Test Method Title
Total Hardness
Reference Number
ISRM & Tarkoy
Material
Rock
Test Property
Hardness
Description of Test
The Total Hardness test was developed to make reliable predictions of TBM performance. The Total Hardness is a composite index incorporating both a measure of rock hardness and rock abrasivity. Total Hardness is calculated from the results of a Schmidt Hammer Hardness and a Modified Taber Abrasion Hardness.
Number of Test Specimens
1
Test Specimen Size
A minimum of 6 in of core,; 8 in of core preferred
Keywords
hardness, total