Uncompacted

Uncompacted is an adjective used to describe material that has not been compressed or densified by pressure. It denotes a loose, unconsolidated state in which particles are not tightly packed, and porosity is relatively high. The term can apply to soils, sediments, and waste, among other materials, and implies a condition that may change upon application of load or time.

In soils and civil engineering, uncompacted soil typically has a higher void ratio and lower bulk density, which influences permeability, moisture retention, and strength. Such soils may infiltrate water readily but bear less load until compacted. Compaction is commonly used to increase bearing capacity and stability for foundations, roads, and embankments. Tests like the Proctor test determine the maximum dry density and optimum moisture content for effective compaction. Uncompacted soils are more prone to settlement under load, especially if layered or saturating conditions exist.

In geology and sedimentology, freshly deposited sediments are often unconsolidated or uncompacted. Over time, burial under overburden causes compaction, reducing porosity and expelling fluids in a process called diagenesis. The degree of compaction affects porosity, permeability, and the interpretation of sedimentary histories, and it can influence the quality of hydrocarbon reservoirs in some basins.

In waste management and handling, uncompacted materials occupy more volume and require more storage space. Compaction reduces volume and transportation costs but can affect handling, sorting, and decomposition dynamics. The term emphasizes the contrast with compacted or densified states across various disciplines.