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.
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Corporate Authors:
American Concrete Institute (ACI)
38800 Country Club Drive
Farmington Hills, MI United States 48331 -
Authors:
- Mobasher, B
- LI, C Y
- Arino, A
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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