Runway Resurfacing, RAF Odiham
FM Conway’s A&A division worked with Toppesfield to design and supply a porous asphalt surface course for a runway at RAF Odiham.
Services used on this project
Aggregates & Asphalt
Delivering Innovation
FM Conway received an interesting request from their colleagues at Toppesfield: to design and supply a porous asphalt surface course for a runway on an RAF base. Traditionally, runways in the UK are surfaced using dense mix Marshall Asphalt or the French BBA standard, so porous asphalt is an unusual choice.
Porous asphalt is much better at minimising standing water due to its open structure that enables rainwater to flow into the pavement structure and then be released into the ground. It usually includes a relatively soft bitumen, making it susceptible to rutting and fretting. However, the softer bitumen prevents reflective cracking.
FM Conway initially created a mix that included a soft penetration bitumen to meet the Defence Infrastructure Organisation (DIO) specification. Then, working with the Technology Centre, the team developed an alternative mix that still had an open structure but included the company’s own high-quality polymer modified binder to stop the asphalt rutting and fretting whilst also minimising reflective cracking.
FM Conway spent 5 months developing and testing the mix now known as SurePol HD.
“Porous asphalt is not usually the first choice for longevity, but in this case, they were looking for longevity and to reduce standing water,” explains FM Conway development director Tim Metcalf.
Challenges and Solutions
What set us aside from competitors was our ability to dedicate the Theale asphalt plant solely to producing the new mix for the contract.
FM Conway development director, Tim Metcalf, explained: “You have to set up the plant, calibrate it and then run it continually for this type of material. It demands a high standard of quality control, and the best way to get that is not to run different materials through the plant.”
Once the plant was up and running, it produced up to 600t of asphalt a day, delivering over 8,500t to the site in total to be laid to a thickness of 40mm.
Outcomes
Working with Toppesfield and the Defence Infrastructure Organisation, FM Conway designed and supplied a unique porous asphalt mix which met DIO specification, preventing rutting and fretting whilst minimising reflective cracking.
Toppesfield contracts director (south) Steve Whittingham describes the project as “an excellent demonstration of collaboration between Toppesfield, our client and supply chain partners” and says it was “a fantastic effort from everyone involved.” He adds “Using FM Conway’s SurePol HD material, we have been able to offer our client asset resilience.”