Hourglass-shaped specimen: Compressive strength of concrete and mortar (numerical and experimental analyses)

  • Ulisses Targino Bezerra IFPB
  • Salustiano Souza Alves IFPB
  • Normando Perazzo Barbosa UFPB
  • Sandro Marden Torres UFPB

Abstract

Cylindrical specimens whose diameter is equal to half its height have been used worldwide. The statistical scattering in experimental testing of cementitious materials is a phenomenon known in literature and one reason is linked to the geometry of the specimens, which implies the possibility of different failure modes. This paper shows the evaluation of an hourglass-shaped sample , in which the highest stress occurs at the centre of the specimen, with negligible influence of stress distribuition from its ends. An amount of 260 cylindrical and hourglass samples were tested, with varying water/cement ratio and age. FEM analyses showed that stress in the central part of the hourglass specimens is 2.25 higher than that present at its ends. Modes of failure occured in differente ways in cylindrical specimens, whereas only one mode of failure was verified in hourglass specimens. The cylindrical samples showed bimodal frequency distribution, demonstrating the influence of the central part (material properties) and of its ends (boundary conditions), while the hourglass displayed a Gaussian distribution.
Published
Jul 12, 2016
How to Cite
BEZERRA, Ulisses Targino et al. Hourglass-shaped specimen: Compressive strength of concrete and mortar (numerical and experimental analyses). RIEM - IBRACON Structures and Materials Journal, [S.l.], v. 9, n. 4, july 2016. ISSN 1983-4195. Available at: <http://revistas.ibracon.org.br/index.php/riem/article/view/797>. Date accessed: 21 july 2019.
Section
Artigos