We used to call these cinder blocks but I guess the proper term is Concrete Masonary Unit. Anyway, I am wondering what the typical strength of these blocks is supposed to be. The reason I ask is because I am an American (retired Air Force) living in the Philippines and block makers here are a dime a dozen. I just walked my dog about 4 kilometers and we probably passed by 4 or 5 block makers. The problem is the block they make is worthless by US standards. Much of it is hand packed into forms and stacked in the sun to dry. There is so little cement in the blocks it has to be covered to protect it from the rain. Masons can actually cut the block with a trowel. After a wall is built here they smear it with concrete in a stucco like fashion or the rain would soon leave it a pile of sand. There are some machine made block here which are better but still not very strong. I did find one place that makes a 6X8X16 block that they say is rated at 750psi and a friend used it to build his wall. He said that when they dropped one from 10 ft up it didn't break. I know US block must be stronger than that though. I believe it is due to kiln drying. Is that correct? I have a rather large wall and eventually house project coming up. The wall will require around 3000 block and no idea on the house yet. So I am considering buying my own block maker which will make 6X8X16 blocks 3 at a time for about $800. I would then be able to know what went into the block first hand. Would I be able to make stronger block than 750psi or would that require additional equipment? Thanks and God bless, TJ

I'm trying to figure out my required materials for a large wall project. I know that an 80lb sack of premix makes about 2/3 ft^3 of concrete. We don't get premix here and have to mix ourselves. Our bags of portland cement are 40Kg or 88.2 lbs. so if that were premix it would be .735 ft^3. If we did a 123 mix with 2 bags sand and 3 bags gravel (which is pretty strong I believe) that would be 6 bags of material producing 4.41 ft^3 or about 1/6th yd^3 or 1/8 mtr^3. Is this correct logic or am I missing something here?