The process of measurement of ingredients (cement, fine aggregate, coarse aggregate and water) for making concrete is called batching.
Batching is done in two ways
1) Volume batching
2) Weigh batching
Volume batching:
- This method is generally adopted for small jobs.
- Gauge boxes are used for measuring the fine and coarse aggregate.
- The volume of gauge box is equal to the volume of one bag of cement.
- Gauge bow are also called as FARMAS.
- They can be made of timbers or steel.
- They are made generally deep and narrow.
- Bottomless gauge boxes are generally avoided.
- While filling the gauge boxes the material should be filled loosely, no compaction is allowed.
Weigh batching:
- Batching by weight is more preferable to volume batching, as it is more accurate and leads to more uniform proportioning.
- It does not have uncertainties associated with bulking.
- Its equipment’s falls into 3 general categories.
- Manual
- Semi-automatic
- Fully automatic.
- In case of manual batching all weighing and batching of concrete are done manually. It is used for small jobs.
- In case of semi-automatic batching the aggregate bin gates are opened by manually operated switches and gates are closed automatically when the material has been delivered. This system also contains interlock which prevents charging and discharging.
