Educational Linkage Approach In Cultural Heritage Educational Toolkit Basic Course Teaching Material Topic 3.6 Decay and environment Module 3 Prof. Antonia

Educational Linkage Approach In Cultural Heritage

Educational Educational ToolkitToolkit

Basic Basic CourseCourse

Teaching Material Teaching Material

TopicTopic 3.3.66

Decay and environment ModulModulee

33

Prof. Antonia Moropoulou - NTUA – National Technical University of Prof. Antonia Moropoulou - NTUA – National Technical University of Athens Athens

Diagnosis of Decay: Methodology, criteria and techniquesNon destructive and instrumental laboratory techniques for diagnosis of decay and assessment of conservation


Copyright ©ELAICH Beneficiaries 2009-2012This 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.

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Abstract Diagnosis of decay: Mechanisms, criteria and techniques Non destructive and instrumental laboratory techniques for diagnosis of decay and assessment of conservation

The current presentation examines the main steps of a cultural heritage protection oriented diagnostic methodology, which is the prerequisite for any effective protection or restoration intervention, as it ensures that the intervention itself addresses the main decay problems that monuments are facing.

This methodology fuses data from documentation, in-situ measurements with non-destructive techniques, characterization of decay products in the laboratory using analytical techniques, and correlates intrinsic and extrinsic factors on the monument scale, leading to a working hypothesis regarding the acting environmental decay factors and the prevailing decay mechanisms. Parallel simulation of the phenomena under accelerated ageing provide an insight into the kinetics of the decay, allowing a thorough diagnosis of the decay state of monuments.



Content


Table of contents of this presentation3.6.1. Diagnosis of decay – Methodology of diagnostic study

3.6.1.1. Documentation3.6.1.2. Monitoring of the acting environmental factors3.6.1.3. In situ macroscopic observations for material’s decay state

and type and structure’s pathology3.6.1.4 In situ NDT – Decay mapping (environmental impact

assessment)3.6.1.5. Building material’s characterization and study of their

provenance3.6.1.6. In lab study of decay products and mechanisms

(microscopic scale)3.6.1.7. Correlation of intrinsic and extrinsic factors on the

monument scale3.6.1.8. Working hypothesis on the prevalent acting environmental

factors and decay mechanisms3.6.1.9. Parametric analysis – Simulation of the phenomena under

accelerated ageing (comparison of various scenarios)3.6.1.10. Diagnosis

3.6.2. Non-destructive techniques for decay diagnosis3.6.2.1. Non-destructive techniques3.6.2.2. Validation of non-destructive techniques by laboratory

techniques3.6.2.3. Integration of non destructive techniques


3.6.1. Diagnosis of decay – Methodology of diagnostic study

Documentation

In situ macroscopic observations for materials’ decay state and type, and structures’ pathology

Monitoring of the acting environmental factors

In situ NDT- Decay mapping(environmental impact assessment)

Building materials’ characterization and study of their provenance

In lab study of decay products and Mechanisms (microscopic scale)

Correlation of intrinsic and extrinsic factors on the monument scale

Working hypothesis on the prevalent acting environmental factors and decay mechanisms

DIAGNOSISDIAGNOSISParametric analysis - Simulation of the phenomena under accelerated ageing

(comparison of various scenarios)

Assessment MethodologyAssessment Methodology

Prof. Antonia Moropoulou – Topic 3.6: Diagnosis of decay: Mechanisms, criteria and techniques


3.6.1.1 Documentation

Surveying Documentatio

n

In order to understand what is the current decay state of the monument, so that we intervene appropriately, the diagnostic study needs to be integrated with historic, surveying, architectural and materials documentation

In order to understand what is the current decay state of the monument, so that we intervene appropriately, the diagnostic study needs to be integrated with historic, surveying, architectural and materials documentation

Architectural Documentatio

n

Diagnostic Study

IntegrationIntegration

Complete “picture” of the current state of the

monument

Complete “picture” of the current state of the

monument

Historic documentation- History of the structure and past

interventions- History of the monument system. Study

of historic archives and comparison with previous photos & designs

Materials Documentatio

n




The existing building materials of monuments have an exposure history to environmental factors that is not readily known

Since the effect of the environment on building materials is closely related to their susceptibility to decay, any protection or restoration intervention on monuments, should initiate with a thorough knowledge of the prevailing decay mechanisms and their current

decay state

3.6.1.2 Monitoring of the acting environmental factors

Microclimate (temperature, humidity, precipitation, speed, direction and frequency of winds, etc.)Pollutants (aerosols, drain waste & leakages, solid waste)Chemical analysis of the soil and monitoring of the rising dampSalts in liquid or solid state

Labropoulos K. “Characterization of wet and dry depositions on the marble surfaces of the archaelogical site of Eleusis – Impact on their decay” Diploma Thesis, supervisor A. Moropoulou, School of Chem. Eng., NTUA (1995)



3.6.1.3 In situ macroscopic observations for material’s decay state and type and structure’s pathology Materials decay state Type of decay phenomena Record any interventions


3.6.1.4 In situ NDT – Decay mapping (environmental impact assessment)

Materials mapping Weathering mapping Assessment of environmental effects


3.6.1.5 Building material’s characterization

Mineralogical & petrographic analyses

Analysis of samples from the monument

& from the original quarry


Moropoulou, A., Zezza, F., Aires Barros, L., Christaras, B., Fassina, V., Fitzner, B., Galan, E., Van Grieken, R., Kassoli-Fournaraki, A., “Marine spray and polluted atmosphere as factors of damage to

monuments in the Mediterranean coastal environment - a preliminary approach to the case of Demeter Sanctuary in

Eleusis”, in Proc. 3rd International Symposium on the Conservation of Monuments in the Mediterranean Basin, ed. V.

