Which test result is used in the field density test for soil?

In the context of field density tests for soil, the compaction test is pivotal as it directly measures the soil's density achieved through compaction processes. This test provides data on how much the soil has been compacted, which is vital for ensuring that a soil layer will bear loads adequately in construction applications.

The compaction test is often conducted in situ, which means it occurs at the actual site of construction, to determine the degree of compaction achieved compared to the maximum compaction possible for that specific soil type. This information is crucial for engineers to assess whether the soil meets the necessary specifications for structural support.

Other tests, such as the plasticity test, sieve analysis test, and moisture content test, provide valuable information about the soil’s characteristics, such as its behavior under stress, grain size distribution, and moisture level, but they do not directly quantify the in-place density of the soil. These tests contribute to the overall understanding of soil properties, but the compaction test is specifically designed to evaluate the effectiveness of the compaction effort and is therefore the correct choice for field density assessment.