructure of compacted soils. Roller compaction and traffic cycles were carried out in the laboratory on two soils composed by mixtures of Speswhite kaolin clay and Hostun sand, submitted to different hydric states and compaction degrees. Test results underline that the soil degradation under traffic cycles is governed by the compaction configuration. The grain size distribution of eroded particles features aggregates coarser than in the reference soil. Traffic cycles and compaction modify the soil microstructure. A decrease in the macropore size is measured for all the tested compaction configurations. However, combination of traffic cycles and drying presents a less significant effect on the decrease of the macro-pore sizes.