Tracktex Formation Treatment
For new track where sub-grade erosion is anticipated, or at renewal time where sub-grade erosion has caused premature failure.
Tracktex is a micro-porous filter sandwiched between two geotextile protectors which, when deployed at the base of ballast, prevents rain water penetrating through to the underlying formation but allows upward movement of water whilst filtering any fine soil particles.
This innovative material is lightweight & can be installed in a fraction of the time needed for a sand blanket.
Tracktex composite is the subject of Network Rail Certificate of Acceptance 0504238. View the Certificate in PDF format.
The result of 10 years' pioneering research using a full-size rig
After having built a full-sized rig & established the conditions for sub-grade erosion - 1M cycles - the same conditions were used to evaluate potential solutions. The most-successful composite, a micro-porous filter sandwiched between two geotextile protectors, sustained 10M cycles (the equivalent of 140 gross tonnes) without damage or ballast contamination.
Tracktex Features
- Pore water is relieved upwards through the composite under the cyclic loading
- Rainfall cannot penetrate the micro-porous filter & is drained laterally to the sides of the track
- Any residual slurry becomes desiccated as any pore water is dissipated
- Conforms to surface depressions in the formation preventing the formation of slurry pockets
- Faster installation rates can be used to reduce the likelihood of overruns or increase the coverage for a given possession time
- No requirement for specialist plant
- Geogrids can be placed immediately on top of the composite
- Predicted durability of greater than 100 years in soils with pH in the range 1.5 to 12.2
- UKAS-accredited lab tested
- The compact 25m & 50m long rolls (3.5m & 3.9m wide) mean that difficult-to-access track becomes an easier proposition to manage
Environmental Benefits
The use of a Tracktex composite reduces the depth of excavation that would be required with a sand blanket. This has the effect of reducing the number of vehicles required to deliver materials & decreasing the amount of spoil being taken away for landfill.
0.5m wide overlaps should be formed, when necessary, to maintain the filter by peeling back textile & interleaving as shown. Double-sided tape is provided to form joints.
The composite should be covered with a minimum of 150mm ballast prior to tracking with lightweight plant.
UK Sales: contact Aqua Geocomposites www.aquafab.co.uk
Sales outside the UK: contact GEOfabrics Limited
The TRACKTEX composite is the subject of International (PCT) Patent Application No. PCT/GB2010/050779.