Abstract
The impact hardness of rock is normally determined by using a ‘Protodyakonov’ type drop hammer. However, this test cannot be applied to a wide range of rocks. Therefore, standardized impact hardness test using the ‘Protodyakonov’ type drop hammer was carried out and the correlati ons of the resulting values of impact hardness with the mechanical properties obtained from usual laboratory tests were investigated.
The results show that the impact hardness has, a generally good correlation with the tensile or the compressive strength of rocks. Therefore, the impact hardness can be used as a strength index in the estimation of rock properties. Moreover, the performance of rock drilling or machine roadway drivage can be predicted using the impact hardness of rock.
