Nene Bridge, constructed over the river Nene, is an award-winning structure. It is very much famous for its V-shaped piers. Located in the city of Peterborough, England, it is one of the major traffic routes. It connects and thus gives access to vehicles travelling from A1 to A47. The Nene bridge is a favourite way of cyclist and pedestrians going between the north and south of the city.
More than 40 years old, this bridge that carries A1139 Frank Perkins Parkway over the river Nene. The time and the weather have caused its damage to this beautiful structure. A recent inspection showed that there are cracking to the saddles of the pier and structural distress to the bearings. Because of its unique V-shaped piers, it was deemed difficult to execute replacement and reinforcement using the traditional methods. The absence of jacking points within the box girders is one of the reasons. Another one is that the architectural design did not allow positioning of jacks beneath the superstructure.
Presently the bridge is under extensive refurbishment work that is being carried out by Skanska. The work includes pier reinforcement and bearing replacement. They found a solution to the tricky situation. It was to encase the piers in reinforced concrete jackets This way the piers are strengthened and it also helps to provide jacking platform for the superstructure making it possible for bearing replacement.
But for this solution to work, it requires a concrete with self-compacting ability, so that it would flow around the congest steel reinforcement. It also has to be lightweight so as not to give additional load on the foundation. A strong concrete is required to strengthen the piers. It was Aggregate Industries which suggested the using Lytacrete – high strength and self-compacting concrete mix from Lytag. By using this, the unique V-shaped piers were able to maintain.
The refurbishment of the Nene bridge has proved that the industry is growing and is capable of meeting and overcoming the challenges in the way.