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Educational Linkage Approach In Cultural HeritageEducational ToolkitTeaching MaterialAdvanced TopicModule 2               ...
Educational Linkage Approach In Cultural Heritage           Copyright           ©ELAICH Beneficiaries 2009-2012           ...
Educational Linkage Approach In Cultural HeritageAbstract      The current presentation demonstrates the integrated diagno...
Educational Linkage Approach In Cultural HeritageContent                                             Table of contents of...
Educational Linkage Approach In Cultural Heritage                  Diagnostic study          of the Hagia Sophia dome mosa...
Educational Linkage Approach In Cultural Heritage                                   A VERY short history of the Hagia Soph...
Educational Linkage Approach In Cultural Heritage                              Hagia Sophia Dome Mosaics - ReviewThe chara...
Educational Linkage Approach In Cultural Heritage                          Evaluation of the preservation state        Eva...
Educational Linkage Approach In Cultural Heritage                      Pilot panel with plastered mosaic for laboratory ND...
Educational Linkage Approach In Cultural Heritage                     Diagnostic study (Lab) – 6th cent. glass tesserae   ...
Educational Linkage Approach In Cultural Heritage                              Diagnostic study (Lab) – 6th cent. glass te...
Educational Linkage Approach In Cultural Heritage                              Diagnostic study (Lab) – 6th cent. glass te...
Educational Linkage Approach In Cultural Heritage                        Diagnostic study (Lab) – 6th cent. glass tesserae...
Educational Linkage Approach In Cultural Heritage                    Diagnostic study (Lab) – 10th cent. glass tesserae   ...
Educational Linkage Approach In Cultural Heritage                       Diagnostic study (Lab) – 10th cent. glass tesserae...
Educational Linkage Approach In Cultural Heritage                                  Diagnostic study (Lab) – Bedding mortar...
Educational Linkage Approach In Cultural Heritage                                        Diagnostic study (Lab) – Bedding ...
Educational Linkage Approach In Cultural Heritage                              Diagnostic study (Lab) – Bedding mortarsThe...
Educational Linkage Approach In Cultural Heritage                            Diagnostic study (Lab) – Bedding mortarsMercu...
Educational Linkage Approach In Cultural Heritage                             Diagnostic study (Lab) – Bedding mortarsTota...
Educational Linkage Approach In Cultural Heritage                            Diagnostic study (Lab) – Bedding mortarsFresc...
Educational Linkage Approach In Cultural Heritage                                     Diagnostic study (in-situ)          ...
Educational Linkage Approach In Cultural Heritage                           Diagnostic study (in-situ) – Surface ET       ...
Educational Linkage Approach In Cultural Heritage                                 Diagnostic study (in-situ) – Surface ETU...
Educational Linkage Approach In Cultural Heritage                            Diagnostic study (in-situ) – Surface ETGround...
Educational Linkage Approach In Cultural Heritage                            Diagnostic study (in-situ) – Surface ETInfrar...
Educational Linkage Approach In Cultural Heritage                                Diagnostic study (in-situ) – Surface ET  ...
Educational Linkage Approach In Cultural Heritage                                     Diagnostic study (in-situ) – Surface...
Educational Linkage Approach In Cultural Heritage                           Diagnostic study (in-situ) – Surface PSTUltras...
Educational Linkage Approach In Cultural Heritage                               Diagnostic study (in-situ) – Surface PSTGr...
Educational Linkage Approach In Cultural Heritage                             Diagnostic study (in-situ) – Surface PSTInfr...
Educational Linkage Approach In Cultural Heritage                             Diagnostic study (in-situ) – Surface PSTFibr...
Educational Linkage Approach In Cultural Heritage                              Diagnostic study (in-situ) – Surface PSTFib...
Educational Linkage Approach In Cultural Heritage                              Diagnostic study (in-situ) – Surface PST   ...
Educational Linkage Approach In Cultural Heritage                                    Diagnostic study (in-situ) – Surface ...
Educational Linkage Approach In Cultural Heritage                           Diagnostic study (in-situ) – Surface PSKTUltra...
Educational Linkage Approach In Cultural Heritage                           Diagnostic study (in-situ) – Surface PSKTGroun...
Educational Linkage Approach In Cultural Heritage                            Diagnostic study (in-situ) – Surface PSKTInfr...
Educational Linkage Approach In Cultural Heritage                             Diagnostic study (in-situ) – Surface PSKT Fi...
Educational Linkage Approach In Cultural Heritage                            Diagnostic study (in-situ) – Surface PSKTFibr...
Educational Linkage Approach In Cultural Heritage                               Diagnostic study (in-situ) - Conclusions  ...
Educational Linkage Approach In Cultural Heritage                                     In the framework                    ...
Educational Linkage Approach In Cultural HeritageELAICH Istanbul Course    Prof. Antonia Moropoulou – Topic 2.6: Mosaics
Educational Linkage Approach In Cultural Heritage                                  Use of Ground Penetrating Radar        ...
Educational Linkage Approach In Cultural Heritage                                                                         ...
Educational Linkage Approach In Cultural Heritage                                      Use of Ground Penetrating Radar    ...
Educational Linkage Approach In Cultural Heritage                                                                         ...
Educational Linkage Approach In Cultural Heritage                                                                         ...
