Acoustic tomography for evaluation of unreinforced masonry

A joint U.S./Italian effort is investigating the effectiveness of grout injection for repair of damaged or deteriorated masonry structures. A nondestructive acoustic tomographic imaging technique has been used throughout the program to determine the effectiveness of the repair processes. Pulse velocity information is used for input into a computer program which develops a three-dimensional image of the velocity distribution through the section. Recent work to characterize input waveforms, investigate the effect of mortar joints on measured pulse travel times, and smoothing of analytical data has improved the accuracy of velocity reconstructions.