Educational Linkage Approach In Cultural Heritage Prof. Guido Biscontin & Dr. Francesca Caterina...

Educational Linkage Approach In Cultural Heritage

Prof. Guido Biscontin & Dr. Francesca Caterina Izzo - University Ca’ Foscari of Venice

Educational Toolkit

Monitoring and Maintenance

Module

5

Basic Course

Topic 5.1 Definition of monitoring

Teaching Material

AbstractThe aim of the present module is to introduce Professors and students to the concept of monitoring as fundamental part of a conservation project. Whenever people speak about conservation or restoration always think about the practical intervention involving for example the cleaning of the architectural and decorative surfaces(stones, frescos, mosaics, etc.). The artefact materials are in fact subject to alteration over time, which is due to the interaction between the artefact and physical (light, temperature, relative humidity, etc.), chemical (atmospheric oxygen, various pollutants), and biological (bacteria, funguses, insects, etc.) factors. For many years the attention was mainly devoted to the intervention itself aiming to the stabilization of the degradation processes without thinking of the after intervention. Only during the last decay, strong has become the attention to the concept of monitoring in Cultural Heritage as Preventive Conservation. The term “monitoring” in Cultural Heritage means not only checking the conservation state of the artefact before, during and after the restoration process but finding the link with the environment where is located. Architecture and decorative surfaces would in fact present different problems/degradation processes or phenomena depending on the specific environment: indoor- outdoor, urban- rural, marine, etc. therefore also the interventions and products would be different in order to obtain a successful intervention.In this context, crucial will be the definition and selection of suitable parameters and easy methods for monitoring over time not only the artefact conservation state but also the stability and efficiency of the products .


Prof. Guido Biscontin&Dr.Francesca Caterina Izzo - University Ca’ Foscari of Venice

Content


Main topics of this presentation

Definition of monitoring:

a) Monitoring applied to architectural and decorative surfaces (stones, frescos, mosaics, stuccos, etc.) after the intervention

b) Monitoring actions linked to specific environment

• Indoor-outdoor

• Urban-rural

• Marine, ect.

c) Evaluation of conservative intervention

• Selection of best treatments

• Determination of most useful parameters

d) Management and use

e) Examples

f) What to remember about monitoring

Prof. Guido Biscontin&Dr.Francesca Caterina Izzo - University Ca’ Foscari of Venice


5.1. Definition

Prof. G.Biscontin & Dr.F.C. Izzo – Topic 5.1: Definiton of Monitoring

Monitoring in the conservation of Cultural Heritage can be applied to all architectural and decorative surfaces: stones, frescos, mosaics, etc.

Conservation of surfaces needs continuous actions because weathering processes often continue even on restored surfaces. In recent years a sustainable conservation policy of Cultural Heritage is searched and progressively frequent soft conservation works are preferred instead of an impressive one.

In this frame monitoring become a part of the conservation plan and of the intervention itself helping in the choice of the most successful intervention.

Mosaics of Lourdes, Aachen

Monitoring & Maintenance (post-conservation process)


5.1. Definition


The term “monitoring” in Cultural Heritage means not only checking the conservation state of the artefact before, during and after the restoration process but finding the link with the environment where is located, the degradation processes and the new and old products-treatments. .

Monitoring

Environment Decay Treatments

Preventive Conservation

Architecture and decorative surfaces would in fact present different depending on the specific environment:

• indoor- outdoor, • urban- rural, • marine, etc.

The interventions and products would be different in order to obtain a successful intervention.


5.1. Monitoring means…


a) to overview and understand the kinetics of the stability of CH, repeating measurements over time

No control: rapid decay

Maintenance,monitoring study, analyis, etc.: less rapid and more prepredictable trend

time

100%

0%

stab

ility



b) to perform evaluation tests on conservation products and treatments


Selection of the best conservative treatments considering: aesthetic and material compatibility with the system, sustainability, low environmental impact, low toxicity, etc.

Determination of the most relevant indexes for the correct evaluation of the use of innovative methodologies or new products (meaningful, objective, measurable and repeatable parameters)

In situ

In laboratory



b) evaluation tests on conservation products and treatments in laboratory


Biblioteca Marciana, S. Mark’s square, Venice

Analysis of superficial architectural layers

Patina with silicium and calcium oxalate



b) evaluation tests on conservation products and treatments in situ


Application of differnt products

Select the best one

Check the stability, compatibility of the products over time



c) to carry out evaluation tests at the end of the conservation intervention and over time to control:


the efficiency of the intervention and of the products in term of compatibility-Reversibility- Water repellence - Permeability-Stability-Low toxicity-Transparency- Low colour changes, etc.

