APPLICATION OF THE SONIC TEST TO EXPERIMENTAL FREEZE-THAW STUDIES IN GEOMORPHIC RESEARCH

Frost action is normally regarded as the primary mechanism responsible for rock disintegration and the production of fines in cold climates. However, the results of previous studies aimed at establishing its effectiveness on the basis of weight loss incurred or the amount of debris liberated by samples during experimental freeze-thaw have been inconclusive. In this study, a sonometer is used to detect the progressive deterioration in the strength of 2 carbonate rocks during a sequence of freeze-thaw cycles by measuring the reduction in Young's modulus. The results are compared with those derived from the more conventional weight loss procedure. Hand specimens and trimmed blocks lost less than 0.5% of their total weight after 200 'accelerated' freeze-thaw cycles. In the sonic test, a 60-80% increase in wet Young's modulus was experienced by all samples during the first 10 to 12 cycles. Little change was observed beyond 25 cycles.-Authors