What does compaction testing help determine for site contractors?

Compaction testing is an essential process in construction and site development that helps determine the specific compaction value that must be achieved for the soil on a construction site. By conducting compaction tests, contractors can assess the soil's density in relation to its maximum density, which is crucial for ensuring that the soils have been adequately compacted to support structural loads and prevent settlement.

Achieving the specified compaction levels is vital for creating a stable foundation. Insufficient compaction can lead to issues like settlement, tilting, or cracking of structures over time. Thus, understanding the specific compaction value enables site contractors to meet engineering specifications and ensure the quality of the site preparation.

The other options, while related to site conditions and preparation, do not directly pertain to the role of compaction testing. Determining the type of soil moisture present, excavation depth, or cost estimates of materials does not fundamentally involve the assessment of how well the soil has been compacted. Hence, the core focus of compaction testing lies in identifying the precise compaction value required to secure a solid foundation for future construction.