A CRACKED HINGE BASED MESO-SCALE FORMULATION FOR RC BEAMS WITH FIBER REINFORCED CONCRETE

CAGGIANO, ANTONIO; FOLINO, PAULA CECILIA; RIPANI, MARIANELA; MARTINELLI, ENZO; XARGAY HERNÁN

New York

Congreso; 13th World Congress on Computational Mechanics (WCCM XIII) and 2nd Pan American Congress on Computational Mechanics (PANACM II); 2018

This paper aims to analyze the post-cracking behavior of Fiber Reinforced Concrete (FRC) elements. It proposes a model based on combining an appropriate fracture-based stress-crack opening relationship, for the plain concrete matrix, with proper constitutive laws for capturing the crack-bridging effect of macro steel fibers. An original meso-scale approach is followed for reproducing the complex influence of fibers on the overall response depending on the cracking onset and evolution. Particularly, bridging mechanisms such as the sliding action and the effect of the fiber hooked end are explicitly modelled. Fiber type, geometry and spatial distribution are taking into account, and, consequently, the possible presence of different types of fibers in FRC is covered by the model. The mechanical contribution of steel reinforcing bars, when available, is also taken into consideration in the current formulation. Small beams (Rilem standard) and real scale RC elements made of FRC were tested recently under four-point-bending at the University of Buenos Aires and taken as reference for calibrating purposes. Numerical analyses demonstrate the accuracy of the proposed model, as their output are in very good agreement with the experimental results. Therefore, the variations of key parameters such as the fracture energy, post-peak strength and cracking behavior with different fiber/reinforcement contents are evaluated and compared against experimental data. Research activities presented in this paper stem out of the ?SUPERCONCRETE? (H2020-MSCA-RISE-2014 n 645704) project, funded by the EU as part of the H2020 Framework Programme.