A Computational Sectional Approach for the Flexural Creep Behavior of Cracked FRC

This paper presents a computational model to calculate and predict the flexural creep behavior in a cracked fiber reinforced concrete (FRC) section. The proposed model is based on uniaxial creep data and consists of three steps. In the first step, an inverse analysis algorithm is presented to model the monotonic bending behavior of a notched FRC beam in accordance with EN 14651. A simplified and numerically optimized method is compared to experimental data and a good agreement is found. In a second step, the unloading behavior of the beam is taken into account. Calibrated on experimental data, the model is able to accurately and precisely predict the unloading behavior. Further validation comes from the location of the neutral axis, and the deformation profile. In a third step, the flexural creep behavior is predicted based on the results in the second step. The creep data is supplied in uniaxial form, which allows greater applicability across various FRC mixtures. The proposed approach is able to take into account stress redistribution following fiber fracture. Furthermore, the time-dependent effects of the stress redistributions are also accounted for. As such, the model is able to predict tertiary creep and structural failure under sustained loading.