Sectional analysis of the flexural creep of cracked fiber reinforced concrete

Abstract

This paper presents a sectional analysis of cracked fiber reinforced concrete (FRC) under flexural loading. The approach considers three separate loading conditions: monotonic, cyclic, and creep bending loads. Different parts of the approach are experimentally calibrated and validated with tests on polypropylene FRC. In the monotonic regime, numerical optimization is used to find the optimal stress–strain relation of FRC to capture the experimental bending behavior as closely as possible, while satisfying the horizontal force and bending moment equilibrium. To model the cyclic behavior, the constitutive law is extended by introducing a tension‐only scalar damage function. The agreement between the predicted and measured response is again very good, and the measured upwards shift of the neutral axis during unloading is predicted as well. Finally, the flexural creep response of a cracked FRC beam is simulated by using uniaxial creep data. The approach predicts the time‐dependent crack widening under sustained flexural loading and can be used to check SLS criteria in the design of FRC elements.

Numerically optimized post‐cracking branch of the constitutive tensile model for fiber‐reinforced concrete with natural and recycled aggregates

“…The inverse analysis method is also well-known in the area of fiber-reinforced concrete. 45,46 Consequently, this technique is also used in current study to verify and improve the existing constitutive tensile models for FRC, T A B L E 3 Mechanical concrete properties [SD] of the glass fiber-reinforced concrete mixtures.…”

“…As an example, Ghasemzadeh et al 43 investigate the long‐term compressive creep behavior of concrete by the inverse analysis technique, while Bocciarelli et al 44 identify the hygro‐thermo‐chemical–mechanical model parameters of concrete through inverse analysis. The inverse analysis method is also well‐known in the area of fiber‐reinforced concrete 45,46 . Consequently, this technique is also used in current study to verify and improve the existing constitutive tensile models for FRC, and the applied method can be summarized by the following five steps: The notched beam's cross‐section is divided into 125 layers with a defined height of 1 mm.…”

Sectional analysis of the cyclic behavior of steel fiber reinforced concrete

“…The studies above only focus on monotonic loading; the cyclic behavior of SFRC has been studied to a limited extent with sectional analysis. Vrijdaghs et al 39 have used sectional analysis to capture the cyclic flexural and creep behavior of polypropylene fiber reinforced concrete using experimental cyclic 3PBTs. The current paper has adapted this method to avoid the need of cyclic experimental testing, by including a linear relation between the deformation at unloading and reloading, as found by Li et al 32 and Abbasnia and Ziaadiny 33 for SFRC.…”

Improvements in test methodology and characterisation of long-term flexure behaviour of fibre-reinforced concrete

“…It is worth mentioning that only publications related to experimental tests on flexure creep were included in Table 2. Publications related to modelling flexure long-term behaviour [116,117] without experimental tests and results were not included.…”