ASTM D 7625 : 2010

CONTAINED IN VOL. 04.09, 2015 Defines the determination of the abrasiveness of rock by the CERCHAR Abrasiveness Index (CAI) method.

1.1 This test method covers the determination of the abrasiveness of rock by the CERCHAR Abrasiveness Index (CAI) method. The test method consists of measuring the wear on the tip of steel stylus with a cone shape and known Rockwell Hardness, caused by scratching against a freshly broken or saw cut rock surface for a prescribed 10 mm distance using one of the two test apparatus.

1.2 This test method is intended for freshly broken rock surfaces; however, saw cut surfaces are covered for when a satisfactory rock surface cannot be obtained.

1.3 Stylus Rockwell Hardness (HRC) can have a profound effect on the results and the focus of this test method is an HRC value of 55 for every test (1,2). However, there are situations where stylus with different Rockwell Hardness can be used Therefore, this test method includes discussions on stylus with different Rockwell Hardness.

1.4 All observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice D6026.

1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.