The deformation of concrete
Deformation under instantaneous loads
As with all other materials, concrete is deformable, and is considered to exhibit linear elastic behaviour under short duration moderate loads. This means that its deformation is proportional to the applied loads.
The instantaneous elastic modulus of concrete is between 30,000 and 35,000 MPa.
Deformation under long duration loads: creep
When loads exceed a certain level, concrete behaves as a plastic body. After removal of the load there is still a residual permanent deformation, known as creep.
The deformation due to the process of creep, which continues for months or even years, is of the order of three times the instantaneous deformation.