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CRYSPOM IV, 11-13 JUNE 2014, AMSTERDAM
Optical measurement
of the alteration kinetics
of porous building materials
during salt crystallization
Teresa Diaz Gonçalves
Jessica Musacchi
Vânia Brito
CRYSPOM IV, 11-13 JUNE 2014, AMSTERDAM
Igreja da Graça (1380), Santarém, Portugal
http://andromeda.lnec.pt:9080/netlnec/edicoes/logotipos/LNEC-Logo1_COR.png/image_view_fullscreen
CRYSPOM IV, 11-13 JUNE 2014, AMSTERDAM
Optical measurement of the alteration kinetics of porous building materials during salt crystallization
Introduction
2
Salt crystallization tests
Santa Cruz Monastery (1132-1223), Coimbra
– courtesy of J Delgado Rodrigues
understand damage mechanisms
help avoid problems in practical conservation
CRYSPOM IV, 11-13 JUNE 2014, AMSTERDAM
Optical measurement of the alteration kinetics of porous building materials during salt crystallization
Introduction
3
Salt crystallization tests
Extreme conditions to obtain measurable changes in a short period of time:
• High temperature ASTM; CEN; RILEM V.1a => oven drying at 105ºC
• Successive wet/dry cycles ASTM; CEN; RILEM V.1a,V.1b,V.2 => several cycles
ASTM (2005) Standard test method for soundness of aggregates by use of sodium sulphate or magnesium sulphate. ASTM C88-05.
CEN (1999b) Natural stone test methods. Determination of resistance to salt crystallization. EN 12370
RILEM TC 25-PEM (1980) Recommended tests to measure the deterioration of stone and to assess the effectiveness of treatment methods, Materials and
Structures 13, 233-235 (test V.1a), 235-237 (test V.1b) and 237-239 (test V.2).
CRYSPOM IV, 11-13 JUNE 2014, AMSTERDAM
Optical measurement of the alteration kinetics of porous building materials during salt crystallization
Introduction
4
Salt crystallization tests
Sodium sulfate:
Solubility diagram of sodium sulfate: Adapted from Rodríguez-Navarro C, Doehne E, Sebastián E (2000) How does sodium sulfate crystallize? Implications for
the decay and testing of building materials, Cement and Concrete Research 30, 1527-1534.
CRYSPOM IV, 11-13 JUNE 2014, AMSTERDAM
Optical measurement of the alteration kinetics of porous building materials during salt crystallization
Introduction
5
Salt crystallization tests
Sodium sulfate:
Solubility diagram of sodium sulfate: Adapted from Rodríguez-Navarro C, Doehne E, Sebastián E (2000) How does sodium sulfate crystallize? Implications for
the decay and testing of building materials, Cement and Concrete Research 30, 1527-1534.
Arnold A (1982) Rising damp and saline minerals. In Fourth International Congress on the Deterioration and Preservation of Stone Objects, ed. K. L.Gauri and J.
A.Gwinn. Louisville, Ky.: University of Louisville. 11–28.
CRYSPOM IV, 11-13 JUNE 2014, AMSTERDAM
Optical measurement of the alteration kinetics of porous building materials during salt crystallization
Introduction
6
Salt crystallization tests
Solubility diagram of sodium sulfate: Adapted from Rodríguez-Navarro C, Doehne E, Sebastián E (2000) How does sodium sulfate crystallize? Implications for
the decay and testing of building materials, Cement and Concrete Research 30, 1527-1534.
Sodium sulfate:
three crystalline phases with different solubility
solubility is temperature-dependent
CRYSPOM IV, 11-13 JUNE 2014, AMSTERDAM
Optical measurement of the alteration kinetics of porous building materials during salt crystallization
Introduction
7
Salt crystallization tests
high temperatures => temperature-induced crystallization 1
successive wet/dry cycles => contact-induced crystallization 2
Sodium sulfate:
three crystalline phases with different solubility
solubility is temperature-dependent
1 Doehne E, Selwitz C, Carson DM (2002) The damage mechanism of sodium sulfate in porous stone In Proc. SALTeXPERT Meeting, Prague. European
Research on Cultural Heritage. State-of-the-Art Studies, Vol. 5, 2006, 127-160
2 Chatterji S, Jensen AD (1989) Efflorescence and breakdown of building materials, Nordic Concrete Research 8, 56-61.
CRYSPOM IV, 11-13 JUNE 2014, AMSTERDAM
Optical measurement of the alteration kinetics of porous building materials during salt crystallization
Introduction
8
Salt crystallization tests
Sodium sulfate:
three crystalline phases with different solubility
solubility is temperature-dependent
Massive decay
patterns that hardly
happen in
constructions …
high temperatures => temperature-induced crystallization 1
successive wet/dry cycles => contact-induced crystallization 2
1 Doehne E, Selwitz C, Carson DM (2002) The damage mechanism of sodium sulfate in porous stone In Proc. SALTeXPERT Meeting, Prague. European
Research on Cultural Heritage. State-of-the-Art Studies, Vol. 5, 2006, 127-160
2 Chatterji S, Jensen AD (1989) Efflorescence and breakdown of building materials, Nordic Concrete Research 8, 56-61.
CRYSPOM IV, 11-13 JUNE 2014, AMSTERDAM
Optical measurement of the alteration kinetics of porous building materials during salt crystallization
Introduction
9
Salt crystallization tests
Sodium sulfate:
three crystalline phases with different solubility
solubility is temperature-dependent
Massive decay
patterns that hardly
happen in
constructions …
high temperatures => temperature-induced crystallization
successive wet/dry cycles => contact-induced crystallization
Can sodium sulfate be as much destructive in field conditions,
where wet/dry cycles are slow and temperature variations smaller / less abrupt?
