formula for solid core in 8'' block

[colonial carpentry]

I need to figure the amount of crete for 8x8x16 cmu's.need to pour cores every 24'',is this overkill.

[Rich]

Enough with the all caps :)
Didn't I just email this to you?
For 8" block use .01053 cubic yards per block...
Or you can use .01185 cubic yards per square foot.

And if they require it by code - then I wouldn't consider it overkill.

[Tom R]

Then divide by 3? In other words, is that the formula for filling all the cores? From his question, it sounds like he only needs to fill the ones with the rebar. Hey, just ASKING. :D

[Rich]

Kind of - the square foot amount would be the total square footage divided by 1.5 - not 3. Essentially it's 24/16 for each block.

The per block amount would be the total lineal foot divided by 12 multiplied by 1.333333 multiplied by the height and then multiplied by the height of the wall.. then multiplied by .01185 :)

[Tom R]

But that answer is to fill the entire wall, right? Then I'm thinking he only needs to fill every 3rd core (if he's using 2-core block)

[colonial carpentry]

Sorry about the caps rich ,it wont happen again.i checked my email then posted,i didnt hear from you so i posted.tom ,i am only pouring where rebar is placed.please let me know how to correctly figure this factor in.i hate calling in the order,the supply company dispatch really treats us newbies like the total idiots that we are!

[colonial carpentry]

i also knew the answer i was going to get to my overkill question as soon as i posted it,thanx rich i walked right into that one!lmao

[Rich]

Tom - the per block amount is a full 8x8x16 block - not just a core. You're right on the 3 though - I was putting the 1.5 because I was thinking about blocks not cores.. so 2 cores per block makes it 3.
colonial - np on the caps or anything else for that matter. It's all good :)

[Tom R]

Rich is the expert on this, not me, I'm just still not sure if that formula is for the whole wall or the cores every 24". Seems to me it's the whole wall, then if you're using 2-core block, you would divide that answer by 3, because you would only be filling every 3rd core to meet the 24" code for the rebar. But like I say, wait for Rich's next reply. He usually checks in pretty often - - if not, we may have to give him his 'lay-off' slip. :lol:

[colonial carpentry]

I think rich is giving me an accurate formula there.that comes out to about 1cy per 90 block in which i would divide by 2 to only fill one core in a double core block , thanks rich i appreciate it.

[Tom R]

Sorry, Colonial, our anwers are out of order, I guess Rich types faster than me, so I guess laying him off is out of the question. :lol: Anyway, it sounds like you need to figure how many block you have and multiply that number by .00351 to get your cubic yardage (.01053/3). Or, figure your square footage of block and multiply that number by .00395 to get your cubic yardage (.01185/3). And then add your waste factor (5 -10 %?). Hope this helps.

[Tom R]

You would divide by 3, because if you went with 2 (filling one core out of every double-core block, that would by every 16"). You want to fill every 'THIRD' core for 24" spacing on the rebar.

[colonial carpentry]

O.k tom ,thanks for the clarification. thanks for the help!

[Tom R]

No problem, let us know how it goes.

[Shanley]

A rule of thumb that I use is 1 c.y. of concrete grout fills approximately 200 8" cmu cells

[Tom R]

Where were you last night? :lol:

[colonial carpentry]

Yeah shanley where were you last night? Dont you know that you are our cmu superman?lol So i can go with that figure of 1cy fills 200 cores?and another question the crete supply called me back and left a message asking me to clarify what type of mix i want can you offer any expertise on this matter? 134' perimeter of 8'' block at 13 course poured every 24'' can you give me a guesstimate on that?

[Tom R]

Colonial,

I come up with just over 4.5 cubic yards, so I'd order 5, but don't go by me, wait for one of the concrete experts. And I would think about a 2000 lb. mix, but that's a guess. Concrete's not really my 'bag'. :lol:

[Shanley]

Icome up with just over 4 cy (4.16)...I use either 2500 or 3000 psi fine grout (no large aggregate)...the fine grouth has a better chance of reaching the bottom course than a pea stone (3/8 aggregate) mix and is easier to pump (if your pumping the grout)...The fine grout is more expensive

[colonial carpentry]

thanks shanley thanks tom i appreciate the answers.i'm ready to call in the order! now i can act like i know what i'm talking about.thanks for the much needed help on this matter.

[colonial carpentry]

Hey you guys were right on the money with the estimate on the grout ! I had six yards on the truck. I lost some when i poured into a core that had weep hole block on the bottm course and it went right through out the bottom,I didnt do that twice!Lol.