摘要: |
Railways are an important component of multi-modal freight transport that present great potential for expansion. Specific problem areas include increasing railway car tonnages, speed limitations due to poor track conditions, and other freight transportation logistic bottlenecks. Ever increasing volume, tonnage, and speeds on our nation's rail system are stressing rail substructure to levels never before evaluated or considered in depth. Ballast is a crucial material for structural support of rail tracks and trains and provides fast drainage during precipitation. The structural integrity of seriously fouled ballast (i.e., containing fine particles) and problematic railway elements (i.e., bolted rail joints, intersections, bridge approaches, etc.) can be compromised leading to track instability and ultimately, train derailments. Because of this serious consequence, costly maintenance activities, such as ballast maintenance and track reconstruction, are routinely performed by railroads, especially on tracks serving the heavy axle loads. Despite numerous advancements in maintenance technology within the rail industry, railroads annually invest billions of dollars in maintenance activities. Because demand for railway freight transportation is increasing and sustainability is now entrenched in our public consciousness, new cost-effective methods must be adopted. An application of polyurethane void filling and particle bonding technology has been developed and has shown the promise to mitigate impacts of ballast fouling and to enhance rail freight capacity in new clean ballast. However, its effectiveness in remediating already fouled ballast has not been explored. Further development of this technology into already fouled ballast has significant potential to transform track-substructure maintenance activities and efficiencies. |