CRYSPOM IV, 11-13 JUNE 2014, AMSTERDAM
Optical measurement of the alteration kinetics of porous building materials during salt crystallization
Methods - Crystallization test (single isothermal drying event)
10
one or two central points and stick to that material
CRYSPOM IV, 11-13 JUNE 2014, AMSTERDAM
Optical measurement of the alteration kinetics of porous building materials during salt crystallization
Methods - Crystallization test (single isothermal drying event)
test specimens:
– cubes with 24 mm edge
– laterally sealed with epoxy
partial immersion during 3 days in:
– saturated Na2SO4 solution
– pure water (blank)
bottom-sealed
let dry at 20ºC and 50% RH
11
CRYSPOM IV, 11-13 JUNE 2014, AMSTERDAM
Optical measurement of the alteration kinetics of porous building materials during salt crystallization
1 - Evaporation curve
Objective: evaluate the drying kinetics
RILEM TC 25-PEM (1980) Recommended tests to measure the deterioration of stone and to assess the effectiveness of treatment methods, Materials and
Structures 13, 204-207 (test II.5 “Evaporation curve”)
specimens periodically weighed
0
2
4
6
8
10
12
0 100 200 300 400
W (
%)
Time (h)
Drying kinetics
12
Methods - Crystallization test (single isothermal drying event)
CRYSPOM IV, 11-13 JUNE 2014, AMSTERDAM
Optical measurement of the alteration kinetics of porous building materials during salt crystallization
3D profilometer
(Talysurf® CLI1000, by byTaylor Hobson )
Non-contact white light gauge based on the principle of
chromatic length aberration (CLA)
• vertical range = 3 mm
• vertical resolution = 100 nm
• lateral resolution = 5 μm
2 - Optical profilometry
Objective: monitor the morphological alterations of the surface (very small changes…)
Test
specimens
• and measuring slope
of 13º.
13
Methods - Crystallization test (single isothermal drying event)
texture affects the way materials look, feel and
function
CRYSPOM IV, 11-13 JUNE 2014, AMSTERDAM
Optical measurement of the alteration kinetics of porous building materials during salt crystallization
Foto dos primeiros momentos
ançã visto de lado
x
z
2 - Optical profilometry
Objective: monitor the morphological alterations of the surface
14
• Profiles obtained every 3 hours: speed =2 mm/s; spacing = 5 µm
Methods - Crystallization test (single isothermal drying event)
CRYSPOM IV, 11-13 JUNE 2014, AMSTERDAM
Optical measurement of the alteration kinetics of porous building materials during salt crystallization
2 - Optical profilometry
Objective: monitor the morphological alterations of the surface
• Profiles obtained every 3 hours: speed =2 mm/s; spacing = 5 µm
• Alteration curve calculated: expresses the average lifting of the surface during the experiment
15
29.0
29.2
29.4
29.6
0 5 10 15
Zm
ed (
mm
)
Time (h)
P0
P1 P2
P3
P4
Alteration kinetics
0 2.5 5 7.5 10 12.5 15 17.5 20 mm
mm
29.1
29.2
29.3
29.4
29.5
29.6
29.7
29.8
29.9
30
x
z
P1
P2
P3
P4
P0
Methods - Crystallization test (single isothermal drying event)
Alteration curve
CRYSPOM IV, 11-13 JUNE 2014, AMSTERDAM
Optical measurement of the alteration kinetics of porous building materials during salt crystallization
3 – Time-lapse photography
Objective: record the alteration process
1) Caraterísticas da máquina
fotográfica (marca e modelo)
2) Caraterísticas do software
(freeware, dizer quem desenvolveu)
3) fonte de alimentação (tipo,
caraterísticas, porque é que se
utilizou)
4) Lente: caraterísticas e razão da
sua utilização
5) Parâmetros (velocidade, intervalo
de tempo entre fotografias, outros)
(1) (2)
(3)
(4)
(5)
1) Camera with time-lapse software
2) Power supply
3) Lens
4) Light source
5) Test-specimen
Set-up we used to film the specimens laterally
Canon (PowerShot SX230 HS)
16
Methods - Crystallization test (single isothermal drying event)
CRYSPOM IV, 11-13 JUNE 2014, AMSTERDAM
Optical measurement of the alteration kinetics of porous building materials during salt crystallization
Materials
Three natural stones relevant for cultural heritage
Ançã limestone (CA) Grey limestone (CC) Bentheimer sandstone (B)
http://commons.wikimedia.org/
Christ Convent in Tomar, Portugal Nieuwe Kerk in Delft, The Netherlands Portuguese pavement
17
http://www.google.pt/url?sa=i&source=images&cd=&cad=rja&docid=2IWo8EdfgVu3cM&tbnid=b2E2bWhDbmBeLM:&ved=0CAgQjRwwAA&url=http://photos.void7.com/?title=Cal%E7ada Portuguesa&ei=YRrMUePKL-KU7Qah8oGgCA&psig=AFQjCNGI-bNSpid8TrJeiPZxUgrIfW7Vig&ust=1372416993817657
CRYSPOM IV, 11-13 JUNE 2014, AMSTERDAM
Optical measurement of the alteration kinetics of porous building materials during salt crystallization
