Concrete pumping logistics: under typical site conditions, concrete transported by pump is commonly limited to what approximate horizontal distance?
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A100 m
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B200 m
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C300 m
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D400 m
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ENone of these
Answer
Correct Answer: 300 m
Explanation
Introduction / Context:Pumping concrete enables placement in high-rise and congested sites. However, pump line length, bends, elevation, and mix rheology limit practical reach. Knowing typical limits helps plan pump placement and pipeline routing.
Given Data / Assumptions:
- Ordinary piston/boom pumps with steel pipelines and standard elbows.
- Good pumpable mix with suitable fines and slump.
- Question asks for a commonly quoted horizontal reach, not an extreme or specialized record.
Concept / Approach:Rules of thumb: about 300 m horizontal or about 30–40 m vertical are common practical limits for many jobs without extraordinary measures. Longer distances are possible but require special planning (larger pumps, fewer bends, lubrication, high fines content).
Step-by-Step Solution:Identify typical horizontal range: ≈ 300 m for standard setups.Select 300 m accordingly.
Verification / Alternative check:Manufacturers and guides often cite 300 m horizontal as a reference limit for standard concrete and lines.
Why Other Options Are Wrong:
- 100/200 m: too conservative for standard boom/line pumps.
- 400 m: achievable in special cases, but not the typical planning value.
- None: incorrect because a common planning figure exists.
Common Pitfalls:Ignoring equivalent length added by bends/valves; using non-pumpable mixes (gap-graded, harsh) that reduce feasible distance.
Final Answer:300 m