31. Evaluation of steel fibers for applications in structural concrete

Title: 31. Evaluation of steel fibers for applications in structural concrete
Author(s): A.E. Naaman
Paper category : conference
Book title: 6th International RILEM Symposium on Fibre Reinforced Concretes
Editor(s): M. di Prisco, R. Felicetti and G.A. Plizzari
Print-ISBN: 2-912143-51-9
e-ISBN: 2912143748
Publisher: RILEM Publications SARL
Publication year: 2004
Pages: 389 - 400
Total Pages: 12
Nb references: 36
Language: English

Abstract: Discontinuous fibers having optimized geometries for use as reinforcement of cement and ceramic matrices have been recently developed. These fibers have a primarily triangular or square cross section; they have a fiber intrinsic efficiency ratio higher than that of round fibers, and are twisted along their longitudinal axis. They are identified here as Torex fibers. When embedded in cement matrices, they exhibit under pull-out a unique slip-hardening bond behavior. Such behavior implies that the more the fiber slips out of the matrix under pull-out, the higher the apparent bond strength. Thus a composite reinforced with such fibers will develop increased resistance, when in a cracked state, leading to multiple cracking, strain hardening characteristics, large strain to failure, ductility, and increased energy absorption capacity. This paper describes several bond mechanisms associated with typical steel fibers and makes the case that maintaining a pull-out resistance up to large slips is key to the development of high performance fiber reinforced cement composites with relatively low fiber contents, of the order of 1% to 2% by volume. This simple technical result has significant implications for the practical use of fiber reinforced cement composites in large scale structural applications.

Online publication: 2004-08-30
Publication type : full_text
Public price (Euros): 0.00