Caracterización experimental de la resistencia a tracción y cortante del hormigón reforzado con fibras de poliolefina

Abstract

In the last decades, certain types of non-metallic fbres have been found suitable for structural concrete elements. Polyolefn macro-fbres can meet the requirements set in the standards in order to consider their contribution in the structural design. Previous experimental campaigns carried out with polyolefn fbre reinforced concrete (PFRC) have evaluated their flexural fracture behaviour, with several amounts of fbre dosages. Given that the structural requirements were set based on the results obtained by following UNE-EN 14651:2007+A1 that only considers the flexural behaviour, the contributions of the fbres when the structural element is subjected to more complex stress states is a matter that deserves further studied. The main objective of this contribution is to assess the performance of PFRC subjected to tensile stresses and shear stresses, using low performance concrete and water/cement ratio greater than the maximum indicated by the EHE-08, that can be used in ground slabs, gutters and pipes, replacing traditional reinforcement. This was carried out developing uniaxial tensile tests and push-off tests. In order to do so, the remaining halves of PFRC samples already tested following UNE-EN 14651 were used. Two PFRC formulations were studied, one with 6kg/m3 of fbres and another with 7.5kg/m3 of fbres. In both cases 48mm-long fbres were added. These tests were also recorded in order to analyse the damage patterns and the appearance, growing and coalescence of cracks by means of digital image correlations techniques. Non-standardised test results showed a remarkable PFRC behaviour both under tensile and shear stresses. Such results confrmed the suitability of PFRC as a structural material. In addition, the test results widened the knowledge of the mechanical response of PFRC under complex stress states. © 2019 Publicaciones Dyna Sl. All rights reserved.