Indirect tensile testing of anisotropic rocks

1973 ◽  
Vol 5 (4) ◽  
pp. 215-230 ◽  
Author(s):  
G. Barla ◽  
N. Innaurato
2002 ◽  
Vol 39 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Li Li ◽  
Michel Aubertin

Rocks are generally more or less anisotropic, depending on their structure at the scale of interest. In engineering applications, the magnitude of such anisotropy must often be determined for compressive as well as tensile loading conditions. In this paper, the authors present the results of an investigation on tensile failure of transversely isotropic rocks, based on Inglis' analytical solution for the stress at the boundary of an elliptical flaw. The strength of transversely isotropic rocks is assumed to be controlled by the maximum tensile local stress along the crack boundary. Equations are developed and compared with tensile test data taken from the literature. The results show that the proposed formulations represent well the direct and indirect tensile strength of anisotropic rocks as a function of bedding plane orientation. It is also shown that the proposed physical model correlates well with the results obtained from more empirical formulations.Key words: rock mechanics, anisotropy, transverse isotropy, tensile strength, Brazilian test, crack.


Author(s):  
Todd Thomas ◽  
Arlis Kadrmas ◽  
John Huffman

In 1997 an experimental partial-depth cold in-place recycling project was performed on US-283 in Kansas. Two sections approximately equal in length, one with Class C fly ash and the other with an emulsion with lime slurry, were recycled. On both sections a hot-mix asphalt overlay was placed after curing. Field observations in 1998 showed minor transverse cracking in the fly ash section, but no cracking was evident in the emulsion-plus-lime section. Transverse cracking increased in the fly ash section in 1999 and was noted for the first time in the emulsion-plus-lime section during this same evaluation. Longitudinal cracking in the wheel-paths of the fly ash section was also first observed in 1999. Rutting was not observed in either section during the evaluations. The results of Superpave indirect tensile testing in the laboratory confirmed that the fly ash section should crack before the emulsion-plus-lime section; laboratory testing with the Superpave shear tester and the asphalt pavement analyzer also indicated that the mixtures were not susceptible to rutting.


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