The effect of rock moisture on Schmidt hammer rebound: Tests on rock samples from Marion Island and South Africa

In an assessment of the influence of internal rock moisture content on Schmidt hammer readings, rebound (R) values are found to decrease with increasing moisture content. For samples of basalt, sandstone and dolerite the maximum decrease in R-values is found between oven dry values and saturated rock rebound values, the magnitude of which varies from 2 to 10 points on the R-scale. A quartzite block has the greatest decline of 6 points at 60 per cent saturation. For certain rock types under differing site-to-site field moisture conditions the moisture effect can be a significant factor in the interpretation of the relative state of weathering from rebound values. Copyright (C) 2002 John Wiley Sons, Ltd.