An innovative surface treatment approach by Foster Contracting Limited has been developed for use on a £745million roads project in Aberdeen, Scotland. The specialist contractor, Foster Contracting Limited (FCL), has played a key role in a major project, to build the Aberdeen Western Peripheral Route/Balmedie-Tipperty (AWPR/B-T).
AWPR Construction Joint Venture, the contractor appointed to design and construct the project, approached FCL to provide a customised treatment to remove the latency from the slipform concrete pavement that makes up the main carriageway of the new road.
Through its in-house research and development capability, two machines, a 40tonne eight-wheeler and a 70tonne ‘road train’ respectively, were reconfigured to meet the client’s requirements for the project. Successful trials were carried out in late 2016, which passed all the necessary criteria for adhesion between the interfaces. Between June 2017 and May 2018, FCL then treated 58km of new dual carriageway in each direction before 460,000litres of bond coat was applied to treated carriageway, 90,000tonnes of thin surface course paved, and over 300km of white lines sprayed on the AWPR/B-T mainline with no disruption to other works.
Utilising its new runway rubber removal machines, equipped with multi-sapphire nozzle cleaning heads, FCL was able to remove concrete latency at speeds of up to 800m2/hour while both machines operated at high pressure with full vacuum recovery.
One key element of the project was to ensure environmental compliance and 26,000litres/day of waste water used during the operation was removed by vacuum tanker for specialist disposal.
Sean Gibb, Manager at FCL North, stated: “The AWPR/B-T was on a different scale to anything that we have undertaken as a company before. Whilst we have significant experience of major civil engineering works, such as motorways and runways, the size and complexity of this project was on a different level.
The AWPR/B-T will help to reduce congestion, cut journey times, improve safety and lower pollution in Aberdeen city centre. Over the next three decades, it is expected to bring an additional £6 billion to the local economy and create around 14,000 new jobs.
Tracing its origins to the 1890s as the Essex Steam Rolling Association, the services now offered by FCL include the supply and installation of geosynthetics for asphalt reinforcement, removal of rubber deposits from runways, road retexturing, bond coat spraying and surface dressing.
FCL has installed anti-crack geosynthetics on numerous sites including the recent M3 Smart Motorway scheme between junctions 2 and 4A and the Military Road through Glencoe, parallel to the A83 and the “Rest and Be Thankful”.
