ABSTRACT
This chapter describes a wide reflection on the investigations plan for assessing the historic building characteristics and more detailed considerations on a non-destructive technique: the sonic test. A series of direct sonic tests and thermographic tests were proposed for a diffused characterization of the masonry walls and their constructive techniques. The chapter presents the difficulties for organizing a reliable diagnostic plan and draws some indications for exploiting the main potentialities of the tests. The direct sonic tests can be applied on masonry structures presenting different thickness in order to detect some inhomogeneity. Leaving the theory and moving to practice, the tests providing direct characterizations has more relevance than the one collecting qualitative results. Some standards recommend the application of sonic tests for concrete structures or natural stones. Ultrasonic tests are considered for the damage detection on single material elements and the application of sonic tests is recommended for an indirect evaluation of the mechanical properties of the structural elements.
