2015 Volume 13 Issue 10 Pages 449-464
The strut-tie model approaches of current design codes have proven to be effective in the ultimate strength analysis and design of disturbed regions in structural concrete. For the reliable analysis and safe design of disturbed regions using these approaches, the effective strength of concrete struts must be determined accurately. In this study, we proposed equations for the effective strengths of concrete struts that are useful for the three types of statically determinate and indeterminate strut-tie models of reinforced concrete deep beams with shear span-to-effective depth ratio of less than 3.0. The effects of the shear span-to-effective depth ratio, the compressive strength of concrete, and the flexural and shear reinforcement ratios were reflected in the proposed equations. To validate the proposed equations, the ultimate strengths of 395 reinforced concrete deep beams, tested to failure, were evaluated by using the three types of strut-tie models with existing and proposed equations.