The airport, home to the country's first powered flight in 1908, hosts the famous Farnborough International Airshow but its main function is as a business aviation dedicated airport. The Farnborough service centre will be executive jet manufacturer Gulfstream Aerospace Corporation's largest international facility.

Our works were carried out in two visits, both 'airside' adjacent to existing taxiways. During the first visit the footprint of the 220,000sq.ft three bay hangar was stabilised to achieve the required 15% CBR using a lime/cement mix. This turned out to be the more straight forward part of the project. The second visit envisaged the reuse of stockpiled tarmac from previous taxiway removal for the new 275,000sq.ft apron to the front of the facility.

It was discovered however that coal tar was present in the stored material. A HBM (Hydraulically Bound Mixture) in accordance with Series 800 of the Manual of Contract Documents for Highway Works Specification for Highways Works was proposed to encapsulate the coal tar. We carried out leachate testing which proved the mix for use on the project and meant that an Environment Agency environmental permit was not required. It also meant that the material did not need to be removed as a hazardous waste resulting in a significant cost saving. The laying of the apron slab directly onto the stabilised layer further added to savings as subbase was not required.