FRACTURE TOUGHNESS

The authors describe modifications to a simple test using a circumferentially notched round bar under bending (cnrbb) making the loading of small specimens easier. In this test the concrete specimens are subjected to eccentric loading and need to be cut cleanly to provide a flat loading surface. Stress analysis is used to derive an expression for fracture toughness. The resulting equation, expressed in terms of the stress intensity factor k, is shown graphically. No special loading rig is required for the test, and the failure load is higher than the limits of sensitivity of some testing machines. Specimens as short as 3 cm may be used with the method. It is important that the circumferential notch is deep for small specimens to prevent shear failure occurring before crack propagation at the notch. Results given from fracture toughness tests on samples from a concrete beam show less variability compared with those of other traditional tests. /TRRL/

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/00105317
• Corporate Authors:

  Cement and Concrete Association

  Wexham Spring
  Slough SL3 6PL, Buckinghamshire,   England 
• Authors:
  • Barr, B
  • Bear, T
• Publication Date: 1977

Language

• English

Media Info

• Features: Figures; References; Tables;
• Pagination: p. 30-32
• Serial:
  • CONCRETE
  • Volume: 11
  • Issue Number: 4
  • Publisher: THE CONCRETE SOCIETY
  • ISSN: 0010-5317

Subject/Index Terms

• TRT Terms: Bars (Building materials); Beams; Concrete; Deflection; Eccentricity; Equipment; Failure; Fracture mechanics; Loads; Mathematical models; Notch tests; Sensitivity; Strength of materials; Structural analysis; Tests
• Uncontrolled Terms: Concrete beams; Eccentric loading; Fracture
• Old TRIS Terms: Notch; Shear failures
• ITRD Terms: 3461: Bar; 3472: Beam; 4755: Concrete; 5586: Deflection; 3674: Equipment; 5520: Failure; 5567: Load; 6473: Mathematical model; 6242: Notch (effect); 5928: Sensitivity; 5544: Strength (mater); 5573: Stress analysis; 6255: Test
• Subject Areas: Highways; Materials; Planning and Forecasting; I32: Concrete; I72: Traffic and Transport Planning;

Filing Info

• Accession Number: 00163858
• Record Type: Publication
• Source Agency: Transport and Road Research Laboratory (TRRL)
• Report/Paper Numbers: Analytic
• Files: ITRD, TRIS
• Created Date: Dec 27 1977 12:00AM