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Elaich module 2 topic 2.6 advanced - Diagnostic study of the Hagia Sophia mosaics

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Diagnostic study of the Hagia Sophia mosaics

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    1. 1. Educational Linkage Approach In Cultural HeritageEducational ToolkitTeaching MaterialAdvanced TopicModule 2 Knowing the built heritageTopic 2.8 Diagnostic study of the Hagia Sophia mosaicsProf. Antonia Moropoulou - NTUA – National Technical University of Athens
    2. 2. Educational Linkage Approach In Cultural Heritage Copyright ©ELAICH Beneficiaries 2009-2012 This material is an integral part of the “ELAICH – educational toolkit” and developed as part of the project ELAICH – Educational Linkage Approach in Cultural Heritage within the framework of EuroMed Cultural Heritage 4 Programme under grant agreement ENPI 150583. All rights reserved to the ELAICH Beneficiaries. This material, in its entirety only, may be used in "fair use" only as part of the ELAICH – educational toolkit for the educational purposes by non-profit educational establishments or in self-education, by any means at all times and on any downloads, copies and or, adaptations, clearly indicating “©ELAICH Beneficiaries 2009-2011” and making reference to these terms. Use of the material amounting to a distortion or mutilation of the material or is otherwise prejudicial to the honor or reputation of ELAICH Beneficiaries 2009-2011 is forbidden. Use of parts of the material is strictly forbidden. No part of this material may be: (1) used other than intended (2) copied, reproduced or distributed in any physical or electronic form (3) reproduced in any publication of any kind (4) used as part of any other teaching material in any framework; unless prior written permission of the ELAICH Beneficiaries has been obtained. Disclaimer This document has been produced with the financial assistance of the European Union. The contents of this document are the sole responsibility of the ELAICH Consortium and can under no circumstances be regarded as reflecting the position of the European Union.Prof. Antonia Moropoulou - NTUA – National Technical University of Athens
    3. 3. Educational Linkage Approach In Cultural HeritageAbstract The current presentation demonstrates the integrated diagnostic study performed on the Hagia Sophia’s dome mosaics, aiming to evaluate their preservation state. This evaluation is accomplished at two levels. The first, at the laboratory scale involves characterization of materials with analytical techniques. The second, at the monument scale, involves non-destructive techniques (NDT) for diagnosing the decay of the mosaics. The laboratory characterization of materials is performed on samples of 6th and 10th century mosaics, and their bedding mortars. Before in-situ diagnosis of decay is performed, NDT validation at the laboratory is developed to ensure that the non- destructive techniques reveal the true state of decay in-situ. Prof. Antonia Moropoulou - NTUA – National Technical University of Athens
    4. 4. Educational Linkage Approach In Cultural HeritageContent  Table of contents of this presentation A VERY short history of Hagia Sophia’s mosaics  Hagia Sophia dome mosaics – review  Evaluation of the preservation state  Pilot panel with plastered mosaic for laboratory NDT investigation  Diagnostic study (Lab) – 6th cent. glass tesserae  Diagnostic study (Lab) – 10th cent. glass tesserae  Diagnostic study (Lab) – Bedding mortars  Diagnostic study (in-situ)  Surface ET  Surface PST  Surface PSKT iagnostic study (in-situ) - Conclusions eferences Prof. Antonia Moropoulou - NTUA – National Technical University of Athens
    5. 5. Educational Linkage Approach In Cultural Heritage Diagnostic study of the Hagia Sophia dome mosaics Prof. A. Moropoulou E. Aggelakopoulou, A. Aggelopoulos, N. Avdelidis, A. Bakolas, G. Charalampopoulos, E. T. Delegou, M. Giannoulaki, M. Karoglou, K. Labropoulos, P. Karmis NATIONAL TECHNICAL UNIVERSITY OF ATHENS School of Chemical Engineering Laboratory of Materials Science and EngineeringProf. Antonia Moropoulou – Topic 2.6: Mosaics
    6. 6. Educational Linkage Approach In Cultural Heritage A VERY short history of the Hagia Sophia’s Mosaics The emperor Justinian I, inaugurated the new basilica of Constantinople, named “Ναός τῆς Ἁγίας τοῦ Θεοῦ Σοφίας” (Church of the Holy Wisdom of God – Hagia Sophia) on 27 December 537. The mosaics inside the church were only completed under the reign of Emperor Justin II (565–578). The architects were Isidore of Miletus and Anthemius of Tralles. The construction is described by the Byzantine historian Procopius «Περί Κτισμάτων» (On Buildings). The emperor brought material from all over the empire and more than 10.000 people were employed during its construction. It was decorated with marvelous mosaics. The basilica has suffered from damage throughout the centuries. The dome collapsed completely during an earthquake in 558 and rebuilt with lighter materials by 562. Thereafter, the new dome and its mosaic decoration collapsed partially in many cases (fire in 859, earthquakes in 569, 989, 1344) following which they were repaired. Upon the capture of Constantinople during the 4th Crusade, the church was ransacked and desecrated by the Latin Christians in 1204. When the Ottoman Turks conquered Constantinople in 1453, the Hagia Sophia was converted into the Ayasofya Mosque. Many mosaics were plastered. An