ABSTRACT
The performance of geogrid-polyurethane composite-stabilized ballast (CSB) was evaluated based on large-scale cyclic tests under high-frequency cyclic loading. In this scheme of ballast stabilization, a layer of geogrid is placed at the ballast-subballast interface, and the top 76 and 152 mm of ballast layer is treated with polyurethane. The test results indicated that the deformations of CSB samples were significantly reduced, and performance was enhanced when compared to that of unstabilized ballast (USB). From the ease of application and economical perspective, placing the geogrid at the ballast-subballast interface and treating the top 76mm of ballast with polyurethane is a feasible stabilization approach. Further, from an ease of application and performance point of view, placing the geogrid at the ballast-subballast interface and treating the top 152mm of ballast with polyurethane can be a viable alternative.
