INFLUENCE OF THE THICKNESS OF THE COMPRESSION HEAD ON THE FRACTURE OF REINFORCED CONCRETE T-BEAMS

Luiz Carlos de Almeida  Gonzalo Ruiz       

Anales de la Mecánica de la Fractura, nº 25 . 2008 . Pág. -
Ver (.pdf): 9-4

Resumen: The experimental program reported in this paper was planned to investigate the influence of the thickness of the compression head on the fracture of reinforced concrete T-beams. Particularly, we wanted to corroborate numerical predictions by Ruiz and Carmona (G. Ruiz and J.R. Carmona, Mater. & Struct. 39, pp. 343-352, 2006) indicating that such effect is analogous to the effect of the size on the fracture process, i.e. the strength of the beam should vary differently than expected according to traditional mechanics. Besides, in the case of T-beams, the initiation of the crack propagation through the head should also generate a secondary load-peak. To do that we chose scaled T-beams made out of a micro-concrete whose head varied in width from the limit case of the T becoming a rectangle to having a headthickness equal in length to the beam depth. The micro-concrete mechanical and fracture properties as well as the properties of the steel re-bars and of the interface between the two materials were all obtained from independent tests. The experimental results demonstrate that the cited numerical predictions were correct, since we get a shape-effect curve for the beam strength that resembles variations due to changes in the size. Besides, the beginning of the propagation of the crack through the beam head provokes a secondary load-peak, although it is milder than that predicted numerically.

LocalizaciónSigüenza

Faculdade de Engenharia Civil, Arquitetura e Urbanismo, Universidade Estadual de Campinas Avenida Albert Einstein, 951 13083-853 Campinas, Brasil
E.T.S. de Ingenieros de Caminos, Canales y Puertos, Universidad de Castilla-La Mancha Avda. Camilo José Cela s/n 13071 Ciudad Real, España