Strain-hardening UHP-FRC with low fiber contents

This research work focuses on the optimization of strength and ductility of ultra high performance fiber reinforced concretes (UHP-FRC) under direct tensile loading. An ultra high performance concrete (UHPC) with a compressive strength of 200 MPa (29 ksi) providing high bond strength between fiber and matrix was developed. In addition to the high strength smooth steel fibers, currently used for typical UHP-FRC, high strength deformed steel fibers were used in this study to enhance the mechanical bond and ductility. The study first shows that, with appropriate high strength steel fibers, a fiber volume fraction of 1% is sufficient to trigger strain hardening behavior accompanied by multiple cracking, a characteristic essential to achieve high ductility. By improving both the matrix and fiber parameters, an UHP-FRC with only 1.5% deformed steel fibers by volume resulted in an average tensile strength of 13 MPa (1.9 ksi) and a maximum post-cracking strain of 0.6%.

[1]  Pierre Rossi,et al.  Bending and compressive behaviours of a new cement composite , 2005 .

[2]  Antoine E. Naaman,et al.  Tensile stress-strain Properties of SIFCON, , 1989 .

[3]  Antoine E. Naaman,et al.  Proposed classification of HPFRC composites based on their tensile response , 2007 .

[4]  J. Dugat,et al.  Ductal®: New ultra high performance concretes. Damage resistance and micromechanical analysis , 2000 .

[5]  Jörg Jungwirth,et al.  Zum Tragverhalten von zugbeanspruchten Bauteilen aus Ultra-Hochleistungs-Faserbeton , 2006 .

[6]  M. An,et al.  Size effect on compressive strength of reactive powder concrete , 2008 .

[7]  C. Sujivorakul.  Development of high performance fiber -reinforced cement composites using twisted polygonal steel fibers. , 2002 .

[8]  A. Naaman,et al.  Tensile Response of HPFRC Composites Using Twisted Polygonal Steel Fibers , 2003, SP-216: Innovations in Fiber-Reinforced Concrete for Value.

[9]  Y. Malier,et al.  Effect of steel fibres at two different stages: The material and the structure , 1987 .

[10]  P. Richard,et al.  Composition of reactive powder concretes , 1995 .

[11]  Ekkehard Fehling,et al.  Ultra‐Hochleistungsbeton UHPC ‐ Herstellung, Eigenschaften und Anwendungsmöglichkeiten , 2001 .

[12]  Bhushan Lal Karihaloo,et al.  CARDIFRC - Development and mechanical properties. Part I: Development and workability , 2005 .

[13]  Bhushan Lal Karihaloo,et al.  CARDIFRC® – Development and mechanical properties. Part III: Uniaxial tensile response and other mechanical properties , 2005 .

[14]  T Sedran,et al.  Optimization of ultra-high-performance concrete by the use of a packing model , 1994 .

[15]  A. Naaman.  Tensile strain-hardening FRC composites: Historical evolution since the 1960 , 2007 .

[16]  H. H. Beche.  Densified Cement/Ultrafine Particle-based Materials , 1981 .

[17]  C Fritz,et al.  OPTIMIZATION OF SIFCON MIX. FIBRE REINFORCED CEMENTS AND CONCRETES: RECENT DEVELOPMENTS. PROCEEDINGS OF AN INTERNATIONAL CONFERENCE HELD AT THE UNIVERSITY OF WALES, COLLEGE OF CARDIFF, SCHOOL OF ENGINEERING, UNITED KINGDOM, SEPTEMBER 18-20, 1989 , 1989 .

[18]  P. Rossi,et al.  High Performance Multimodal Fiber Reinforced Cement Composites (HPMFRCC) , 1997 .

[19]  Benjamin A. Graybeal,et al.  Cylinder or Cube: Strength Testing of 80 to 200 MPa (11.6 to 29 ksi) Ultra-High-Performance Fiber-Reinforced Concrete , 2008 .

[20]  Mahmoud A. Issa,et al.  Specimen and Aggregate Size Effect on Concrete Compressive Strength , 2000 .

[21]  I. Marković,et al.  High-Performance Hybrid-Fibre Concrete: Development and Utilisation , 2006 .

[22]  E. Brühwiler,et al.  Development of the mechanical properties of an Ultra-High Performance Fiber Reinforced Concrete (UHPFRC) , 2006 .

[23]  Antoine E. Naaman,et al.  High Performance Fiber Reinforced Cement Composites , 2008 .

[24]  Antoine E. Naaman,et al.  Ultra-High Performance Concrete with Compressive Strength Exceeding 150 MPa (22 ksi): A Simpler Way , 2011 .