Methoden zur Analyse des Bruchverhaltens hochfester Stahlfaserbetone

Methods for analyzing the fracture behavior of high-strength steel fiber-reinforced concretes

High-strength and ultra-high strength fiber-reinforced concretes are most suitable for applications with extreme mechanical loads. These extreme conditions require a ductile behavior under tensile loading, which is obtained solely by the addition of steel fibers and their working mechanism. Profound knowledge on the working mechanism of the steel fibers is necessary for optimizing this material. Usually, this knowledge is obtained by means of classical measuring techniques of destructive tests. Adopting measuring techniques from non-destructive material testing helps to analyze and to identify the different stages of the fracture mechanism of high-strength and ultra-high strength fiber-reinforced concretes in detail.
The application of different non-destructive measuring techniques is shown exemplary on tensile tests conducted on an ultra-high strength fiber-reinforced concrete and its applicability for analyzing the fracture behavior is discussed. The main focus is on the characterization of the relevant failure modes under tensile loading by the different measuring techniques and the comparison with classical measuring techniques (e. g. extensometer). The tensile tests have been analyzed by optical deformation measurements using digital image correlation (DIC), acoustic emission analysis (AE), and 3D computed tomography (CT).