Fassina, H. Ott & F. Zezza, Publ. Sopritendenza ai Beni Artistici e Storici di Venezia, Venice (1994) pp. 275-286

Moropoulou, A., Zezza, F., Aires Barros, L., Christaras, B., Fassina, V., Fitzner, B., Galan, E., Van Grieken, R., Kassoli-Fournaraki, A., “Marine spray and polluted atmosphere as factors of damage to

monuments in the Mediterranean coastal environment - a preliminary approach to the case of Demeter Sanctuary in

Eleusis”, in Proc. 3rd International Symposium on the Conservation of Monuments in the Mediterranean Basin, ed. V.

Fassina, H. Ott & F. Zezza, Publ. Sopritendenza ai Beni Artistici e Storici di Venezia, Venice (1994) pp. 275-286

Optical Microscopy images from porous stone samples

from the Medieval City of Rhodes

Optical Microscopy images from porous stone samples

from the Medieval City of Rhodes




Chemical analysis (chemical structure) Physical analysis (e.g. grain size distribution) Physicochemical analysis (e.g. density, porosity,

permeability)

Maravelaki-Kalaitzaki, P., Bakolas, A., Moropoulou, A., “Physico-chemical study of

cretan ancient mortars”, Cement and Concrete Research, 33 [5]

(2003) pp. 651-661

Maravelaki-Kalaitzaki, P., Bakolas, A., Moropoulou, A., “Physico-chemical study of

cretan ancient mortars”, Cement and Concrete Research, 33 [5]

(2003) pp. 651-661

Chemical Analysis of Cretan ancient mortarsChemical Analysis of

Cretan ancient mortars

Grain size distribution of Cretan ancient mortars

Grain size distribution of Cretan ancient mortars




Methodology Differential Thermal Analysis and

Thermogravimetric Analysis for the classification of Historic Mortars

Maravelaki-Kalaitzaki, P., Bakolas, A., Moropoulou, A., “Physico-chemical study of cretan ancient mortars”, Cement and Concrete Research, 33 [5] (2003) pp. 651-661Maravelaki-Kalaitzaki, P., Bakolas, A., Moropoulou, A., “Physico-chemical study of cretan ancient mortars”, Cement and Concrete Research, 33 [5] (2003) pp. 651-661

Thermal Analysis of Cretan ancient mortarsThermal Analysis of Cretan ancient mortars

CO2/H2O ratio of Cretan ancient mortars

CO2/H2O ratio of Cretan ancient mortars

Moropoulou, A., Bakolas, A., Bisbikou, K., “Characterization of ancient, byzantine and later historic mortars by thermal analysis and X-ray diffraction techniques”, Thermochimica Acta, 269/270 (1995) pp. 779-795


3.6.1.5 Building material’s characterization and study of their provenance

Mechanical analysis (compression strength, tensile strength, modulus of elasticity, fracture toughness etc)


Correlation between the tensile strength (Fmt.k) and hydraulicity of mortars (inverse CO2 / structurally bound water)

Moropoulou, A., Bakolas, A., Michailidis, P., Chronopoulos, M., Spanos, Ch., “Traditional technologies in Crete providing mortars with effective mechanical properties”, Structural Studies of Historical Buildings IV, ed. C.A. Brebbia, and B. Leftheris, Computational Mechanics Publications, Southampton Boston, Vol. 1 (1995) pp. 151-161



3.6.1.5 Building material’s characterization and study of their provenance

Neutron Activation analysis (determine the concentration of

elements)


Moropoulou, A., Cakmak, A.S., Polykreti, K., “Provenance and technology investigations of the Agia Sophia bricks”, J. American Ceramic Society,

85 [2] (2002) pp. 366-372

Moropoulou, A., Cakmak, A.S., Polykreti, K., “Provenance and technology investigations of the Agia Sophia bricks”, J. American Ceramic Society,

85 [2] (2002) pp. 366-372

The possibility the bricks from the dome of Hagia Sophia originating from Rhodes is up to 97% compared with the raw materials of ceramics used in other Byzantine Monuments of Istanbul

The possibility the bricks from the dome of Hagia Sophia originating from Rhodes is up to 97% compared with the raw materials of ceramics used in other Byzantine Monuments of Istanbul

Description of the sampled bricks and

tiles

Description of the sampled bricks and

tiles

Probabilities of the Hagia Sophia samples belonging to

the Istanbul or Rhodes groups

Probabilities of the Hagia Sophia samples belonging to

the Istanbul or Rhodes groups


3.6.1.6 In-lab study of decay products and mechanisms (microscopic scale)

Systematic & representative sampling of all decay types present in the monument from characteristic locations