In situ biological disinfestation test on external buildings

Instrian stone water permeability before and after protection treatment

before

after


5.1. Monitoring: evaluation of conservation intervention (1)


Evaluation of conservation intervention for architectonic surfaces (stones, frescoes, plasters, mosaics, etc.)

Determination of the most relevant INDEXES FOR THE CORRECT EVALUATION of the use of innovative methodologies or new products (meaningful, objective, measurable and repeatable parameters)

Initial choice of the BEST CONSERVATIVE TREATMENTS considering required performances :

aesthetic and material compatibility with the system,efficiency, ease of implementation, economy, low environmental impact, etc.

Area A1 : disinfestation treatment hasn’t reached a good level





a) Measurements and monitoring actions by following determined repeatable PROCEDURES (where present, international PROTOCOLS AND NORMATIVES)

• Colour measurements on the surfaces (in loco)

• Measurements of soluble salts (in laboratory)

• Water absorption measurements : e.g. in laboratory water absorption and contact angle measurements

35°

135°

105°Angle <90° = wettability

Angle >90° = water repellence





• Water absorption measurements : e.g. in laboratory water absorption and contact angle measurements

35°

135°105°Angle <90° = wettability

Angle >90° = water repellence

CONTACT ANGLE MEASUREMENTS

EVALUATION OF WATER REPELLENCE/WATER AFFINITY OF STONE SAMPLES




e.g. Colour measurements on the surfaces (in loco and in alboratory)

CIELAB system:

•L * defines the brightness •a * indicates the value between red and green: a * positive values appear reddish, negative a * values greenish.•b * indicates the value between yellow and blue: positive b * values appear yellowish, negative b * values bluish.

Color representation using three-dimensional space (coordinates of tristimulus)

Graphical representation of chromaticity coordinates in space CIE L * a * b *

0

10

20

30

40

50

60

70

80

90

100

-16

-14

-12

-10

-8

-6

-4

-2

0

2

4

6

810

1214

16

-10 -8 -6 -4 -2 0 2 4 6 8 10

a*

b*

TAL QUALE (b) (c) (d) (e)

L*



DE = the difference of recorded colour values (L*a*b*)


e.g. Colour measurements on the surfaces (in loco and in alboratory)

DE =10 highest accepted value

DE >10 DE <10

Colour measurements provide an excellent tool to describe the evolution of the deterioration of the work over time, pointing to the color change, the emergence of various forms of degradation.

Servirebberodue foto da inserire per far vedere




b) Determination of performance reference levels for evaluating conservative treatments fitness and the right time for a new intervention (MONITORING AND PROGRAMMED ACTIONS)


0

0,001

0,002

0,003

0 5 10 15 20

Absorbed water (ml/cm2)

Time (min)

Non treated material

Treated material

Treated and ageing material

Water absorption

Product is deteriorated

Time for a maintenance intervention!!


5.1.2 Monitoring actions linked to specific environment


• Marine, ect

• Indoor-outdoor

• Urban-rural

Venice – high salt level!!

Study material resistance to salts

Air humidity level, sun exposition, pollution, dust, particles, etc.

People, cars, vibrations, vegetations, etc.


5.1. 3 Management and Use


Monitoring the conservation state

and products

Cultural heritage

(after consevation

intervention)

Follow over time the “heath” of the

surfaces

Check the efficiency of the

products

Planned interventions

Good management of money and

resources



5.1. 4 ExampleAntigraffiti System:

Organic system capable of forming a protection of

the material (microcrystalline wax)System easy to applySystem completely chemically and physically inertSystem capable of giving very low chromatic

variations

•System with excellent reversibility

Removable system (after the writing of graffiti) with

ease and with non-invasive methods, totally

compatible with the historical material

Application of antigraffiti system



5.1. 4 Example

S. Mark’s square – Stone protected with antigraffiti products

Before and after cleaning treatment


5.1. 5 What to remember about monitoring…


.

can be applied to all architectural and decorative surfaces: stones, frescos, mosaics, etc.

checking the conservation state of the artefact before, during and after the restoration process

finding the link with the environment where is located, the degradation processes and the new and old products-treatments

architecture and decorative surfaces would in fact present different depending on the specific environment: indoor- outdoor, urban- rural, marine, etc.

interventions and products would be different in order to obtain a successful interventionMonitoring aims to preventive conservations: wise management of money and of resources!!!

Educational Linkage Approach In Cultural Heritage Prof. Guido Biscontin & Dr. Francesca Caterina...

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