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Abstract

Cerchar abrasivity index (CAI) test is widely used for determining the abrasivity of rocks. This test is applied to estimate bit life and determine the wear in various mining and tunneling machines. The results of tests in different laboratories have been showing some variations depending on type of test apparatus (classic or West) and tested specimen surface conditions. In this study, the effects of these factors on CAI tests were investigated. In this context, CAI tests were performed using two separate testing apparatus both on rough and on saw cut specimen surfaces of 13 different rock samples. The results indicated that there are some differences between rough and saw cut specimen surfaces. It was also founded that rough surface CAI values were generally higher than the saw cut surface values. In addition, the statistical analysis in these experiments revealed that there exist linear relationships between CAI values on rough and saw cut surface. Additionally, CAI values on rough surface is about 15% higher than CAI values on saw cut surface. However, it was seen that the type of testing apparatus has insignificant effects on CAI measurements. Because, CAI measured by Classical test device was found higher than CAI measured by West apparatus and the difference was about 1%.