CA CC B
Capillary porosity (%V) 22.8 9.1 17.7
Pore radius (µm) – MIP modal value 0.35 0.13 20
Sorptivity - S
x 106 (m/s1/2) pure water 166 20 305
sat Na2SO4 sol 114 17 229
Materials
a - by RILEM procedure II.1 (RILEM 1980)
b - by Mercury Intrusion Porosimetry (MIP)
c - data from Brito and Gonçalves 2013
d - data from Dautriat et al. (2009)
e - by RILEM procedure II.6 (RILEM 1980)
.A
Mi
Sorptivity expresses the capability of a material to absorb and transmit liquids by capillarity:
t ½ (s )
i (m
)
a 𝑆 = 𝑡𝑔 α =
𝑖
𝑡1/2 ∆M (kg) - cumulative mass of absorbed liquid
A (m2) - area of the absorption surface
ρ (kg/m3) - density of the liquid
i =𝛥𝑀
𝐴.𝜌
1D capillary suction
(RILEM 1980)
Three natural stones relevant for cultural heritage
18
CRYSPOM IV, 11-13 JUNE 2014, AMSTERDAM
Optical measurement of the alteration kinetics of porous building materials during salt crystallization
Results and discussion
19
CRYSPOM IV, 11-13 JUNE 2014, AMSTERDAM
Optical measurement of the alteration kinetics of porous building materials during salt crystallization
Bentheimer sandstone (B)
Drying kinetics with the
saturated Na2SO4 solution
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
0 200 400 600 800
W (
%)
Time (h)
B.Sat.3 (main test)
B.Sat (replication)
Bentheimer sandstone:
drying kinetics with saturated Na2SO4 solution
Results and discussion
Surface alteration:
efflorescence
20
CRYSPOM IV, 11-13 JUNE 2014, AMSTERDAM
Optical measurement of the alteration kinetics of porous building materials during salt crystallization
Bentheimer sandstone (B)
Non-contact profilometry: Profiles every 12 hours
Non-contact profilometry: Profiles every 12 hours
Results and discussion
Surface alteration:
efflorescence
21
CRYSPOM IV, 11-13 JUNE 2014, AMSTERDAM
Optical measurement of the alteration kinetics of porous building materials during salt crystallization
Rodríguez-Navarro C, Doehne E, Sebastián E (2000) How does sodium sulfate crystallize? Implications for the decay and testing of building materials, Cement
and Concrete Research 30, 1527-1534.
Linnow K, Zeunert A, Steiger M (2006) Investigation of sodium sulfate phase transitions in a porous material using humidity-and-temperature-controlled X-ray
diffraction, Analytical Chemistry 78, 4683-4689.
Solubility
phase diagram (Rodriguez-Navarro et al. 2000)
RH/T
phase diagram (Linnow et al. 2006)
Bentheimer sandstone (B)
Results and discussion
22
CRYSPOM IV, 11-13 JUNE 2014, AMSTERDAM
Optical measurement of the alteration kinetics of porous building materials during salt crystallization
Rodríguez-Navarro C, Doehne E, Sebastián E (2000) How does sodium sulfate crystallize? Implications for the decay and testing of building materials, Cement
and Concrete Research 30, 1527-1534.
Linnow K, Zeunert A, Steiger M (2006) Investigation of sodium sulfate phase transitions in a porous material using humidity-and-temperature-controlled X-ray
diffraction, Analytical Chemistry 78, 4683-4689.
Solubility
phase diagram (Rodriguez-Navarro et al. 2000)
RH/T
phase diagram (Linnow et al. 2006)
Bentheimer sandstone (B)
Results and discussion
23
CRYSPOM IV, 11-13 JUNE 2014, AMSTERDAM
Optical measurement of the alteration kinetics of porous building materials during salt crystallization
0
2
4
6
8
10
12
0 100 200 300 400 500 600
W (
%)
Tempo (h)
CA.Sat.1 (main test)CA.Sat.2 (main test)
CA.Sat.3 (main test)
CA.Sat.4 (main test)
CA.Sat.5 (replication)
CA.Sat.6 (replication)
CA.Sat.7 (replication)
Ançã limestone:
drying kinetics with saturated Na2SO4 solution
Ançã limestone (CA)
Drying kinetics with the
saturated Na2SO4 solution
Results and discussion
Surface alteration:
multi-layer delamination
24
• Multi-layer
delamination pattern:
does not require
wet/dry cycles
CRYSPOM IV, 11-13 JUNE 2014, AMSTERDAM
Optical measurement of the alteration kinetics of porous building materials during salt crystallization
0
2
4
6
8
10
12
0 100 200 300 400 500 600
W (
%)
Tempo (h)
CA.Sat.1 (main test)CA.Sat.2 (main test)
CA.Sat.3 (main test)
CA.Sat.4 (main test)
CA.Sat.5 (replication)
CA.Sat.6 (replication)
CA.Sat.7 (replication)
Ançã limestone:
drying kinetics with saturated Na2SO4 solution
Ançã limestone (CA)
Drying kinetics with the
saturated Na2SO4 solution
Results and discussion
Surface alteration:
multi-layer delamination
25
• Multi-layer
delamination pattern:
does not require
wet/dry cycles
Columns at the cloister of Santa Cruz Monastery (1132-1223), Coimbra, Portugal,
with delamination of Ançã limestone – courtesy of J Delgado Rodrigues
