New Formula for Creep of Concrete in fib Model Code 2010

Description

Advances in concrete technology and the adoption of new materials have required the calibration of a new model for creep ofconcrete in the fib Model Code 2010. The model covers also a wider range of concrete grades. The main factors affecting theprediction of concrete creep are limited to code-type levels. To describe creep, a well-established concept for basic creep hasbeen developed. In the paper, for the presentation and comparison of creep deformation, creep coefficients and creep function areused as the most common and comprehensive parameters for the time-dependent analysis of concrete structures. The presentedcreep data are calculated using a standard computer spreadsheet program. The fib MC2010 model for creep introducesimprovements in the analysis and assessment of the time-dependent deformation of concrete structures. The complexity of creepprediction is significantly reduced and a range of influencing parameters is excluded from the model for simplicity and easyadoption at the design level. Simple comparison with previously used creep models allows it to be stated that the fib MC2010generally gives even higher values of final creep deformation than Eurocode 2. The model predicts final creep coefficients for upto 50 years of loading with good approximation, but results of recent practical observations show higher values of creep after 30to 50 years in service.