project: Gatwick Airport MSCP Refurbishment

client: BAA London Gatwick Airport
location:
 London
duration: 16 months
value: £4,100,000

scope of works:

Extensive concrete repairs
Installation of Impressed
Current Cathodic Protection (ICCP) system
Application of anti-carbonation coating
Application of an anti-slip waterproof surface coating
Replacement vehicle and pedestrian barriers
New lighting installation

CRL completed a total and in-depth structural restoration and upgrade to the main Gatwick car parks outside the South Terminal, the second largest airport in the UK. As a result, the parking environment has become light and easy-to-negotiate which ensures swift and safe passage from entry, to parking and then into the Airport Terminal itself. The car park is a critical part of the airport infrastructure so before work fully commenced on site the survey division, CRL Surveys, undertook a detailed investigation of the car park and assisted in the preparation of the specification and scope of works. Then a full scale trial was undertaken to demonstrate the method of repair and quality control procedures prior to the main contract.

All vehicle / pedestrian barriers were replaced and to further enhance safety, over 21,000m² of anti-slip waterproof deck coatings were applied to all the deck surfaces including the colour-coded drive aisles, parking and disabled bays, pedestrian walkways and luggage trolley points. A further 250m² of anti-slip deck coating was applied in the escape stairwells.

The original lightweight decking (only 70 mm thick) required precise concrete repair and extensive temporary propping from two floors below the deck being worked on. Hydrodemolition was used to remove the defective areas of concrete and the waste water was collected, cleaned using a siltbuster unit and reused to minimize water consumption and waste.

Wherever the chloride content and half cell potential plots indicated significant risk of corrosion activity, a combined ICCP system consisting of conductive anode paint applied to the slab soffits, and titanium ribbon anode buried in chases in the main insitu beams were installed to stop further corrosion of the embedded reinforcing steel and extend the life of the structure. Approx 8000m² of the car parks deck surface is now protected by the ICCP system. Around 1500m² of spalling and cracked concrete in the deck surfaces were replaced.