Sampling is a crucial process for the in-lab study of the decay products and mechanisms as it has to be representative of all decay types

present and be well documented so that correlation with the prevailing environmental factors is feasible

Sampling is a crucial process for the in-lab study of the decay products and mechanisms as it has to be representative of all decay types

present and be well documented so that correlation with the prevailing environmental factors is feasible

Sampling locations in the Medieval City of Rhodes for the study of the decay of the

porous stone

Moropoulou, A., Theoulakis, P., Chrysophakis, T., “Correlation between stone weathering and environmental factors in marine atmosphere”, Atmospheric Environment, 29, No 8 (1995) pp. 895-903


3.6.1.6 In-lab study of decay products and mechanisms (microscopic scale)

Study of the properties of the weathered materials (mineralogical, physical, physicochemical, chemical and mechanical)

Study of the decay products (mineralogical, chemical)

Comparison of the results between healthy and decayed materials to obtain information regarding:

Type and the extent of corrosion State of the corrosion products Physical state of the decayed stone Causes



3.6.1.7 Correlation of intrinsic and extrinsic factors on the monument scale

Stochastic correlation of the environmental factors and the materials’ decay data

with the use of multi-criteria analysis


Case study: Medieval City of Rhodes

Justification: The environment is a combination of marine and urban. Due to its location the climate of the City of Rhodes is is characterized by frequent west winds (43%), high relative humidity (70%), high sun exposure (over 200 days / year) and relatively high mean temperatures (13-27oC)

Main decay mechanism: Salt decay – The Rhodes sandstone deterioration appears primarily as an irregular loss of material, following an alveolar weathering pattern, which starts with selective pitting and proceeds to the formation of deep holes and interconnected cavities

Principal component analysis: It concerns a multivariate analysis, allowing to create a set of new variables, called principal components, as linear combination of the initial ones. It is a useful technique to reduce the number of variables included in a data set through the establishment of linear combinations between those variables that explain most of the variance.

Case study: Medieval City of Rhodes

Justification: The environment is a combination of marine and urban. Due to its location the climate of the City of Rhodes is is characterized by frequent west winds (43%), high relative humidity (70%), high sun exposure (over 200 days / year) and relatively high mean temperatures (13-27oC)

Main decay mechanism: Salt decay – The Rhodes sandstone deterioration appears primarily as an irregular loss of material, following an alveolar weathering pattern, which starts with selective pitting and proceeds to the formation of deep holes and interconnected cavities

Principal component analysis: It concerns a multivariate analysis, allowing to create a set of new variables, called principal components, as linear combination of the initial ones. It is a useful technique to reduce the number of variables included in a data set through the establishment of linear combinations between those variables that explain most of the variance.


Sampling: 19 sites throughout the Medieval City of Rhodes (see 3.6.2.6 Systematic & representative sampling)


Principal components analysisStep 1: Selection of variables, from two variable groups:

Intrinsic: Chemical analysis concerning soluble saltsVariables: Cl- chlorides, SO4

2- sulphates and HCO3- bicarbonates

Values: Expressed as percentages of stone dry weight

Extrinsic: Environmental conditions prevailing on each sampling point locationVariables: Sun Exposure (SunExp). The value 1 is given for sampling points with southern orientation, 0.66 for SW or SE and 0.33 for N, NE, NW

Sea Exposure (SeaExp). The various locations according to the orientation, the height and the sea distance of the masonry are submitted either to direct sea-salt spray absorption and deposition or to sea-salt spray absorption and deposition or to sea-salt solutions accumulation due to capillary and ground water percolation. Values 1, 0.5 and 0.2 are given respectively

Air Flow (AirFlow). The quantification of this variable is based on the results of research concerning the drastic way that air flow influences the rate of solution evaporation and consequently crystallization processes. As is known, accelerated evaporation leads to granular disintegration. The values given are based on the characteristics of sampling locations concerning the velocity and type of air flow (surface orientation, narrow passages, prominences on the wall etc)


The six lines intersecting at (0,0) represent the original variables. The length of each vector is proportional to its contribution to the principal components, while the angle between any two is inversely proportional to the correlation between them. “Cl”, “SO4”, “SeaExp” are strongly correlated and very important for the decay processes appearing at sampling locations 1, 2, ..8. “HCO3” has a less strong correlation with “SunExp” and is a very influencing variable for sampling points 13, 14, …19. “AirFlow” and “SunExp” have a weak correlation and both of them seem to influence the group 9, 10, 11, 12.

