Crumlin Bridge, South Wales, UK
New third-generation Bond Coat provides high performance adhesion combined with durability
The Crumlin Bridge was leaking with corrosion evident in the structure. It required a new waterproofing solution as part of the refurbishment works to the bridge, not only this, but due to the schedule of works it required a solution which would enable the tack coat to be trafficked prior to laying the asphalt.
The bridge became another structure to benefit from Stirling Lloyd’s 3rd-generation bond coat in conjunction with its market leading Eliminator waterproofing system. The development of Bond Coat 3 represents a major leap forward in the provision of high-performance; heatactivated bond coats.
Caerphilly County Borough Council
- Crumlin Bridge, South Wales
Stirling Lloyd Polychem understands the parameters a Main Contractor is faced with when working on site. Factors such as possession working, limited access, restricted working hours, and traffic management all need to be considered.
Due to not having a full road closure on this site, it meant that the refurbishment works had to be split into two phases over a short period of time with one section of the carriageway being completed first before moving on to the second section.
This included deck preparation, installation of expansion joints, application of the waterproofing system, and the installation of kerbs followed by the asphalt binder and surfacing courses. Eliminator’s unparalleled track record and rapid cure times made it an easy decision when specifying a waterproofing solution for the Crumlin Bridge refurbishments.
The kerbs were scheduled to be installed after the waterproofing system had been applied by Metrail, this meant the area would be subject to heavy on-site traffic. With this in mind, it made it an ideal opportunity for Stirling Lloyd to propose its 3rd generation Bond Coat, the option of using the newly developed Bond Coat provides a number of significant advantages.
Bond Coat 3 is a cold reactive resin system that can be roller or sprayapplied using the same application equipment that is employed to apply the primer and Eliminator membrane. The new Bond Coat cures to provide a hard tack-free protective finish that is resistant to contamination and damage from site traffic, and completely eliminates the risk of tyre pick-up.
Bond Coat 3 reacts with the lower temperature asphalt mixes that are in widespread use today, having an activation temperature of just 90°C, although to give a factor of safety, a minimum asphalt placement temperature of 130°C is usually recommended.
Dyer and Butler, having been presented with these features decided to move forward with Bond Coat 3, not only for its impressive resistance and durability, but for its high adhesion between the waterproofing membrane and asphalt course that will provide their client with tong-term performance.
Prior to application, shot blasting and fine milling was carried out, with Metaset Resifilla being used to repair rough and damaged areas of the bridge deck in preparation to receive the waterproofing system.
A primer was then applied to seal the bridge deck, also maximising the adhesion of the subsequent membrane to the structure. The Eliminator membrane was then spray-applied and checked using a wet film gauge to confirm the required coverage and thickness had been achieved.
Watch the video below to see the spray application of Bond Coat 3:
Once the waterproofing membrane had been applied and left approximately 30 minutes to cure, it was electrically integrity tested to confirm that a defect-free, fully waterproof barrier had been achieved. Bond Coat 3 was then applied by spray to provide a hard tack free finish, which was a crucial factor on this particular site; in order to accommodate the heavy site traffic.
This allowed the following trades to proceed in compliance with the programme of works without unnecessary delays, saving time, money and further disruption.
Watch the video below to see hot asphalt being applied on top of Bond Coat 3:
Due to the success of the project on the first 1150 metres of carriageway, the second phase of the project went ahead as planned completing the refurbishment of the Crumlin Bridge.
Compared to polymermodified bituminous bond coats, Stirling Lloyd’s Bond Coat 3 achieves high adhesion values, requires no additional application equipment and is quicker and safer to apply. The ability to traffic the membrane ensured the project was completed in the shortest time possible. Crumlin Bridge will now be protected by a thoroughly well bonded waterproofing system and asphalt composite that is designed to resist the stresses caused by vehicular traffic over many years to come.
The ability to traffic the membrane ensured the project was completed in the shortest time possible. Crumlin Bridge will now be protected by a thoroughly well bonded waterproofing system and asphalt composite that is designed to resist the stresses caused by vehicular traffic over many years to come.