PERHAPS BECAUSE Gatwick's concrete wave wall blends so well into its environment the report of its high commendation in the small project category was missed out of last week's supplement on the British Construction Industry Awards.
The wall is an attractive, space saving and economical solution to the old problem of containing aircraft noise - normally a job for ugly structures. But at Gatwick, BAA commissioned a sound attenuation barrier that sets an entirely new standard.
The airport operator began with a design competition giving the basic dimensions of the barrier needed to fulfil conditions of a planning approval for additional aircraft stands. The specification was for an 11m high wall 450m long, tight up against a road.
Coming up with the winning design, Anthony Hunt Associates proposed a sinusoidal wall of 10m wavelength built with massive precast concrete units stressed down to a piled foundation. Inherent stability against jet blast and wind forces derives from the plan shape; joints between the units are featured to give interest and scale; while grey granite aggregate and sparkling sand give an attractive finish when grit blasted.
Main contractor was Gatwick Airport Pavement Team. During design development precast concrete manufacturer Buchan refined the concept to a working scheme, reducing the volume of concrete by 10% and making each units 12t to suit trucks delivering them just in time for erection.
Stacked eight high to form the wall, the match cast units only required normal reinforcing bars cast into vertical ducts to link them together rather than prestressing. Cost savings on the wall itself enabled it to be produced for pounds 1.25M against the original budget of pounds 1.6M.