What is bridge deck waterproofing and why is it crucial?
Services: Bridge Deck Waterproofing & Anti Skid Applications
What is bridge deck waterproofing?
Bridge deck waterproofing is a system applied to the bridge deck to minimise the risk of deterioration of the surface.
Specialist coatings are applied to the entire upper surface of the bridge deck between parapet upstands, including footways and central reserves, verges, service bays and under kerbs, acting as a barrier against water infiltration and chemical damage.
Benefits of bridge deck waterproofing
Bridge deck waterproofing is crucial to preserving the structural integrity and safety of the users.
Implementing a PWS (Permitted Waterproofing System), is an essential part of any bridge construction or refurbishment, to prevent ingress of water along with chemicals. When moisture or chemicals such as de-icing products and oils from vehicles, permeate the bridge deck, this leads to deterioration of the surface and even corrosion of the structural steel framework.
Preventing long-term damage to the surface and more importantly, the structure of the bridge is paramount to extending its lifespan.
Waterproofing systems are typically combined with additional surfacing layers, such as anti-skid coatings, to further enhance the bridge’s surface traction and safety for users.
Applying a bridge deck waterproof system
Waterproofing a bridge deck is a multi-step process, involving surface preparation/priming and the application of a special coating.
- Surface preparation and priming
The bridge surface is inspected, to determine the best system for the bridge’s characteristics. Varying factors such as traffic load, the surrounding environment and the bridge deck material, will be considered when selecting the appropriate system. The bridge deck will then be thoroughly cleaned and prepared to remove dirt and debris. In an instance where a waterproofing system is being replaced, captive blasting will need to be undertaken to remove the existing coating and provide a key for the new coating to be applied. Once the surface has been prepared a primer is then applied, to penetrate the concrete or seal the metal substrate for a permanent bond.
- Applying the Waterproof membrane
The application typically involves a polyurethane system such as Bimagrip®, based on a polyurethane primer, a fast-cure polyurethane adhesive compound and an aggregate. This rapid-curing product is resistant to oil, fuels and the corrosive effects of water and frost-thaw cycles.
- Surfacing and APL (Additional Protective Layers)
Once the waterproof system has been applied it is overlaid with asphalt, to shield it from UV radiation and wear and tear from traffic. Additional protective layers may be incorporated within this, to enhance friction and improve safety.
Bridge deck waterproofing contractors
Waterproofing should only be installed by competent bridge deck waterproofing contractors, approved by a system certificate holder. The system should have a BPA HAPAS certificate, conforming to compliance with requirements defined by a specialist group*.
WJ Industrial have been protecting highway and network rail bridges for decades. Our experience Includes projects such as the Great Yarmouth Third River Crossing, a double-leaf bascule bridge which carries 1,200 vehicles each day during peak hours.
Are you looking for a bridge deck waterproofing contractor? Contact us today to discuss your project.
*Specialist group 7: Association of Consulting Engineers (ACE), Bridge Deck Waterproofing Association (BWA), British Board of Agrément (BBA), ADEPT (Association of Directors of Environment, Economy, Planning and Development), The Highways Agency (HA) – also representing other overseeing organisations.