Aggregates moisture management: which on-site stockpile practices help keep aggregate moisture content nearly constant for accurate concrete batching?
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AProvide a larger plan area for each stockpile to reduce localized wetting/drying
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BLimit the height of each stockpile to not more than 1.50 m
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CAllow the stockpile to stand for about 24 hours before use to stabilize moisture
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DAvoid conical heaps that promote runoff and non-uniform moisture
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Eall the above
Answer
Correct Answer: all the above
Explanation
Introduction / Context:Accurate water–cement ratio control demands predictable aggregate moisture. Poor stockpile practices cause random moisture swings, leading to inconsistent workability and strength.
Given Data / Assumptions:
- Aggregates stored outdoors in open yards.
- Objective is uniform moisture prior to batching.
Concept / Approach:Large plan area and limited height reduce internal drainage gradients; avoiding cone piles minimizes moisture stratification; a 24-hour stand time lets moisture equalize throughout the pile.
Step-by-Step Solution:Adopt flat, well-drained bases with larger pile footprints.Restrict pile height to about 1.5 m to limit compaction and runoff channels.Avoid conical heaps to reduce edge drying and funnel drainage.Stabilize moisture by leaving piles for ~24 h before use.
Verification / Alternative check:Ready-mix quality manuals and IS 2386 practices echo these measures to keep moisture predictable.
Why Other Options Are Wrong:
- Each listed measure contributes to moisture uniformity; omitting any increases variability.
Common Pitfalls:
- Skipping moisture corrections in batching even after good stockpiling, defeating the purpose.
Final Answer:all the above