## A method is described for determining the fracture toughness of plain concrete from three-point bend specimens which accounts for the pre-peak crack growth that occurs upon loading. The fracture toughness so determined is shown not to depend on the size and geometry of the test specimen but on
Effective crack model for the determination of fracture toughness (KIce) of concrete
โ Scribed by B.L Karihaloo; P Nallathambi
- Publisher
- Elsevier Science
- Year
- 1990
- Tongue
- English
- Weight
- 80 KB
- Volume
- 35
- Category
- Article
- ISSN
- 0013-7944
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โฆ Synopsis
A method is described for determining the fracture toughness of plain concrete from three-point bend specimens which accounts for the pre-peak crack growth that occurs upon loading. The fracture toughness so determined is shown not to depend on the size and geometry of the test specimen but on the mix variables only. The regression equations presented for determining the effective notch depth should be very accurate because they are based on an analysis of not only the authors' test data but that of several researchers around the world. They are shown not to depend on the size and geometry of test specimens. In fact, although these expressions were developed using three-point bend data, it is shown that they may be applicable to CT, CLWL, and four-point bend specimens. It is also shown that the predictions of the effective crack model are in good agreement with two non-linear models namely, the two parameter model and the size effect law.
๐ SIMILAR VOLUMES
To evaluate the parameters in the two-parameter fracture model, i.e. the critical stress intensity factor and critiLcal crack tip opening displacement for the fracture of plain concrete in Mode 1 for the given test configuration and geometry, considerable computational effort is necessary. A simple
analysis of fracture toughness test data should provide dist~butional parameter estimates for the population of toughness predictions for use in integrity assessments. Standard statistical techniques are available which provide such information where the appropriate distributional form is normal but
## Abatrac-Equations based on the fictitious crack model (FCM) for a mode I crack in concrete are developed. Once the material properties-the strain softening diagram-are evaluated through experiments, the length of the fracture process zone, the fracture stress and the stress distribution ahead o
Fracture toughness tests have been carried out on two different heat-treated steels 60Si2MnA using both through-cracked specimens with different a/W ratios and semi-elliptical cracked ones with variable crack size and shape. Effects of crack depth and shape on fracture toughness have been studied. R