CRYSPOM IV, 11-13 JUNE 2014, AMSTERDAM
Optical measurement of the alteration kinetics of porous building materials during salt crystallization
Ançã limestone (CA)
Surface alteration:
multi-layer delamination
Results and discussion
26
CRYSPOM IV, 11-13 JUNE 2014, AMSTERDAM
Optical measurement of the alteration kinetics of porous building materials during salt crystallization
Ançã limestone (CA)
Non-contact profilometry: Profiles every 3 hours
Non-contact profilometry: Profiles every 3 hours
Results and discussion
Surface alteration:
multi-layer delamination
27
CRYSPOM IV, 11-13 JUNE 2014, AMSTERDAM
Optical measurement of the alteration kinetics of porous building materials during salt crystallization
Grey limestone (CC)
Surface alteration:
uni-layer delamination
0.0
1.0
2.0
3.0
4.0
5.0
0 1000 2000 3000 4000 5000
W (
%)
Time (h)
CC.Sat.1 (main test)
CC.Sat.2 (main test)
CC.Sat.3 (main test)
CC.Sat (replication)
Grey limestone:
drying kinetics with saturated Na2SO4 solution
Drying kinetics with the
saturated Na2SO4 solution
Results and discussion
28
CRYSPOM IV, 11-13 JUNE 2014, AMSTERDAM
Optical measurement of the alteration kinetics of porous building materials during salt crystallization
Grey limestone (CC)
Surface alteration:
uni-layer delamination
Results and discussion
29
CRYSPOM IV, 11-13 JUNE 2014, AMSTERDAM
Optical measurement of the alteration kinetics of porous building materials during salt crystallization
Grey limestone (CC)
Surface alteration:
uni-layer delamination
Results and discussion
30
CRYSPOM IV, 11-13 JUNE 2014, AMSTERDAM
Optical measurement of the alteration kinetics of porous building materials during salt crystallization
Grey limestone (CC)
Non-contact profilometry: Profiles every 6 hours
Non-contact profilometry: Profiles every 6 hours
Results and discussion
Surface alteration:
uni-layer delamination
31
CRYSPOM IV, 11-13 JUNE 2014, AMSTERDAM
Optical measurement of the alteration kinetics of porous building materials during salt crystallization
Grey limestone
uni-layer delamination
Ançã limestone
multi-layer delamination Bentheimer sandstone
efflorescence
28.5
29.5
30.5
31.5
32.5
33.5
0
2
4
6
8
10
12
0 100 200 300 400
Z (
mm
)
W (
%)
Time (h)
Ançã limestone: with sat Na2SO4 solution:
drying kinetics + alteration kinetics
29.6
29.8
30
30.2
30.4
30.6
30.8
0
1
2
3
4
5
6
7
0 100 200 300 400 500 600 700
Z (
mm
)
W (
%)
Time (h)
Bentheimer sandstone with sat Na2SO4 solution:
drying kinetics + alteration kinetics
28.0
28.5
29.0
29.5
30.0
30.5
0
1
2
3
4
5
0 200 400 600 800 1000
Z (m
m)
W (
%)
Time (h)
Grey limestone with sat Na2SO4 solution:
drying kinetics + alteration kinetics
Results and discussion
32
CRYSPOM IV, 11-13 JUNE 2014, AMSTERDAM
Optical measurement of the alteration kinetics of porous building materials during salt crystallization
Ançã limestone
multi-layer delamination Bentheimer sandstone
efflorescence
28.5
29.5
30.5
31.5
32.5
33.5
0
2
4
6
8
10
12
0 100 200 300 400
Z (
mm
)
W (
%)
Time (h)
Ançã limestone: with sat Na2SO4 solution:
drying kinetics + alteration kinetics
29.6
29.8
30
30.2
30.4
30.6
30.8
0
1
2
3
4
5
6
7
0 100 200 300 400 500 600 700
Z (
mm
)
W (
%)
Time (h)
Bentheimer sandstone with sat Na2SO4 solution:
drying kinetics + alteration kinetics
Results and discussion
33
Stage II Stage I
Time
Mois
ture
conte
nt
- M
C Stage I
Stage II
Stage IIIcritical MC
w
MCcrit = critical moisture content
tt
w0
Time
Mois
ture
conte
nt
- M
C Stage I
Stage II
Stage IIIcritical MC
w
MCcrit = critical moisture content
tt
w0
Time
Mois
ture
conte
nt
- M
C Stage I
Stage II
Stage IIIcritical MC
w
MCcrit = critical moisture content
tt
w0 Stage I
Stage II
Typical drying kinetics curve Stage I => straight line
Drying of porous materials
with pure water
CRYSPOM IV, 11-13 JUNE 2014, AMSTERDAM
Optical measurement of the alteration kinetics of porous building materials during salt crystallization
0
2
4
6
8
10
12
14
0 100 200 300 400 500 600
Mo
istu
re c
on
ten
t (%
)
Time (h)
Na2SO4
Ançã limestone
multi-layer delamination Bentheimer sandstone
efflorescence
28.5
29.5
30.5
31.5
32.5
33.5
0
2
4
6
8
10
12
0 100 200 300 400
Z (
mm
)
W (
%)
Time (h)
Ançã limestone: with sat Na2SO4 solution:
drying kinetics + alteration kinetics
29.6
29.8
30
30.2
30.4
30.6
30.8
0
1
2
3
4
5
6
7
0 100 200 300 400 500 600 700
Z (
mm
)
W (
%)
Time (h)
Bentheimer sandstone with sat Na2SO4 solution:
drying kinetics + alteration kinetics
Results and discussion
34
Stage II Stage I
Example of a drying curve slower drying + irregularities
Drying of porous materials
with salt solutions
