Creep is a time-dependent increase of a plastic deformation under a permanent load.
In principle, it is necessary to consider creep in constructional tasks, such as mechanical engineering or civil engineering, as it affects the behavior of the respective objects to a considerable extent. Especially in the case of concrete, creep is a property that has to be considered in the design of reinforced concrete components.
Concrete creep depends on the following properties:
- Size and duration of the load (deformation increases with the duration)
- Water-cement ratio, w/c ratio (deformation increases with a higher w/c ratio)
- Type of aggregate (deformation decreases with the stiffness of an aggregate)
- Degree of hardening at the loading start
In addition, what is known as "creep-producing stress" has a significant influence on the creep deformations. Therefore, the creep effects reduce the stiffness of structural components and lead to greater deformations.
In timber structures, creep deformations must also be calculated proportionally for deflections.