Car parks are unique buildings in that almost all elements of the structure are normally exposed to the public. These constructions face unique challenges as well as exposure to niche stresses not to mention substantial chemical and physical abuse, explains, Vivekanandan, Managing Director Flowcrete India Pvt Ltd.
In the modern world, there are more vehicles on the roads than ever before, which in turn means that parking has become a routine part of everyday life. As a result, the demand for car parking spaces is at an all-time high with vehicle owners searching for safe and secure environments in which to house their vehicles when they are without them.
The car park is the first point of contact for a visitor in any shopping centre. It is the “front door” of the building and provides a person with their first impression of a mall, while at the same time serving its primary functional role. There is absolutely no doubt that initial appearance, ease of use, signage, bright lighting and clear directional marking all combine to make a car park a more positive and safer environment. It is not just a case of new car parking developments frequently adding to the urban landscape, as it is just as common for existing structures to be refurbished and brought into line with modern design and safety requirements.
Specialized Surface materials
One essential design consideration is the deck coating material chosen to protect the reinforced concrete structure, in order to protect against the ingress of water as well as corrosive de-icing salts and other pollutants. Specifying the most suitable deck coating materials is largely dependent on what conditions the material will be subjected to and where in the multi-level or underground parking facility it will be installed. This can range from slip-resistance, durability and service life requirements to temperature cycling, UV exposure and problematic existing substrate conditions as well as any anticipated movement within the structure.
The nature of car park facilities demands that they are constructed with vast clear spans encompassing a minimum number of supporting columns, in order to achieve the maximum number of parked vehicles. This type of construction, when subject to cyclical traffic flow, invariably leads to the structure being susceptible to flexing and movement.
Epoxy and polyurethane resin based car park decking and wearing systems are most common although methyl methacrylate (MMA) systems, which offer rapid installation speeds in order to keep disruption to car park operations at a minimum during renovation, are increasingly being specified, particularly in refurbishment situations.
A large volume of vehicles traversing a car parking structure over time can lead to dynamic loading, where vibrations impart through the decks into the structure, increasing the risk of movement across all construction, expansion and movement joints within the frame of the structure and decks themselves. In order to significantly reduce the risk of dynamic loading, flexible, crackbridging polyurethane based deck coatings systems are commonly used to move alongside the structure, helping to prevent any long-lasting damage to the surface or the building itself.
Usually fully exposed to the elements, car parks are subject to high temperatures, extreme sunlight, UV exposure, low temperatures, freezing and thawing, high levels of rain and extreme temperature fluctuation. All of these factors can impact negatively on the fabric of the structure, imposing dynamic stresses, which can lead to the early cracking of the host concrete and potentially expensive structural failure.
Resin systems are installed at differing thicknesses dependent on the specification, not only to protect the substrate but also to enhance aesthetics and safety, thus ensuring a warm, welcoming impression for visitors. Again, specialist resin-based decking coating systems act as a protective coating by accommodating thermal movement in order to prevent thermal cycling over a 24 hour period or seasonal change from posing any permanent problems.
Applied coatings, whether on the deck, soffit or wall must meet the most stringent of criteria if they are to succeed in their primary function of car park protection. Non-protection of any car park will undoubtedly result in long term maintenance programmes, resulting in increased operations costs and in some extreme cases, deck failure.
Overexposure to traffic causes abrasion and mechanical wear of the surface, which is naturally increased on car park ramps, pedestrian walkways and particularly in turning areas. This is also true of exits and entrances from the car park into shopping centres as well as at elevator waiting areas. The deck waterproofing and wearing surface system selected must have skid resistance and abrasion resistance properties that are suitable for the exposure of the area in question. Using positively textured aggregates, the anti-skid profile of the surface can be increased in areas of high stress.
Highly resistant resin-based deck coating systems can be used to prevent the early onset of corrosion, providing a protective barrier between the host substrate and contaminants such as: airborne water, de-icing salts and automotive fluids; anti-freeze, battery acid, AC fluid, diesel and petrol as well as toxic gases from exhaust pipes.
Pigmented resin coating systems can protect a parking structure while simultaneously transforming the environment with the addition of colour, improving lighting levels through its reflective properties and enhancing the overall ambience of the car park, making it a safer and
brighter place for people to park.
Coloured line marking products can also be laid in conjunction with resin based solutions to define both pedestrian and vehicle areas, ensuring the safety of both people and cars by regulating pedestrian movement and traffic flow.
Considering the unique structural design associated with car park buildings as well as a range of aggressively corrosive service conditions at specification stage, the blueprints of multi-storey and underground car parking facilities must take this into account by to ensure the optimum service life, free from major dilapidation works or early renovation.