The Effect of Water Saturation on the Ultrasonic Pulse Velocities of Different Stones

Water saturation is considered one of the major factors influencing stones deterioration. The effect of moisture on the deterioration process of stone was investigated with the help of ultrasonic wave velocities. P and S waves velocities were calculated for twelve different lithotypes including limestone (porous limestone, laminated and less-laminated travertine, cemented limestone), sandstone and basalt. Water saturation tests were carried out based on the standard procedure of EN 13755. With the help of the Geotron device, P and S waves velocities in dry condition and during water saturation test were measured. Changes in physical parameters of stones (dynamic modulus of elasticity and Poisson’s ratio) were calculated based on ultrasonic results. The results showed that changes in water contents did not correlate linearly with ultrasonic pulse velocity and S wave velocity was more sensitive to water content. The various limestone lithologies show distinct water saturation patterns. The influence of micro cracks and discontinuities on ultrasonic pulse velocity of saturated samples were analyzed and higher shear wave velocity was considered due to connectivity of pores and cracks and their ability for absorb water. There was a nonlinear relationship between Dynamic modulus of elasticity and porosity and high porous stones had a lower Modulus of elasticity than less porous stones. During water saturation, the Modulus of elasticity increased for all the stones.