Pick up the correct statement from the following.
Correct Answer: D. All options are correct
📚 Detailed Explanation: Three Correct Statements on Workability
Why D (All correct) is correct:
(A) Higher workability = unexpected increase in moisture: On site, if measured slump is suddenly higher than the target, the most likely cause is extra water in the mix (wet aggregates, extra water added by operator). This is a quality control warning sign.
(B) Higher workability = deficiency of sand: Sand (fine aggregate) provides surface area that absorbs free water. Less sand = less surface area = more free water = more fluid mix = higher workability. A low sand content (sand deficiency) produces a more fluid, potentially prone-to-segregation mix.
(C) Dry mix = zero slump: An earth-moist or very dry mix has insufficient free water for the concrete to deform under its own weight. After removing the mould, the shape holds = zero slump.
(A) Higher workability = unexpected increase in moisture: On site, if measured slump is suddenly higher than the target, the most likely cause is extra water in the mix (wet aggregates, extra water added by operator). This is a quality control warning sign.
(B) Higher workability = deficiency of sand: Sand (fine aggregate) provides surface area that absorbs free water. Less sand = less surface area = more free water = more fluid mix = higher workability. A low sand content (sand deficiency) produces a more fluid, potentially prone-to-segregation mix.
(C) Dry mix = zero slump: An earth-moist or very dry mix has insufficient free water for the concrete to deform under its own weight. After removing the mould, the shape holds = zero slump.
Site Interpretation of Slump Changes
| Observation | Likely Cause |
|---|---|
| Slump higher than target | Extra water / wet aggregates / sand deficiency |
| Slump lower than target | Less water / dry aggregates / extra sand |
| Zero slump | Very dry mix (earth-moist condition) |
| Collapse slump | Excessive water / very high w/c |
- All three statements describe real, observable phenomena in site concrete quality control.
- Monitoring slump provides early warning of batching errors or material changes.