Non-destructive characterization of ancient clay brick walls by indirect ultrasonic measurements

In this work, ultrasonic tests were carried out on the external walls of the Nossa Senhora do Rosário dos Pretos Church, an ancient masonry structure from the 18th century placed at Aracati, Brasil. The main aim of this research was to characterize the ultrasonic velocities of the external walls of the church, in view of further maintenance measures, as well to collect quantitative data on the state of conservation of the church. Fort that purpose, a methodology based on indirect ultrasonic measurements was developed and is presented in this paper. The results show that ultrasonic tests can be applied for characterizing wall homogeneity, offering useful information for control of maintenance or retrofitting measures.