Benefits of the Tensar Solution
Reduction in sub-base layer thickness which comprised site won recycled crushed concrete from the existing carriageway to avoid the financial and environmental costs of imported fill.
The Tensar Solution
The pqc was broken out, removed and crushed to a DoT Type 1 grading and placed as sub-base over Tensar geocomposite SS30-G over the whole roadway.
Technical Project Description
The 4km long A19 Thirsk By-Pass was originally constructed in the early 1970’s using 250mm thick pqc jointed slabs. These had deteriorated significantly after 30 years in-service, particularly at the joints allowing significant water ingress and softening of the clay formation. The pqc was broken out and crushed on site to a DoT grading and re-used over the entire road width on top of a Tensar geocomposite consisting of Tensar SS30 geogrid factory bonded to a needle punched geotextile.
The geocomposite is placed geogrid side up so that the sub-base particles interlock with the grid structure and are mechanically stabilised. The geotextile component was used as a separator to prevent any upward migration of fines from the subgrade into the sub-base. The Tensar geocomposite was laid out by two operatives and installed with simple overlap joints.
The new road was of flexible pavement construction and surfaced with a thin polymer modified asphalt layer to reduce noise and spray.
