The leeb (Equotip) hardness test for rock materials: An overview, assessments on the factors influencing test results, and prediction models based on a large database
Reşat Ulusay, Hakan Ersoy, Muhammet Oguz Sünnetçi, Murat Karahan
Abstract
Abstract This study aims to assess several factors affecting Leeb hardness (LH) test results for rock materials. Regression models for predicting some strength and deformability properties from L D values were proposed and compared based on a larger database from a comprehensive experimental program conducted and those compiled from the literature. The results indicate that Single Impact Method (SIM) is the most suitable method to obtain more reliable L D values when compared to Repeated Impact Method (RIM). In addition, RIM causes the formation of pits and bulges on the sample surface. 15 single impacts are sufficient to determine L D value that statistically represents optimal number of impacts to be applied. The test should be performed on samples with a length of (L) ≥ 50 mm (L/D ≥ 1) and the impacts should be applied by leaving a minimum distance at least equal to the diameter of the tester supporting ring from sample edge.