What does construction specifications typically require for field moisture during compaction?

The requirement for field moisture during compaction is critical for achieving optimal soil density and stability. The correct answer highlights that moisture levels should generally be maintained between 1 and 5 percent above optimum moisture content.

At this range, the soil has enough moisture to facilitate the compaction process, allowing soil particles to adequately slide past each other and form a denser structure. Insufficient moisture can lead to inadequate compaction, resulting in loose soil that does not support loads effectively. Conversely, excessive moisture can lead to saturation, resulting in instability and potential failure of the compacted layer.

By specifying this range, construction specifications ensure that the moisture content is sufficient to promote effective compaction while avoiding the pitfalls associated with either extreme. This balance is essential in construction and civil engineering to maintain the integrity of structures built on compacted soils.