A new round panel test for the characterization of fiber reinforced concrete: a broad experimental study

Standard test methods for determining the mechanical properties of Fiber Reinforced Concrete (FRC) are properly defined if they reproduce the actual structural behavior. Among many proposals, a round panel test seems to have all potentials to become an easy-to-use tool and, at the same time, a reliable procedure for the characterization of FRC, in terms of toughness and the post-cracking constitutive cohesive law. A new geometry for the round panel test is herein proposed and discussed in order to make the panel easier to place, handle, and test, therefore avoiding one of the major drawbacks that limit an extensive utilization of the panel test.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 on panels. All specimens herein compared have the same concrete mechanical properties and fiber content. The aim of the experimental investigation is to critically discuss the 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. Suitable correlations among the different fracture and energy parameters defined in the standards considered are finally reported, and the results are very useful for harmonizing the available standards.