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E.M. Perez-Monserrat1, M.J. Varas1,2, R. Fort1, M. Alvarez de Buergo1,
1 Institute of Economic Geology (CSIC – UCM), Madrid (Spain)2 School of Geological Sciences, Complutense University of Madrid (Spain)
ASSESSING THE CLEANING METHODS ON THE LIMESTONE FAÇADES IN THE FORMERLY WORKERS HOSPITAL OF MADRID, SPAIN
Assessing the cleaning methods on the limestone façades in the Formerly Workers Hospital of Madrid, Spain
1. INTRODUCTION 1. INTRODUCTION
2. AIMS AND METHODOLOGY 2. AIMS AND METHODOLOGY
3. RESULTS3. RESULTS
4. CONCLUSIONS4. CONCLUSIONS
Assessing the cleaning methods on the limestone façades in the Formerly Workers Hospital of Madrid, Spain
1. INTRODUCTION (a)1. INTRODUCTION (a)
Designed by Antonio Palacios in the Nothern enlargement of Madrid.
Constructed between 1909-1916.
The building and its surrounding wall are mostly built with limestone masonry (Colmenar stone).
Abandoned at the beginning 70´s.
The Government of Madrid purchased the property and commissioned its restoration (1984 – 1986).
Assessing the cleaning methods on the limestone façades in the Formerly Workers Hospital of Madrid, Spain
1. INTRODUCTION (b)1. INTRODUCTION (b)
70´s 1986
Works restorationWorks restoration 1984 1984 -- 19861986
One of the most important tasks was the stone façades cleaning
and the application of conservation treatments.
Assessing the cleaning methods on the limestone façades in the Formerly Workers Hospital of Madrid, Spain
2006
2006
Main decay formsMain decay forms
Soiling processes
Black crusts
Principal soiling causesPrincipal soiling causes
Urban environmentFaçades design
Rusticated finishing ashlarsPassage of time
WallWall
1. INTRODUCTION (c)1. INTRODUCTION (c)
Assessing the cleaning methods on the limestone façades in the Formerly Workers Hospital of Madrid, Spain
2. AIMS AND METHODOLOGY (a)2. AIMS AND METHODOLOGY (a)
To assess the most effective and suitable stone cleaning method.To assess the most effective and suitable stone cleaning method.
1. Alkaline gels
NaOH KOH
3. Glass microspheresblasting
1:4 ratio (w:µsp)
50-100 µm 60 kg/cm2
2. Pressured hot water jet
60 kg/cm2 60ºC
4. Latex-based product
10% EDTA Ammonia
Assessing the cleaning methods on the limestone façades in the Formerly Workers Hospital of Madrid, Spain
2. AIMS AND METHODOLOGY (a)2. AIMS AND METHODOLOGY (a)
To assess the most effective and suitable stone cleaning method.To assess the most effective and suitable stone cleaning method.
1. Alkaline gels
NaOH KOH
2. Pressured hot water jet
60 kg/cm2 60ºC
3. Glass microspheresblasting
1:4 ratio (w:µsp)
50-100 µm 60 kg/cm2
4. Latex-based product
10% EDTA Ammonia
Assessing the cleaning methods on the limestone façades in the Formerly Workers Hospital of Madrid, Spain
2. AIMS AND METHODOLOGY (b)2. AIMS AND METHODOLOGY (b)
To assess the most effective and suitable stone cleaning method.To assess the most effective and suitable stone cleaning method.
