Car parks are hardworking structures that need life care planning and maintenance to ensure they remain safe and structurally protected.
The top deck of the 25-year-old podium car park at Edinburgh College’s Granton Campus was extensively cracked with widespread ponding water. With concerns about water ingress and chloride contamination from de-icing salts causing long-term damage to the structure, a project to improve the falls and drainage was undertaken in 2020. Waterproofing, surfacing and protection works followed in the summer of 2021.
The car park deck is of composite design, formed with precast Bison-type concrete planks and a reinforced concrete topping, all supported by a steel frame. Since construction, the bare concrete finish was unprotected and at risk from the extremes of weather in this region. Extensive cracking was visible in the reinforced concrete topping, particularly along the longitudinal sides of the 1.2m wide precast concrete planks and above supporting beams. Deflections within the precast units, rotation over beams and differential properties between the individual precast units typically lead to cracking of this nature.
Triflex worked in conjunction with authorised contractor, Fraser Bruce Group, to install a cold liquid applied, rapid curing waterproofing, surfacing and protection system. The Triflex ProPark® fully reinforced system was specified due to its long-term protection capabilities, together with its heavy-duty dynamic crack bridging properties.
The system is specifically designed for external decks at high risk of cracking, is BBA and ETA certified and delivers the highest class of dynamic crack bridging under EN 1504-2 at B 4.2 (-20°C). Here, the multiple cracks in the car park surface were locally reinforced with a 200mm wide strip of Triflex ProPark, extending a minimum of 75mm either side of each crack. The Triflex ProPark system was then applied across the entire deck, including over the previously reprofiled gulleys. Thanks to the system’s dynamic crack bridging properties, further movement will be accommodated, and the system will prevent water ingress to the decks below, providing waterproofing protection.
The Triflex ProPark system is based on PMMA resin technology. As each layer of the liquid applied system cured in typically less than an hour, which contributed to the efficient and on time project delivery.
On the two car park ramps, the system also incorporated a 1.0 - 3.0mm emery aggregate, providing a hard wearing and robust anti-skid surface with high PTV. As the system is unaffected by ponding water and is resistant to chlorides (including from road salts), carbon dioxide ingress, petrol, diesel, brake fluid, engine oil, battery acid, and de-icing and cleaning products, it will provide protection to the car park for years to come.
To differentiate areas, the durable surface finish of the cold liquid applied PMMA Triflex ProPark system was coloured Traffic Grey in the driving aisles, with parking bays in Traffic Blue. Bay marking was completed with white Triflex Preco Line 300, and directional arrows with Triflex Cold Plastic, a PMMA system capable of withstanding the rigours of heavy traffic.
The rapid curing systems meant that the project could be completed quickly, with minimal disruption, enabling a full reopening soon after completion.
Steven Murray, ISS Contract Manager responsible for the project at Edinburgh College, commented: “Both the client and ourselves are really happy with the end result. The car park looks fantastic, and as a result of the structural repairs and Triflex waterproofing system, we now have no water leaking down to the lower levels.”
