daru,

Could you describe or provide a reference to this test?

Jeff

Jeffrey T. Donville, PE
TTL Associates, Inc.
www.ttlassoc.com

I believe it is a split tensile test for Rock cores.  I don't have the proper reference with me currently to comment on the specifics.

It helps make a more accurate (some say) shear strength estimation. If a rock core is broken in compression (qu), then the shear strength is taken as 1/2 that. Since shear strength is a 'two way' street, rock is not the same in tension as compression, and the tension is tested and factored into that.

Check out at the end of the FDOT Soils and Foundation Manual Appendix A downloaded at

http://www.dot.state.fl.us/structures/Manuals/SFH.04-22-2004.pdf

Hi,
Brazilian test is an indirect experimental method to measure the tensile strength of rock.
Because the strength of rocks is more pronounced in compression and shear, the tensile strength is less significant. However, tensile strength (along with the triaxial compression strength) can be used to obtain precisly the Mohr criterion of failure (cohesion and compression).
The tensile strength is also required when I do a numerical modelling of a case study in rock mechanics.

Just some backup:  ASTM D3967
Check out:
http://hrcweb.nevada.edu/qa/IPR/IPR-010R1.pdf
http://www.nhi.fhwa.dot.gov/download/material/132031/PW/RML08.pdf
  One other application is pull-out of anchors/bolts.  Usually you neglect tension in cone pull-out to be conservative.  Knowing the tension might help under some circumstances.

This test is mainly used, at least in France, for tensile strength of concrete. The test is carried out on cylindrical samples and the tensile strength is generally close to 1/10 th of the compressive strength.