Principal components analysisStep 2: Graphic representation of the whole array of data in 2-D

scatterplotsStep 3: Estimation of the role and weight factor of each variable

in the two groups


Assessing and evaluating the validity of the statistically derived classification, by the results of the decay study in the laboratory and in-situ, the following could be derived

The prevailing weathering form near the sampling locations of the first group (1,…,8) is alveolar disease. Stone decay appearing through the mechanism of granular disintegration is usually in an advanced stage, following the relatively high levels of Cl-Formation of a hard carbonate crust characterizes the areas near the third group sampling points (13,…,19), following the relatively high levels of HCO3

-


Evaluation of data obtained in the laboratory

Evaluation of data obtained in-situ with non-destructive measurements

Conclusions & Creation Conclusions & Creation of a Working of a Working HypothesisHypothesis

3.6.1.8 Working hypothesis on the prevalent acting environmental factors and decay mechanisms


ELAICH – Athens Experimental Course:In situ use of ground penetrating radar at the archaeological site of Eleusis


3.6.1.9 Parametric analysis - Simulation of the phenomena under accelerated ageing (comparison of

various scenarios)


The simulation of the decay phenomena in a laboratory allows for detailed monitoring – under controlled conditions – of the time evolution of decay and for collection of data quantifying its mechanism. Furthermore, it is a useful assessment method for the effectiveness of various protection interventions

Salt spray chamber

Durability of surface protection

interventions against salt spray

Environmental Test Chamber

Wetting – Drying cycles

Durability of materials against decay factors(Temperature, relative

humidity, pollutant gases, UV radiation)

Durability of materials against decay from salt crystallization



NTUA uses an Angelantoni Industrie S.p.A ACS DCTC600P salt spray chamber, consisting of a fibre-

glass reinforced plastic test chamber where the samples are placed, a shell-type heating system (to control chamber temperature), a salt solution tank

(NaCl), a salt solution atomization system (spray nozzle), a compressed air supply, and a transparent

plastic hood for observation of the tests.Salt solution (NaCl) is sprayed onto the specimens at

100% R.H. and controlled temperature. Drying is allowed to take place with or without the aid of air

flow. If required, additional salt-spray cycles can be added or continuous salt-spraying can be employed.

After the end of the test, specimens are removed and their decay is examined

Salt spray chamber

Weight variation values of untreated and treated porous stone as a function of days of exposure

Moropoulou, A., Kouloumbi, N., Haralampopoulos, G., Konstanti, A., Michailidis, P., “Criteria and methodology for the evaluation

of conservation interventions on treated porous stone susceptible to salt decay”, Progress in Organic Coatings, 48 [2-

4] (2003) pp. 259-270



Environmental test chamber

Accelerated aging tests (SO2 . 95%

Relative humidity, T=25oC) for various

mortar types

Dry weight concentration of

bisulfite or sulfuric salts

NTUA uses an Angelantoni Industrie S.p.A ACS GTS environmental chamber, which consists of a temperature controlled and humidity controlled chamber in which SO2 gas is fed at a controlled flow. Temperature and relative

humidity can be programmed to increase/decrease/stabilized as required by the test

specifications. Optionally, other pollutant gases can be fed, or the chamber be equipped with UV lamp for

specific tests.

Relevant data C. Sabbioni, “Assessment of damage caused by air pollution” ITECOM Advanced Study Course and Materials for the Conservation of Monuments, 8-20/12 Athens, (2003)

Relevant data C. Sabbioni, “Assessment of damage caused by air pollution” ITECOM Advanced Study Course and Materials for the Conservation of Monuments, 8-20/12 Athens, (2003)



Wetting - Drying cycles

Variation of the environmental conditions enhance decay of materials. One test to study material’s decay and assess the effectiveness of protection/conservation interventions is to expose them in a variable environment such as immersion in a liquid followed by drying under controlled conditions (drying rate, temperature) and repeat of this wetting – drying cycle

Selection of the immersion solution and the drying temperature depends on the corrosive environment to be studied. Assessment of decay of the material under study is performed after the completion of each wetting-drying cycle or after a predetermined number of cycles. This is typically done by weighing the material and calculating the weight loss or weight gain of the samples

Salt crystallization test resultsCycle descriptionCommision 25-PEM Test No V.1b, sodium suplphate immersion - drying cycles, Materiaux et Constructions, 13 (75)

a. 2 hours immersion in 15% Na2SO4solutionb. 20 hours drying at 75oCc. 2 hours at room temperatured. 20 hours curing in an atmosphere with a high relative humiditye. 2 hours at room temperature

C Consolidation treatment: Calcium hydroxide suspension 10% (w/v)

F Water repellency treatment: Fomblin CO Slate fluoroelastomer (100g/m2)

CF Combination of C & F

Moropoulou, A., Theoulakis, P., Dogas, Th., “The behaviour of fluoropolymers and silicon resins as water repellents under salt decay conditions in combination with consolidation treatments on highly porous stone”, Science and Technology for Cultural Heritage, 3 (1994) pp. 113-122



DIAGNOSIS - RESULTS

3.6.1.10 Diagnosis

Diagnostic study at the acropolis of Sarantapicho and the acropolis of Erimokastro, Rhodes, NTUA (2008)

Diagnostic study at the acropolis of Sarantapicho and the acropolis of Erimokastro, Rhodes, NTUA (2008)

See Module 5 – Topic 5.1.2

Non Destructive testing and Quality Control on monuments for monitoring the decay state

and the compatibility of conservation interventions

Prof. A. Moropoulou, NTUA

See Module 5 – Topic 5.1.2

Non Destructive testing and Quality Control on monuments for monitoring the decay state

and the compatibility of conservation interventions

Prof. A. Moropoulou, NTUA

For more information:


3.6.2 Non Destructive Techniques for decay diagnosis

Destructive sampling is prohibitedDestructive sampling is prohibited in the conservation of historic monuments They offer certain unique capabilities unique capabilities in a variety of applications

Non-Destructive Techniques (NDT) are used in Cultural Heritage protection because:

Ultrasonics Infrared Thermography Fibre Optics MicroscopyDigital Image Processing

Ground Penetrating RadarColorimetry

ApplicationsMaterials quality control, as well as for technology assessment regarding the production of advanced materialsEnvironmental impact assessment - materials and weathering mappingEvaluation of conservation materials compatibility and conservation interventions effectiveness on the scale of architectural surfaces and historic masonriesStrategic planning for the conservation interventions. Environmental management for the protection of Cultural Heritage



3.6.2.1 NDT - Ultrasonics

Basic PrinciplesBasic PrinciplesMeasures the velocity of ultrasounds traveling through a media, which depends on the media’s density and the presence of voids and cracks.

