Title:
AN APPRAISAL OF STEEL FIBRES AS MINIMUM SHEAR REINFORCEMENT IN CONCRETE BEAMS (with Appendix)
Author(s):
Bhupinder Singh and Kranti Jain
Publication:
Structural Journal
Volume:
111
Issue:
5
Appears on pages(s):
1191-1202
Keywords:
aspect ratio; deformed steel fibers; diagonal crack; minimum shear reinforcement; shear strength; shear stress; volume fraction
DOI:
10.14359/51686969
Date:
9/1/2014
Abstract:
The shear strength of longitudinally reinforced normal-strength and high-strength concrete beams containing either hooked-end or crimped-type deformed steel fibers proposed to be used as minimum shear reinforcement has been investigated for various fiber-aspect ratios and volume fractions. The behavior of the fibrous concrete beams was benchmarked against the performance of beams conventionally detailed with the ACI Building Code-specified
minimum shear reinforcement. The validity of the Code-recommended flexural performance criteria governing the use of steel fibers as minimum shear reinforcement has been examined and their shortcomings are highlighted. For both grades of concrete, the measured shear strengths across the two fiber types, the aspect ratios, and the volume fractions under investigation were higher than a lower-bound value for steel fibrous concrete, as given in literature, as well as predicted values of conventionally detailed beams. A simple mechanics-based shear-strength predictive model considering the contribution of only the compressed concrete and
tensile resistance of the steel fibrous concrete has been proposed and validated.