extended restoration was ordered by Sultan Abdülmecid and completed between 1847 and 1849, under the supervision of the Swiss-Italian architect brothers Gaspare and Giuseppe Fossati. The brothers consolidated the dome and vaults, straightened the columns, and revised the decoration of the exterior and the interior of the building. This work did not include repairing the mosaics and after recording the details about an image, the Fossatis painted it over again. In some cases, the Fossatis recreated damaged decorative mosaic patterns in paint, sometimes redesigning them in the process. The Fossati intervention was executed in ochre oil paint or tempera over a lime base rendering, which was overlaid with gold leaf and red stencilled pattern, varnished with a lacquer. In the early 1900’s, a second intervention was carried out under the General Directorate of Pious Foundations, known as the “Vakif intervention”. The plaster of this intervention was covered with an opaque yellow pigment in a glue medium. Stencil ornaments in pattern double the size of Fossati’s were applied on this yellow ground In 1932 Byzantine Institute of America, working with the Turkish government and President Mustafa Kemal Atatürk, began the task of uncovering and restoring the surviving mosaics (many have disappeared since the Image of the face of hexapterya figure Fossati restoration). The building reopened as a museum in 1934. The restoration was completed by1964. courtesy of Dr. Hasan Fırat Diker“Restoration and Conservation of Northeast Quarter of the Main Dome and Narthex Mosaics” Istanbul Directorate of Surveying and Monuments / Restoration of the building and its decorations continues on by the Istanbul Directorate of Surveying and Ministry of Culture and Tourism of Turkish Republic Monuments of the Ministry of Culture and Tourism of Turkish Republic Prof. Antonia Moropoulou – Topic 2.6: Mosaics
    7. 7. Educational Linkage Approach In Cultural Heritage Hagia Sophia Dome Mosaics - ReviewThe characteristic areas of Hagia Sophia dome are:  6th century mosaics  10th century mosaics  14th century mosaics  Fossati intervention areas (1847-47)  Vakif intervention areas (after 1910) Original mosaic: 1000m2 =53% Fossati: 280m2 =15% Vakif: 560m2 =29% Total loss: 60m2 =3% Prof. Antonia Moropoulou – Topic 2.6: Mosaics
    8. 8. Educational Linkage Approach In Cultural Heritage Evaluation of the preservation state Evaluation of the preservation state of the mosaics and the previous interventions Characterization of Materials Diagnosis of decay Laboratory scale Monument scale• Optical microscopy • IR-Thermography• Stereomicroscopy • Ultrasonics• Fibre Optics Microscopy • Fibre Optics Microscopy• Scanning Electron Microscopy • Ground Penetrating Radar• Grain Size Distribution• Mercury Intrusion Porosimetry• Soluble salts analysis• Calcimetry (CO2 analysis)• X-Ray Diffraction• FTIR• Thermal Analyses (DTA, TG) Prof. Antonia Moropoulou – Topic 2.6: Mosaics
    9. 9. Educational Linkage Approach In Cultural Heritage Pilot panel with plastered mosaic for laboratory NDT investigation Minor temperature Tesserae variations are observed due 1st Rendering to the presence of one solid material and not a combination of different layers in the panel Subsurface of MosaicBlank Gold tesserae 2nd Rendering “Hot colours” render the presence of gold in the investigated panel. This is due to the low absorption Tessera intensity (high reflection) of the material (gold). GE2LM Infrared Thermography can reveal mosaics even if they are plasteredMoropoulou, A., Avdelidis, N.P., Aggelakopoulou, E., Griniezakis, S., Koui, M., Aggelopoulos, A., Karmis, P.,Uzunoglou, N.K., “Examination of plastered mosaic surfaces using NDT techniques”, INSIGHT J. of theBritish Institute of non-destructive testing, 43, No 4 (2001) pp. 241-243 Prof. Antonia Moropoulou – Topic 5.9: NDT and quality control for monitoring and compatibility assessment
    10. 10. Educational Linkage Approach In Cultural Heritage Diagnostic study (Lab) – 6th cent. glass tesserae  Bubbles on the top thin glass layer  Attributed to the production technology of the tesserae, low thaw Temperature  Micro-cracking, micro-fissures on the gold/silver leaves,  whitish grains & scratches on the top thin glass layer Attributed to the tesserae prolonged exposure to the rather corrosive environment of Hagia Sophia Moropoulou, A., Bakolas, A., Giannoulaki, M., Karoglou, M., “Characterization of Dome mosaics of Hagia Sophia in Constantinople”, Scienza e Beni Culturali XVIII, ed. G. Biscontin, G. Driussi, Publ. Arcadia Ricerche, (2002) pp. 225-235 Moropoulou, A., Avdelidis, N.P., Delegou, E.T., Gill, C.H., Smith, J., “Study of deterioration mechanisms of vitreous tesserae mosaics”, Scienza e Beni Culturali XVIII, ed. G. Biscontin, G. Driussi, Publ. Arcadia Ricerche, (2002) pp. 843-851Prof. Antonia Moropoulou – Topic 2.6: Mosaics
    11. 11. Educational Linkage Approach In Cultural Heritage Diagnostic study (Lab) – 6th cent. glass tesserae Au MappingGOLD SEM EDAXSILVER Ag Mapping SEM EDAX Ibid Prof. Antonia Moropoulou – Topic 2.6: Mosaics
    12. 12. Educational Linkage Approach In Cultural Heritage Diagnostic study (Lab) – 6th cent. glass tesserae Top thin glass layer Thick base glassGOLD EDAX Top thin glass layer Thick base glassSILVER EDAX Ibid Prof. Antonia Moropoulou – Topic 2.6: Mosaics