ApplicationsApplicationsEstimation of the depth of the decay patterns (crusts, cracks etc), evaluation of the effectiveness and the depth of penetration of restoration interventions.

NTUA uses a Portable Ultrasonic Non-Destructive Indicating Tester

(PUNDIT) with transducers of various frequencies

Depth of Crust

A Β C

T: Transmitter R1 R2 R3 R4 : Receiver

A Β C

T: Transmitter R1 R2 R3 R4 : Receiver

2/1

2

DS

DSo

VV

VVl

where Vs, VD, are the ultrasonic velocities in the healthy and damaged part of the stone, respectively and lo the distance between the transducers where a

change in slope of the distance-time curve is observed

Evaluation of Pilot Consolidation Interventions:

Penetration depth of consolidation material

0 20 40 60 80 100 120

Distance (X, mm)mm)

0

20

40

60

80

100

120

140

160

Rodos Ag. Aikaterini - P-wave Site PH

T

D1=15.3mm

D2=21.1mm

Moropoulou, A., Tsiourva, Th., Theoulakis, P., Christaras, B., Koui., M., “Non destructive evalution of pilot scale treatments for porous stone consolidation in the Medieval City of Rhodes”, PACT, J. European Study Group on Physical, Chemical, Biological and Mathematical Techniques Applied to Archaeology, 56 (1998) pp. 259-278


G. Batis, A. Moropoulou “Non-destructive testing of materials – Ultrasonics” in Laboratory notes of the Course 5202 “Building Materials” School of Chemical Engineering, National Technical University of Athens, pp. 69-77 (2011)

G. Batis, A. Moropoulou “Non-destructive testing of materials – Ultrasonics” in Laboratory notes of the Course 5202 “Building Materials” School of Chemical Engineering, National Technical University of Athens, pp. 69-77 (2011)


3.6.2.1 NDT - Infrared Thermography (IRT)Basic PrinciplesBasic PrinciplesMeasures the thermal radiation (infra-red range in the electromagnetic spectrum) emitted by materials and renders an image of the surface area in pseudo-colors which are related to a temperature scaleApplicationsApplicationsIdentification of decay patterns on monuments, assessment of physicochemical compatibility of materials & structures, detection of defects in materials or structures, study of water transport mechanisms

NTUA uses FLIR System B200 IR camera

[7.5-13 μm / Thermal sensitivity 70mK]

Evaluation of restoration materials: Monument scale

Venetian Fortifications of Heraklion

Pentelic Marble, Athens

Academy

Before cleaning After cleaning

Cleaning Method: wet micro blasting method, particles of spherical calcium carbonate, d< 80μm, P<1 atm, suspension’s proportion 2:1

Evaluation of pilot cleaning interventions: Monument scale

The incompatibility of replacement stones is indicated by the difference in temperature compared with the historic materials


Avdelidis, N.P., Moropoulou, A., “Applications of infrared thermography for the investigation of historic structures: a review study”, Journal of Cultural Heritage, 5 [1] (2004) pp. 119-127


Moropoulou, A., Avdelidis, N.P., Delegou, E.T., Koui, M., «Infrared thermography in the evaluation of cleaning interventions on architectural surfaces», in Proc. INFRAMATION Int. Conf. on infrared thermography, Orlando (2001) pp. 171-175



3.6.2.1 NDT - Fibre Optics Microscopy (FOM)Basic PrinciplesBasic PrinciplesCaptures images in the visible spectrum. Image is transmitted via optical fibres and then transformed into electric signals which are stored in a video unit or digitized and stored on a computerApplicationsApplicationsIdentifies differences in the texture and composition of surfaces, materials classification, microstudy of the decay phenomena, evaluation of restoration interventions

ELAICH – Athens Experimental Course:In situ use of fibre optics microscopy to identify the decay patterns on marble surfaces at the archaeological site of

EleusisInvestigation of materials’ surface morphology Evaluation of consolidation interventions

6th Century Mosaic (x50), Hagia Sophia, Dome

Weathered Mortar Surface (x50), Hagia Sophia, N/W Outer

Narthex

10th Century Mosaic (x50), Hagia Sophia, Dome

Inner Part of Compact Mortar Surface (x25), Hagia Sophia,

N/W Outer Narthex

Clay Plaster (x25), Stadiou Historic Building in Athens

Interface of Cement Plasters (x25), Stadiou Historic

Building in Athens

Untreated Surface, Rhodes Porous

Stone (x50),

Surface treated with PH (pre-

ydrolysed ethyl silicate with amorphous silica) (x50)

