Comparison of ultrasonic velocity and IR thermography for the characterisation of stones

Preliminary results of a study aiming to implement a new non-destructive methodology about physical and elastic characteristics of building materials are presented. Our target is to assess the state of decay of wall stones by means of the correlation of thermal and elastic waves. At first, thermal diffusivity and ultrasound velocities have been measured on samples of known mechanical properties. An effective testing procedure for the evaluation of the stone durability has been performed on a historical Church. In particular, the variation of ultrasonic velocity mainly due to cracks is mapped and compared with thermographic readings