Title:
Deformation and Ultimate Strength in Flexure of Reinforced Concrete Beams Made with Steel Fiber Concrete
Author(s):
R. N. Swamy and Sa’ad A. AI-Ta’an
Publication:
Journal Proceedings
Volume:
78
Issue:
5
Appears on pages(s):
395-405
Keywords:
beams (supports); cracking (fracturing); crack width and spacing;deflection; deformation; fiber reinforced concretes; flexural strength; metal fibers; structural analysis.
DOI:
10.14359/10525
Date:
9/1/1981
Abstract:
Tests are reported on the influence of fiber reinforcement on the deformation characteristics and ultimate strength in flexure of concrete beams made with 20 mm maximum size of aggregates and reinforced with bar reinforcement with specified minimum yield strengths of 460 and 617 N/mm2, respectively. The fiber concrete was provided either over the whole depth of the beam or in the effective tension zone only surrounding the steel bars. It is shown that while ultimate strength is increased only marginally, the fibers arrest advancing cracks and increase postcracking stiffness at all stages of loading up to failure which results in narrower crack widths and substantially less deformation. The tests showed that at failure the concrete compressive strains reached values of 0.005 to O.006 and the steel bars attained stresses well in excess of their yield strengths. An ultimate strength theory based on British and American codes and taking in to consideration the increased steel strains at failure is presented and shows very good agreement with the strength data. It is also shown that the value of the bond efficiency factor is not critical to the analysis.