Why would there be asbestos in a concrete slab?
On a nearby project I heard that they had suspected that there was asbestos in the concrete slab? I was wondering what the purpose of this would be. M...
On a nearby project I heard that they had suspected that there was asbestos in the concrete slab? I was wondering what the purpose of this would be. My first idea was possibly to increase strength and then I read that sometime is was used in concrete roofs to make them lighter. So I am thinking that it does provide strength while allowing the concrete to be lighter, but that wouldn't explain a slab on grade.
Asbestos cement sheeting used to be used a lot in building (especially roofing). It added flexibility and strength to thinner sheets that otherwise could not be made with normal concrete.
These days; with the dangers of asbestos being well known, they use cellulose and other fibrous materials in place of asbestos.
But there are still a lot of old buildings around containing asbestos cement sheeting, and care has to be taken in disposing of it (especially if it has to be cut, sawn or drilled; which can release minute asbestos fibres.
There may have been cut-back adhesive used on the slab to adhere composite vinyl tile. It was common back in the day to use asbestos in the adhesive to give better adhesion between the tile and the concrete. Cutback is a sticky looking black material that actually chips off to a certain extent. If it has asbestos, it can become friable (airborne) when the concrete is broken up.