Evaluating durability of parking deck systems

Multistorey car parks are challenging structures. Floors and deck surfaces are under constant attack due to the circulation of vehicles - abrasion, abrupt braking, sudden changes of direction - and to chemical damage due to accidental leak of liquids such as petrol, diesel, antifreeze and brake fluid.

Top decks and other decks, when the car park is open, are additionally exposed to weathering due to environmental actions such as sunlight, rain and snow. In cold climates, the use of de-icing salts can be an additional source of attack for reinforced concrete.

Intermediate decks are normally less exposed to environmental conditions as they are sheltered by upper decks, at least partially. But they are still subjected to continuous mechanical and chemical stresses.

Additionally, intermediate decks are exposed to the action of exhaust fumes, produced by the combustion of hydrocarbons, which are a big source of carbon dioxide and water vapour, increasing the degree of concrete degradation due to carbonation.

Finally, the surfaces of ramps need special protection against mechanical loads, especially abrasion due to sudden acceleration or braking.

Nowadays, cars have increased in size, but parking bay sizes have not. This means that cars need to manoeuvre more to get in and out of parking spaces. Wheels are also getting bigger which means a bigger contact surface with the finishing layer and higher exposure to friction. In some cities, increasing numbers of electric vehicles, which tend to be heavier due to their batteries, could also add to surface damage.

Aesthetics and traffic safety

On all trafficked surfaces, and especially on ramps, it is important to have anti-slip surfaces to secure the grip of a vehicle's tyres and to maintain traction. A road with low skid resistance can cause vehicles to skid, slide, or lose control, increasing the risk of accidents. Also, for pedestrians walking on the surface, the risk of accidents, especially on wet surfaces should be minimised.

But this is not enough: aesthetics should not be overlooked in the design and construction of car parks, as it can greatly impact the functionality, safety, and appeal of the facility.

Aesthetics in car parks play a crucial role in shaping the overall experience of a parking facility. A well-designed and attractive car park can enhance the perception of the building or area it serves, improve user comfort, and increase safety.

The way a car park looks can make it more inviting and easier to navigate, making it a more desirable place to park and helping to reduce congestion in the surrounding area. Furthermore, a well-designed car park can also increase the value of the surrounding real estate, making it a smart investment for developers and owners.

Mechanical resistance of a car park surface finishing system

The stresses that most affect the performance of a parking deck surface finish are abrasion and, sometimes, impact. A parking surface that shows signs of wear due to traffic looks less attractive.

The wear resistance of a protective system depends on numerous factors such as thickness, surface roughness, cohesive strength, adhesion between layers and elasticity or toughness. Determining the influence of each of these factors can be challenging.

The usual abrasion resistance tests (e.g., Taber or BCA) provide a good basis for comparison between different systems, but do not adequately simulate the effects of abrasion on car park decks. A new method that is closer to the real effects has therefore been developed.

The Parking Abrasion Test (PAT)

The Parking Abrasion Test (PAT) simulates the mechanical abrasive stress of a car tyre rotating around its vertical axis. The test method has been tested in several laboratories and allows the classification of wear properties.

The PAT wear test stand consists of a stable steel frame with a weighted passenger tyre mounted within it so that the tyre can rotate. Under an axle load of 400 kg and cyclical rotational movements, turning the tyre through 90° (at a tyre pressure of 2.2 bar), the test procedure simulates realistic stress due to a passenger car.

After a predefined number of test cycles, the machine stops, the superstructure is lifted and, after cleaning the surface of rubber abrasion, the coated panel is subjected to a visual inspection for damage and classified into one of the wear classes VK-1 to VK-6 shown below.

The following paragraphs show examples of two systems tested using the PAT methodology.

MasterSeal Traffic 2239

In this system, both the waterproofing layer and the wearing or top layer are made of MasterSeal M 689 polyurea. Applied by hot spraying, the system can be driven on again extremely quickly and does not require any additional topcoat, saving a lot of time compared to other solutions.

The outstanding benefit of MasterSeal Traffic 2239 is its amazing durability and resistance. The PAT test of the system offers extraordinary results even after 30,000 cycles:

Download a case history where MasterSeal Traffic 2239 system was applied here.

MasterSeal Traffic 2264

MasterSeal Traffic 2264 is a multi-layer high crack bridging product, which enables a fast return to service. It provides very high wear and abrasion resistance with a combined membrane and wear coat in one single layer using MasterSeal M 869 top-coated with MasterSeal TC 374. For use on intermediate decks and on ground floors, the system successfully passes 15,000 cycles.

To easily access information about Master Builders Solutions’ systems, use the “Car Parks” module in the Online Planning Tool to scope out potential projects.

The tool asks for input about the repairs needed and requirements for the different decks of the car park (exposed top decks, intermediate decks, ground and below-ground floors or ramps). It will then recommend the best possible surface finishing and waterproofing system in each case.

After the solution has been defined, the tool can generate a customized specification report which includes all related product documentation, such as datasheets, certificates and BIM objects.

More information about the systems and experiences of Master Builders Solutions for car parks can be found in the links below:

• Blog post: 9 factors to consider when choosing a protective car park waterproofing system
• Blog Post: Refurbishing car parks: MasterProtect 8500 CI Corrosion inhibitor to protect concrete
• Blog Post: Refurbishing car parks: Finding places for 340 million cars