Which property indicates the total volume of empty or pore space in a material?

Porosity is a key property in civil engineering that quantifies the total volume of pore spaces, or voids, within a material, typically expressed as a percentage of the total volume. This property is crucial in understanding the storage capacity of soil or rock, especially in contexts like groundwater movement, the behavior of soil during construction, and the stability of structures.

Knowing the porosity of a material allows engineers to predict how much fluid can be stored and how readily it can move through those voids. For instance, higher porosity indicates a greater potential for water storage, which is vital in applications like foundation engineering and environmental management.

While void ratio, moisture content, and permeability are also important properties in the study of soil mechanics, they focus on different aspects. The void ratio relates the volume of voids to the volume of solids, moisture content refers to the amount of water present compared to the dry weight of the solid material, and permeability measures how easily fluids can flow through the material. Thus, porosity is the most direct measure of the total volume of empty space within a material.