M25 Ship Lane Overbridge (between Junction 2 & 3) carries the M25 motorway over Ship Lane and was constructed in 1977.
An investigation carried out by WSP in early 2021 identified leakage through the joint in the middle of the bridge and extensive spalling around the joint area. It was recommended that the longitudinal and expansion joints were replaced, and a full deck waterproofing system be installed to prevent further leakage which was deemed to be the cause of the spalling concrete.
CRL was awarded the contract, valued at £104k, through Octavius Infrastructure Limited (formerly Osborne Infrastructure) for the works and moved onto site in early May. Due to the underpass having to be closed the works were programmed to run 24/7 for 11no. 12 hr shifts.
The repair process consisted of the removal of the defective concrete either side of the soffit expansion joint and abutment walls by hydrodemolition, the installation of CPT Patch Gard galvanic anodes within the patches and the reinstatement thereof, with Weber DS & RS spray.
The larger repairs either side of the soffit expansion joint were carried out in phases, and it was a requirement of the specification that the ribbed feature of the abutment walls was maintained necessitating the use of straight edge timbers to form the ribbed feature within the repair.
An investigation carried out by WSP in early 2021 identified leakage through the joint in the middle of the bridge and extensive spalling around the joint area. It was recommended that the longitudinal and expansion joints were replaced, and a full deck waterproofing system be installed to prevent further leakage which was deemed to be the cause of the spalling concrete.
CRL was awarded the contract, valued at £104k, through Octavius Infrastructure Limited (formerly Osborne Infrastructure) for the works and moved onto site in early May. Due to the underpass having to be closed the works were programmed to run 24/7 for 11no. 12 hr shifts.
The repair process consisted of the removal of the defective concrete either side of the soffit expansion joint and abutment walls by hydrodemolition, the installation of CPT Patch Gard galvanic anodes within the patches and the reinstatement thereof, with Weber DS & RS spray.
The larger repairs either side of the soffit expansion joint were carried out in phases, and it was a requirement of the specification that the ribbed feature of the abutment walls was maintained necessitating the use of straight edge timbers to form the ribbed feature within the repair.
M25 Ship Lane Underpass Repairs
Michael Balletta
06/06/22
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Ship Lane, Swanley passing under the M25
cc-by-sa/2.0 - © Marathon - geograph.org.uk/p/2762229
cc-by-sa/2.0 - © Marathon - geograph.org.uk/p/2762229