On which of the following does the correct proportion of ingredients of concrete depend upon?
Correct Answer: D. All options are correct
📚 Detailed Explanation: Factors Affecting Concrete Mix Proportions
Why D (All options correct) is correct: The mix proportions must account for all three factors:
A — Bulking of sand: In volume batching, moist sand bulks by up to 30%. The measured volume must be corrected to deliver the intended dry sand quantity.
B — Water content: The primary variable in mix design; controls w/c ratio (strength), workability, and durability.
C — Absorption and workability: Aggregate absorption affects free water available (absorbed water is “locked up” and doesn't contribute to paste fluidity); required workability sets the target water content.
A — Bulking of sand: In volume batching, moist sand bulks by up to 30%. The measured volume must be corrected to deliver the intended dry sand quantity.
B — Water content: The primary variable in mix design; controls w/c ratio (strength), workability, and durability.
C — Absorption and workability: Aggregate absorption affects free water available (absorbed water is “locked up” and doesn't contribute to paste fluidity); required workability sets the target water content.
How Each Factor Affects Proportioning
| Factor | Effect on Proportioning |
|---|---|
| Bulking of sand | Requires increased measured volume to deliver correct dry weight |
| Water content | Sets w/c ratio; primary determinant of strength and workability |
| Aggregate absorption | Absorbed water reduces free water; must be corrected in water content calculation |
| Required workability | Determines minimum water content needed for placement |
- All three factors — bulking, water content, and absorption/workability — must be considered for correct proportioning.