EXPERIMENTAL R-CURVES FOR ASSESSMENT OF TOUGHENING IN FIBER REINFORCED CEMENTITIOUS COMPOSITES

Procedures to obtain the experimental R-Curves using a compliance calibration technique are examined. R-Curves provide a convenient means to study the process of fracture and the brittle-ductile transition in materials. Single edge notched beam specimens are tested under closed loop rack mouth opening control. The procedure to obtain the R-Curves using loading/unloading compliance and the residual displacements are discussed. An elastically equivalent toughness K(superscript)R as a function of crack extension is defined to compare the R-Curves with the available data in the literature. The developed test method is applied to fiber reinforced concrete (FRC) composites with up to 8 percent by volume of short, chopped alumina, carbon, and polypropylene (PP) fibers. Significant strengthening of the matrix due to the addition of short carbon and alumina fibers are observed. R-Curves in these composites are characterized by an increase in the steady state fracture toughness. In PP-FRC composites, energy dissipation due to fiber pullout increases the ascending rate of the R-Curve well after the main crack has formed. The work of fracture is calculated from the cyclic loading/unloading tests and the results are compared with the R-Curves.

• Corporate Authors:

  American Concrete Institute (ACI)

  38800 Country Club Drive
  Farmington Hills, MI  United States  48331
• Authors:
  • Mobasher, B
  • LI, C Y
  • Arino, A
• Conference:
  • 1995 American Concrete Institute (ACI) Spring Conference, Testing of Fiber Reinforced Concrete (Technical Sessions)
  • Location: Salt Lake City, Utah
  • Date: 1995-3-5 to 1995-3-10
• Publication Date: 1995

Language

• English

Media Info

• Features: Figures; References; Tables;
• Pagination: p. 93-114

Subject/Index Terms

• TRT Terms: Aluminum oxide; Carbon; Composite materials; Concrete; Fiber reinforced concrete; Fibers; Fracture mechanics; Mortar; Polypropylene; Toughness
• Old TRIS Terms: R curves
• Subject Areas: Highways; Materials; I32: Concrete;

Filing Info

• Accession Number: 00730750
• Record Type: Publication
• Report/Paper Numbers: SP-155-5
• Files: TRIS
• Created Date: Feb 3 1997 12:00AM