ICF wall creation question

[Helavagal]

Very interesting. I need to check that out. Thank you all for the input. I am doing now three houses in ICF and I am working on my own which will be done in ICF too. ( there are now tax breaks if you build with "green" friendly products FYI)

[slatta]

no one really knows for sure if honeycombing is a problem in a particular instance because you cannot see the finished product, probably great for a crawlspace in a dry environment, but I also have a hard time with it on basements. basements are hard enough to to keep dry as it is.

I have done a few of them too, and have not heard of any problems yet so i guess itf you use the mix and placement procedures you'll be ok.

as far as drawing it in chief, i just show a 12" wall and paint on the finish I need

[Curtis Johnson]

Mike: What do the ingredients for the mix look like (aggregate specifically)? I think I remember seeing an article on this type of material but I think the article talked about using it for filling block walls.

[slatta]

the aggregate is "pea gravel" max. size 3/4" but look at the manufacturers spec data to be sure

[Helavagal]

3/4" is what Nudura asks for.

[Curtis Johnson]

Slatta:

I quit calling gravel "pea gravel" when it gets bigger than -3/8". I suppose they put some super duper slippery stuff in the mix - or do they just add extra cement for enhancing flow?

[mlluxarch]

SCC Aggregate size is typiccally 1/2" to 3/4" along with a higher percentage of fines. Fo residential work, ICF's and foundations, I wouldn't see a need for much over 3/4", but larger is possible.

[Curtis Johnson]

I just checked Arxx's concrete specs which are:
1. Max. aggr. size = 3/4" (depending on amount of steel in wall, etc.)
2. Recommended aggr. size for 4" & 6" forms is 3/8", or 1/2", depending on amount of steel.
3. Recommended aggr. size for 8" & 10" forms is 3/4", or 1/2".
4. A slump of 5" to 6" is desirable. Increased workability of mix is achievable so long as the water to cement ratio is not affected.
5. Recommended min. concr. strength is 2500 psi (28 day).
6. Water to cement ratio must be less than 0.60.
7. Use Type 1 normal Portland Cement unless otherwise specified (engrg.).
8. Concrete admixtures can be used for special applications, under strict compliance with the engineer's specifications.

One reason ICF walls achieve greater strength than conventionally poured concrete walls is the near perfect curing environment. Somewhere in Arxx's website there should be actual test data comparing the two types of walls' strength.