Repairs to the Kyle Tongue Bridge, which carries the A383 road along the north coast, are almost complete. The bridge has suffered significant concrete deterioration since it was built in 1971 and will be fully repaired and restored under the project, which is expected to be completed this winter.
Concrete Repairs Ltd. are carrying out the project for The Highland Council and Aecom are the designers.
The £1.2m project began in June 2011 and has comprised the concrete repair of reinforced concrete pier corossheads and prestressed concrete beams. In addition, the road has been resurfaced and the bridge parapets replaced. The requirement for parapets on this type of all-purpose ‘A’ road is to withstand impact from a vehicle weight of 1.5 tonnes, travelling at 50mph at an angle of impact of 20 degrees. The steel piles that support the structure above the sea have also been cleaned and repainted.
The renewal of the bridge deck waterproofing system is a critical part of the project. In order to minimise the time required to apply the system, which is weather sensitive and spray-applied, the contractor proposed a temporary full closure of the A838 road. Although a short term inconvenience to the travelling public, it had the benefit of saving a significant period (possibly several weeks) of single way traffic operation at the site.
Interesting aspects of the project include the cathodic protection of the prestressed concrete beams and reinforced concrete pile caps and the refurbishment of the existing sacrificial anode cathodic protection system to the piles.
David MacKenzie from The Highland Council said: “It was quite a challenging project as we were working in a very exposed location. The 180m long, 18 span structure is over an arm of the sea and therefore the weather was a constant challenge. In addition, it is the only route along the north coast that can carry heavy vehicles; subsequently, it was critical to get the traffic management correct during the construction.
“The works are currently on programme, and the main contractor has done an excellent job. We have managed to build up a good relationship with the contractor and the engineer for the project, along with good communication and relationships with the local community and the travelling public.”