The A303 River Avon Bridge near Amesbury, Wiltshire, is a critical highway structure within the National Highways network, spanning the River Avon through a designated Site of Special Scientific Interest. Constructed to accommodate significant traffic volumes, the bridge required refurbishment to address deteriorated pot bearings and associated concrete defects.
Concrete Repairs Ltd was appointed as principal contractor to deliver a 21-week programme of bearing replacement and concrete repairs, commencing in October and delivered within a £387,058 contract value. The works were essential to maintain structural integrity, manage long-term asset performance, and ensure continued safe operation while carefully protecting the environmentally sensitive surroundings.
Services Undertaken
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Replacement of 44 bridge pot bearings
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Concrete breakout using hydrodemolition
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Installation of new reinforcement to bearing shelves
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Reprofiling of bearing shelves
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Installation of hydraulic jacks and lateral restraints
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Structural monitoring using LVDT gauges
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Flowable concrete and epoxy grout bearing installation
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Suspended scaffold access over river
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Traffic management and environmental protection measures
The project centred on the replacement of 44 deteriorated pot bearings, primarily on the west side of the bridge, alongside targeted concrete repairs to bearing shelves and associated elements. Given the sensitive SSSI location and restricted access over the River Avon, CRL developed a detailed engineering methodology underpinned by extensive planning and early design input. Suspended scaffolding systems were installed to provide safe access beneath the structure, minimising environmental disturbance while enabling efficient working.
Hydrodemolition was selected to remove defective concrete accurately while preserving sound substrates and existing reinforcement. This approach supported the installation of new reinforcement and ensured high-quality interfaces for reinstatement works. Bearing shelves were reprofiled before the installation of hydraulic jacks and lateral restraints, allowing controlled lifting and precise management of differential movements during bearing replacement. Continuous monitoring using LVDT gauges recorded hydraulic forces and movements in real time, ensuring structural stability throughout the jacking process.
New bearings were installed with a high degree of accuracy using flowable concrete and epoxy grout to achieve full bearing contact and long-term performance. Works were delivered under carefully coordinated traffic management arrangements, maintaining network operation while protecting workforce safety. On-site delivery was supported by rigorous health and safety oversight, including senior safety advisors and independent consultants. Close collaboration between CRL, National Highways, FM Conway, and Volker Laser ensured that specialist activities were seamlessly integrated, risks were managed effectively, and environmental controls were maintained at all times.
Beyond the immediate replacement of bearings and concrete repairs, the project delivered lasting asset management benefits for a vital section of the strategic road network. The renewed bearings restore structural functionality, accommodate thermal movements, and significantly extend the bridge’s service life, reducing future maintenance interventions. Careful surface preparation, precision installation, and robust reinstatement measures underpin improved durability and resilience in a challenging environment.
CRL’s phased planning and disciplined delivery enabled works to be completed on programme and within budget, while safeguarding the SSSI and maintaining traffic flow. The project demonstrates CRL’s capability to deliver complex structural repairs UK-wide, combining technical expertise, environmental stewardship, and collaborative working. The outcome provides National Highways with a strengthened asset, improved operational continuity, and confidence in long-term performance through proactive, sustainable infrastructure management.
