Mechanical Properties of Historic Masonry Stones Obtained by In Situ Non-Destructive Tests on the St. Agostino Church in Amatrice (Italy)

The design of strengthening and securing work for historic buildings requires knowledge of the masonry mechanical characteristics, often obtainable through laboratory tests that require invasive samples. The non-destructive techniques, applicable in situ in a rapid and non-invasive way, represent a valid alternative to estimate mechanical strengths without destructive sampling. In this study, a methodology was calibrated which, by combining the results of the ultrasonic and impact tests, makes it possible to reach a good estimate of the compression strength and elastic modulus of a particular rock: sandstone. Most buildings in Amatrice, the city devastated by the violent earthquake of Central Italy in 2016, were built by means of this sedimentary rock. By carrying out a diagnostic campaign on the remaining walls of the St. Agostino church in Amatrice, it was possible to obtain a correlation, specific for this case study, between the compression strengths from laboratory tests and the results of the ultrasonic and impact tests. Unlike the traditional Sonreb methods, this methodology wanted to favor the use of the impact method instead of the sclerometrer test. In this way, it will be possible to operate on other damaged buildings of similar construction types located in the seismic crater of Amatrice, evaluating the mechanical characteristics of the masonry structures be means of in situ non-destructive tests in order to design the safety and strengthening work.