Concrete Repair & Cathodic Protection – M1 Aerodrome Road Bridge, London

hydrodemolitionHydrodemolition Concrete Repair & Cathodic Protection

Highways Agency

HA Area 5 Manager
Connect Plus

Principle Contractor
Jackson Civil Engineering

Consulting Engineer


Works Commenced
June 2011

Works Completed
September 2011

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Freyssinet was appointed by Jackson Civil Engineering to complete concrete repair and minor cathodic protection works on the bridge which carries the M1 motorway over Aerodrome Road in Barnet, London.

The maintenance work was contracted by Connect Plus, area managers for the Highways Agency, in order to ensure the continued safety of the bridge and reduce the need for emergency repair work in the future.

The works were carried out to the under bridge section of Aerodrome Road Bridge, following a design and method of work set by Atkins.

The existing defective concrete was broken out utilising high pressure water jetting, by Freyssinet’s in-house hydrodemolition team . In comparison to conventional methods of removing concrete, such as by jack hammer, hydrodemolition has a number of benefits, such as no cracking in the structure, no damage to reinforcing steel, dust and debris is eliminated and the potential for hand arm vibration is removed. Following hydrodemolition, surfaces are ideally prepared for new concrete.

A total of 25m3 of defective concrete was removed from the structure. A galvanic anode cathodic protection system was then installed to prevent corrosion to the exposed reinforcement steel within the repair areas.

Concrete was then reinstated by two methods. Areas requiring a plain concrete finish were reinstated by sprayed concrete application and flowable concrete repair techniques were used in areas requiring a profiled finish. Pressure pumping utilising specialised plant and equipment and gravity feed methods were applied.

The works were completed on schedule and within budget, to the satisfaction of both Jackson Civil Engineering and Connect Plus.