How many cubic inches in a cinder block core?

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Old 10-01-14, 04:38 PM
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How many cubic inches in a cinder block core?

On-line I've seen 624 cubic inches (CI) per block. Don't you calculate width x length x height? If a core is 5"x6"x8", seems to me that's 240 cubic inches per core and 480 CI per block.
 
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Old 10-01-14, 04:42 PM
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What size block? How many cores in the block? I have seen 2 and 3 core.
 
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Old 10-01-14, 04:48 PM
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They're 16x8x8......Two core. Each core is 5x6x8............Really 5.5x6x8.
 
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Old 10-01-14, 04:57 PM
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624 cu in = 2 * (6.25 x 6.25 x 8)

Maybe they are also including the end webs in the core volume.
 
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Old 10-01-14, 05:04 PM
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The guy says to calculate 6x6.5x8 per core...............That doesn't make any sense.
 
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Old 10-01-14, 05:42 PM
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Flip the block upside down and measure it.
 
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Old 10-01-14, 08:05 PM
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How accurate do you need to be?

And 8x8x16 nominal block is actually 7-5/8" x 7-5/8" x 15-5/8" in actual dimensions. - You can do the calculations for the gross volume.

There a wide range of block configurations for all block depending on local traditions. - number of cores, shape of the cores ("square", pear shaped, rounded) and whether it has small "half cores" on the ends. Also, the core sides are never parallel to the face and many suppliers make block with a flared core that creates a wider top ledge (top and bottom are not always the same) for a wide mortar bed.-This is done for contractors to reduce labor costs despite a very small weight difference. - A good ball-park average to get from gross volume is to is multiply that by 50% to 55% to get the net volume.


The concrete is a block can have a density of about 133-138 pcf and lightweight block (more expensive) can have a density from 90 to 115 pcf.

What do you need the volume of the individual block? - The calculated the wall weight (you must add the mortar to the block weights). If you are interested in the filling of cores, that is highly variable depending what you are filling (grout, insulation or foam) it with and by what method. For local ballpark numbers look at the NCMA (National Concrete Masonry Association) TEK notes on that and many other subjects.

You must be looking at a typical Vegas style 8x8x16 2 core block with two rounded/"squarish" cores, one center web with flush ends.

Dick
 
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Old 10-01-14, 10:41 PM
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These are perfectly rectangle. Cores are 5*6*8.........May very well be Vegas-style, I'm in Carson city.

This is only one layer high, and dry. It's for the other side of the fence, used to build up the elevation to help prevent city drain from running down into my yard. They're basically buried on one side, and 3" deep on the side that faces the fence. I just laid them on a gravel base. I have some doubts how long this plan will last, as I understand cinder block is not ideal for ground contact and water. But I figure they'll be good for 20 years maybe, and I can always add something to the front, if I had to. I didn't treat them.

I think I may add a rebar pin to at least every other core. I wish they had a 15" piece. Not sure if I should use 12" rebar and sink em 8", or 18" rebar and sink em 10". The 18" are more than twice the cost (RIP). Any thoughts are appreciated.

Maybe I should have used retention block instead, but I'd have needed to stack them two high, which means I'd have needed to glue the entire 2nd level, or use the lip by putting them in backwards (front facing fence). More money and more hassle.

I normally build walls out of rock. This didn't warrant that, as cosmetics isn't a concern. I just need something that works. I got burned by the city drain in a flood. Once was enough. And trust me, I've done a lot more than the cinder blocks. The city needs to get their butts out here and make things right. I've already re-routed and rocked 30 feet of their drain (my side of course). They get the rest. It's a pipe that comes out from under the road. It's literally at the corner of the top of my property. My house is below. First time since I lived here (13 years) water has come out of that pipe. Their drain system wasn't ready, and neither was I.
 
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Old 10-02-14, 12:36 AM
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i got .3055555555555555555cf void per block w/o considering web ends who's right & why ? raise your hand !!!!!!!!!!!!!!!!
 
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