Analysis of the Leeb Hardness Test Data Obtained by Using Two Different Rock Core Holders

Authors : Nurdan GÜNEŞ YILMAZ, R Mete GÖKTAN

Pages : 24-31

Doi:10.19113/sdufbed.28343

View : 18 | Download : 11

Publication Date : 2018-03-01

Article Type : Research Paper

Abstract :In this study, an investigation was carried out to elucidate if the core holder type affects the measured Leeb hardness values insert ignore into journalissuearticles values(HL); of rock materials obtained by using the Equotip hardness tester. To achieve this goal, NX-size core specimens of different rock samples were subjected to Leeb hardness testing by employing an ‘Arch-shaped’ and a ‘V-shaped’ core holder. The results indicated a strong degree of linear correlation insert ignore into journalissuearticles values(R 2  0.95); between mean rebound hardness values determined in the arch-shaped holder insert ignore into journalissuearticles values(HL A ); and V-shaped holder insert ignore into journalissuearticles values(HL V );. The maximum difference in HL values obtained from the two holders was 74.2 units on the HL-scale, corresponding to a difference of 10.2 %. Although the differences in magnitudes of HL A and HL V values were small and varied from one rock variety to another, there was a tendency of the V-shaped holder to give relatively lower values. On the other hand, when compared to the minimum values, a higher statistical correspondence was observed between maximum HL A and HL V values. The results also showed that it is possible to predict uniaxial compressive strength of the tested rocks reliably by employing any of the holders.
Keywords : Core holder, Equotip hardness tester, Leeb hardness, Uniaxial compressive strength, Rebound hardness