Drift och underhåll av grusvägar- Tillståndsbedömning samt analys av bärförmåga och grusslitlager

Sammanfattning: An extensive part of the road network in Sweden still consists of gravel roads, but operation and maintenance of these roads is complex due to the Swedish climate and the low traffic volume. This report further examines how operation and maintenance of gravel roads is executed and how it can be done in a cost effective way. In order to do so, the report contains both a literature study and a field study. The literature study provides essential information about different operation and maintenance methods, the deterioration process of a road construction, different types of damages on gravel roads and different ways of performing condition classifications. The field study of this report was carried out in the area of Bjäre-Åsbo, Skåne County. Visual condition classifications and measurements of the bearing capacity were carried out for chosen gravel roads in this area along with analysis of the surface course’s grain size distribution and organic content. Results from this report show that water has a huge impact on the condition of a gravel road, both in terms of the surface condition and the bearing capacity. Results also stress the importance of an appropriate grain size distribution and thickness of the surface course. By ensuring that the road also has an adequate crossing gradient, operation and maintenance costs can be reduced. Furthermore, execution of edge cutting and gravel recycling seems to improve the grain size distribution of the surface course but also to slightly increase its organic content.