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Trends Journal of Sciences Research (2015) 2(3):95-103 http://www.tjsr.org
Characterization and Weathering of the Building Materials of
Sanctuaries in the Archaeological Site of Dion, Greece
Spathis P.1, Papanikolaou E.2, Melfos V.2, Samara C.1, Christaras B.2, Katsiotis N.3
1School of Chemistry, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece,
2School of Geology, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece,
3School of Chemical Engineering, National Technical University of Athens, 15780 Athens, Greece
Correspondence: Spathis P. (spathis@chem.auth.gr)
Abstract The sanctuaries of Demeter and Asklepios are part of the Dion archaeological site that sits among the
eastern foothills of Mount Olympus. The main building materials are limestones and conglomerates. Sandstones,
marbles, and ceramic plinths were also used. The materials consist mainly of calcite and/or dolomite, whereas the
deteriorated surfaces contain also secondary and recrystallized calcite and dolomite, gypsum, various inorganic
compounds, fluoroapatite, microorganisms and other organic compounds. Cracks and holes were observed in
various parts of the stones. The influence of specific weathering agents and factors to the behavior of the materials
was examined. The particular environmental conditions in Dion combine increased moisture and rain fall, insolation
and great temperature differences, abundance of intensive surface and underground water bodies in the surrounding
area, an area full of plants and trees, therefore, they can cause extensive chemical, biological and mechanical decay
of the monuments. The following physical characteristics of the building materials have been studied: bulk density,
open porosity, pore size distribution, water absorption and desorption, capillary absorption and desorption. The
chemical composition of bulk precipitation, surface and underground water was investigated. The salts presence and
crystallization was examined. The influence of the water presence to the behavior of the materials was examined by
in situ IR thermometer measurements. Temperature values increased from the lower to the upper parts of the
building stones and they significantly depend on the orientation of the walls. The results indicate the existence of
water in the bulk of the materials due to capillary penetration. The existence of water in the bulk of the materials
due to capillary penetration, the cycles of wet-dry conditions, correlated with the intensive surface and underground
water presence in the whole surrounding area, lead to partial dissolution-recrystallization of the carbonate material
and loss of the structural cohesion and the surface stability.
Keywords: : stone, deterioration, physical characteristics, capillary rise, IR thermometry.
Citation: Spathis P., Papanikolaou E., Melfos V., Samara C., Christaras B., Katsiotis N. Characterization
and Weathering of the Building Materials of Sanctuaries in the Archaeological Site of Dion,
Greece. Trends Journal of Sciences Research. Vol. 2, No. 3, 2015, pp. 95-103.
Introduction
Deterioration of historical monuments is the result
of chemical reactions of polluted air, soil and water with
the stone building materials. The crystallization and
hydration of weathering products result in their expansion
causing the degradation of dolomite, limestone, marble,
sandstone and other building materials. In most cases the
stone surfaces are gradually covered by salts and black
crusts containing calcium, magnesium, sodium, potassium
sulphates, nitrates and other constituents. Also the water
can easily penetrate and remain into the building stone
materials, resulting in a destructive influence due to the
absorption and evaporation of the moisture that affects
their volume and causes cracks leading to the deterioration
of the structure[1]. Under these conditions, the stone
surfaces disintegrate into powder and the building
materials gradually lose their mechanical strength and
their artistic form[2-6]. In the case of marbles the main
mechanism of deterioration is the sulphation of their
surfaces, leading to the formation of gypsum layers on the
stone surface, due to the solid state diffusion of Ca2+ [7-13].
Various destructive or non-destructive methods are used
for the study of the weathering of the building stone
materials of the monuments, being part of their
conservation[14-16].
The aim of the present work is the study of the effect of
the environmental factors and the deterioration problems
of stone monuments of Demeter and Asklepios sanctuaries
in Dion archaeological site (Figure 1), one of the most
important religious centers of ancient Greeks in central
Macedonia. In earlier works[17-20] it was found that the
main building materials of the monuments are limestones
and conglomerates. Sandstones, marbles and ceramic
plinths were also used. The materials consist mainly of
calcite and/or dolomite. The surfaces of the building
materials are partially covered by the weathering products
of the primary minerals such as secondary carbonate
(calcite-dolomite) precipitated from water solutions,
recrystallized calcite and dolomite and in some cases
gypsum. The presence of crusts of various
96 Spathis P., Papanikolaou E., Melfos V. et al: Characterization and Weathering of the Building
Materials of Sanctuaries in the Archaeological Site of Dion, Greece
inorganic/organic compounds, such as illite, kaolinite,
sericite, rutile, Fe-oxides, Mn-oxides, fluoroapatite,
fragments of fossils, is related to various sediments that
covered the primary materials. No significant amounts of
salts were found on the surface or inside the pore of the
materials. The purpose of this investigation is the analysis
of the environmental conditions in the area of the
archaeological site, the examination of their contribution
to the deterioration of the building materials and the study
of the influence of the water presence to the behavior of
the materials by in situ IR thermometer measurements and
laboratory measurements of their physical characteristics.
