Which statement defines the compaction test?

Which statement defines the compaction test?

• A. A field test for measuring bearing capacity.
• B. Laboratory method of experimentally determining the optimal moisture content at which a given soil type will become most dense and achieve its maximum dry density.
• C. A test to measure pore water pressure.
• D. A method to determine soil shear strength.

Answer: (B)

Compaction tests identify how densely a soil can be packed at different moisture contents when subjected to a fixed amount of compaction effort. In the lab, you compact soil samples across a range of water contents and measure the resulting dry density. Plotting dry density versus moisture content yields a curve whose highest point is the maximum dry density, and the moisture content at that peak is the optimum moisture content. This information guides field compaction to achieve the desired density for a stable foundation. This is why the statement describing a laboratory method to determine the optimal moisture content at which a soil type becomes most dense and achieves its maximum dry density is the best fit. The other options describe different tests—bearing capacity tests, pore water pressure measurements, and shear strength tests—not the compaction test.

Compaction tests identify how densely a soil can be packed at different moisture contents when subjected to a fixed amount of compaction effort. In the lab, you compact soil samples across a range of water contents and measure the resulting dry density. Plotting dry density versus moisture content yields a curve whose highest point is the maximum dry density, and the moisture content at that peak is the optimum moisture content. This information guides field compaction to achieve the desired density for a stable foundation.

This is why the statement describing a laboratory method to determine the optimal moisture content at which a soil type becomes most dense and achieves its maximum dry density is the best fit. The other options describe different tests—bearing capacity tests, pore water pressure measurements, and shear strength tests—not the compaction test.