In this paper, the documentation of an historic building registered as Cultural Heritage asset is presented. The aim of the survey is to create a 3D geometric representation of a historic building and in accordance with multidisciplinary study extract useful information regarding the extent of degradation, constructions’ durability etc. For the implementation of the survey, a combination of different types of acquisition technologies is used. The project focuses on the study of Villa Klonaridi, in Athens, Greece. For the complete documentation of the building, conventional topography, photogrammetric and laser scanning techniques is combined. Close range photogrammetric techniques are used for the acquisition of the façades and architectural details. One of the main objectives is the development of an accurate 3D model, where the photorealistic representation of the building is achieved, along with the decay pathology, historical phases and architectural components. In order to achieve a suitable graphical representation for the study of the material and decay patterns beyond the 2D representation, 3D modelling and additional information modelling is performed for comparative analysis. The study provides various conclusions regarding the scale of deterioration obtained by the 2D and 3D analysis respectively. Considering the variation in material and decay patterns, comparative results are obtained regarding the degradation of the building. Overall, the paper describes a process performed on a Historic Building, where the 3D digital acquisition of the monuments’ structure is realized with the combination of close range surveying and laser scanning methods.
The church of Hagia Sophia in Istanbul is a world heritage monument that epitomizes the byzantine ecclesiastic
architecture. The church is decorated with mosaics from various historic periods. The preservation state of the mosaics is
of high importance. In this study, non-destructive techniques (ground penetrating radar, infra-red thermography, fibreoptics
microscopy) were employed on south upper gallery mosaic areas. The main aim of this on-site investigation was
the evaluation of the preservation state of the mosaics and the previous interventions (materials characterization and
decay diagnosis) in order to assess the performance of previous conservation/restoration interventions, as well as to
verify the presence of mosaics in layers below the external plaster surfaces. Results indicated that is indeed possible to
locate the grid of rendered mosaics. Regarding the preservation state of the mosaics, it was indicated that the main
environmental decay factors were the high relative humidity levels with co-action of salt damp as well as the air
pollutants. Moreover, it was revealed that previous incompatible restoration/conservation interventions have often
accelerated the mosaics' degradation processes. Using non-destructive techniques it was possible to identify areas where
the mosaic materials (tesserae and mortars) presented decay problems and in addition identify sub-layers that pose risk of
detachment or decay intensification. In this way, NDT can contribute to the development of a strategic planning for
mosaics conservation, protection and revealing.
Two non-contact NDT and E (non-destructive testing and evaluation) techniques were employed in the inspection of quarry Pentelic marble samples; surface profilometry and infrared thermography. The samples were processed with different roughness treatments (i.e. 60, 80, 100, 220, 400 and 600 mesh) and were evaluated in the laboratory. Furthermore, different surface cleaning treatments were applied to a Pentelic marble surface in situ and then representative samples were collected and evaluated in the laboratory by the means of these two non-destructive techniques. Quantitative analysis of all samples was performed. In particular, the surface roughness parameter Rq at a specific length scale and 3-D micro-topography plots were attained by the use of the laser profilometry scanning approach, whilst temperature - time plots displaying the intensity of pixels as a function of time on the obtained thermal images were also obtained with the intention of distinguishing the influence of the applied roughness treatments. Results indicate that these two non-destructive techniques can be used for the assessment of surface roughness.
In this work, infrared thermography was applied and investigated as a non-destructive tool in the assessment of materials and techniques for the protection of cultural heritage. Diagnostic studies on monuments and historic buildings, situated in Greece, were performed. Long wave infrared thermography was used on restoration and traditional - historic materials concerning architectural surfaces and historic structures for research purposes such as: the assessment of moisture impact to porous stone masonries and the evaluation of conservation interventions (materials and techniques) regarding, consolidation interventions on porous stone masonries, restoration of masonries by repair mortars, and cleaning of facades. The results of this work indicate that thermography can be considered as a powerful diagnostic nondestructive tool for the preservation and protection of cultural heritage.