Materials And Methods
A series of samples of the various building materials
were collected from different locations of both
monuments, Asklepios and Demeter. The accurate
sampling sites were previously mentioned and
presented[17]. The in situ measurements were focused in
two monuments, Asklepios Temple, Altar in Demeter
sanctuary (Figure 1).
Figure 1 General view of the sanctuaries of a) Asklepios, b) Demeter.
The mineralogical study of thin sections of the samples
was carried out by optical microscopy using a Leitz
Laborlux 11 POL S microscope. Scanning electron
microscopy (SEM) was used to study the surface of
samples. The SEM experiments were carried out with a
JEOL, JSM-840 A scanning microscope, connected with
an Energy Dispenser Spectrometer - EDS - (LINK, AN
10/55S). The physical properties of the materials were
studied according standard methods[21].
Twelve samples of bulk precipitation were collected on
a monthly basis (December 2010 to November 2011)
using a bulk precipitation collector located in the
archaeological area for a period of one year. Three
samples of surface waters were also collected from
Vaphyras river and two rillets, all passing from the
archaeological area. Upon receipt in the Laboratory,
precipitation and surface water samples were filtered
through 0.45 μm pore diameter cellulose membranes to
remove particles. Chemical analysis for the determination
of the chloride, nitrate and sulphate ions was carried out
by Ion Chromatography.
Two series of IR thermometer in situ measurements, in
conditions of sunny or wet weather, were carried out by a
portable infrared laser thermometer (Center 358, Infrared
thermometer, Range:-18o C~ 315o C). The question was to
determine the high of the capillary water at the base of
building stones, at the contact with the soil, given that the
aquifer is very high, quite near to the foundation level of
the monument. The idea was to use an infrared
thermometer, because the inside temperature of the wet
part of a stone is different than the next dry part, of the
same stone, for the same time and weather conditions. The
environment temperature during the measurements was ~
28ο C (sunny conditions) or ~ 9ο C (wet conditions). In
this study, infrared thermometer measurements were used
in the assessment of moisture in porous stones. Due to the
difference between the thermal diffusivities of moist and
the dry stones, IR thermometer measurements are capable
of showing qualitative variations in respiration behaviour
(i.e. moisture impact), appearing as surface temperature
fluctuations[22-23].
Results and Discussion
The results of the mineralogical analysis of the
deteriorated surfaces and inside the pores in the bulk of
the materials are shown in Table 1 and Figures 2-3.
From these results it is evident that the surfaces of the
building materials are partially covered by the weathering
products of the primary minerals such as secondary
carbonate (calcite-dolomite) precipitated from water
solutions, recrystallized calcite and dolomite and in some
cases gypsum. An intense presence of lichens and
bryophyte is observed. The presence of crusts of various
inorganic/organic compounds, such as illite, kaolinite,
sericite, rutile, chromite, Fe-oxides, Mn-oxides,
fluoroapatite, fragments of fossils, is related to various
sediments that covered the primary materials.
Trends Journal of Sciences Research 2015, 2(3): 95-103 97
Table 1. Mineralogical composition of the deteriorated surfaces of the building materials of Asklepios and
Demeter sanctuaries.
Primary minerals
Secondary minerals
(sediments products)
Secondary minerals
(deterioration products)
Calcite: CaCO3
Aragonite: CaCO3
Dolomite: CaMg(CO3)2
Quartz: SiO2
White mica and sericite:
KAl2(Si3Al)O10(OH,F)2
Albite: NaAlSi3O8
Amphibole:
Ca2(Mg,Fe)5Si8O22(OH)2
Epidote: Ca2(FeAl)3(SiO4)3(OH)
K-feldspar: KAlSi3O8
Kaolinite: Al2Si2O5(OH)4
Illite: (K,H3O)(Al,Mg,Fe)2(Si,Al)4O10[(OH)2,(H2O)]
Mn-oxides
Rutile: TiO2
Hematite: Fe2O3
Fluoroapatite: Ca5(PO4)3F
Chromite: FeCr2O4
Organic matter
Gypsum: CaSO4•2(H2O)
Secondary carbonate (calcite-
dolomite)
precipitated from water
solutions
Recrystallized calcite-
dolomite crystals
Figure 2 Photomicrographs of calcite limestone (a-d) and dolomitic limestone (e-f), secondary mineralogical composition of the deteriorated surface, a)
Secondary carbonate (calcite-dolomite) precipitated from water solutions, SEM, b) secondary calcite-dolomite crystals, SEM, c) recrystallized calcite-
dolomite crystals, SEM, d) gypsum crystal, SEM, e) secondary dolomite-calcite, SEM, f) carbonate (dolomite-calcite) precipitated from water solutions,
SEM.
