Ekaterini T. Delegou

Infrared thermographic assessment of materials and techniques for the protection of cultural heritage

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.

Assessment of Cleaning Conservation Interventions on Architectural Surfaces Using an Integrated Methodology

In this work, pilot cleaning interventions applied by a wet micro-blasting method on architectural surfaces of three historic buildings in marble and porous stone were evaluated in situ and in the laboratory. The investigation was performed on characteristic stone surfaces (marbles and porous stone) of the following historic buildings: Athens Academy and National Library of Greece in Athens center polluted urban environment and Bank of Greece in Piraeus marine environment. The materials of the facades were characterized, and the mechanism of decay was diagnosed. In addition, the cleaning method’s efficiency was evaluated based on the acceptability of the alteration of the cleaned architectural surfaces. Criteria were both aesthetic and physico-chemical. In particular, the architectural surfaces were examined in situ by the means of fiber optic microscopy, infrared thermography and colorimetry. In the laboratory, methods of investigation were optical microscopy, X-ray diffraction, scanning electron microscopy with energy dispersion by X-ray analysis, mercury intrusion porosimetry, Fourier transform infrared spectroscopy, conductivity and pH measurements. The majority of measurements and analyses were applied before and after the pilot cleaning interventions. Finally, the results of this study contribute to the development of an integrated methodology for the assessment of cleaning interventions applied on architectural surfaces.

Mapping of Building Materials and Consevation Interventions Using GIS: The Case of Sarantapicho Acropolis and Erimokastro Acropolis in Rhodes

The geometric documentation of characteristic parts of the walls of the Sarantapicho Acropolis and Erimokastro Acropolis in Rhodes, Greece, in accordance with GIS modeling and analysis operations are utilized to accomplish the mapping of building materials, decay patterns and conservation interventions of both investigated sites. Ortho-rectified images as base-maps and the building materials and decay data, comprised the spatial and attribute data sets. Building materials and decay data were collected after the application of non-destructive testing and evaluation techniques in situ and analytical techniques in lab after sampling. The result was the development of thematic maps of building materials and decay. Moreover, using geoprocessing analysis the thematic map of conservation interventions was produced incorporating attribute data from both building materials and decay themes. This multidisciplinary approach provides the basis for the compatibility assessment of conservation interventions (whenever a...

Five-Dimensional (5D) Modelling of the Holy Aedicule of the Church of the Holy Sepulchre Through an Innovative and Interdisciplinary Approach

The Church of the Holy Sepulchre (Church of the Resurrection) is one of the most important historical sites of Christianity. The current Aedicule structure is the result of various construction phases, damages and destructions, reconstructions, and protection interventions, and as such, it serves as an emblematic case study for five-dimensional (5D) modelling. The innovative and interdisciplinary approach adopted for the modelling of the Holy Aedicule of the Church of the Holy Sepulchre utilizes data from the following: (a) architectural documentation: Description of the current form and structure, as well as its evolution through the ages, based on historic documentation; (b) analysis of construction phases: The construction phases were revealed by a ground-penetrating radar (GPR) survey that was implemented within an integrated methodology, which enabled the technique to identify the various interfaces; (c) geometric documentation: Generation of a 3D high-resolution model, through an automated image-based method and through using terrestrial laser scanning; (d) materials documentation: A wide range of analytical and nondestructive techniques have been used in order to characterize the building materials and extract data for fusion in 5D modelling; and (e) 5D modelling: visualization of the historic construction phases of the Holy Aedicule of the Church of the Holy Sepulchre. The integrated modelling which, after the above analysis, includes enhanced information covering all aspects of the Aedicule structure, geometry, and materials and forms the basis for the creation of an innovative tool that induces mixed reality (MR) with the focus on the Aedicule’s structural evolution (time factor—4D) and on its materials (5D).

THE COMBINATION OF NDTS FOR THE DIAGNOSTIC STUDY OF HISTORICAL BUILDINGS: THE CASE OF KAISARIANI MONASTERY

Diagnosis is the first and most crucial step in the process of monument protection. Diagnosis demands a variety of information and can be a complicated procedure especially when dealing with historical buildings and the limitations that these induce; nevertheless when the correct methodology is followed, diagnosis can be carried out whilst minimizing the amount of samples needed, as important features are already revealed and representative samples can be located. This is achieved through a thorough and organized survey of the historical building and the implementation of various non-destructive techniques (NDTs). The in-situ optical inspection of a historical building can offer valuable information regarding the preservation state of the building as well as utility problems which might create problems for the masonry, such as humidity problems due to the movement of rainwater. Following the optical inspection, the researchers can apply NDTs on the structure as a whole, focusing however on problematic areas or areas of interest. In this study NDTs were employed in order to investigate the type of masonry structure followed by the original masonry workers, the original building materials, the different construction phases and materials, as well as non-documented conservation interventions. However, the use of one NDT alone cannot offer the required information; a combination of various NDTs is necessary in order to extract meaningful and useful results. In the case of Kaisariani monastery, presented here, after a thorough in-situ optical inspection, a variety of NDTs were applied: Ground-penetrating Radar (GRP), Infrared Thermography (IR), Fiber Optics Microscopy (FOM) and Schmidt rebound hammer. The results were analyzed and combined in order to extract results regarding the original building materials, the type of masonry construction, the preservation state of the building materials, as well as information regarding non-documented different construction phases and conservation interventions.

An Intercultural Approach for the Protection and Promotion of Common Cultural Heritage: The Case of Byzantine Monuments in Serbia

In this work the documentation and classification of monuments based on common characteristics in architecture and painting is examined, aiming at the protection and promotion of common cultural heritage. A comparative study was elaborated between Greek and Serbian monasteries in the Byzantine period. The fields and parameters of the study were set by historical data. The operations of a Geographical Information System were used to define the relations between Greek and Serbian monasteries and to classify the Serbian monuments by field of research: architectural typology, exterior decoration and painting style. The comparative study resulted in the consolidation of the selected monasteries into two cultural routes. It is concluded that the identification and documentation of common cultural heritage through intercultural data and information technology can advance the exchange of knowledge, technologies, practices and policies and the establishment of a common strategic plan for the safeguarding and promo...

Advanced and Novel Methodology for Scientific Support on Decision-Making for Stone Cleaning

The configuration of assessment criteria, methodology compilation, and the strategic planning of cleaning interventions applied on architectural surfaces of monuments are discussed in this chapter. This is accomplished by the use of an integrated decision-making system to assess cleaning interventions on stone architectural surfaces that present the characteristic decay pattern of black crusts. The system was developed by the incorporation of a fuzzy logic model into GIS enabling strategic planning through constant response in relation to the cleaning performance in a pointed spatial entity and environmental conditions. The developed, advanced, and novel methodology for scientific support on stone cleaning was demonstrated in practice on marble surfaces of a historic building in Athens, Greece.

Geoinformation techniques for the 3D visualisation of historic buildings and representation of a building's pathology

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.

NDT and E for the surface roughness of marble

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.