CST (Core Strangle Test) is a new indirect testing apparatus for determination of rock material strength.

The basis of the proposed testing method partly depends on the indirect determination of the UCS by point load index testing method. The main problem related to point load index testing method is sourced from the loading of very small area (point) in spite of the heterogeneity and anisotropy of the rocks. In order to overcome this problem, a new testing method in which loads are applied through a circle (line), had been developed. Thus, loaded numbers of points were extremely increased. The Core Strangle Test (CST) is intended as an index test for the strength classification of rock materials, and for determination of unconfined compressive strength. The test measures the Core Strangle Index (CSI) of rock specimens in the form of core having a length of 25 mm or more, and rock specimens are broken by the load applied through a circle perpendicular to the core axis as a “strangle”. The test can be performed with portable equipment in the laboratory. If the facility for coring the rocks is available, it can also be conducted in the field.

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Recommended papers for details of CST:

Yilmaz, I. 2009. A new testing method for indirect determination of the unconfined compressive strength of rocks. International Journal of Rock Mechanics and Mining Sciences, 46 (8): 1349-1357.

Yilmaz, I., 2010. Use of the Core Strangle Test for tensile strength estimation and rock mass classification. International Journal of Rock Mechanics and Mining Sciences, 47 (5): 845-850.

Yilmaz, I., Yucel, Ö., 2014. Use of the core strangle test for determining strength anisotropy of rocks. International Journal of Rock Mechanics and Mining Sciences, 66, 57-63.

It is very interesting tool for determination of UCS indirectly.

I also congratulate the already published article in IJRMMS related to the performance on the use of CST in determination of strength anisotropy of rocks.

It was interesting.