G. DIANA (1,2) / S. FAIS (1, 3)
(1University of Cagliari, Italy / 2Vetorix Engineering S.r.l., Marcon (VE), Italy and RixGamma S.r.l., Ravenna, Italy / 3Consorzio Interuniversitario Nazionale per l’Ingegneria delle Georisorse (CI.NI.Geo), Roma, Italy)
Several investigation techniques have been implemented in the past years in Cultural Heritage diagnostics and the tendency has been to use non-destructive techniques as much as possible for an adequate assessment prior to any restoration. This paper presents a few cases regarding the application of non-destructive Infrared (IR) thermography and ultrasonic techniques in evaluating the conservation state of valuable finds and monumental structures. As is known IR thermography is one of the most widely used technology in Cultural Heritage diagnostics. Each material has a specific thermal response that is detectable by infrared measurements. The thermal response of each material can change according to many variables, such as thickness, integrity, conditions and possible presence of moisture or other materials of a different nature. Therefore with a thermographic investigation we can detect a large number of data that are fundamental for a precise diagnosis of the shallow parts of the investigated objects.
Ultrasonic methods are very effective in detecting the elastic characteristics of the materials and thus their mechanical behaviour. They are non-destructive and effective both for site and laboratory tests, though it should be pointed out that ultrasonic data interpretation is extremely complex as elastic wave velocity heavily depends on moisture, heterogeneity, porosity and other physical properties of the materials.
From our tests it appears that due to the peculiarities of the two above mentioned methods, their integrated application can be very useful. In fact, the IR thermography, which is highly productive is limited by its low probing depth, a problem that can be solved by coupling ultrasonic velocity measurement on the investigated objects.
Cultural heritage diagnostics, non-destructive testing, IR thermography, ultrasonic techniques, building materials.