Tensar® InterAx® stabilises platform for a popular food outlet

The contractor faced major groundwater issues in a very weak clay subgrade, at depths of over 1.5m. Subgrade CBRs were as low as 1.5%. They needed to stabilise this subgrade quickly to continue construction and minimise costs and delays. The removal of redundant underground fuel tanks posed further complications during construction.

Two layers of Tensar® InterAx® geogrids were incorporated to form a mechanically stabilised layer, providing a stabilised construction platform and improved pavement foundation for the rigid pavement. The upper portion of the second geogrid layer (120-170mm) served as the subbase for the concrete pavement. A lower-quality sub-base material (TMR Type 3.4) was used between the two InterAx layers, proving that Tensar geogrids don’t always require high-quality crushed rock for effective stabilisation. This delivered additional cost savings. Instead of waiting days for the subgrade to dry out, the contractor stabilised the platform quickly, achieving considerable time savings in both site remediation (including reinstatement of the fuel tank area) and construction of the permanent concrete pavement.