not necessarily a
CRYSPOM IV, 11-13 JUNE 2014, AMSTERDAM
Optical measurement of the alteration kinetics of porous building materials during salt crystallization
29.6
29.8
30
30.2
30.4
30.6
30.8
0
1
2
3
4
5
6
7
0 100 200 300 400 500 600 700
Z (
mm
)
W (
%)
Time (h)
Bentheimer sandstone with sat Na2SO4 solution:
drying kinetics + alteration kinetics
(i) (ii) (iii) (iv) (v)
Results and discussion
35
28.5
29.5
30.5
31.5
32.5
33.5
0
2
4
6
8
10
12
0 100 200 300 400
Z (
mm
)
W (
%)
Time (h)
Ançã limestone: with sat Na2SO4 solution:
drying kinetics + alteration kinetics
28.0
28.5
29.0
29.5
30.0
30.5
0
1
2
3
4
5
0 200 400 600 800 1000
Z (m
m)
W (
%)
Time (h)
Grey limestone with sat Na2SO4 solution:
drying kinetics + alteration kinetics
Bentheimer
sandstone
efflorescence
CRYSPOM IV, 11-13 JUNE 2014, AMSTERDAM
Optical measurement of the alteration kinetics of porous building materials during salt crystallization
29.6
29.8
30
30.2
30.4
30.6
30.8
0
1
2
3
4
5
6
7
0 100 200 300 400 500 600 700
Z (
mm
)
W (
%)
Time (h)
Bentheimer sandstone with sat Na2SO4 solution:
drying kinetics + alteration kinetics
(i) (ii) (iii) (iv) (v)
Results and discussion
i. Efflorescence grows at constant rate (surface is saturated)
ii. Efflorescence has stopped growing (no more liquid continuity to the surface)
iii. Efflorescence dehydrates
iv. No more changes
36
28.5
29.5
30.5
31.5
32.5
33.5
0
2
4
6
8
10
12
0 100 200 300 400
Z (
mm
)
W (
%)
Time (h)
Ançã limestone: with sat Na2SO4 solution:
drying kinetics + alteration kinetics
28.0
28.5
29.0
29.5
30.0
30.5
0
1
2
3
4
5
0 200 400 600 800 1000
Z (m
m)
W (
%)
Time (h)
Grey limestone with sat Na2SO4 solution:
drying kinetics + alteration kinetics
Bentheimer
sandstone
efflorescence
CRYSPOM IV, 11-13 JUNE 2014, AMSTERDAM
Optical measurement of the alteration kinetics of porous building materials during salt crystallization
29.6
29.8
30
30.2
30.4
30.6
30.8
0
1
2
3
4
5
6
7
0 100 200 300 400 500 600 700
Z (
mm
)
W (
%)
Time (h)
Bentheimer sandstone with sat Na2SO4 solution:
drying kinetics + alteration kinetics
(i) (ii) (iii) (iv) (v)
Results and discussion
i. Efflorescence grows at constant rate (surface is saturated)
ii. Efflorescence grows at decreasing rate (liquid continuity to the surface progressively reduced)
iii. Efflorescence has stopped growing (no more liquid continuity to the surface)
iv. Efflorescence dehydrates
v. No more changes
37
28.5
29.5
30.5
31.5
32.5
33.5
0
2
4
6
8
10
12
0 100 200 300 400
Z (
mm
)
W (
%)
Time (h)
Ançã limestone: with sat Na2SO4 solution:
drying kinetics + alteration kinetics
28.0
28.5
29.0
29.5
30.0
30.5
0
1
2
3
4
5
0 200 400 600 800 1000
Z (m
m)
W (
%)
Time (h)
Grey limestone with sat Na2SO4 solution:
drying kinetics + alteration kinetics
Bentheimer
sandstone
efflorescence
CRYSPOM IV, 11-13 JUNE 2014, AMSTERDAM
Optical measurement of the alteration kinetics of porous building materials during salt crystallization
29.6
29.8
30
30.2
30.4
30.6
30.8
0
1
2
3
4
5
6
7
0 100 200 300 400 500 600 700
Z (
mm
)
W (
%)
Time (h)
Bentheimer sandstone with sat Na2SO4 solution:
drying kinetics + alteration kinetics
(i) (ii) (iii) (iv) (v)
Results and discussion
i. Efflorescence grows at constant rate (surface is saturated)
ii. Efflorescence grows at decreasing rate (liquid continuity to the surface progressively reduced)
iii. Efflorescence has stopped growing (no more liquid continuity to the surface)
Efflorescence growth stops
(liquid continuity to the surface was broken)
38
28.5
29.5
30.5
31.5
32.5
33.5
0
2
4
6
8
10
12
0 100 200 300 400
Z (
mm
)
W (
%)
Time (h)
Ançã limestone: with sat Na2SO4 solution:
drying kinetics + alteration kinetics
28.0
28.5
29.0
29.5
30.0
30.5
0
1
2
3
4
5
0 200 400 600 800 1000
Z (m
m)
W (
%)
Time (h)
Grey limestone with sat Na2SO4 solution:
drying kinetics + alteration kinetics
Bentheimer
sandstone
efflorescence
CRYSPOM IV, 11-13 JUNE 2014, AMSTERDAM
Optical measurement of the alteration kinetics of porous building materials during salt crystallization
29.6
29.8
30
30.2
30.4
30.6
30.8
0
1
2
3
4
5
6
7
0 100 200 300 400 500 600 700
Z (
mm
)
W (
%)
Time (h)
Bentheimer sandstone with sat Na2SO4 solution:
drying kinetics + alteration kinetics
(i) (ii) (iii) (iv) (v)
Results and discussion
i. Efflorescence grows at constant rate (surface is saturated)
ii. Efflorescence grows at decreasing rate (liquid continuity to the surface progressively reduced)
iii. Efflorescence has stopped growing (no more liquid continuity to the surface)
Efflorescence growth stops
(liquid continuity to the surface was broken)
