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GATE 2023 CE (CE1) – Question 40

Geotechnical Engineering · Compaction and one-dimensional consolidation · 2 marks · Multiple choice

With reference to the compaction test conducted on soils, which of the following is INCORRECT?

  1. Peak point of the compaction curve gives the maximum dry unit weight and optimum moisture content
  2. With increase in the compaction effort, the maximum dry unit weight increases
  3. With increase in the compaction effort, the optimum moisture content decreases
  4. Compaction curve crosses the zero-air-voids curve

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Correct answer: (D) Compaction curve crosses the zero-air-voids curve

Explanation

The zero-air-voids line is the theoretical upper limit of the dry unit weight at each water content (100% saturation). A compaction curve always stays below it and never crosses it, so D is incorrect. A, B and C are the standard behaviour.