R-Value for Air Entrained Concrete 1

[MJB315]

All,

I am seeing that air entrained concrete has a higher R-Value than standard poured concrete (see below). Whereas it makes sense, the difference surprises me. Is air-entrained concrete really this good at insulating?

Standard Concrete: R = 0.8 (F*h*sqft/BTU)/in
Air Entrained Concrete: R = 3.9 (F*h*sqft/BTU)/in

If so, how much air needs to be entrained? The standard 6% +/- per volume? Is anyone aware of an actual source / experiment where this 3.9 value was determined?

MJB

 

[HeavyCivil]

I've seen the same numbers and am also skeptical. I can't provide any help here but I'll be watching for an answer as well.

 

[Ron]

MJB315...the numbers for the air entrained concrete are about right for cellular or lightweight insulating concrete, but way too high for structural concrete. I would not apply that value to structural concrete.