39
28.5
29.5
30.5
31.5
32.5
33.5
0
2
4
6
8
10
12
0 100 200 300 400
Z (
mm
)
W (
%)
Time (h)
Ançã limestone: with sat Na2SO4 solution:
drying kinetics + alteration kinetics
28.0
28.5
29.0
29.5
30.0
30.5
0
1
2
3
4
5
0 200 400 600 800 1000
Z (m
m)
W (
%)
Time (h)
Grey limestone with sat Na2SO4 solution:
drying kinetics + alteration kinetics
Bentheimer
sandstone
efflorescence
CRYSPOM IV, 11-13 JUNE 2014, AMSTERDAM
Optical measurement of the alteration kinetics of porous building materials during salt crystallization
29.6
29.8
30
30.2
30.4
30.6
30.8
0
1
2
3
4
5
6
7
0 100 200 300 400 500 600 700
Z (
mm
)
W (
%)
Time (h)
Bentheimer sandstone with sat Na2SO4 solution:
drying kinetics + alteration kinetics
(i) (ii) (iii) (iv) (v)
Results and discussion
i. Efflorescence grows at constant rate (surface is saturated)
ii. Efflorescence grows at decreasing rate (liquid continuity to the surface progressively reduced)
iii. Efflorescence has stopped growing (no more liquid continuity to the surface)
iv. Efflorescence dehydrates
Efflorescence growth stops
(liquid continuity to the surface was broken)
40
28.5
29.5
30.5
31.5
32.5
33.5
0
2
4
6
8
10
12
0 100 200 300 400
Z (
mm
)
W (
%)
Time (h)
Ançã limestone: with sat Na2SO4 solution:
drying kinetics + alteration kinetics
28.0
28.5
29.0
29.5
30.0
30.5
0
1
2
3
4
5
0 200 400 600 800 1000
Z (m
m)
W (
%)
Time (h)
Grey limestone with sat Na2SO4 solution:
drying kinetics + alteration kinetics
Bentheimer
sandstone
efflorescence
CRYSPOM IV, 11-13 JUNE 2014, AMSTERDAM
Optical measurement of the alteration kinetics of porous building materials during salt crystallization
29.6
29.8
30
30.2
30.4
30.6
30.8
0
1
2
3
4
5
6
7
0 100 200 300 400 500 600 700
Z (
mm
)
W (
%)
Time (h)
Bentheimer sandstone with sat Na2SO4 solution:
drying kinetics + alteration kinetics
(i) (ii) (iii) (iv) (v)
Results and discussion
i. Efflorescence grows at constant rate (surface is saturated)
ii. Efflorescence grows at decreasing rate (liquid continuity to the surface progressively reduced)
iii. Efflorescence has stopped growing (no more liquid continuity to the surface)
iv. Efflorescence dehydrates
v. No more changes
Efflorescence growth stops
(liquid continuity to the surface was broken)
41
28.5
29.5
30.5
31.5
32.5
33.5
0
2
4
6
8
10
12
0 100 200 300 400
Z (
mm
)
W (
%)
Time (h)
Ançã limestone: with sat Na2SO4 solution:
drying kinetics + alteration kinetics
28.0
28.5
29.0
29.5
30.0
30.5
0
1
2
3
4
5
0 200 400 600 800 1000
Z (m
m)
W (
%)
Time (h)
Grey limestone with sat Na2SO4 solution:
drying kinetics + alteration kinetics
Bentheimer
sandstone
efflorescence
CRYSPOM IV, 11-13 JUNE 2014, AMSTERDAM
Optical measurement of the alteration kinetics of porous building materials during salt crystallization
28.5
29.5
30.5
31.5
32.5
33.5
0
2
4
6
8
10
12
0 100 200 300 400
Z (
mm
)
W (
%)
Time (h)
Ançã limestone: with sat Na2SO4 solution:
drying kinetics + alteration kinetics
(i) (ii) (iii) (iv) (v)
29.6
29.8
30
30.2
30.4
30.6
30.8
0
1
2
3
4
5
6
7
0 100 200 300 400 500 600 700
Z (
mm
)
W (
%)
Time (h)
Bentheimer sandstone with sat Na2SO4 solution:
drying kinetics + alteration kinetics
(i) (ii) (iii) (iv) (v)
Results and discussion
i. Florescence grows at constant rate (surface is saturated)
ii. Florescence grows at decreasing rate (liquid continuity to the surface progressively reduced)
iii. Florescence has stopped growing (no more liquid continuity to the surface)
iv. Florescence dehydrates
v. No more changes
Florescence growth stops
(liquid continuity to the surface was broken)
42
28.0
28.5
29.0
29.5
30.0
30.5
0
1
2
3
4
5
0 200 400 600 800 1000
Z (m
m)
W (
%)
Time (h)
Grey limestone with sat Na2SO4 solution:
drying kinetics + alteration kinetics
Ançã
limestone
multi-layer
delamination
CRYSPOM IV, 11-13 JUNE 2014, AMSTERDAM
Optical measurement of the alteration kinetics of porous building materials during salt crystallization
i. Florescence grows at constant rate (surface is saturated)
ii. Florescence grows at decreasing rate (liquid continuity to the surface progressively reduced)
iii. Florescence has stopped growing (no more liquid continuity to the surface)
iv. Florescence dehydrates
v. No more changes
29.0
30.0
31.0
32.0
0
2
4
6
8
10
12
0 72 144 216 288 360
Z (
mm
) W (
%)
Time (h)
Ançã limestone: with sat Na2SO4 solution:
drying kinetics + alteration kinetics
Results and discussion
43
29.6
29.8
30
30.2
30.4
30.6
30.8
0
1
2
3
4
5
6
7
0 100 200 300 400 500 600 700
Z (
mm
)
W (
%)
Time (h)
Bentheimer sandstone with sat Na2SO4 solution:
drying kinetics + alteration kinetics
