Title: Ultimate Torsional Properties of Rectangular Reinforced Concrete Beams*

Author(s): G. C. Ernst

Publication: Journal Proceedings

Volume: 54

Issue: 10

Appears on pages(s): 341-356

Keywords: no keywords

DOI: 10.14359/11443

Date: 10/1/1957

Abstract:
Principal object of this investigation was to determine the quantity of transverse steel required to develop the yield point in longitudinal bars placed in the corners of rectangular beams subjected to pure torsion. Eighteen tests are reported: six each with #3, #4, or #5 longitudinal bars, on.e in each corner. Transverse ties were spaced at 2% 14, 7, and 4 in., and also in pairs at 4 in. for each group all of #2 size. One beam in each group contained no transverse reinforcement, and the nominal concrete strength of all groups was 4000 psi. Results indicate that yield strains can be developed in longitudinal corner bars as well as in transverse ties, resulting in either a diagonal tension type of fracture or a hybrid failure in transverse shear and diagonal tension. Initial cracking corresponded to, the failure of unreinforced concrete in torsion for all beams, at an average unit shearing stress of 312 psi. Evidence also developed supporting the concept of a transition from elastic to plastic states of as the ratio of transverse t o longitudinal steel approaches unity. Stress