Title: Combined Torsion and Flexure Tests on Reinforced Rectangular Concrete Beams

Author(s): K.T. Sundara, Raja Iyengar and N. Rampra-Kash

Publication: Journal Proceedings

Volume: 71

Issue: 7

Appears on pages(s): 362-367

Keywords: beams (supports); bending; flexural tests; hoops reinforced concrete; research; structural design; structural engineering; torsion tests; trusses; web reinforcement.

DOI: 10.14359/7099

Date: 7/1/1974

Abstract:
Results Of tests on 30 rectangular reinforced concrete beams under torsion and flexure are reported. The reinforcement superposition principle of design for combined torsion and flexure is assessed, with the help of 25 beam results. The five other beams had reinforcements ranging from one beam with no web reinforcement to one with a large amount of web reinforcement. The amount of longtitud ina reinforcements in these five beams were small, con-stitu ting a class of beams corresponding to beams for low Some of the beams tested had a hoop spacing flexure levels. corresponding to half the larger dimension of the hoop cage and had a longitudinal bar at each of the centers of the larger sides of the hoop cage The predicted strengths from the ACI equations the skew bending approach equations Of Collins et al., and the truss analogy approach equations of Lampert et al, are compared. The skew bending approach is found to be and less conservative for these test results than the sui table, other two, A study of the results on the superposition tests shows that the principle is safe. lt must yet be pointed out the web reinforced beams were that in these beams provided with one longltudrnal bar at each of the centers of the lalger sides of the hoop cage. An analysis of all the results from different Perspectives with the ACI recommendations in view shows that a maximum hoop spacing limit of half the larger dimension of the hoop cage is adequate for these beams. It is felt that a longitudinal bar at each of the centers of the larger sides of the hoop cage should be provided to carry the horizontal component of the diagonal tension. All these aspects are discussed, including the provi-sions on longitudinal bars and their spacings.