    13. 13. Educational Linkage Approach In Cultural Heritage Diagnostic study (Lab) – 6th cent. glass tesserae The same production technology of glass was used for the silver and the gold glass tesserae The addition of CaO was not always done deliberately, but its presence was attributed to the supplement of sand and increases the stability of glass, since it commits the free oxygen in the network Si-O-Si. The Al is principally used for strengthening of the glass, since it holds the possibility of activating the alkaline ions (Na, K), so that they cannot travel disengaged in the glass network. Fe2O3 is the source of the amber hue observed in the gold tesserae, while FeO + Fe2O3 is responsible for the greenish hue that was detected in the silver tesserae Light amber and greenish hue in the thick base glass resulted by the deliberate addition of MnO, which decolourises glasses, minimising the colouring effect of accidentally introduced iron EDAX confirms the existence of Au & Ag, verifying the historical data that gold & silver was used in the production technology of the Hagia Sophia dome mosaics tesserae. Ibid Prof. Antonia Moropoulou – Topic 2.6: Mosaics
    14. 14. Educational Linkage Approach In Cultural Heritage Diagnostic study (Lab) – 10th cent. glass tesserae  Setting bed mortar with two glass tesserae on the top. On the left the “silver” glass tesserae.  The bedding mortars were located on approximately 2-2,5m above the ring of the tympanum in the northwest quarter of the dome of Hagia Sophia – 10th century mosaics region. IbidProf. Antonia Moropoulou – Topic 2.6: Mosaics
    15. 15. Educational Linkage Approach In Cultural Heritage Diagnostic study (Lab) – 10th cent. glass tesserae Mapping images presented a homogenous distribution of the elements in the glass, with higher percentage of silicon. The presence of Na, K is probably attributed to the addition of ash of vegetable provenance, used for the reduction of the melting point of the initial mixture. Addition of FeO+Fe2O3 resulted in the green appearance of the thick base glass, whereas the light greenish hue is attributed to Mn presence which discolors glass. The EDAX analysis of the supposed silver leaf reveals an alloy of Cu, Zn, Fe and Cr without any presence of silver. The ratio of Cu /Zn was 2/1 with a presence of Fe and Cr in minor quantities. This type of alloy simulates the silver appearance and has an excellent chemical stability. The use of this alloy is indicative of the reduced financial strength of the Byzantine Empire in the 10th century period, verifying the historic data that report the better quality construction of the 6th century mosaics. Ibid Prof. Antonia Moropoulou – Topic 2.6: Mosaics
    16. 16. Educational Linkage Approach In Cultural Heritage Diagnostic study (Lab) – Bedding mortars Samples Dimensions (LxWxH-cm) Description HgSf1 2,93 x 1,99 x 1,310 Setting bed with 2 glass tesserae, the one with silver foil HgSf2 3,27 x 1,41 x 1,22 Piece of mortar with straws, between setting and intermediate bed HgSf3 5,57 x 5,13 x 2,19 Setting bed with fresco (red ochres and black pigment), intermediate bed HgSf4 Small fragments of mortar of intermediate bed mortar HgSf5 7,72 x 5,22 x 2,98 Intermediate bed with straws Setting bed with fresco,intermediate bed [HgSf-3] HgSf6 3,93 x 2,65 x 2,72 Intermediate bed HgSf7a, b a: 4,69 x 3,60 x1,72 Setting bed in two pieces Rendering bed b : 2,04 x 1,73 x1,43 HgSf8 6,09 x 6,15 x 3,09 Intermediate bed with straws Giannoulaki M. “Study of HgSf9 2,00 x 1,59 x1,22 Small piece from the intermediate bed the manufacturing technology and assembly technique of the Hagia Sophia dome Macroscopic observations mosaics” Master Thesis, Interdepartmental Setting bed: Whitish colour / very compact Postgraduate Course Tesserae Intermediate bed: brown-yellowish colour / “Protection of contains aggregates of broken monuments, sites and complexes”, National ceramics and straws / small Technical University of Setting bed pieces easily detached Athens, supervisor Prof.Masonry Preparative fresco: Mixture of red ochres and A. Moropoulou (2002) black pigment Intermediate bed Prof. Antonia Moropoulou – Topic 2.6: Mosaics
    17. 17. Educational Linkage Approach In Cultural Heritage Diagnostic study (Lab) – Bedding mortarsGranulometry INTERMEDIATE BED MORTAR  Binder / aggregate ratio ~ 1/1  Ceramic aggregates exhibit grain distribution shifted to >0,5mm  Binder phase shifted to <0.5mm Sample Composition XRD SETTING BED MORTAR HgSf1 Calcite, Quartz, Halite HgSf2 Calcite, Quartz, Halite  Main component: Calcite HgSf3 Calcite, Quartz, Mica, Albite, Anorthite, Halite  Presence of quartz as HgSf4 Calcite, Quartz, Albite, Anorthite, Halite, Chlorite, Hematite accessory mineral HgSf5 Calcite, Quartz, Mica, Albite, Anorthite, Halite  Halite attributed to the HgSf6 Calcite, Quartz, Albite, Anorthite, Halite, Dolomite effect of marine environment HgSf7 Calcite, Quartz, Halite HgSf8 Calcite, Quartz, Albite, Anorthite, Halite, Gypsum INTERMEDIATE BED MORTAR HgSf9 Calcite, Quartz, Albite, Anorthite, Halite HgSf5B Calcite, Quartz, Albite, Halite  Calcite & quartz as above HgSf5BE Quartz, Rosenhanite  Presence of mical, albite and HgSf8B Calcite, Quartz, Albite, Halite anorthite HgSf8BE Quartz, Wollastonite Ibid Prof. Antonia Moropoulou – Topic 2.6: Mosaics
