Monitoring of Cracks in Historic Concrete Structures Using Optical, Thermal and Acoustical Methods

Digital holographic interferometry for cultural heritage structural diagnostics: A coherent and a low‐coherence optical set‐up for the study of a marquetry sample

“…The diagnosis and detailed analysis of the state of an object is an essential part of the conservation protocol concerning the documentation of both mobile and immobile art works and structures, and before any conservation and/or restoration procedure takes place. Deterioration features are considered in relation to the constituents of a piece, in terms of physical and chemical alterations of the surface and/or the subsurface like, for example, in paintings and sculptures assessed with the help of laser spectroscopy and chemical analytical methods, and/or mechanical alterations of the subsurface in rigid objects addressed with the help of optical, acoustical, and thermal techniques …”

“…Deterioration features are considered in relation to the constituents of a piece, in terms of physical and chemical alterations of the surface and/or the subsurface like, for example, in paintings and sculptures assessed with the help of laser spectroscopy and chemical analytical methods, [9][10][11][12][13] and/or mechanical alterations of the subsurface in rigid objects addressed with the help of optical, acoustical, and thermal techniques. [14][15][16] Considering its structural integrity, a piece of art is likely to undergo two types of defects, known in art conservation as cracks and detachments, which very often occur below the surface and are nondetectable with bare eye. [17,18] These are generated either gradually or abruptly from natural or other stress-related phenomena and can seriously threaten the cohesion of the constituent parts and the structural integrity of the objects of interest.…”

Determination of the applicability and limits of void and delamination detection in concrete structures using infrared thermography

“…Additional basic research involving the quantitative analysis of experimental and numerical pulsed thermography data has also been performed on concrete specimens with artificially created defects [16][17][18]. Recently, there has been interest in the combining of thermographic results with the results obtained from, for example, ground penetrating radar and ultrasound for the detection of cracks, voids, and delamination [19][20][21]. In such cases the availability of data about the sensitivity of each particular NDT method is of great importance for defect characterization.…”

Instruments for Assessing Historical Built Environments in Emergency Contexts: Non-Destructive Techniques for Sustainable Recovery

“…Thermal imaging, for example, is a rapid, non-invasive technique that can be used to provide information concerning the historic building envelope [22], structural aspects such as cracks [23], and to monitor forms of degradation, caused, for example, by moisture or the presence of water [24]. By analyzing thermal imaging data, it is also possible to establish the differing thermal capacity of materials used in construction and therefore trace back transformations such as the sealing or opening up of different rooms, integrations, planning accretions or interventions subsequently covered up by further stratification [25].…”

“…In addition, the use of thermal imaging under experimental conditions, varying the surface temperature [23], allowed the identification of different stratigraphs and construction techniques, in particular of the oldest part of the complex and surrounding buildings dating back to the 1950s. This section in fact was the most seriously damaged and will therefore be subject to significant interventions structurally, as well as in terms of energy saving (Figure 7) [35].…”