Whether small manual block machine, movable brick machine, hydraulic automatic block production line you use, cement ratio is similar. You can add cement ratio from 5%-12%. This according to your other material quality and concrete block quality you want.
Common raw material:
- Cement, sand and small stone(stone powder)
- 10% cement in weight, 45% sand and 45% stone(stone powder)
- 10% cement in weight, 30% sand and 60% stone
- Cement, fly ash ,sand and gravel or stone powder
- 12% cement in weight, 4% fly ash, 30% sand and 54% gravel
- 12% cement in weight, 4% fly ash, 84% stone powder
- 8% cement in weight, 50% fly ash, 7% sand and 35% gravel
- 8% cement in weight, 50% fly ash, 42% stone powder
Note: cement quantity you can adjust according your sand and stone quality. Usually from 5-12%. If stone powder have big stickiness, you can add more sand and decrease cement.
Mixing dry material about 30s is better, then shower water little by little.
The water/cement ratio is very important. the water/cement ratio should be 0.3-0.4.
You can also use construction dustbin or other material as concrete hollow block raw material.