Riziko křehkého porušení železobetonových prvků konstrukčně vyztužených na účinky smyku a kroucení

Risk of a brittle failure of the concrete members with the minimum shear and torsional reinforcement

According to the ČSN EN 1992, a shear reinforcement of the concrete member does not need to be checked when no cracks occur due to the shear force and/​or the torsional moment; in such a case only the minimum shear reinforcement is required. This presented parametric study and nonlinear numerical models show that the recommendation of the Eurocode 2 may easily lead to the design of the insufficient reinforcement for common rectangular and circular cross-section. Subsequently, if a single shear crack occurs, a sudden brittle failure of the whole member may follow, for example even for a small cross-section with dimensions 100 × 300 mm.