Major repair work will begin on a crumbling section of Spaghetti junction on Monday.
The Highways Agency will remove the temporary support which has propped up a section of the iconic motorway since December 2007.
The Agency admitted three years ago that part of the ‘underbelly’ was crumbling and was monitored 24 hours a day by engineers on hydraulic platforms. The work, on the underside of the slip road onto the Aston Expressway from the M6 northbound carriageway, will cost £2.7 million.
The temporary support will be replaced with a concrete column and the work has been described as “vital” in keeping Birmingham’s iconic motorway junction in a safe condition.
As well as the new concrete column, the work, which will be completed by September 2011, will include repairs to a joint between two parts of the bridge deck on the underside of the structure.
Traffic on the M6 will not be affected by the works, which will mainly take place during daytime hours.
The work is in addition to ongoing preventative maintenance work on Spaghetti Junction to repair concrete beams, replace damaged concrete and repair corroded reinforcement.
A cathodic protection system is being installed on both sets of work to prevent future corrosion of reinforcement bars caused by road salt.
Matthew Taylor, project sponsor at the Highways Agency, said: “These works will help keep Spaghetti Junction operating both safely and reliably for years to come.
“We shall remove the metal temporary prop that is currently in place and replace it with a new concrete column.
“By doing this work now we will help prevent more costly works in the future.
“The construction works may be noisy for the first few weeks as we have to undertake piling work. We are in the process of notifying local residents and apologise in advance for any disturbance.”
Spaghetti Junction was opened in 1972 and now carries more than 160,000 vehicles a day.
*There will be occasional night time and weekend closures to complete major construction works. There will also be occasional night time closures on the link roads between the Aston Expressway and the A38 Tyburn Road and A4127 Lichfield, as they are immediately adjacent to the affected link road. Well signed diversion routes will be in place where needed.