This is not a documented value, and cement as surface makes no sense, as cement powder is both expensive, unstable and makes for a poor surface.
I suspect that it is result of language confusion and surface=concrete (or concrete:plates or concrete:lanes) is a correct tag.
You can use overpass turbo to look for it in your area, you can also use MapRoulette to find objects.
I investigated and mostly fixed similar surface=beton (ābetonā is word for concrete in multiple languages and was misused instead of surface=concrete). Here I really would appreciate help, especially as scale of use is far larger than was with surface=beton
You can help by
asking users who added it to explain what they meant by this tagging (using changeset comments)
resurveying nearby to you objects
by mapping correct surface based on super-high quality aerial imagery if provided. Or Mapillary or Bing street view imagery or other compatible with OSM sources
fixing value if you can be sure that specific objects are wrong (maybe some languages have ācementā as word for beton, maybe as slang term? In such regions it may qualify for bot edit)
In Croatian, ācementā is technically the same what it is in English (stuff which when mixed with gravel, sand and water produces āconcreteā AKA ābetonā in Croatian), but I can easily see the non-technical people confusing the two (especially as the only case here was a newbie account)ā¦
Iād guess it is the same elsewhere, especially as cement as the surface would last only until first rain, when it would start becoming concrete by curing itself after being mixed with water.
Agree with @Matija_Nalis and @ezekielf ā¦ also in Germany many people with non-technical background use the term āZementā (cement) when they talk about āBetonā (concrete). From my point of view there is nothing mysterious about that, just a mix-up of the 2 terms.
In fact there are different surfaces of materials containing cement as a major ingredient, like concrete, screed, artificial stone tiles, terrazzo etc., but for surface of roads and tracks you can simply say cement=concrete, according to my background in civil construction for many years.
For Greece cases, as I wrote in a note of yours, itās indeed language confusion as both cement and concrete have the same translation. I keep finding ways to better understand the factual difference and how to properly tag them, and I think I found something. I will propose it to the local community to finally standardize it and release this confusion.
I have seen, but never tagged, surfaces in cement. Specially small rural roofed areas and stuff like that.
Iām not sure a mechanical edit would be a good choice.
No, I have no pictures. Those things get deteriorated over time; but that doesnāt prevent people from making them.
They just fill an hollow area with cement to make the surface, something like some sort of foundation.
As to whyā¦ you know, people might find themselves with a lot of bags of cement and just decide theyāre going to use them somehow rather than letting it get humid in the basement.
Come on, nobody will create a complete road surface like that ā¦ I can imagine that someone might fill some old half-hardened cement into a pothole as a clumsy attemt to repair or to get rid of that stuff, but never a larger surface.
ā¦ how it worked? has someone put cement powder on surface? ā¦
Imagine the mess you would create by doing so ā¦ every vehicle passing there would raise huge clouds of cement dust covering the whole vehicle after having passed this place. I would not believe it until I saw a surface like this myself.
Again, if someone might have tons of cement in access would he not rather sell it instead of pouring it onto a road surface and risking to get sued for polluting the environment?
If weāre talking about roads I agree, but nowhere is stated this tag is used only on roads.
Probably a lot of these are tagging errors, but thereās no real way to know whether all of them are.
Yes, you are right, I can imagine that someone might believe, a surface of pure fine cement without any aggregates for his new garden terrace would be a great idea (like baking a bread form pure yeast without spoiling it with flour ā¦ ), or another guy wants to get rid of some 5 tons of cement and decides to create the surface for the new parking space on his plot with these. I could imagine that for private premises but as far as I know we do not map private premises in such detail.
On public ground this would not happen imho because those people to take decisions about the surface of public roads, ways, places etc. mostly do have some basical knowledge about what they are doing. So any public area tagged as surface=cement must be either concret or screed (which is also nothing but a concrete with finer aggregates).
Cement is cement. Not cement powder. You can have concrete covered by a thin layer of cement (cement + water, possibly + sand but without gravel). As for me, if you describe the surface of a small area, thatās OK.
Hydraulic cement (with is by far the most common) can be used in wet condition.
So against a mechanical edit, expect if restricted on roads where it couldnāt stand long. Pretty much in line with @davidoskky.
I donāt know where this information is coming from but creating a surface of pure cement does not make any sense as it is more expensive than a mixturen with some aggregates and does not provide any advantage. Cement is a binding agent and not designed to be used without being mixed with some aggregates except for very special purposes like underground borehole injections.
If you mix cement powder with water (adding nothing else) you get cement paste (binding agent) which you can use to create small items like bowls or vases if you like but there are better suited materials to do so. Pouring such mixture onto a concrete surface will result in a very hard top layer with lots of cracks and easily braking.
Adding some sand will reduce the tendency to crack but then the mixture is no more cement but a cement mortar which is identical to a very fine concrete. Adding some sand and fine gravel will result in a mixture known as screed which is a fine concrete as well. Adding some sand and a mixture of gravel (or crushed stone) of various sizes will provide the standard concrete material.
It is perfectly correct to call all of these materials concrete whereas it would be misleading to call them cement.
), or another guy wants to get rid of some 5 tons of cement and decides to create the surface for the new parking space on his plot with these. I could imagine that for private premises but as far as I know we do not map private premises in such detail.