Surface treated with PL

(aqueous colloidal

dispersion of silica particles),

(x50)After consolidation treatments, information regarding microstructural modifications of porous materials, as

well as the deposition mechanism of the applied materials, can be obtained by using fibre optics

microscopy


Photos 1, 2, 4, 5: Moropoulou et als (2002b), Photos 3, 6: Moropoulou et als (2005), Photos 7-9: Moropoulou et als (2000a, 2000b) Photos 1, 2, 4, 5: Moropoulou et als (2002b), Photos 3, 6: Moropoulou et als (2005), Photos 7-9: Moropoulou et als (2000a, 2000b)

11 22 33

44 55 66


3.6.2.1 NDT - Digital Image Processing (DIP)Basic PrinciplesBasic PrinciplesDepending on the material type, the surface texture and morphology, and the decay state, a variation of the reflectance and absorption of electromagnetic radiation is observed, which can be identified.ApplicationsApplicationsImages from FOM, IRT, Optical and Scanning Electron Microscopyare digitally processed identifying differences in texture and decay state of surfaces, lithotypes, and allowing material and decay mapping

Decay Mapping, National Library of Athens

Basic Principle Microstructural analysis – Image Pro X

Change of the energy content of the gray levels. The position on the x-axis is determined by the color of the material, the dispersion of the values can be correlated to the characteristics of the material and its decay state. The degree of weathering of the material is related to the width (x-axis) of the gray levels; the width increases with increasing decay state


Kapsalas et als (2007)

Kapsalas et als (2007)

1. Optical microscopy image

2. Conversion to grayscale – Gray level histogram

3. Process – Segmentation / Threshold 4. Microstructural analysisA. Moropoulou, A. Konstanti “Laboratory notes on digital image processing”, Interdepartmental Postgraduate Course “Protection of monuments, sites and

complexes”, Nat. Techn. Univ of Athens

A. Moropoulou, A. Konstanti “Laboratory notes on digital image processing”, Interdepartmental Postgraduate Course “Protection of monuments, sites and

complexes”, Nat. Techn. Univ of Athens

Moropoulou, A., Koui, M., Theoulakis, P., Kourteli, Ch., Zezza, F., “Digital Image Processing for the Environmental Impact Assessment on Architectural Surfaces”, J. Environmental Chemistry and Technology, 1 (1995) pp. 23-32



3.6.2.1 NDT - Ground Penetrating Radar (GPR)Basic PrinciplesBasic PrinciplesA short electromagnetic pulse (10MHz – 10GHz) is produced and propagated into the structure, part of the pulse energy is reflected (due to the presence of internal interfaces between materials of different dielectric constant), rendering a 2-D or 3-D image of the sub-surfaceApplicationsApplicationsReveal internal structure of masonries, location of cavities, identification of detachments and internal cracks, assessment of decay depth

NTUA uses the MALÅ ProEx system with 1.6GHz and 2.3GHz antennas and RadExplorer v.1.41 software

Decay state of the structure - Church of the Holy Sepulchre

Evaluation of the decay state of mosaics – Hagia Sophia

(Left) Presence of two cracks (T1 & T2) that penetrate the external layer of the Katholikon Dome Base. (Right) Presence of three double reinforcing bars A1, A2, A3 and a reinforcing matrix 5x5cm B1 (Moropoulou et als Report to the Patriarchate of Jerusalem on NDT Assessment of the Church of the Holy Sepulchre, NTUA, 2011)

Katholikon NW Dome base (exterior)

Katholikon north view of

the north masonry

(interior of the church)

Areas around the revealed mosaic where the presence of void spaces below the plastered mosaic layer has been identified by ground penetrating radar

The space indicated with dashed line is possibly filled with mortar and bricks. Care should be taken at this junction area regarding the cohesion of the preserved mosaic with its support mortar and the structure (Moropoulou et als, 2012)



Basic PrinciplesBasic PrinciplesColorimetry involves the use of a spectrophotometer of visible light to measure the color coordinates of architectural surfaces as these are modified due to environmental impact and/or protection interventionsApplicationsApplicationsIdentification of decay patterns, evaluation of the effectiveness of cleaning interventions on architectural surfaces

Evaluation of decay patterns on pentelic marble – Academy of Athens

AA2: grey crustAA3: dust fall

AA4: washed out surface AA6: black-grey crust

AA7: area of grey veins

Estimation of color parameters’ modification of different decay patterns on

exterior marble surfaces

ΔΕ*ab=[(ΔL*)2+ (Δa*)2+(Δb*)2]1/2

-20

0

20

40

60

80

ΔL*ab Δa* Δb* ΔE*ab ΔC*ab

AA2

AA3

AA4

AA6

AA7

NTUA uses the spectro-color DRLANGE color-pen: Color measurements evaluated in L*a*b* color system

Aesthetic parameters:

ΔC*ab < 0 less saturated areas after cleaning

Δa* < 0 greener (less red)

Δb*<0 bluer (less yellow)

