Interesting. All the cement work I had done was manual mix, well over 100 bags of mix.
Got me thinking as I have been buying 50 KG bags of cement (100 baht) and adding sand and rock. I asked on the internet:
how many kg of cement in a cubic meter?
The answer came:
In 1:2:4 concrete, you mix by volume 1part of loose cement, 2 parts of loose sand and 4 parts of loose aggregates plus water.
These 7 parts of mix + water gives you 4.44 parts of solid concrete.
The ratio of volume of loose mix / solid volume = 7 / 4.44
To have 1 cu.m. of solid concrete, we must have 7 /4.44 cu.m of loose mix.
As 7 cu. m. of loose mix contain 1 cu. m of cement, 7/4.44 cu.m. of loose mix will contain 1/4.44 cu.m of cement.
As loose cement weighs 1440 kg/ cu.m, 1/4.44 cu.m. of cement will weigh
1440/4.44 , which is 324 Kg
So if I understand the bottom line correctly, a cubic meter would be 324 KG. That would be less than 5 bags of 50 KG cement (250 KG), plus the sand, rock and water.
5 bags of cement (500 baht) Rock and Sand (price TBD, but 1000 baht of each gets a lot), and the weight of the water. I am thinking the manual mix with Thai Labor may be more cost effective.
However, in the manual mix you can end up with sand pockets that will cause holes to appear, I am finding that in my current carport.