A2 Bexley Interchange
Bearing Replacement Scheme
As part of Carillion supply chain, Topbond were asked to provide early contactor involvement (ECI) for a scheme to replace the bearings of 3 bridges on the A2.
Due to the high volume of traffic on the bridges, the client was concerned about the possible impact on traffic during the works and Topbond were asked to offer an alternative scheme. Topbond's proposals, which were discussed with Carillion and Mouchel, allowed for the existing bearings to remaining insitu whilst the replacement bearing were installed between the existing bearings. Consequently the works could be undertaken without a suspension of traffic flows.
Pocket of the concrete abutment were broken out between the existing bearing locations. Topbond used high pressure water jetting (HPWJ) techniques to remove the concrete due to the speed, safety and to minimise damage to the adjacent concrete. Once the pocket had been broken out the reinforcement was cut out to provide a working space.
The soffit of the bridge was lightly broken out to confirm the position of the existing deck reinforcement, and once identified, the soffit was drilled and new fixings installed to secure the bearings.
After the bearings had been positioned new reinforcement was installed in the pockets and butt welded to the existing. The front of the void was then shuttered and a flowable concrete pumped into the voided areas.
The bearings were levelled and the voided areas above and below grouted up.
Once the new bearings were secured in position the existing bearings were removed using HPWJ to remove the concrete around the bearings and gas cutting to remove the fixings.
Topbond worked on all 3 bridges concurrently and works were completed on time and to budget.