Sydney Trains: Recycled rubber geogrids for improved rail track performance

Challenge

Track ballast, typically made of crushed rocks, forms the bed on which railroad sleepers are laid. It acts as a load-bearing layer and facilitates water drainage and vegetation control. Spreading and degradation of the ballast, particularly along heavy haul corridors, causes tracks to deteriorate and require frequent and expensive maintenance. In NSW alone, the cost of maintenance for ballast-related work is estimated to be around $14-15 million per year.

Solution

The Transport Research Centre at UTS Tech Lab are investigating the use of rubber grids, made from end-of-life-tires, to improve the performance of ballast. Using a large-scale track simulation, in conjunction with advanced computational modelling based on Discrete (DEM) and Finite Element Modelling (FEM), the team are studying the effect of rubber to increase the energy absorption of the structural layer and reduce noise, vibration, ballast breakage and impact damage to track components.

The use of rubber mats will not only extend track maintenance cycles, it will promote the Australian recycling industry and provide an environmentally friendly way to breathe new life into old tires. The team’s research will also contribute to improved track design and the provision of new guidelines for Australian railways.