Determination of rock abrasivity using the LCPC test - Recommendation No. 24 of the Commission on Rock Testing of the Deutsche Gesellschaft fur Geotechnik e. V.

The Commission on Rock Testing of the Deutsche Gesellschaft fur Geotechnik e. V. (German Geotechnical Society) is compiling instructions for rock testing in laboratory and in situ and for monitoring of rock masses and civil engineering structures. This recommendation No. 24 deals with the LCPC test for investigating hard rock samples in order to determine the abrasivity and the crushability of hard rock. The requirements for the test facility and sample preparation as well as the procedure for carrying out and evaluating LCPC tests are specified. The LCPC test was developed by the Laboratoire Central des Ponts et Chaussees and is used to classify the abrasivity and crushability of rock. This recommendation takes into account the French standard NF P 18-579: 2013-02 [1], but goes beyond it in terms of testing procedure and evaluation. The abrasivity index is determined by exposing a defined steel test plate to a granular sample at a defined speed of rotation for a defined amount of time. The material loss of the test plate is measured and applied for the calculation of an index value for the abrasivity of the original hard rock sample. In addition, an index value for the crushability can be determined from the change in grain size compared to the initial sample.