London Underground Limited
Bridge ES301 supports the A40 (Western Avenue) through Acton where it crosses the Central Underground Line.
The structure showed severe signs of distress due to inherent low cover and chlorides leaking through a poorly waterproofed deck.
The secondary reason behind the refurbishment was to improve the aesthetic appearance of the bridge.
The works first involved erection of a substantial crash deck over the underground lines. One stipulation from the client was that no water or debris should be allowed to fall onto the track areas, therefore the crash deck and access scaffold were required to be watertight.
Defective concrete was removed using hydrodemolition methods, and then reinstated with sprayed concrete. Following completion of the strengthening works the soffit area and up-stand, beams were coated with anti-carbonation coatings.
All works were undertaken during night time engineering hours and were subject to the comprehensive safety regulations as laid down by London Underground.
Makers Freyssinet protection staff, all suitably qualified to LUL’s approved standards, oversaw all works. The works were completed on time and within budget, to the satisfaction of the client.