The long-term service behavior of modern concrete structures, whose final static configuration is frequently the result of a complex sequence of phases of loading and restraint conditions, are influenced largely by creep.
Creep substantially modifies the initial stress and strain patterns:

• increasing the deformations induced by sustained loads
• relaxing the stresses due to sustained imposed deformations (either artificially introduced, e.g. by jacking, or due to natural causes like shrinkage or settlements)
• activating the delayed additional restraints.

The resulting influences on serviceability and durability are twofold, creep acting both positively and negatively on the long-term response of the structure.
Reliable methods for the estimation of these effects are necessary to appropriately define the safety levels, with prevailing regard to serviceability, and to adopt the convenient countermeasures. In fact, unreliable approximations or purely qualitative and sometime theoretically unjustified interpretations, are still encountered rather frequently in professional practices.
The present site is intended to offer all the convenient design aids for an adequate computation of the creep structural effects.
A special emphasis is given to the compact formulations derived directly from the fundamental theorems of the theory of linear viscoelasticity for aging materials and based on the use of the fundamental functions characterizing the properties of concrete. Such solutions – that are based on the assumption of homogeneous concrete properties throughout the structure – are particularly helpful in the preliminary design stages and in checking the final numerical investigations.
The design aids section allows to obtain in real time (downloadable software) the fundamental functions for the principal creep prediction models considered by international codes and technical guidance documents.
However, the same section offers all the necessary information for performing numerical computations through the availability – as a downloadable software – of the numerical program for the solution of the typical Volterra integral equations.
In alternative, if the algebrized Age Adjusted Effective Modulus method is adopted, the aging coefficient for every creep prediction model can be derived in real time.