Title:
Concrete Reinforced with Deformed Steel Fibers
Part II: Toughness Characterization
Author(s):
Nemkumar Banthia dn Jean-Francois Trottier
Publication:
Materials Journal
Volume:
92
Issue:
2
Appears on pages(s):
146-154
Keywords:
fiber reinforced concretes; fibers; pullout tests; toughness.
DOI:
10.14359/9765
Date:
3/1/1995
Abstract:
Four deformed commercial jibers with widely different geometries were investigated in steel fiber reinforced concrete. The fibers investigated include crimped jibers with circular and flat sections and end-deformed fibers with hooked and conical ends. Three matrixes with compressive strengths of 42, 52, and 85 MPa were reinforced with jibers at a dosage rate of 40 kg/m 3 , and properties such as compressive strength, elastic mod-ulus, etc., were determined. The focus of the study, however was toughness assessment and characterization, for which beam specimens were tested in four-point bending with accurate dejection measurements. Toughness improvements were characterized using ASTM C 1018 and the Japanese Society of Civil Engineers Standard SF-4 techniques. An attempt was also made to qualitatively relate the fiber-matrix bond-slip information generated from pullout tests in Part I of this paper to flexural load-deflection behavior. A strong influence of both fiber geometry and matrix strength on toughness characteristics of jiber reinforced concrete was observed. The jibers deformed only at the extremities were, in general, more effective than those deformed along their entire lengths. The bond-slip data appear to correlate well, at least in the qualitative sense, with the flexural load-dejlection plots. The paper points out limitations of the current methods of toughness characterization and proposes an alternative technique addressing commonly raised concerns.