Resumo

TENA COLUNGA, Arturo; URBINA CALIFORNIAS, Luis Angel  e  ARCHUNDIA ARANDA, Hans I.. Continuous reinforced concrete haunched beams designed to fail in shear. Part 2: shear-resisting mechanics. Ing. sísm [online]. 2017, n.97, pp.35-63. ISSN 0185-092X.  https://doi.org/10.18867/ris.97.452.

Research results and interpretations of the testing of five prototype continuous reinforced concrete beams (four haunched and one prismatic) designed to develop a shear failure under cyclic loading are presented. Subject beams were tested with minimum shear reinforcement. The studied haunched length is one-third the effective span of the beam. The considered angles of slope of haunch from horizontal vary from 00 (prismatic) to 100. Cyclic tests were displacement-controlled, and two cycles at the same displacement were set in the displacement history which considers a geometrical increment of target displacements. The parameters under study with respect to the shear-resisting mechanism are: (a) the angle of haunch from horizontal and its impact on the concrete strength, (b) the contribution of the inclined longitudinal steel reinforcement, (c) the contribution of the transverse steel reinforcement and, d) the angle of inclination of the main shear crack. Previously proposed design equations were examined based upon: a) the section approach and, b) strut-and-tie (truss model). It was confirmed that, for design purposes, reasonable assessments of the shear strength of haunched beams are obtained with the proposed equations.

Palavras-chave : haunched beams; shear strength; section design approach; strut-and-tie models.