Title: Shear Strength of Reinforced Concrete Beams Part 2-Tests of Restrained Beams Without Web Reinforcement

Author(s): K. G. Moody, I. M. Viest, R. C. Elstner, and E. Hognestad

Publication: Journal Proceedings

Volume: 51

Issue: 1

Appears on pages(s): 417-434

Keywords: no keywords

DOI: 10.14359/11686

Date: 1/1/1955

Abstract:
Data are presented on the shear strength of 61 restrained beams without web reinforcement. Tests were carried out in five series with the following variables: (1) concrete strength and percentage of longitudinal reinforcement, (2) beam depth, (3) ratio of shear span to effective depth of beam, (4) cutting off the reinforcement in accordance with the ACI Building Code, and (5) relative magnitude of negative and positive moments. The beams were tested with one concentrated load at each overhang and one or two concentrated loads in the span. All beams failed in shear after one or more diagonal tension cracks formed in the regions of maximum shear. Up to the formation of diagonal tension cracks, the behavior of all beams was the same as that of beams failing in flexure. Formation of diagonal tension cracks led to a new distribution of internal stresses which prevailed until failure. Magnitude of the load causing the formation of the initial diagonal tension cracks depended primarily on the dimensions of the cross section and on the strength of the concrete. Increases of load beyond the cracking load were made possible by redistribution of internal stresses. At failure, the compression zone of concrete was destroyed at the critical section. Magnitude of the ultimate loads depended primarily on the dimensions of the cross section, on the amount of longitudinal reinforcement, on the concrete strength, and on the ratio M/Vcl. Ratio of the ultimate load to the cracking load decreased with increasing rat,io of shear span to effective depth.