(i) (ii) (iii) (iv) (v)
28.0
28.5
29.0
29.5
30.0
30.5
0
1
2
3
4
5
0 200 400 600 800 1000
Z (m
m)
W (
%)
Time (h)
Grey limestone with sat Na2SO4 solution:
drying kinetics + alteration kinetics
Ançã
limestone
multi-layer
delamination
CRYSPOM IV, 11-13 JUNE 2014, AMSTERDAM
Optical measurement of the alteration kinetics of porous building materials during salt crystallization
28.5
29.5
30.5
31.5
32.5
33.5
0
2
4
6
8
10
12
0 100 200 300 400
Z (
mm
)
W (
%)
Time (h)
Ançã limestone: with sat Na2SO4 solution:
drying kinetics + alteration kinetics
(i) (ii) (iii) (iv) (v)
29.6
29.8
30
30.2
30.4
30.6
30.8
0
1
2
3
4
5
6
7
0 100 200 300 400 500 600 700
Z (
mm
)
W (
%)
Time (h)
Bentheimer sandstone with sat Na2SO4 solution:
drying kinetics + alteration kinetics
(i) (ii) (iii) (iv) (v)
28.0
28.5
29.0
29.5
30.0
30.5
0
1
2
3
4
5
0 200 400 600 800 1000
Z (m
m)
W (
%)
Time (h)
(i) (ii) (iii) (iv) (v)
Grey limestone with sat Na2SO4 solution:
drying kinetics + alteration kinetics
Results and discussion
i. Florescence grows at constant rate (surface is saturated)
ii. Florescence grows at decreasing rate (liquid continuity to the surface progressively reduced)
iii. Florescence has stopped growing (no more liquid continuity to the surface)
iv. Florescence dehydrates
v. No more changes
Florescence growth stops
(liquid continuity to the surface was broken)
Grey
limestone
uni-layer
delamination
44
CRYSPOM IV, 11-13 JUNE 2014, AMSTERDAM
Optical measurement of the alteration kinetics of porous building materials during salt crystallization
28.5
29.5
30.5
31.5
32.5
33.5
0
2
4
6
8
10
12
0 100 200 300 400
Z (
mm
)
W (
%)
Time (h)
Ançã limestone: with sat Na2SO4 solution:
drying kinetics + alteration kinetics
(i) (ii) (iii) (iv) (v)
29.6
29.8
30
30.2
30.4
30.6
30.8
0
1
2
3
4
5
6
7
0 100 200 300 400 500 600 700
Z (
mm
)
W (
%)
Time (h)
Bentheimer sandstone with sat Na2SO4 solution:
drying kinetics + alteration kinetics
(i) (ii) (iii) (iv) (v)
28.0
28.5
29.0
29.5
30.0
30.5
0
1
2
3
4
5
0 200 400 600 800 1000
Z (m
m)
W (
%)
Time (h)
(i) (ii) (iii) (iv) (v)
Grey limestone with sat Na2SO4 solution:
drying kinetics + alteration kinetics
Results and discussion
i. Florescence grows at constant rate (surface is saturated)
ii. Florescence grows at decreasing rate (liquid continuity to the surface progressively reduced)
iii. Florescence has stopped growing (no more liquid continuity to the surface)
iv. Florescence dehydrates
v. No more changes
Florescence growth stops
(liquid continuity to the surface was broken)
Detachment of the
surface layer
45 Grey
limestone
uni-layer
delamination
CRYSPOM IV, 11-13 JUNE 2014, AMSTERDAM
Optical measurement of the alteration kinetics of porous building materials during salt crystallization
28.5
29.5
30.5
31.5
32.5
33.5
0
2
4
6
8
10
12
0 100 200 300 400
Z (
mm
)
W (
%)
Time (h)
Ançã limestone: with sat Na2SO4 solution:
drying kinetics + alteration kinetics
(i) (ii) (iii) (iv) (v)
29.6
29.8
30
30.2
30.4
30.6
30.8
0
1
2
3
4
5
6
7
0 100 200 300 400 500 600 700
Z (
mm
)
W (
%)
Time (h)
Bentheimer sandstone with sat Na2SO4 solution:
drying kinetics + alteration kinetics
(i) (ii) (iii) (iv) (v)
28.0
28.5
29.0
29.5
30.0
30.5
0
1
2
3
4
5
0 200 400 600 800 1000
Z (m
m)
W (
%)
Time (h)
(i) (ii) (iii) (iv) (v)
Grey limestone with sat Na2SO4 solution:
drying kinetics + alteration kinetics
Results and discussion
i. Florescence grows at constant rate (surface is saturated)
ii. Florescence grows at decreasing rate (liquid continuity to the surface progressively reduced)
iii. Florescence has stopped growing (no more liquid continuity to the surface)
iv. Florescence dehydrates
v. No more changes
Florescence growth stops
(liquid continuity to the surface was broken)
Detachment of the
surface layer
46 Grey
limestone
uni-layer
delamination
CRYSPOM IV, 11-13 JUNE 2014, AMSTERDAM
Optical measurement of the alteration kinetics of porous building materials during salt crystallization
Conclusions objectives were to
characterize the degradation
forms to which sodium sulfate
gave rise and explain the
underlying mechanisms.
47
The Conclusion/Summary
section should condense
your results and
implications. This should be
brief - a bullet or outline form
is especially helpful. Be sure
to connect your results
with the overview
statements in the
Introduction. Don't have too
many points - three or four
is usually the maximum.
Diaz Gonçalves T and Brito V (in press) Alteration kinetics of natural stones due to sodium sulphate crystallization: can reality match experimental simulations?
