Tag:surface=concrete

Cement based concrete [1] can be used to create long lasting surfaces for roads and tracks. Usually concrete surfaces are cast in place. As concrete is a material with very low flexibility, concrete surfaces tend to crack over time. To avoid irregular cracking, control joints [2] can be cut into the finished surface. A more effective (and more elaborate) option is to divide the surface into slabs of limited size, separated from each other by expansion gaps, later on filled with sand, bitumen or other material.

Surfaces made up of concrete slabs cast in place and divided by control joints or expansion gaps sometimes are mixed up with surfaces made up of precast (prefabricated) concrete plates, see surface=concrete:plates. For differentiation please pay attention to these characteristics:

• Precast concrete plates always have appliances to adapt the lifting hooks as they can only be laid in place by a lifting device. These appliances (steel loops or bars) are normally found in cavities in the top or at the edges of the plates.
• Usually precast concrete plates are of identical shape and size.
• Concrete slabs cast in place may be of similar shape and size but in most cases are not identical.
• The surface of in situ concrete often shows traces of manual work during production and the edges may be of irregular shape.

If you are not absolutely sure if a concrete surface is made up from prefabricated plates or slabs please use surface=concrete for it.

For a concrete surface made up of 2 narrow concrete lanes separated by a middle strip of grass, ground or any other surface see surface=concrete:lanes.

For a surface covered with paving stones or paving slabs made of concrete see surface=paving_stones.

Photos

• 
  Large decorative concrete slabs surface at Gateway Arch NP
• 
  Bicycle track with a surface of concrete slabs cast in place
• 
  Concrete slabs cast in place, separated by expansion gaps filled with grass
• 
  A sidewalk made of concrete cast in place, showing (bottom to top) a stamp of the construction company, an expansion joint, and a control joint. The surface is also sloped
• 
  A laneway made of concrete cast in place, with expansion joints. Some of the concrete slabs have shifted slightly, creating an appearance similar to that of concrete:plates, but note that the slab sizes are not uniform, and a channel for water drainage was formed when the concrete was poured.

External links

• topic at OSM forum discussing this tag