Our aviation infrastructure division has pioneered the use of cold-in-place recycling (CIR) for runway rehabilitation, delivering a 35% reduction in project duration at Philadelphia International Airport. The method also reduces material waste by over 60%, making it our most sustainable paving solution to date.
What is Cold-In-Place Recycling?
Cold-in-place recycling is a pavement rehabilitation technique in which the existing asphalt surface is milled, mixed with recycling agents and new binder on-site, and immediately re-laid as a renewed base course — all in a single continuous operation. Unlike traditional methods that require removing, transporting, and replacing material, CIR recycles up to 95% of the existing pavement in place.
The process uses a self-propelled recycling train that can process up to 500 metres of runway per shift, significantly outpacing conventional mill-and-fill operations. The reduction in vehicle movements alone eliminates thousands of truck journeys per project, cutting carbon emissions and disruption to airport operations.
Application at Philadelphia International Airport
Our CIR technique was deployed on a 2.8km rehabilitation of Runway 27R at Philadelphia International Airport — one of the busiest runways. The rehabilitation window was restricted to a 90-day summer maintenance period, with the runway needing to return to service by September 1, 2024.
Using CIR, our team completed the base course rehabilitation in 53 days — 32 days ahead of schedule — leaving ample time for the asphalt wearing course and line marking to be completed. The runway passed FAA compliance testing on first inspection with no remedial works required.
Sustainability Impact
The Philadelphia project diverted an estimated 1,800 tonnes of asphalt from landfill and eliminated over 2,400 heavy vehicle movements. CO₂ equivalent emissions were reduced by 38% compared to our baseline traditional resurfacing methodology. Wexmoor Builders is now certifying CIR as a standard methodology for all future runway rehabilitation contracts.
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