    18. 18. Educational Linkage Approach In Cultural Heritage Diagnostic study (Lab) – Bedding mortarsThermogravimetry Weight loss in each temperature range (oC) Samples CO2/H2OSETTING BED MORTAR <120 120-200 200-600 >600 Highest % CO2/H2O indicating (%) mixtures of binders and HgSf1 1,07 0,35 3,19 38,24 11,98 aggregates of carbonate HgSf2 0,90 0,38 3,21 39,66 12,35 nature Probably, this layer was HgSf3 1,22 0,56 3,88 20,94 5,39 prepared with lime and marble HgSf3upper 1,31 0,43 3,22 39,99 12,42 powder as indicated in HgSf4 1,26 0,64 4,29 21,34 4,97 literature HgSf5 1,37 0,49 4,50 22,64 5,03 organic substances traced  possibly white of egg, which improves HgSf6 1,17 0,49 4,56 19,99 4,38 mechanical characteristics and HgSf7 1,30 0,63 5,18 38,34 7,40 improvement of adhesion of glass tesserrae HgSf8 0,99 0,42 4,13 25,47 6,17 HgSf9 1,12 0,54 4,42 21,61 4,88INTERMEDIATE BED MORTAR The intermediate layer was prepared by slightly hydraulic lime and ceramic-sand aggregates, with a binder/aggregate ratio of about 1/1. Chopped straws were added (exothermic peak at 320 oC -> organic compound decomposition), for reinforcement and improvement of adhesion between components of the mortar Ibid Prof. Antonia Moropoulou – Topic 2.6: Mosaics
    19. 19. Educational Linkage Approach In Cultural Heritage Diagnostic study (Lab) – Bedding mortarsMercury Intrusion Porosimetry Cum. Vol. Bulk Dens. Total Poros. Av. Pore Rad. Sp. Surf. Area Sample (mm3/g) (g/cm3) (%) (μm) (m2/g) HgSf5 393.3 1.30 51.1 0.69 4.43 HgSf8 367.7 1.37 50.4 0.55 7.02INTERMEDIATE BED MORTAR Indicative of a lightweight mortar with high total porosity and high values of elasticity, because of the use of ~50% ceramic-sand aggregates. The construction of a lightweight mortar was a necessity since the mosaics are located at a height and under severe slope. Microstructural characteristics similar to those of the support structure (bricks and masonry mortar).  Lightweight mortars were constructed with good adhesion among their components and good cohesion to the dome masonry. Ibid Prof. Antonia Moropoulou – Topic 2.6: Mosaics
    20. 20. Educational Linkage Approach In Cultural Heritage Diagnostic study (Lab) – Bedding mortarsTotal Soluble Salts and Qualitative Determination of Representative AnionsSample S.S.T% Chlorides Sulphates Nitrates The determination of total soluble salts was carried out according to the Normal 13/83HgSf1 10,09 +++ - ++ and the qualitative identification of chlorites, sulphates, and nitrates by spotHgSf2 8,16 ++ + ++ testsHgSf3 4,62 ++ + ++HgSf4 4,92 + - ++HgSf5 4,61 ++ - ++HgSf6 4,62 + - ++HgSf7 8,29 ++ + ++HgSf8 4,42 + - ++HgSf9 4,60 ++ + ++ The setting bed mortars present the highest values of the total soluble salts attributed to the direct environmental impact to the external layer Presence of chlorites is attributed to the marine environment, Presence of nitrates is attributed to the decomposition of organic compounds present in the mortars. Presence of sulphates were identified only in a few samples in traces, probably due to the interaction of the carbonate component of mortars with the polluted environment. Ibid Prof. Antonia Moropoulou – Topic 2.6: Mosaics
    21. 21. Educational Linkage Approach In Cultural Heritage Diagnostic study (Lab) – Bedding mortarsFresco Renderings SEM / EDAX Oxide Composition, s weight % CaO 67,7 Na2O 17,9 Cl 4,6 SiO2 4,9 Fe2O3 2,5 Al2O3 1,6 Setting bed with fresco, MgO 1,0 intermediate bed [HgSf-3] K2 O 0,3 Total 100  The setting bed showed remnants of red pigment on its surface, originating from the preliminary sketches, which were usually drawn to help the mosaics workers.  The natural earth colour, whose red color is attributed to the presence of iron oxides, seems similar to the Byzantine Sinopean Earth. Ibid Prof. Antonia Moropoulou – Topic 2.6: Mosaics
    22. 22. Educational Linkage Approach In Cultural Heritage Diagnostic study (in-situ) Moropoulou, A., Koui, M., Avdelidis, N.P., Delegou, E.T., Aggelakopoulou, E., Karoglou, M., Karmis, P., Aggelopoulos, A., Griniezakis, S., Karagianni, E.A., Uzunoglou, N.K., “Investigation for the compatibility of conservation interventions on Hagia Sophia mosaics using NDT techniques”, PACT, J. PST European Study Group on Physical, Chemical, Biological and Mathematical Techniques Applied to Archaeology, 59 (2000) pp. 103-120 ET PSKT Located between the 19th and the 30th rib at the northwest part of the dome Contain 6th & 10th cent. mosaics & surfaces of Fossati & Vakif interventions Prof. Antonia Moropoulou – Topic 2.6: Mosaics
    23. 23. Educational Linkage Approach In Cultural Heritage Diagnostic study (in-situ) – Surface ET DESCRIPTION  Characteristic surface of Vakif intervention  Situated between the 19th and the 20th rib, 16m from the centre of the dome. AIM OF THE NDT & E  Extent of the rendered mosaic area  Preservation state of the rendered mosaic area and Vakif interventionsProf. Antonia Moropoulou – Topic 2.6: Mosaics
    24. 24. Educational Linkage Approach In Cultural Heritage Diagnostic study (in-situ) – Surface ETUltrasonicsThree different areas are identified in ET2 region: (blue) Vakif painted plaster (average velocity 1600 m/sec) (red) rendered mosaic (average velocity 590 m/sec) (black) Area with detachment or absence of tesserae (very low velocity) Prof. Antonia Moropoulou – Topic 2.6: Mosaics
    25. 25. Educational Linkage Approach In Cultural Heritage Diagnostic study (in-situ) – Surface ETGround Penetrating RadarΕΤ 2  Confirmation of ultrasonic results – location of area of detached tesserae  Area of increased conductivity, due to presence of moisture and salts  Attributed to the exfoliation of the Vakif paint layer, revealing the decayed Fossati gilded plaster  the Vakif paint layer is more compact than the lime based Fossati gilded plaster, ΕΤ 1 resulting in the decrease of the masonry moisture evaporation rate Prof. Antonia Moropoulou – Topic 2.6: Mosaics
