Pavement slab
Pavement slabs have been and are used in Europe as paving for many sidewalks . Mostly made of natural stone or concrete , they come in different shapes, but in modern times mainly in rectangular dimensions. The panel thickness can vary between 4 and 12 cm depending on the intended use and the expected load.
Until the advent of industrially manufactured concrete around 1900, sidewalks were paved with slabs of natural stone from the respective region. In special cases, when the surroundings did not produce a suitable natural material, the road builders procured such surfaces from quarries at greater distances from the place of use.
Rocks with good natural fissile properties were in demand due to the low processing effort . These include some sandstones , plans , quartzites , limestones , gneisses or granites . Many slates are less suitable because their split surface is usually very smooth and therefore does not provide the slabs with good slip resistance.
Since the development of machines in the natural stone industry in the 19th century, countless slabs of crust have been produced when sawing natural stone slabs from raw blocks . This is the name given to the plates that bear the rough outside of the raw blocks on one side. In the subsequent work process, these are preferably formatted as paving slabs. Depending on how the raw blocks are extracted, their outsides are slightly convex. This belly allows for a stable position of the plates in the base layer of the substructure and the plates are also referred to as pork bellies ; in Berlin they are known as Charlottenburg platters .
Reinforcing iron is also embedded in the back of the panels and glued or mortared, which allows trucks to drive over the panels .
The plates are usually placed on gravel or chippings , which is intended to avoid waterlogging. The joints are usually filled with sand, which can also be bound with lime , cement or epoxy resin to prevent it from being washed out.
In Berlin, large paving slabs made of granite are also known as the “pork belly”.
Modern trend with substitutes
In the 1970s in particular, pavement slabs with exposed aggregate concrete were used in private areas. Instead of concrete pavement slabs, asphalt pavements or concrete paving stones are increasingly being used. However, the proportion of such concrete elements used in road construction varies greatly from country to country.
Individual evidence
- ^ Norbert WF Meier: Berlin Geology - Above and below the pavement of the big city . 1st edition. Berlin Story Verlag, Berlin 2014, ISBN 978-3-95723-002-7 , pp. 127 .
- ↑ Sidewalks have a bulge underneath
- ↑ Sidewalk design - a stone - (almost) too heavy to steal. Accessed June 1, 2019 (German).
- ↑ Matthias Thieme: The trail of the stones leads from China to Berlin. September 6, 2015, accessed June 1, 2019 (German).
- ↑ ggh: In search of the pork bellies: Tour on the “Day of Stones in the City” | Geographical Society in Hamburg e. V. Accessed June 1, 2019 (German).
- ↑ Jörg Niendorf: Sidewalks have a bulge underneath . November 7, 2006 ( welt.de [accessed June 1, 2019]).
- ↑ Maritta Adam-Tkalec: What a performance, Berlin! No city has such a beautiful pavement. April 29, 2019, accessed June 1, 2019 (German).