Title: Database with Shear Tests on Non-Slender Reinforced Concrete Beams with Vertical Stirrups

Author(s): Leonardo Todisco, Karl-Heinz Reineck, and Oguzhan Bayrak

Publication: Structural Journal

Volume: 112

Issue: 6

Appears on pages(s): 761-769

Keywords: beams; database; reinforced concrete; shear reinforcement; shear slenderness; shear strength; shear tests; strut-and-tie models

DOI: 10.14359/51688055

Date: 11/1/2015

Abstract:
A database is presented with 278 tests on non-slender reinforced concrete beams with vertical stirrups. These beams are commonly referred to as non-slender beams because they have shear spandepth ratios (a/d) less than 2.4. In keeping with European terminology, the term “deep beams” is not used for these beams, because in Europe, deep beams are often defined only for ratios of a/d < 1 and always contain vertical as well as horizontal reinforcement in their web. After having applied several control/filtering criteria, 178 beams remained in the evaluation database that can be used to check conservativeness and accuracy of relevant design provisions. For example, the application of strut-and-tie models of ACI 318-14 to non-slender beams with stirrups (and without any horizontal skin reinforcement) was unconservative—that is, it yielded database analysis results that were above the desired 5% fractile. Almost all unconservative estimations were obtained for test specimens with very low amounts of stirrups. This problem can be solved either by increasing the required amount of minimum reinforcement in the vertical direction or by placing a minimum amount of reinforcement in both the horizontal and vertical direction. It is also important to note that a comparison with Kani’s shear valley showed that for a/d < 1, the valley was not filled up to the full flexural capacity, despite the presence of vertical stirrups in test specimens.