    26. 26. Educational Linkage Approach In Cultural Heritage Diagnostic study (in-situ) – Surface ETInfrared Thermography  Coated mosaic area is displayed by the darker grey areas (lower T values)  The areas where mosaic is detached are displayed by lighter grey areas (higher Temperature values due to different thermal diffusion rate) Prof. Antonia Moropoulou – Topic 2.6: Mosaics
    27. 27. Educational Linkage Approach In Cultural Heritage Diagnostic study (in-situ) – Surface ET Research Outcome of NDT & E on Ε Τ Surface Measurements demonstrated the existence of matrices of different materials Determination of the extent of the rendered mosaic Detection of the areas of detached tesserae in the rendered mosaic The reduction of the masonrys water-vapour permeability (moisture evaporation rate), due to the application of the Vakif paint layer, favors phenomena like salt crystallization and detachment of superficial layers in a polluted and highly relative humidity environment Consequently, this conservation intervention is considered incompatible, However, if the reason of the mosaics coating is to consolidate them, consolidation treatments should be searched out through the application of bedding mortars and revealing of mosaics, according to international deontology of revealing materials and art surfaces. Prof. Antonia Moropoulou – Topic 2.6: Mosaics
    28. 28. Educational Linkage Approach In Cultural Heritage Diagnostic study (in-situ) – Surface PSTDESCRIPTION Joint surface of 6th and 10th cent.m mosaics and an interface area with Fossati restoration plaster Situated between the 27th and the 30th rib, 7m from the centre of the dome.AIM OF THE NDT & E Determination of mosaic areas ready for detachment Development of the macroscopically observed crack on the gilded Fossati plaster Evaluation of Fossati intervention Prof. Antonia Moropoulou – Topic 2.6: Mosaics
    29. 29. Educational Linkage Approach In Cultural Heritage Diagnostic study (in-situ) – Surface PSTUltrasonics  6th century mosaic (velocity 1650 m/sec) more compact than 10th century mosaic (velocity 1380 m/sec),  Confirmation of historical data, that 6th century mosaics were assembled with high quality of workmanship and technique  Detection of local irregularities into the Fossati gilded plaster - evidence for the distribution of the cracking, (multiple fractured area)  First and third areas displaying much higher velocities (~2000 m/sec)  Second and fourth areas corresponding to very low velocities (358 m/sec and 500 m/sec respectively) Area 1 (blue line): 60 – 73 cm ⇒ Sound Area Area 2 (red line): 73 – 79 cm ⇒ Fracture Area 3 (black line): 79 – 83 cm ⇒ Sound Area Area 4 (green line): 83 – 87 cm ⇒ Fracture Prof. Antonia Moropoulou – Topic 2.6: Mosaics
    30. 30. Educational Linkage Approach In Cultural Heritage Diagnostic study (in-situ) – Surface PSTGround Penetrating Radar 6th century mosaic 10th century mosaic  Determination of fractured area at the Fossati gilded plaster region. The macroscopically observed fracture must have been developed into a multiple fractured area.  Location of a discontinuity (fracture / void) at the 10th century mosaic (not macroscopically observed). Prof. Antonia Moropoulou – Topic 2.6: Mosaics
    31. 31. Educational Linkage Approach In Cultural Heritage Diagnostic study (in-situ) – Surface PSTInfrared Thermography 10th century mosaic Coloured tesserae show lower temperature values, probably due to moisture presence. Location of remains from the detached Fossati plaster on the mosaic surface. Fossati gilded plaster area Determination of surface alterations - light grey areas (higher temperature values) Prof. Antonia Moropoulou – Topic 2.6: Mosaics
    32. 32. Educational Linkage Approach In Cultural Heritage Diagnostic study (in-situ) – Surface PSTFibre Optics Microscopy The 6th century gold tesserae present extended micro- fractures on the gold surface (a), leading to exfoliation and partial removal of the gold leaf (b). (a) (b) 10th century gold tesserae similarly present partial removal of the gold leaf, since the glass-covering layer has been removed, while the thicker base glass seems to be corroded (c). The blue glass tesserae suffer from pitting corrosion (d). (c) (d) Micro fractures are evidenced at the gold leaf and the red-stencilled pattern on the Fossati gilded plaster (e), as well as surface alterations due to the varnish oxidation. The removed gilded layer of the plaster reveals a cracked lime substrate (f). (e) (f) x50 x25 Prof. Antonia Moropoulou – Topic 2.6: Mosaics
    33. 33. Educational Linkage Approach In Cultural Heritage Diagnostic study (in-situ) – Surface PSTFibre Optics Microscopy (g) x25 (h) x25  Remains of the detached Fossati plaster, among the joints of the gold tesserae and parts of small gilded plaster, used in the Fossati conservation interventions, in order to fill in the gaps of lost tesserae, (g)  Straws within the plasters used in the Fossati conservation interventions are observed (g)  The top glass of the revealed gold tesserae (after the removal of the Fossati plaster) exhibits dulling and surface fracturing, whilst parts of the gold leaf have been detached (h) Prof. Antonia Moropoulou – Topic 2.6: Mosaics