ΔL*ab > 0 so higher luminosity values after cleaning

Validation according to ASTM D2244-93 Standard Test Method

Colorimetry

Biscontin, G., Bakolas, A., Bertoncello, R., Longega, G., Moropoulou, A., Tondello, E., Zendri, E., “Investigation of the effects of the cleaning procedures applied to stone surfaces”, Materials Issues in Art and Archaeology IV, Vol. 352, ed. J.R. Druzik, P.B. Vandiver, Publ. Materials Research Society, Pittsburgh (1995) pp. 857-864

Moropoulou, A., Delegou, E.T., Avdelidis, N.P., Koui., M., “Assessment of cleaning conservation interventions on architectural surfaces using an intergrated methodology”, Materials Issues in Art and Archaeology VI, Vol. 712, ed. P. Vandiver, M. Goodway, J.R. Druzik, J.L. Mass, Publ. Materials Research Society, Pittsburgh (2002), pp. 69-76



Validation of NDT by Laboratory TechniquesMacroscopic investigation:Macroscopic investigation:

Classification in order of increasing degree of alveolar

decay (V = max)

Microstructural investigation Microstructural investigation (Mercury Intrusion (Mercury Intrusion

Porosimetry):Porosimetry): Pore volume distribution for

each degree of alveolar decay

DIPDIP

Moropoulou, A., Koui, M., Kourteli, Ch., Achilleopoulos, N., Zezza, F., “Digital image processing and integraded computerised analysis for weathering on planning conservation interventions on historic structures and architectural complexes”, in Proc. EURISCON Conference on European Robotics, Intelligent Systems and Control, Publ. International Association for Mathematics and Computers in Simulation (1999)

Theoulakis, P., Moropoulou, A., “Microstructural and mechanical parameters determining the susceptibility of porous building stones to salt decay”, Construction and Building Materials, 11, No. 1 (1997) pp. 65-71



Validation of NDT by Laboratory Techniques

Hard Carbonate Crust:Hard Carbonate Crust:Medieval City of Rhodes

(Combined assessment with the use of NDT and validation with SEM)

Fibre Optics MicroscopyDigital Image ProcessingScanning Electron Microscopy

Alveolar WeatheringAlveolar WeatheringMedieval City of Rhodes

(Combined assessment with the use of NDT and validation

with SEM)

Fibre Optics MicroscopyDigital Image Processing

Scanning Electron Microscopy

Moropoulou, A., Koui, M., Tsiourva, Th., Kourteli, Ch., Papasotiriou, D., “Macro- and micro non destructive tests for environmental impact assessment on architectural surfaces”, Materials Issues in Art and Archaeology V, Vol. 462, ed. P.B. Vandiver, J.R. Druzik, J.F. Merkel, J. Stewart, Publ. Materials Research Society, Pittsburgh (1997) pp. 343-349




3.6.2.3 Integration of Non Destructive Techniques

In-situIn-situNDTNDT

Validation by Lab Techniques

Advanced Spatial Data Management

& Assessment Methods

Monument Scale

Materials Characterization Evaluation of Materials

Compatibility Environmental Impact

Assessment

Integrated Projects

Strategic Planning of Conservation Interventions on Historic Buildings

Strategic Planning of Environmental Management as a Tool for a Sustainable Preservation of Historic Cities




REFERENCESREFERENCES




Batis G. Moropoulou A. “Non-destructive testing of materials – Ultrasonics” in Laboratory notes of the Course 5202 “Building Materials” School of Chemical Engineering, National Technical University of Athens, pp. 69-77 (2011)


Kapsalas, P., Maravelaki-Kalaitzaki, P., Zervakis, M., Delegou, E.T., Moropoulou, A., “Optical inspection for quantification of decay on stone surfaces”, J. NDT&E International, 40 (2007) pp. 2-11


Maravelaki-Kalaitzaki, P., Bakolas, A., Moropoulou, A., “Physico-chemical study of cretan ancient mortars”, Cement and Concrete Research, 33 [5] (2003) pp. 651-661


Moropoulou, A., Zezza, F., Aires Barros, L., Christaras, B., Fassina, V., Fitzner, B., Galan, E., Van Grieken, R., Kassoli-Fournaraki, A., “Marine spray and polluted atmosphere as factors of damage to monuments in the Mediterranean coastal environment - a preliminary approach to the case of Demeter Sanctuary in Eleusis”, in Proc. 3rd International Symposium on the Conservation of Monuments in the Mediterranean Basin, ed. V. Fassina, H. Ott & F. Zezza, Publ. Sopritendenza ai Beni Artistici e Storici di Venezia, Venice (1994) pp. 275-286






Batis G. Moropoulou A. “Non-destructive testing of materials – Ultrasonics” in Laboratory notes of the Course 5202 “Building Materials” School of Chemical Engineering, National Technical University of Athens, pp. 69-77 (2011)


Kapsalas, P., Maravelaki-Kalaitzaki, P., Zervakis, M., Delegou, E.T., Moropoulou, A., “Optical inspection for quantification of decay on stone surfaces”, J. NDT&E International, 40 (2007) pp. 2-11


Maravelaki-Kalaitzaki, P., Bakolas, A., Moropoulou, A., “Physico-chemical study of cretan ancient mortars”, Cement and Concrete Research, 33 [5] (2003) pp. 651-661


