Title: Effect of Axial Compression on Shear Strength of Reinforced Concrete Frame Members*

Author(s): J. W. Baldwin, Jr. and I. M. Viest

Publication: Journal Proceedings

Volume: 55

Issue: 11

Appears on pages(s): 635-654

Keywords: no keywords

DOI: 10.14359/11379

Date: 11/1/1958

Abstract:
An experimental investigation was conducted to determine the effect of axial compression on the shear strength of reinforced concrete members without web reinforcement. It involved tests of knee frames with ratios of axial force to shear varying from 0 to 6, and covered the entire range from failure caused by shear in the absence of axial load to failure caused by eccentric compression. The investigation was an extension of an earlier study involving specimens with the axial load equal to shear and specimens with no axial load, and was thus limited almost entirely to variations of the load ratio. The observed diagonal tension cracking loads were found in good agreement with the results of the earlier study. On the other hand, the shear compression strength was found to increase with axial load considerably faster than indicated by the earlier tests. A modification of an empirical parameter in an existing theoretical expression for the ultimate strength was found necessary. This modification suggests that at shear compression failure the compatibility of strains, as well as the equilibrium of forces, is a function of the axial load.