Una comparativa normativa – experimental sobre el hormigón reforzado con fibras sometido a esfuerzo de corte directo

The structural concrete codes allow considering the contribution of the fibres in the structural design of fibre reinforced concrete (FRC) according to the results of fracture tests in Mode I. However, regarding fracture in Mode II, it is not clear that such residual strengths (Mode I) are appropriate to be used for structural design. In addition, by using fibres it is possible to reduce the steel bars reinforcement and, in shear, to eliminate the stirrups. In order to deepen the knowledge of the FRC subjected to shear, an experimental campaign on FRC with steel and polyolefin fibres subjected to shear loadings was developed through push-off testing. The tested specimens were the remaining halves of previous bending tests, so the residual strengths were known in accordance with the regulations. Such strengths were compared with Mode II fracture tests resulting that normative values being very conservative for small shear slips. When the slip increased, regulatory and experimental strength values were similar and for larger slips, the normative led to higher values.