Environmental Earth Sciences. DOI:10.1007/s12665-014-3085-0
CRYSPOM IV, 11-13 JUNE 2014, AMSTERDAM
Optical measurement of the alteration kinetics of porous building materials during salt crystallization
• Can sodium sulfate be as much destructive in field conditions? Yes
Conclusions objectives were to
characterize the degradation
forms to which sodium sulfate
gave rise and explain the
underlying mechanisms.
48
The Conclusion/Summary
section should condense
your results and
implications. This should be
brief - a bullet or outline form
is especially helpful. Be sure
to connect your results
with the overview
statements in the
Introduction. Don't have too
many points - three or four
is usually the maximum.
Diaz Gonçalves T and Brito V (in press) Alteration kinetics of natural stones due to sodium sulphate crystallization: can reality match experimental simulations?
Environmental Earth Sciences. DOI:10.1007/s12665-014-3085-0
CRYSPOM IV, 11-13 JUNE 2014, AMSTERDAM
Optical measurement of the alteration kinetics of porous building materials during salt crystallization
• Can sodium sulfate be as much destructive in field conditions? Yes
• Delamination pattern: does not require wet/dry cycles
Conclusions objectives were to
characterize the degradation
forms to which sodium sulfate
gave rise and explain the
underlying mechanisms.
49
The Conclusion/Summary
section should condense
your results and
implications. This should be
brief - a bullet or outline form
is especially helpful. Be sure
to connect your results
with the overview
statements in the
Introduction. Don't have too
many points - three or four
is usually the maximum.
Diaz Gonçalves T and Brito V (in press) Alteration kinetics of natural stones due to sodium sulphate crystallization: can reality match experimental simulations?
Environmental Earth Sciences. DOI:10.1007/s12665-014-3085-0
CRYSPOM IV, 11-13 JUNE 2014, AMSTERDAM
Optical measurement of the alteration kinetics of porous building materials during salt crystallization
• Can sodium sulfate be as much destructive in field conditions? Yes
• Delamination pattern: does not require wet/dry cycles
• New method:
• The optical profiling technique is appropriate to monitor salt decay
Conclusions objectives were to
characterize the degradation
forms to which sodium sulfate
gave rise and explain the
underlying mechanisms.
50
Diaz Gonçalves T and Brito V (in press) Alteration kinetics of natural stones due to sodium sulphate crystallization: can reality match experimental simulations?
Environmental Earth Sciences. DOI:10.1007/s12665-014-3085-0
CRYSPOM IV, 11-13 JUNE 2014, AMSTERDAM
Optical measurement of the alteration kinetics of porous building materials during salt crystallization
• Can sodium sulfate be as much destructive in field conditions? Yes
• Delamination pattern: does not require wet/dry cycles
• New method:
• The optical profiling technique is appropriate to monitor salt decay
• Alteration kinetics curves are useful to:
– complement the information provided by gravimetric drying curves
– understand salt decay mechanisms and behaviours
Conclusions objectives were to
characterize the degradation
forms to which sodium sulfate
gave rise and explain the
underlying mechanisms.
51
The Conclusion/Summary
section should condense
your results and
implications. This should be
brief - a bullet or outline form
is especially helpful. Be sure
to connect your results
with the overview
statements in the
Introduction. Don't have too
many points - three or four
is usually the maximum.
Diaz Gonçalves T and Brito V (in press) Alteration kinetics of natural stones due to sodium sulphate crystallization: can reality match experimental simulations?
Environmental Earth Sciences. DOI:10.1007/s12665-014-3085-0
CRYSPOM IV, 11-13 JUNE 2014, AMSTERDAM
Optical measurement of the alteration kinetics of porous building materials during salt crystallization
Acknowledgements
This work was performed under the research project DRYMASS
(ref. PTDC/ECM/100553/2008) which is supported by national funds through the
Fundação para a Ciência e a Tecnologia (FCT) and the Laboratório Nacional de
Engenharia Civil (LNEC)
We are grateful to:
Tiago Enes Dias
Sílvia Pereira
José Delgado Rodrigues
Luís Nunes
José Costa
Veerle Cnudde
Timo G. Nijland
Manuel Francisco Pereira
Thank you!
52
CRYSPOM IV, 11-13 JUNE 2014, AMSTERDAM
Optical measurement of the alteration kinetics of porous building materials during salt crystallization
Foto dos primeiros momentos
ançã visto de lado
2 - Optical profilometry
Objective: monitor the morphological alterations of the surface
Drying surface
Alteration surface
53
• Profiles obtained every 3 hours: speed =2 mm/s; spacing = 5 µm
• Alteration curve calculated: expresses the average lifting of the surface during the experiment
Methods - Crystallization test (single isothermal drying event)
CRYSPOM IV, 11-13 JUNE 2014, AMSTERDAM
Optical measurement of the alteration kinetics of porous building materials during salt crystallization
Grey limestone
uni-layer delamination
Ançã limestone
multi-layer delamination Bentheimer sandstone
efflorescence
Bentheimer
sandstone
Low
porosity
limestone
Ançã
limestone
Caption:
salt crystals
sealing
Sorptivity
sat Na2SO4 x106 (m/s1/2)
229 114 20
Results and discussion A full explanation of the
different decay patterns
is not possible because
of the many factors
involved ….
… the capillary suction
varies with the moisture
content, …
… we don’t have a
sharp front … and there
is also the mechanical
resistance of the
material.
54
CRYSPOM IV, 11-13 JUNE 2014, AMSTERDAM
Optical measurement of the alteration kinetics of porous building materials during salt crystallization
Foto dos primeiros momentos
ançã visto de lado
x
z
2 - Optical profilometry
Objective: monitor the morphological alterations of the surface
55
• Profiles obtained every 3 hours: speed =2 mm/s; spacing = 5 µm
Methods - Crystallization test (single isothermal drying event)
Profile extraction