    34. 34. Educational Linkage Approach In Cultural Heritage Diagnostic study (in-situ) – Surface PST Research Outcome of NDT & E on PSΤ Surface Confirmation of the historical data that 6th century mosaics were assembled with high quality workmanship and technique, compared to 10th century mosaics, Identification of a deteriorated area (not macroscopically observed) in the 10th century mosaic area, Determination that the macroscopically observed crack developed into a multiple fractured area under the Fossati plaster, since such interventions were carried out for strengthening the structure in vulnerable areas like this one (joint area of 6th and 10th century mosaics), The straws within the Fossati plaster placed for reinforcement, as within the 10th century mosaic bedding mortars, demonstrate that Fossati used traditional technology for the preparation of plasters, i.e. a compatible conservation intervention, The revealed mosaic after the detachment of the Fossati plaster suffers from intense superficial deterioration, indicating an incompatible conservation intervention. Prof. Antonia Moropoulou – Topic 2.6: Mosaics
    35. 35. Educational Linkage Approach In Cultural Heritage Diagnostic study (in-situ) – Surface PSKTDESCRIPTION Characteristic surface of detached mosaic bedding mortars from the brick masonry, a problem that extends in the large area between the 25th and the 28th rib Situated between the 25th and the 26th rib, 21m from the centre of the dome.AIM OF THE NDT & E Evaluation of the preservation state of:- the 10th century mosaic- the Fossati restoration plaster Prof. Antonia Moropoulou – Topic 2.6: Mosaics
    36. 36. Educational Linkage Approach In Cultural Heritage Diagnostic study (in-situ) – Surface PSKTUltrasonics Detection of superficial crack, resulting from the detached tesserae (also macroscopically observed) Identification of sound mosaic area (velocity of 1763 m/sec), attributed to the hydraulic lime grouting impregnated by the UNESCO International Conservation Team (introduced from the edges of the detached mosaic) Prof. Antonia Moropoulou – Topic 2.6: Mosaics
    37. 37. Educational Linkage Approach In Cultural Heritage Diagnostic study (in-situ) – Surface PSKTGround Penetrating Radar  Confirmation of ultrasonic results – location of superficial crack.  Area of increased conductivity, on the Fossati restoration plaster, due to high moisture contents and presence of salts. Prof. Antonia Moropoulou – Topic 2.6: Mosaics
    38. 38. Educational Linkage Approach In Cultural Heritage Diagnostic study (in-situ) – Surface PSKTInfrared Thermography Note: An interface area between the 10th century mosaic and the Fossati restoration plaster. The cold zone (blue coloured) is induced by rising damp and corresponds to the Fossati restoration plastered area. The green coloured region (reduced temperature values compared to the rest of the mosaic) is a mosaic area, directly affected by the transport of water and soluble salts deriving from the plastered area. A void (not macroscopically observed), is also located on the top left corner of the thermograph. Prof. Antonia Moropoulou – Topic 2.6: Mosaics
    39. 39. Educational Linkage Approach In Cultural Heritage Diagnostic study (in-situ) – Surface PSKT Fibre Optics Microscopy Friable grey crusts, due to biological factors, are introduced along with crystallised salts on the tesserae surface (a-b). The representative black regions on (a) x100 (b) x50 the gold mosaic tesserae arise from the partial detachment of the gold leaf and the corrosion of the glass layer underneath (a-b). Salts and exfoliated mosaic bending mortar, which has been expanded towards the tesserae surface due to salts crystallisation, are presented (c) x100 (d) x50 extensively (b).During the Fossati conservation interventions, the gaps of lost tesserae were filled in with a varnish-gilded plaster that also covered up healthy areas of the mosaic. The varnish oxidation initiatedprolonged decay process on the tesserae surface (c-d), inducing severe aesthetical alterations. Prof. Antonia Moropoulou – Topic 2.6: Mosaics
    40. 40. Educational Linkage Approach In Cultural Heritage Diagnostic study (in-situ) – Surface PSKTFibre Optics Microscopy The moisture content and salts crystallisation at the Fossati plaster (e), leads to decohesion of the binding material around the aggregates, (e) x50 (f) x50 turning the material into a friable surface. Thus, plaster sections are detached (f), leading to formation of fractures and cavities. (g) x50 (h) x50The tesserae setting mark on the bending mortar (g) is attributed to the natural earth color (preparatoryfresco painting for the tesserae placement). The interaction and the binding of the restoration grout,used by the UNESCO International Conservation Team, with the substrate of the mosaic can be observed(h). Prof. Antonia Moropoulou – Topic 2.6: Mosaics
    41. 41. Educational Linkage Approach In Cultural Heritage Diagnostic study (in-situ) - Conclusions Research Outcome of NDT & E on Ε Τ and PSKT surfaces Assessment of the preservation state demonstrated the significant deterioration of the mosaic and the Fossati plaster, Moisture and soluble salts were identified as the main decay factors for the Fossati plaster and the 10th century mosaic, Fossati restoration plaster is the medium that permits the moisture front to move towards the mosaic area, intensifying the moisture and soluble salts corrosive action, leading to the deterioration and detachment of bending mortar and also the detachment of tesserae. This indicates that Fossati restoration plaster can not accomplish its restoration role any longer What is the value of the Fossati restoration if in reality it threatens the original materials and mosaics?The emergency treatment of hydraulic lime grout seems to bind together the masonry and the bedding mortar of the 10th century mosaic Prof. Antonia Moropoulou – Topic 2.6: Mosaics
