Vigas de gran altura de hormigon reforzado con fibras: estudio numerico y experimental

Resumo

The study of new materials for structural uses with better properties than traditional ones has
always been the object of study of scientific researches. Thus, traditional materials have been replaced

by others such as the composites, intelligent and biodegradable materials. In this context, this work con-
tributes to a better understanding of the behavior of steel and hybrid fiber reinforced concrete applied to

deep beams. The latter are structural elements loaded as beams but with small shear span/depth ratios.
They have useful applications in many structures, such as tall buildings, foundations, offshore structures,
tanks, etc. Some studies carried out in the last decades have proved that the use of steel fiber concrete
(SFRC) and hybrid fiber reinforced concrete (HFRC) in those structural elements helps to a better control
of cracking, improves the toughness and the tensile behavior. Although there are numerous publications
dedicated to the study of the behavior of this structural element, a few ones evaluate the behavior of
SFRC and HFRC deep beams. In relation to the latter, the existing information in the literature is limited
and in general it is based on experimental works. Even if the experimental data are valuable, numerical
and analytical solutions are also needed to obtain a better understanding and prediction of the behavior
and failure of mechanisms of SFRC and HRF deep beams. Conventional analytical techniques for the
study of concrete are not suitable for the analysis of elements constructed with FRC. In this work, a

numerical-experimental study of the ultimate shear capacity of SFRC and HFRC deep beams is presen-
ted. In the experimental campaign the contribution of the fibers to the shear capacity and ductility was

evaluated. To do this, reinforced concrete deep beams with traditional bars and stirrups, and SFRC and
HFRC beams without stirrups were built. In addition, a numerical model was implemented in a finite
element analysis software in which the fiber reinforced concrete (FRC) was modeled as a homogeneous
composite material. Finally, the experimental and numerical results are discussed in terms of ultimate
loads and they are illustrated by means of tables, graphs and axial load-displacement curves.