Hydrodemolition works at Harrow Road, London

hydrodemolitionFreyssinet is currently carrying out works on Harrow Road, Paddington to remove the existing cathodic protection system. The works include hydrodemolition surface preparation, installation and commissioning of a new cathodic protection system, carried out in collaboration with Freyssinet in-house specialist companies Aquaforce Concrete Services Ltd and Corrosion Control Services Ltd. (CCSL).

The works are taking place next to a Canals and River Trust waterway on one side and a Grade II listed building to the other and in close proximity to public walkways. The adjacent scaffolding is directly over the UPS back-up power supply for Paddington Station. Operations have been meticulously planned by the Freyssinet team in order to avoid disruption to the public and local businesses, and to protect the surrounding rail and waterway environment.

Aquaforce carried out the complex hydrodemolition operation this April, using ultra-high water pressure jetting to remove the concrete and prepare the surface ahead of the installation of the new cathodic protection system.

Prior to the installation of the access scaffolding system, the deck of the works area was lined with sheeting to protect the paving slabs, topped with a high gauge lining membrane to create a water-tight bund. The entirety of the access system was then encapsulated with additional sheeting, with the hydrodemolition taking place inside an encapsulated pier. This system effectively prevented the escape of any hydrodemolition arisings and also contained noise.

The control of waste water has been managed jointly by Principal Contractor FM Conway and Freyssinet. A waste water route was created utilising a conventional domestic drainage system, directing water from the highest access point, to the project water treatment area located 60 metres from the works area. The water was manually pumped from the lowest point within the bund to the entry of the water route, and left to flow naturally down the route to the waste water treatment point. All waste water was pH balanced following the operation and discharged locally in accordance with the Principal Contractors discharge consent.

Operatives accessed the works via an arial walkway, avoiding the use of pedestrian areas, and carried out the hydrodem without any disturbance to the public

The success of the operations has been due to effective collaboration, carefully planned operations and Freyssinet’s exemplary QSE procedures. FM Conway provided the scaffold (by Alltask Scaffolding), the scaffold layout and planning of the works has been by Freyssinet Site Manager Dan Harkin and the Freyssinet site team, with Works Manager Martin Coughlan and Aquaforce executing the works.

View video footage of Harrow Road pier encapsulation here.