A1 Eaton Socon Bypass renewal
Facts and figures
- Client: Highways Agency
- Value: £6,765,000
The A1 Eaton Socon Bypass stretches between the A428 Wyboston Junction and Hail Bridge, near St Neots.
Interserve's works involved full and part depth repairs to the existing concrete pavement construction and a bituminous overlay comprising a geogrid system and polymer modified bituminous materials. We also completed associated works to safety barrier, kerbing, gullies, repairs to the existing drainage, new safety barrier at structures and traffic signs.
In order to keep traffic disruption to a minimum, we undertook all works during mid-week lane closures and part-weekend closures.
Due to the nature of the site, which has dual, two lanes with no hard shoulders, installing contra flows was not a viable option. This ruled out full depth reconstruction, crack and seat of the concrete or very thick overlays, which would have involved lengthy possessions. Our solution was to leave most of the concrete in place and cover the carriageways with a coated glass fibre grid reinforcement embedded within very high strength asphalt during weekend work. The asphalt specified is bound with polymer modified bitumen (PMB), providing modified bitumen (PMB), providing flexibility, to allow – on conjunction with the glass fibre mesh a structural overlay of only 110mm thickness. This meant the contract could be carried out in just 16 weekends with comparatively little disruption to traffic.
Post Project Review Agreement concluded that the scheme had been challenging but a good team effort had overcome the technical issues and limited the impact of the weekend closures on the travelling public.
Despite one of the worst winters of rain and snow in years, Interserve completed the surfacing works prior to Christmas.
Over 40,000 man-hours were worked all at night and weekend possessions during full closures of the A1 with no reportable accidents
Sustainability in action
Interserve took special care to ensure that no environmental spillages or other environmental incidents took place 5,360 tonnes of site-generated, un-reinforced concrete was reused as Type 1 granular sub-base. 170 tonnes of old steel safety barriers, 3,040 tonnes of road planings and 85 per cent of 3,240 tonnes of bulk soil / rock were recycled.