The effect of geogrid reinforcement on unbound aggregates

Improvement of track, highway and runway unbound aggregate behaviour using geogrids is researched. Geogrid reinforcement into unbound aggregate in most cases will improve the performance of the unbound aggregate portion of a transportation support. Unfortunately, the optimal location and number of geogrid layers have not been established. Presented are experimental results for three different construction possibilities of geogrid reinforcement in the unbound aggregate layers. The aggregate layers were subject to both repeated loading and static loading. The advantages of the different construction methods are studied and field applications are discussed. Finally, conclusions are made regarding the optimal position of the geogrid reinforcement. (C) 2003 Elsevier Ltd. All rights reserved.