New Formula for Creep of Concrete in fib Model Code 2010

Advances in concrete technology and the adoption of new materials have required the calibration of a new model for creep of
concrete in the fib Model Code 2010. The model covers also a wider range of concrete grades. The main factors affecting the
prediction of concrete creep are limited to code-type levels. To describe creep, a well-established concept for basic creep has
been developed. In the paper, for the presentation and comparison of creep deformation, creep coefficients and creep function are
used as the most common and comprehensive parameters for the time-dependent analysis of concrete structures. The presented
creep data are calculated using a standard computer spreadsheet program. The fib MC2010 model for creep introduces
improvements in the analysis and assessment of the time-dependent deformation of concrete structures. The complexity of creep
prediction is significantly reduced and a range of influencing parameters is excluded from the model for simplicity and easy
adoption at the design level. Simple comparison with previously used creep models allows it to be stated that the fib MC2010
generally gives even higher values of final creep deformation than Eurocode 2. The model predicts final creep coefficients for up
to 50 years of loading with good approximation, but results of recent practical observations show higher values of creep after 30
to 50 years in service.