A guide for geosynthetics users
TMR MRTS58 is a technical specification relating to the requirements for subgrade reinforcement using pavement geosynthetics.
For contractors, it pays to be aware of the requirements of this specification to ensure that you comply with QLD Transport and Main Roads requirements on your projects.
What is the TMR MRTS58 Specification?
This specification lays out particular requirements for materials and construction methods for reinforcing subgrades when building pavements. It also identifies the conformance requirements for geogrids and geosynthetic fabrics that are used to strengthen the subgrade before paving.
The full specification can be found here, however, the main points are summarised below:
- Contractors need to document their intended construction processes and have them signed off by TMR before work begins.
- The geosynthetics selected need to perform well under testing, showing high strength and adequate interlocking capabilities under dynamic loads – this ‘proof’ needs to be provided by the contractor to TMR (your geosynthetics supplier can provide the necessary documentation). The test records must also be less than a year old.
- When TMR has approved the use of the selected geosynthetic and the construction process to be used, the contractor can take delivery of the material.
- If the project requires a total geosynthetic area of more than 5000 square metres, a site sampling test may need to be undertaken with a piece of the product at least 4m long. This is marked with large arrows showing the longitudinal and transverse directions, and subjected to various tests. The supplier details, date and batch identification details should also be marked on the sample.
- If the sample fails, it can be run once more, however, if it fails again the batch will be rejected. In any case, the TMR administrator must provide acceptance that the product is sound before it is installed.
- When ready for installation, contractors must follow the installation guidelines, which includes notes on subgrade preparation, the direction of the geogrid or geosynthetic material, minimum overlaps, fill thickness and compaction guidelines.
Do Polyfabrics products comply with TMR MRTS58?
Our most popular ranges of pavement geosynthetics are fully compliant with TMR requirements. This includes values that meet or exceed the necessary shear strength, UV resistance, tensile strength and more.
All Polyfabrics pavement geosynthetics are tested under ASTM guidelines in accredited laboratories, giving you peace of mind that you are getting a quality product that will perform in the field.
However, meeting the specification is only part of the overall requirement: understanding the approval process and ensuring your team installs the product correctly is key to a successful and compliant project.
For help and advice contact our expert engineering team for specific questions around TMR MRTS58.