Effective assessmentEffective assessment
Limestone chromatic parameters before and after its cleaning
Global index of colour changecompared to the building
rainwashed limestone
∆E* = (∆L*2 + ∆a*2 + ∆b*2)½
SpectrophotometrySpectrophotometry
-a* +a*
+b*
-b*
Suitability assessmentSuitability assessment
Ion chromatographyIon chromatography
Alteration products formation
SEMSEM
Stone superficial changes
Assessing the cleaning methods on the limestone façades in the Formerly Workers Hospital of Madrid, Spain
NaOH Water MicrospheresKOHLatex
Natural washedstone
LatexNaOH Water MicrospheresKOH
Natural washedstone
3. RESULTS (a)3. RESULTS (a)
Before cleaning
After cleaning
Latex pill off
Assessing the cleaning methods on the limestone façades in the Formerly Workers Hospital of Madrid, Spain
3. RESULTS (b)3. RESULTS (b) Effective assessment: limestone chromatic parameters before and after its cleaning
∆∆EE **Rainwashed stone
Before 29.41
After 8.438.43
Before 38.46
After 11.6111.61
Before 33.05
After 13.7413.74
Before 34.5134.51
After 30.7430.74
Before 35.78
After 27.7927.79
Latex
Water
Microspheres
KOH
NaOH
White and yellow indices increase of the cleaned stones with respect to the rainwashed limestone.
0
5
10
15
20
25
-15 -10 -5 0 5
∆YI
∆ WI
NaOH
KOH
Microspheres
Water
Latex
Global index of colour change∆E* = (∆L*2 + ∆a*2 + ∆b*2)½
Compared to the limestone washed by rain
Assessing the cleaning methods on the limestone façades in the Formerly Workers Hospital of Madrid, Spain
3. RESULTS (c)3. RESULTS (c) Suitability assessment: alteration products formation
ANIONSANIONS CATIONSCATIONS
Chloride Nitrate Sulphate Sodium Potassium Calcium
Rainwashed stone 46.64 119.15 101.79 12.61 4.18 8.64
NaOH 22.51 70.70 50.41 26.62 5.45 21.38
KOH 29.45 59.44 65.94 25.91 26.35 16.65
Microspheres 17.11 1.91 35.58 23.47 3.92 13.73
Artificial rain water cationic and anionic contents over natural washed stone, and limestones tested with the three most effective methods (mg/l).
Lixiviated water chemistry analysis
Anionic content Cationic content
Assessing the cleaning methods on the limestone façades in the Formerly Workers Hospital of Madrid, Spain
3. RESULTS (c)3. RESULTS (c) Suitability assessment: alteration products formation
ANIONSANIONS CATIONSCATIONS
Chloride Nitrate Sulphate Sodium Potassium Calcium
Rainwashed stone 46.64 119.15 101.79 12.61 4.18 8.64
NaOH 22.51 70.70 50.41 26.62 5.45 21.38
KOH 29.45 59.44 65.94 25.91 26.35 16.65
Microspheres 17.11 1.91 35.58 23.47 3.92 13.73
Artificial rain water cationic and anionic contents over natural washed stone, and limestones tested with the three most effective methods (mg/l).
Lixiviated water chemistry analysis
Anionic content Cationic content
Assessing the cleaning methods on the limestone façades in the Formerly Workers Hospital of Madrid, Spain
3. RESULTS (c)3. RESULTS (c) Suitability assessment: alteration products formation
ANIONSANIONS CATIONSCATIONS
Chloride Nitrate Sulphate Sodium Potassium Calcium
Rainwashed stone 46.64 119.15 101.79 12.61 4.18 8.64
NaOH 22.51 70.70 50.41 26.62 5.45 21.38
KOH 29.45 59.44 65.94 25.91 26.35 16.65
Microspheres 17.11 1.91 35.58 23.47 3.92 13.73
Artificial rain water cationic and anionic contents over natural washed stone, and limestones tested with the three most effective methods (mg/l).
Lixiviated water chemistry analysis
Anionic content Cationic content
Assessing the cleaning methods on the limestone façades in the Formerly Workers Hospital of Madrid, Spain
3. RESULTS (c)3. RESULTS (c) Suitability assessment: alteration products formation
ANIONSANIONS CATIONSCATIONS
Chloride Nitrate Sulphate Sodium Potassium Calcium
Rainwashed stone 46.64 119.15 101.79 12.61 4.18 8.64
NaOH 22.51 70.70 50.41 26.62 5.45 21.38
KOH 29.45 59.44 65.94 25.91 26.35 16.65
Microspheres 17.11 1.91 35.58 23.47 3.92 13.73
Artificial rain water cationic and anionic contents over natural washed stone, and limestones tested with the three most effective methods (mg/l).
