Which density excludes water, considering only soils and solids?

• A. Dry Density
• B. Wet Density
• C. Relative Density
• D. Bulk Density

Answer: (A)

Dry density is the density that excludes water. It measures the mass of the soil solids per unit volume after removing all moisture, so only the solids contribute to the weight. This is typically done by oven-drying a sample, which eliminates pore water and leaves behind the solids for the density calculation. Because water isn’t counted, dry density represents the density of the solids alone, not the moist or saturated state of the soil.

Wet density, on the other hand, includes the water in the pores; bulk density includes both solids and any fluids present; and relative density relates to how compact the soil is, not to whether water is included in the weight. So for a density that excludes water, dry density is the correct choice.