Moropoulou, A., Zezza, F., Aires Barros, L., Christaras, B., Fassina, V., Fitzner, B., Galan, E., Van Grieken, R., Kassoli-Fournaraki, A., “Marine spray and polluted atmosphere as factors of damage to monuments in the Mediterranean coastal environment - a preliminary approach to the case of Demeter Sanctuary in Eleusis”, in Proc. 3rd International Symposium on the Conservation of Monuments in the Mediterranean Basin, ed. V. Fassina, H. Ott & F. Zezza, Publ. Sopritendenza ai Beni Artistici e Storici di Venezia, Venice (1994) pp. 275-286










Moropoulou, A., Theoulakis, P., Tsiourva, Th., Haralampopoulos, G., “Compatibility evaluation of consolidation treatments in monuments scale”, PACT, J. European Study Group on Physical, Chemical, Biological and Mathematical Techniques Applied to Archaeology, 59 (2000) pp. 209-230

Moropoulou, A., Haralampopoulos, G., Tsiourva, Th., Theoulakis, P., Koui, M., “Long term performance evaluation of consolidation treatments in situ”, Scienza e Beni Culturali XVI, ed. G. Biscontin, G. Driussi, Publ. Arcadia Ricerche S.r.l. (2000) pp. 239-25


Moropoulou, A., Cakmak, A.S., Polykreti, K., “Provenance and technology investigations of the Agia Sophia bricks”, J. American Ceramic Society, 85 [2] (2002) pp. 366-372

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. 843-851


Moropoulou, A., Kouloumbi, N., Haralampopoulos, G., Konstanti, A., Michailidis, P., “Criteria and methodology for the evaluation of conservation interventions on treated porous stone susceptible to salt decay”, Progress in Organic Coatings, 48 [2-4] (2003) pp. 259-270

Moropoulou, A., Avdelidis, N.P., Delegou, E.T., “NDT and planning on historic buildings and complexes for the protection of cultural heritage”, Cultural Heritage Conservation and Environmental Impact Assessment by Non-Destructive Testing and Micro – Analysis, ed. R.Van Grieken, K. Janssens, Publ. Balkema, Taylor & Francis Group, (2005) pp. 67-76




Moropoulou, A., Theoulakis, P., Tsiourva, Th., Haralampopoulos, G., “Compatibility evaluation of consolidation treatments in monuments scale”, PACT, J. European Study Group on Physical, Chemical, Biological and Mathematical Techniques Applied to Archaeology, 59 (2000) pp. 209-230

Moropoulou, A., Haralampopoulos, G., Tsiourva, Th., Theoulakis, P., Koui, M., “Long term performance evaluation of consolidation treatments in situ”, Scienza e Beni Culturali XVI, ed. G. Biscontin, G. Driussi, Publ. Arcadia Ricerche S.r.l. (2000) pp. 239-25


Moropoulou, A., Cakmak, A.S., Polykreti, K., “Provenance and technology investigations of the Agia Sophia bricks”, J. American Ceramic Society, 85 [2] (2002) pp. 366-372

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. 843-851


Moropoulou, A., Kouloumbi, N., Haralampopoulos, G., Konstanti, A., Michailidis, P., “Criteria and methodology for the evaluation of conservation interventions on treated porous stone susceptible to salt decay”, Progress in Organic Coatings, 48 [2-4] (2003) pp. 259-270

Moropoulou, A., Avdelidis, N.P., Delegou, E.T., “NDT and planning on historic buildings and complexes for the protection of cultural heritage”, Cultural Heritage Conservation and Environmental Impact Assessment by Non-Destructive Testing and Micro – Analysis, ed. R.Van Grieken, K. Janssens, Publ. Balkema, Taylor & Francis Group, (2005) pp. 67-76



Moropoulou A. (Scientific Responsible), A. Bakolas, E. Delegou, M. Karoglou, N. Katsiotis, K. Labropoulos “Report to the Patriarchate of Jerusalem on NDT Assessment of the Church of the Holy Sepulchre”, National Technical University of Athens, (2011)

Moropoulou A. I., Labropoulos K. C., Katsiotis N. S. “Application of ground penetrating radar for the assessment of the decay state of Hagia Sophia’s mosaics” Journal of Materials Science and Engineering A & B, in press (2012)

Sabbioni C. “Assessment of damage caused by air pollution” ITECOM Advanced Study Course and Materials for the Conservation of Monuments, 8-20/12 Athens, (2003)


Moropoulou A. (Scientific Responsible), A. Bakolas, E. Delegou, M. Karoglou, N. Katsiotis, K. Labropoulos “Report to the Patriarchate of Jerusalem on NDT Assessment of the Church of the Holy Sepulchre”, National Technical University of Athens, (2011)

Moropoulou A. I., Labropoulos K. C., Katsiotis N. S. “Application of ground penetrating radar for the assessment of the decay state of Hagia Sophia’s mosaics” Journal of Materials Science and Engineering A & B, in press (2012)

Sabbioni C. “Assessment of damage caused by air pollution” ITECOM Advanced Study Course and Materials for the Conservation of Monuments, 8-20/12 Athens, (2003)


Documents

Educational Linkage Approach In Cultural Heritage Educational Toolkit Basic Course Teaching Material Topic 3.6 Decay and environment Module 3 Prof. Antonia