Blue concrete?

[minisorkis]

Hello!

Is this blåbetong? The picture was taken in an extension/basement built in 1975.

 

[roland53]

To me, it looks like plaster on a cement-based foundation.

Blåbetong is the same structure as lightweight concrete, i.e., some "air bubbles" in the material.

A few more pictures would make it easier to say for sure.

http://www.google.se/url?sa=i&rct=j...9oYtDtBdVwh5j0e0BJJUKuTw&ust=1408291391842814

 

[myrstack]

In the upper left corner where the plaster has fallen off, it looks like blåbetong, a better picture there with something for scale.

 

[HSP]

A bit difficult to determine from your image.
A clearer picture of the upper left corner. would have helped
try nailing in a regular nail. in blåbetong it's very easy.
If it's real concrete, it doesn't work well at all.

 

[minisorkis]

OK, thanks! Here comes a close-up of the upper left corner.



Here is another part of the basement that has had issues with water ingress due to poor/nonexistent drainage for many years (I don't know how many, I'm new here). The picture is taken at the floor, the block in the picture is about 30 cm long, in total it's about 50 cm. Here it really looks like blåbetong if I compare with the pictures I've seen on the internet, but can water affect the color? Right now they are somewhat damp. Water comes in during heavy rain and when the snow melts, so it's from time to time.

So the colors of the lightweight concrete blocks (if that's what they are) do differ quite a bit.

 

[HSP]

It looks like blåbetong.
It gets darker if it becomes damp.

Another thing that doesn't look so good is wood directly against the basement wall.
No problem as long as it doesn't get damp.

 

[minisorkis]

Thank you HSP! I plan to remove the wooden wall. Is there any way to see if it is low-radiating? Is new blåbetong more or less radiating than older - is there any difference? I will be conducting measurements here soon.

And then a little wishful thinking question: is there any microscopic possibility that it could be some other type of lightweight concrete considering that the extension is from 1975, i.e., at the end of the use of blåbetong?

 

[HSP]

You probably can't see with the naked eye if it is high or low radiation.
Don't know if new or old radiates more or less,
it depends on the content and where the raw materials came from.
They used blåbetong until the early 80s. I've seen it in several houses from the 80s.

Your municipality (environment and building department) might have measuring equipment to lend out, they do where I live.

Plastering and paint reduce radiation, and good ventilation ventilates away radon,
Of course, the best is to remove blåbetongen, but that is not always possible or economically feasible.

A measurement shows how high the radon level is, and based on those values, appropriate actions can be determined.

Some info about blåbetong, siporex, ytong, lättbetong, gasbetong. (there are many names)
http://sv.wikipedia.org/wiki/Lättbetong

 

[minisorkis]

Thanks!
Just for fun: Roughly speaking, what would it cost to replace the foundation wall? I suspect that the lättbetong runs from the concrete slab up to the ceiling in the basement/extension, about 2.5 meters in ceiling height. It has about a 10 m long wall, a short side of 4 meters, and a smaller angled wall of about 2 meters. It is thus connected to the "main building" and therefore only has one long side, and one short side has a door and a garage door, so there is no foundation wall there.

 

[myrstack]

Start by measuring to see if you have a problem. You cannot determine anything based on the color of the lättbetong. A short-term measurement for radon levels if you have living space inside that is affected, and a gamma meter to see what the radiation levels are like. As mentioned, whether it is high-radiation or not cannot be seen.