Abstract
Different five series of laboratory and outdoors slaking tests were carried out to investigate the resistibility of mudstone for slaking due to wetting-drying repetitions. Test results were analyzed using some indexes, those which are based on the grain size distribution obtained from sieve analysis at each cycle of the repetitions. These analyses concluded that the grain size distribution after slaking can be effectively evaluated by the negative binomial distribution, and two parameters prescribed the distribution were plotted on an unique relation curve depending on the maximum value of initial grain size distribution used in the tests.
