Posted by Elisa Sacchi - 20 February, 2019
An effective protection and waterproofing coating plays a crucial role in the long-term structural integrity and cost efficiency of any multistorey car park. Master Builders Solutions has developed new protective systems for car parks including a new primer, which is based on the new Xolutec™ technology by BASF for durable construction. Eric Boullenois, Marketing Manager for Industrial and Concrete Refurbishment, explains the general approach and the specific properties that this new solution offers for applications in car parking decks.
Why protecting deck surfaces in parking garages is so important?
Although a massive concrete slab appears extremely robust and seemingly indestructible, this impression is not entirely correct. In multistorey car parks especially, the concrete is subjected to considerable stress. Let us start by considering the mechanical impact: most cars these days weigh about one ton, and most SUVs are considerably heavier; at any given time, multistorey car parks have to deal with dozens or hundreds of those heavyweights, some of them stationary and others in motion. Parking decks are also subject to the impact of exhaust fumes, lubricants, brake fluids and de-icing salt. In addition, the top-level parking deck is constantly exposed to changing weather conditions – wind, rainfall, temperature fluctuations, UV radiation, ice and snow.
How does this impact on the concrete?
The concrete erodes. Weather-related impacts attack the concrete surface making the material increasingly porous and leading to cracks. In time, water and de-icing salt will penetrate down to the reinforcement and initiate and accelerate the corrosion process. Combined with the mechanical loads I have already mentioned, and all this together factors can significantly compromise the integrity, safety and durability of the structure in the absence of a proper protection and waterproofing coating. If an effective protective coating is used, he durability of the structure is improved, making it more sustainable.
What are the main characteristics that such a protective coating must have?
Superior general resilience and crack-bridging properties are key. The protective coating must be sufficiently robust to withstand the typical stress of a multistorey car park. Also, the top deck – usually exposed to the environment – is particularly likely to incur some cracking over time; in such cases, the protective coating must be capable of bridging those cracks to prevent harmful substances from entering the concrete and causing substantial damage. Other technical requirements, like slip resistance and the need for a certain flexibility in visual design, to outline parking spaces or indicate directions on the floor are also important. While all this sounds very simple, it is often quite demanding in practice.
What exactly are the challenges that parking-deck coatings face?
To be effective, coatings used in multistorey car parks are composed of two to four individual layers, each of which has different properties for the different tasks they have to perform. The way these different layers are combined ultimately determines the efficiency and the durability of the coating as well as the time required for installation. Details often vary significantly across different projects, and there is no one solution that fits all cases. This is why we place great emphasis on clarifying all requirements at a very early stage, remaining very close to the customer and supporting them with our know-how and our experience from this stage onward. In most our cases the greatest uncertainty factor is the substrate, which has to be very dry during installation. The reason is that in case of humidity in the substrate during the application of the first layer (the primer), the adhesion can de affected with possible delamination as a consequence, requiring repair or even replacement. The solution for this primary, seemingly inescapable challenge is MasterSeal P 770 primer, based on Xolutec™ technology by BASF.
How does MasterSeal P 770 differ from other primers?
The most distinctive feature of MasterSeal P 770, unlike any other primer available on the market, is that it can be applied to humid substrates. This saves time and makes application considerably more secure. So far, the only possible approach was either to guess or to measure the humidity in the substrate, an estimation that can never be carried out across the entire surface area but only at certain points. Moreover, only very low values are acceptable. If the substrate is not sufficiently dry, delamination of the coating is to be considered a likely consequence. MasterSeal P 770 completely eliminates this basic uncertainty. Our primer always forms a reliable bond with the substrate and can be applied regardless of the substrate’s humidity, with the great advantage that application can proceed according to schedule. Another important benefit is that MasterSeal P 770 is compatible with all other Master Builders Solutions parking-deck coating systems.
What is the reason for the enhanced performances of MasterSeal P 770?
The reason behind of superior performances of this product is Xolutec™ technology, the result of several years of development work on advancing currently available PU and PUA materials. The goal was to solve the problems of concrete and steel in challenging environments, such as wastewater treatment plants and industrial flooring applications. By optimizing the intermolecular interactions between the resin building blocks, an enhanced cross-linked polymer network (XPN) is created, allowing unique properties for many different solutions. The main benefits for users are reduced cost of ownership as a result of longer maintenance cycles and less downtime, or long-lasting aesthetics and increased durability. In particular, Xolutec™ technology provides MasterSeal P 770 with quite exceptional hardening properties, enabling the product to cure even at low temperatures. After on-site mixing, the two components of the material form a cross-linked, interpenetrating network structure combining properties that, until now, were mutually exclusive, such as resistance to even extreme chemical impact with just the right degree of elasticity to bridge cracks effectively. Application is simple and straightforward, as the material can be applied using a roller spray and is suitable for use on humid substrates and in moist environments. MasterSeal P 770 has also been tested by the Fraunhofer Institute in a long-time exposure simulation, which confirmed its exceptional resistance and durability.
Nevertheless, a primer alone cannot ensure effective protection. What about the other layers?
Depending on the specific application and project requirements, additional layers are selected from, a variety of waterproofing membranes, wear coats and top coats. These system layers can have different properties. In the case of multistorey car parks for example, requirements usually vary from level to level. On the top level the coating has to be extremely resistant to all kinds of environmental impact and have high crack-bridging resistance; intermediate decks usually are enclosed spaces that typically are less exposed to sunlight or rain but need to have good crack-bridging properties to increase the safety and durability of the overall structure; and on the bottom level, the properties of the substrate underneath the concrete have to be taken into consideration. In fact, those levels may require additional waterproofing protection against groundwater or earth moisture. In addition, general requirements to be considered and which apply to the entire structure are abrasion, wear, and skid resistance. The Master Builders Solutions by BASF product portfolio provides highly versatile and custom-tailored solutions to meet all these needs. Our recommendation is to use the new MasterSeal P 770 primer as a basis, and to evaluate and combine the other components in line with the specific requirements of each project.