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Vehicle and pedestrian paving

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Vehicle and pedestrian paving

It can’t be neglected the landscape of the roof in case of underground constructions, garages. Aesthetic and formal revaluation of these areas can be performed in several ways, if the structure of the building allows it.

We can build areas for the pedestrian traffic, playgrounds, exhibition spaces, or in case of heavier structures, additional parking places and vegetation can be installed.

Before starting the landscape work, we have to review some general and specific considerations imposed by the urban plan, and a technical expertise must be realized regarding the available safety level of the structure in case of vertical and seismic loads.

Because of the underground landscape, the weight of the construction is seriously increased, so this feature shall be considered already in the design stage. In case of new buildings, regulations in force must be also met.

When building pedestrian or vehicle paving, we have to keep in view the inclination too; for pedestrian traffic about 2% and for the vehicles up to 2,5%. Installing them on flat surfaces is not allowed, because without declivity water accumulation can’t be avoided. Of course, the key element is the drainage course resistant to high pressures, which also ensures water removing, without using other gutter structures.

If we consider the preferences of the client, the carrying capacity of the underground building, traffic green roofs can be landscaped in four variants. These technologies are not rigidly defined; they can be adapted to the features of any type of architecture:

  1. pedestrian
  2. for vehicles
  3. for heavy vehicles (firefighters, ambulances etc.)
  4. “Green”

1st variant. Pedestrian

This type of green roof is meant especially for pedestrian traffic on surfaces with low carrying capacity. Green spaces together with paths and walking areas create a cosy and pleasant environment.

Technical data: ­
Weight: 250­-700 kg/m² ­
Thickness: 120­-400 mm ­
Inclination: 1­-5° (2­-9%) ­
Load: max. 400 KN/m²

Indicative building structure:
On the basis of the pavement there is a 0,2 mm thick, high density polyethylene foil (HDPE) and a protective layer made of a 3-6 mm thick geotextile. This structure helps distributing load.
Drainage boards of 10 mm form a homogeneous drainage course. This course has low weight and its maximum load is about 400 KN/m².
The filtration cover made of polypropylene fibres prevents clogging.
The gravel layer (0­-22 mm) is thick of 70–100 mm, and it equalizes load and inclination. if the green roof and the built-up surface have the same inclination, this layer is not necessary anymore. In this case the structure’s weight will be about 250 kg/m².

The mineral layer is 30-50 mm thick and it’s the basic layer of the surface. It also distributes load. It is a mixture of granules of split face natural tiles, perlite, pumice, volcanic clay, peat and biodegradable fibres. The most important feature when choosing a certain substrate is its water retention capacity, which can vary between 25 and 40 % of the volume, and also the permeability and structural stability.
Surface layer, as required: grass tiles forming a honeycomb structure, seeded with grass, paving, grass, concrete etc. Of course this layer will also have the aspect defined in the landscape plan.

2nd variant. Vehicle traffic

If it’s sure that the structure of the roof can bear heavy loads, like intense pedestrian or vehicle traffic, between the access roads we can landscape green spaces with turf, plants and shrubs. In order to obtain a lower weight, the following method would be suitable.

Technical data: ­ ­
Weight: 250­-700 kg/m² ­
Thickness: de la 180 mm ­
Inclination: 1-­5° (2-­9%) ­
Load: max. 25 KN/m² and vehicles of 2,5t

Structure of the green roof:
On the basis of the pavement there is a 0,2 mm thick, high density polyethylene foil (HDPE) and a protective layer made of a 3-6 mm thick geotextile. This structure helps distributing load.
Drainage course made of 60 mm thick and 3,5 kg/m² boards, and the max. load of 695 KN/m². Drainage boards are connected to each other, so this course does not have interruptions and no other drainage solution is needed under the paving. Drainage elements can be filled with porous volcanic rocks, so the resistance to compression is increasing without hindering drainage.
3 mm thick filtration cover made of polypropylene fibres. It prevents drainage boards of accumulating mud.
Gravel layer of 0-32 mm or 0–45 mm, the minimum thickness about 150 mm, equalizing load and ensuring carrying capacity of the structure.

The mineral layer is 30-50 mm thick and it’s the basic layer of the surface. It also distributes load. It is a mixture of granules of split face natural tiles, perlite, pumice, volcanic clay, peat and biodegradable fibres. The most important feature when choosing a certain substrate is its water retention capacity, which can vary between 25 and 40 % of the volume, and also the permeability and structural stability.
The surface layer of 100–120 mm, as required: turf tiles, paving, concrete etc. This layer will be built according to the decisions made regarding the final look, so turf, perennials, flowers and shrubs will be used to achieve a great visual impact and a proper functionality.

