THE PROBLEM
Approximately 8,500m² of an existing military airfield consisting of 3m x 3m pavement quality concrete (PQC) slabs overlaid by a 100mm thick blacktop surfacing layer which had suffered extensive reflective cracking over a number of years mainly due to thermal stresses. A long term solution was required for the airfield, which is used primarily by Chinook helicopters and sited over a sensitive grade 1 aquifer.
THE SOLUTION
Tensar Glasstex® was chosen not only as a means of inhibiting reflective cracking but also because the fabric component of the composite when impregnated with bitumen, provides an additional barrier against potential contamination of the underlying aquifer from any fuel spillages. The existing cracked blacktop was milled off, a straight run bitumen spray applied and Tensar Glasstex installed by specialist machine on to the milled surface. The Glasstex was covered with a 60mm thick stone mastic asphalt (SMA) binder followed by a 40mm thick hot rolled asphalt (HRA) surfacing with a slurry binder to enhance fuel resistance.
PROJECT DESCRIPTION
The existing asphaltic overlay had undergone extensive reflective cracking from the joints between the PQC slabs below. A new asphaltic overlay was required which would have a high resistance to the thermally induced reflective cracking stresses and also provide a barrier to any fuel spillages so minimising the risk of contamination of the underlying grade 1 aquifer.