Lixiviated water chemistry analysis
Anionic content Cationic content
Assessing the cleaning methods on the limestone façades in the Formerly Workers Hospital of Madrid, Spain
3. RESULTS (c)3. RESULTS (c) Suitability assessment: alteration products formation
ANIONSANIONS CATIONSCATIONS
Chloride Nitrate Sulphate Sodium Potassium Calcium
Rainwashed stone 46.64 119.15 101.79 12.61 4.18 8.64
NaOH 22.51 70.70 50.41 26.62 5.45 21.38
KOH 29.45 59.44 65.94 25.91 26.35 16.65
Microspheres 17.11 1.91 35.58 23.47 3.92 13.73
Artificial rain water cationic and anionic contents over natural washed stone, and limestones tested with the three most effective methods (mg/l).
Lixiviated water chemistry analysis
Anionic content Cationic content
Assessing the cleaning methods on the limestone façades in the Formerly Workers Hospital of Madrid, Spain
3. RESULTS (c)3. RESULTS (c) Suitability assessment: alteration products formation
ANIONSANIONS CATIONSCATIONS
Chloride Nitrate Sulphate Sodium Potassium Calcium
Rainwashed stone 46.64 119.15 101.79 12.61 4.18 8.64
NaOH 22.51 70.70 50.41 26.62 5.45 21.38
KOH 29.45 59.44 65.94 25.91 26.35 16.65
Microspheres 17.11 1.91 35.58 23.47 3.92 13.73
Artificial rain water cationic and anionic contents over natural washed stone, and limestones tested with the three most effective methods (mg/l).
Lixiviated water chemistry analysis
Anionic content Cationic content
Assessing the cleaning methods on the limestone façades in the Formerly Workers Hospital of Madrid, Spain
3. RESULTS (d)3. RESULTS (d) Suitability assessment: stone superficial texture changes
NaOH
Cross section
Area analysis
Surface section
Assessing the cleaning methods on the limestone façades in the Formerly Workers Hospital of Madrid, Spain
3. RESULTS (d)3. RESULTS (d) Suitability assessment: stone superficial texture changes
KOH
Area analysis
Surface section
Cross section
Assessing the cleaning methods on the limestone façades in the Formerly Workers Hospital of Madrid, Spain
3. RESULTS (d)3. RESULTS (d) Suitability assessment: stone superficial texture changes
Microspheres
Cross section
Area analysis
Surface section
Assessing the cleaning methods on the limestone façades in the Formerly Workers Hospital of Madrid, Spain
4. CONCLUSIONS (a)4. CONCLUSIONS (a)
Alkaline gels Pressured hot water jet Glass microspheres blasting Latex-based product
∆E* - ∆YI - ∆WI
NaOH KOH Glass microspheres blasting
Alteration products
NaOH Glass microspheres blasting
NaOH
Superficial texture changes
Glass microspheres blastingwith lower pressure
Assessing the cleaning methods on the limestone façades in the Formerly Workers Hospital of Madrid, Spain
4. CONCLUSIONS (b)4. CONCLUSIONS (b)
2006 2007
2006 2007
Assessing the cleaning methods on the limestone façades in the Formerly Workers Hospital of Madrid, Spain
4. CONCLUSIONS (c)4. CONCLUSIONS (c)
2006
Assessing the cleaning methods on the limestone façades in the Formerly Workers Hospital of Madrid, Spain
4. CONCLUSIONS (d)4. CONCLUSIONS (d)
FUTURE?FUTURE?
Façades cleaning as part of thebuilding maintenance
Preventive maintenance
Assessing the cleaning methods on the limestone façades in the Formerly Workers Hospital of Madrid, Spain
Thank you very much for your attention