Analysis of the Creep Curve Reinforced Concrete Beams in Eurocode 2 via the Three-Parameter Model

Creep is characterized by progressive deformation that occurs in concrete structures when exposed to constant loads during their operation. Factors such as air humidity, temperature, the initial consistency of the concrete, and the strength of the concrete after curing are decisive for the advancement of this phenomenon and the resulting deformation over time. In reinforced concrete beams, these deformations can increase the final deflection corresponding to the serviceability limit state, as well as cause the failure of the system at the ultimate limit state. The three-parameter model is suitable for describing the viscoelastic nature of many solids and is frequently used to study the phenomenon in various scientific fields. In this work, the creep model could be considered in two ways: first, the mathematical model for creep predicted by Eurocode 2 (European Standard EN 1992-1-1), and second, a three-parameter viscoelastic model whose parameters are adjusted to match the results obtained with the use of Eurocode. A three-parameter mathematical model was developed to accurately represent the creep curve of Eurocode 2 using computational modeling. In this context, this study seeks to understand the effects of creep in reinforced concrete structures through numerical modeling using a three-parameter model of a simply supported beam designed for usual building loads. A basic literature review on creep in concrete structures was conducted, followed by a structural analysis at different times during the commonly accepted life expectancy of these structural systems. In the simulation, the three-parameter model was used as an alternative to the creep calculation prescribed in Annex B of EUROCODE 2. During the analysis process, curves representing the investigated phenomenon were generated, considering different ambient temperature values, with the results presented in the form of graphs and tables. The adopted structural element was a rectangular reinforced concrete beam, simply supported at the ends. The adopted load was uniformly distributed. With this, it was possible to assess the displacements over time, enabling the evaluation of creep deformations at different stages of time under the influence of temperature and ambient humidity.