Geosynthetic Reinforcement of the Base Course Layer of Flexible Pavements

To provide a design methodology for use by pavement engineers for the design of flexible pavements using suitable geosynthetics as a reinforcement member contained in the base course layer.

The Montana Department of Transportation (MDT) faces conditions in the eastern portion of the state where quality gravel sources for road construction are scarce and associated haul costs of such material are high. Subgrade conditions in this region consists of A-6 to A-7 soils, resulting in relatively low subgrade support values and relatively thick base course sections. Faced with these conditions, MDT has been interested in investigating the possible use of geosynthetics as reinforcement in the base course layer. MDT is mainly interested in the use of geosynthetics as a reinforcement material for the purpose of reducing the design thickness of the base course aggregate layer. The intention of the project is to provide a design tool that is sufficiently general to allow for this and other performance benefits to be analyzed. Other benefits include the increased traffic life of reinforced sections with a base course thickness that has not been reduced from the unreinforced thickness or partially reduced from this original thickness.