Round panel vs. beam tests toward a comprehensive and harmonic characterization of FRC materials

Standard test methods for determining the mechanical properties of Fibre Reinforced Concrete (FRC) are better defined if they reproduce the actual structural behavior. A comparison between different test typologies for characterizing FRC is reported and discussed in the present paper, with special emphasis on the different scatter that each test produces. Tests are performed on beams as well as panels. All specimens have the same concrete mechanical properties and fibre content. Aim of the investigation is to critically discuss advantages and disadvantages of each testing procedure, focusing on the applicability of the method and on the reliability of results toward a consistent characterization of the structural behavior. A new geometry for the panel test is herein proposed and discussed in order to make the panel easier to place and handle, avoiding one of the major drawbacks which limits an extensive utilization of the panel tests. Suitable correlations among the different fracture and energy parameters defined in the assumed standards are reported, resulting very useful for a harmonization of the available standards. Moreover, an analytical study is finally carried out focusing on the determination of the constitutive σ-w law of FRC materials from panel tests. Results from the analytical study are compared with the experimental results and critically discussed.