3rd variant. Heavy vehicles

There are situations when the sites of underground constructions require the possibility for heavy vehicles to be used as roadways.
These heavy vehicles most of the time are used by intervention teams (fire-fighters, ambulances). Apart from general conditions, the building technology of such roofs has some particularities. Even in this case green areas can be landscaped with turf, plants and shrubs, but the total weight on the surface must be low.

Technical data: ­
Weight: 1000 kg/m² ­
Thickness: de la 550 mm ­
Inclination: 1­-5° (2-­9%) ­
Load: max. 160KN/m² and vehicles of 16 t

Structure of the green roof:
On the basis of the pavement there is a 0,2 mm thick, high density polyethylene foil (HDPE) and a protective layer made of a 3-6 mm thick geotextile. This structure helps distributing load.
Drainage course made of 60 mm thick and 3,5 kg/m² boards, and the max. load of 695 KN/m². Drainage boards are connected to each other, so this course does not have interruptions and no other drainage solution is needed under the paving.
Drainage elements can be filled with porous volcanic rocks, obtaining a 8-16 mm thickness, so the resistance to compression is increasing without hindering drainage.
3 mm thick filtration cover made of polypropylene fibres. It prevents drainage boards of accumulating mud.
Gravel layer of 0–32 mm or 0–45 mm, the minimum thickness about 150 mm, equalizing load and ensuring carrying capacity of the structure.

The mineral layer is 30-50 mm thick and it’s the basic layer of the surface. It also distributes load. It is a mixture of granules of split face natural tiles, perlite, pumice, volcanic clay, peat and biodegradable fibres. The most important feature when choosing a certain substrate is its water retention capacity, which can vary between 25 and 40 % of the volume, and also the permeability and structural stability.
The surface layer of 100–140 mm, as required: turf tiles, paving, concrete etc. This layer will have different thickness, depending on the chose elements: turf or grass tiles installed in honeycomb structures.

4th version. “Green”

Depending on their utilisation, there are several alternatives to build such green roofs, having a joint element: the green sward. We can think about athletic fields with lower carrying capacity, exhibition centres, and occasional or permanent access roads for heavy vehicles. After defining the purpose of the place, the component layers, thickness or height of the green roof can be modified.

Technical data: ­
Weight: 380-600 kg/m² ­
Thickness: 240­-350 mm ­
Inclination: 1-­5° (2-­9%) ­
Load: max. 40 – 220 KN/m² ­
Water retention capacity: 50% ­
Discharge coefficient: 0,5 ­
Water storage: 20 – 35 l/m²

Elements of the green roof’s structure:
On the basis of the pavement there is a 0,2 mm thick, high density polyethylene foil (HDPE) and a protective layer made of a 3-6 mm thick geotextile. This structure helps distributing load.
Drainage course made of 60 mm thick and 3,5 kg/m² boards, and the max. load of 695 KN/m². Drainage boards are connected to each other, so this course does not have interruptions and no other drainage solution is needed under the paving.
Drainage elements can be filled with porous volcanic rocks, obtaining a 8-16 mm thickness, so the resistance to compression is increasing without hindering drainage.
3 mm thick filtration cover made of polypropylene fibres. It prevents drainage boards of accumulating mud.
Gravel layer of 0–32 mm or 0–45 mm, the minimum thickness about 150 mm, equalizing load and ensuring carrying capacity of the structure.
The 200 mm thick mineral or recycled layer is the basic layer of the surface and it also distributes load. It is a mixture of granules of split face natural tiles, perlite, pumice, volcanic clay, peat and biodegradable fibres. The most important feature when choosing a certain substrate is its water retention capacity, which can vary between 25 and 40 % of the volume, and also the permeability and structural stability.
For the grass surface is layer is recommended to use turf rolls with species that can bear intense traffic and also ornamental plants. All maximum loads mentioned above, refer to the 100% water saturated state. In dry conditions, the carrying capacity is reduced with 60-70%.

We offer consultancy for green roof and terrace construction works. Our professional team is ready to help with system solutions for intensive, extensive green roofs or pedestrian/vehicle paving landscaped over underground buildings, and many other ecological solutions.

We are at your disposal with turnkey projects and long-term maintenance. We use reliable building materials, plants especially developed for rooftop gardens and high quality vegetation rolls. Every landscape work of ours offers the best cost/effectiveness/safety balance and every project is adapted to our customers’ aims.

We are able to landscape green terraces, intensive or extensive green roofs on the top of industrial halls, relaxing zones and playgrounds over the underground constructions, inside or outside vertical gardens for office buildings, and intensive green gardens with special relaxing zones, landscape green roofs with pedestrian traffic for shopping malls and many other ecological constructions. To increase the ecological value of the building, photovoltaic panels can be also installed.
We are happy to help you with green projects, system solutions, estimates, and consultancy in the field.

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