    42. 42. Educational Linkage Approach In Cultural Heritage In the framework Directorate General of International Development Cooperation - Hellenic Aid of the Hellenic Ministry of Foreign Affairs ELAICH – Educational Linkage Approach In Cultural Heritage Non-destructive evaluation of Hagia Sophia’s mosaics was performedProf. Antonia Moropoulou – Topic 2.6: Mosaics
    43. 43. Educational Linkage Approach In Cultural HeritageELAICH Istanbul Course Prof. Antonia Moropoulou – Topic 2.6: Mosaics
    44. 44. Educational Linkage Approach In Cultural Heritage Use of Ground Penetrating Radar to assess the cohesion state of mosaicsThe first mosaic area studied islocated at the perpendicularintersection of two arches at thesouth upper gallery and itincludes recently revealed The GPR scans focused on the revealed mosaicmosaic areas, exposed brick areas, where the exterior plaster has been removedstructure and exposed stone and aimed to assess the cohesion state of thestructure. The remaining part, as mosaic with the underlying mortars and themost of the neighboring areas is masonry structure, as well to reveal any othercovered with plaster. imperfectionsA. I. Moropoulou, K. C. Labropoulos, N. S. Katsiotis “Application of ground penetrating radar for the assessment of the decay state of Hagia Sophia’s mosaics” Journalof Materials Science and Engineering A & B, in press (2012) Prof. Antonia Moropoulou – Topic 2.6: Mosaics
    45. 45. Educational Linkage Approach In Cultural Heritage An unknown zone is indicated by the white dashed circle. The target corresponds to the space created at the perpendicular intersection of the left arch (stone structure) with the right arch (outer brick structure sub-area C). This space is possibly filled with mortar and bricks. Care should be taken at this junction area 2.3GHz regarding the cohesion of the preserved mosaic with its support mortar and the structure. The target at Α11 appears to be metallic (possibly a historic metallic pin) and is close at the stone / brick interface. The cohesion of the tesserae with the base mortar at the preserved arch mosaic (sub-area A) appears to be satisfactory with no apparent detachment of the glass tesserae layer. Τhe mosaic preserved at sub-area A, appears to 2.3GHz have good cohesion with its support base mortar and the arch structure.A. I. Moropoulou, K. C. Labropoulos, N. S. Katsiotis “Application of ground penetrating radar for the assessment of the decay state of Hagia Sophia’s mosaics” Journalof Materials Science and Engineering A & B, in press (2012) Prof. Antonia Moropoulou – Topic 2.6: Mosaics
    46. 46. Educational Linkage Approach In Cultural Heritage Use of Ground Penetrating Radar to reveal plastered mosaics The aim was to assess the possibility of further presence of mosaic below the plastered area and to evaluate the risk of detachment of the mosaics (revealed or plastered)The second area studied is locatedbetween two windows at thesouth upper gallery.Part of the plaster area has beenremoved revealing the underlyingmosaic. External damage to theplaster and the mosaic is observedat the lower part of the area due tohumidity problems (from theexterior).A. I. Moropoulou, K. C. Labropoulos, N. S. Katsiotis “Application of ground penetrating radar for the assessment of the decay state of Hagia Sophia’s mosaics” Journalof Materials Science and Engineering A & B, in press (2012) Prof. Antonia Moropoulou – Topic 2.6: Mosaics
    47. 47. Educational Linkage Approach In Cultural Heritage 1,6GHz In Scan A23 a mosaic layer is indicated as being present below the plaster layer. A target (void space below the mosaic layer) is indicated in the scan with a dashed curve and it is in the same position as identified by the Hypothesis: horizontal scan A22. This specific area was damaged in the past The mosaic layer does not appear to be flat. and restored by removing the material and replacing it with new mosaic, that was Τhe mosaic layer appears to be in a slightly larger subsequently covered with plaster as the depth at the start of the scan. rest of area 2 Surface decay is observed due to humidity The possible incompatibility (different problems, on the exact same portion of the compositions of the mosaic support mortars, scanned area or different quality of mosaic / tesserae) may There appears no technical reason why the be responsible for the localization of the mosaic layer should be constructed in a larger decay phenomena at this sub-area. depth (curved inwards),A. I. Moropoulou, K. C. Labropoulos, N. S. Katsiotis “Application of ground penetrating radar for the assessment of the decay state of Hagia Sophia’s mosaics” Journalof Materials Science and Engineering A & B, in press (2012) Prof. Antonia Moropoulou – Topic 2.6: Mosaics
    48. 48. Educational Linkage Approach In Cultural Heritage Proposal: Areas around the revealed mosaic where the presence of void spaces below the plastered mosaic layer has been identified by ground penetrating radar A21 A22 A25 A24 A23A. I. Moropoulou, K. C. Labropoulos, N. S. Katsiotis “Application of ground penetrating radar for the assessment of the decay state of Hagia Sophia’s mosaics” Journalof Materials Science and Engineering A & B, in press (2012) Prof. Antonia Moropoulou – Topic 2.6: Mosaics

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