03-Part 4 - SM For Determining The Shore Hardness Value For Rock - 2006 PDF
03-Part 4 - SM For Determining The Shore Hardness Value For Rock - 2006 PDF
03-Part 4 - SM For Determining The Shore Hardness Value For Rock - 2006 PDF
Abstract
Shore hardness (SH) has been accepted as a convenient and nondestructive method in measuring the hardness of rocks and widely
used in rock mechanics since it can be correlated with other mechanical properties of weak rocks, such as uniaxial compressive
strength (UCS). However, a need has arisen to propose a standard method as a measure of SH to minimize the errors when it is
utilized as a predictor of the UCS as well as other mechanical properties of rocks. Over the last few decades, several studies have
been conducted to predict consistent SH values using different procedures. However, the results of the tests can not be compared
and analyzed in an overall way. Therefore, this experimental study was implemented to meet and discuss the demand for a new
method to determine standardized SH values. In result, a new empirical equation was proposed to estimate size-corrected values of
SH based on a critical specimen volume of 80 cm3.
r 2005 Elsevier Ltd. All rights reserved.
1365-1609/$ - see front matter r 2005 Elsevier Ltd. All rights reserved.
doi:10.1016/j.ijrmms.2005.04.004
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20 R. Altindag, A. Güney / International Journal of Rock Mechanics & Mining Sciences 43 (2006) 19–22
2. Scope
3. Apparatus
4. Procedure
3.1. The apparatus, a C-2 type Shore Hardness
Scleroscope (Fig. 1), used for this purpose is nondes- 4.1. Specimen preparation
tructive and measures the relative values of SH by a
diamond-tipped hammer which is manually dropped 4.1. For testing purposes, the specimens can be
vertically and freely from a rested height on to a prepared as cores or in cubical shapes and a critical
horizontal, polished test surface. specimen volume of close to 80 cm3 (Vc) should be
3.2. Since hardness is a function of the elastic maintained. Fig. 2 shows the relations between the SH
resistance of a surface to local compression, the rebound value and the associated specimen volume, and indicates
height of the diamond-tipped hammer becomes an that the SH values increased as the volume of the
indication of the hardness of the material tested. The specimens became larger—up to the critical specimen
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4.2. Testing