Weight or mass and density of concrete
The weight or mass of a cubic metre of concrete can be expressed as a density. Typically density is expressed as mass divided by volume. The self weight of a concrete element is high and can contribute a high proportion of loading on a structure.
A wide range of concretes of differing densities are used in the construction.
Using a concrete with a lower density may have significant benefits in terms of smaller section size and reduced overall weight therefore allow a reduction in foundation size. Conversely a concrete with a high density can be used as radiation shielding around hospital equipment as well as nuclear devices.
In specialist construction, such as offshore gravity oil platforms, the buoyancy for floatation is critical for stability and a low weight high performance concrete is beneficial.