Which process refers to the proper and accurate measurement of concrete ingredients for uniformity of proportion?
Correct Answer: D. Batching
📚 Detailed Explanation: Batching — Accurate Measurement of Concrete Ingredients
Why D (Batching) is correct: Batching is defined as the process of measuring concrete ingredients in the specified proportions, either by volume or by weight, before mixing. It is the quality control step that ensures every batch of concrete has the same composition and therefore the same properties.
Batching Methods
| Method | How Measured | Accuracy | IS Code Requirement |
|---|---|---|---|
| Volume batching | Gauge boxes (farmas / measure boxes) | Lower (affected by bulking, packing) | Permitted for M15 and below |
| Weigh batching | Weigh batchers, platform scales, load cells | High (mass unaffected by moisture/bulking) | Mandatory for M20 and above (IS 456) |
Distinguishing Similar Terms
| Term | What It Means |
|---|---|
| Grading | Size distribution of aggregate particles; determined by sieve analysis |
| Curing | Maintaining moisture and temperature for strength development |
| Mixing | Combining measured ingredients into homogeneous concrete |
| Batching | Accurately measuring ingredients before mixing |
- Batching = accurate measurement of concrete ingredients in specified proportions.
- Weigh batching is more accurate than volume batching and mandatory for structural concrete (IS 456, M20+).
- Water batching must account for the free moisture in aggregates to maintain the target w/c ratio.