Figure 3 Recrystallization inside the pores of calcite limestone (a, b,), calcite sandstone (c, d)
3.1
3.2
3.3
3.7
3.6
3.5
3.1
3.2
3.3
3.4
3.5
3.6
3.7
98 Spathis P., Papanikolaou E., Melfos V. et al: Characterization and Weathering of the Building
Materials of Sanctuaries in the Archaeological Site of Dion, Greece
The results of the study of the physical properties and
characteristic pores of the materials are shown in Tables 2
and 3 and Figure 4.
These results show that exist great differences in the
values of open porosity, water and capillary absorption
between the various building materials. Despite this, it is
observed that in all cases of materials the values of
capillary absorption are close to the corresponding values
of total water absorption indicating that capillary
absorption is enough for the materials to reach moisture
saturation conditions. It is also shown that a significant
amount of the capillary absorbed water remains in the
material after desorption in environmental conditions. In
the specific conditions of the archaeological area a
permanent intensive presence of surface and underground
waters for all periods of the year and high temperature
values in the dry periods of summer are observed, leading
in repeated cycles of wet-dry conditions of the materials.
From these results and observations, in correlation with
the observed main weathering products, secondary and
recrystallized calcite and dolomite, follow that the main
deterioration problem of the materials is the moisture
presence due to capillary action. The cycles of wet-dry
conditions lead to partial dissolution-recrystallization of
the carbonate material and loss of the structural cohesion
and the surface stability.
Table 2 Physical properties of the building materials of Asklepios and Demeter sanctuaries
Material
Property
Conglo
merate
Lime
stone -
calcite
Lime
stone -
dolomite
Sand
stone -
calcite
Sandstone -
dolomite
Ceramic
Plinth
Marble -
calcite
Marble -
dolomite
Bulk density, γ,
(gr/cm3)
2.56
2.42
2.81
4.04
1.84
1.82
1.99
1.61
Dry bulk
density, γ(d)
(gr/cm3)
2.72
2.59
2.84
5.41
1.93
2.78
2.01
1.62
Porosity
Open, Pop, %
5.69
6.45
0.99
25.46
4.61
33.67
1.15
0.86
Water
absorption,
Wab, %
2.24
3.69
0.47
9.31
3.42
18.41
0.98
0.65
Water
desorption
Wde, %
2.21
3.65
0.44
9.13
3.36
17.05
0.92
0.62
Capillary
absorption
Cab, %
1.80
3.40
0.43
7.72
2.90
17.00
0.86
0.61
Capillary
desorption
Cab, %
1.78
3.37
0.41
7.57
2.83
15.69
0.81
0.59
Remained % of
capillary
absorbed-
environmental
conditions
1.02
0.89
5.03
1.85
2.61
7.73
5.53
3.21
Remained % of
capillary
absorbed
0.31
0.37
0.79
1.12
1.85
0.29
2.35
1.14
Table 3 Pore size Distribution %
Material
Pore
size(μm)
Conglo
merate
Lime
stone,
calcite
Lime
stone,
dolom
Sand
stone,
calcite
Sand
stone,
dolom
Ceramic
Plinth
Marble,
calcite
Marble,
dolom
100-200
23.87
30.49
73.17
23.34
49.63
22.28
46.18
71.82
200-300
76.13
20.71
-
53.15
34.70
45.68
18.21
15.48
300-500
-
21.96
21.26
12.11
11.85
12.29
0.76
0.89
500-700
-
11.76
5.05
8.64
3.54
13.68
19.31
8.54
>700
-
15.00
0.52
2.76
0.28
6.07
15.55
3.27
Trends Journal of Sciences Research 2015, 2(3): 95-103 99
Figure 4 Photomicrographs of characteristic pores of calcite limestone (a, b,), calcite sandstone (c, d), ceramic plinth (e-f).
The results of the chemical analysis of bulk
precipitation and surface water for major anions are shown
in Figure 5.
In all surface water samples, ionic concentrations
followed the order nitrates>sulphates>chlorides while the
highest values were found in Vaphyras river. In all
samples, ionic concentrations were within the range of
values found in the river systems of Macedonia, northern
Greece[24-25].
All bulk precipitation samples exhibited alkaline pH
(6.5-7.5) suggesting neutralization of rainwater with
alkaline reagents, such as gaseous ammonia and
calcareous dust particles. Expectedly, bulk precipitation
samplers, which are continuously open, also sample gases
and particles deposited on the collection surface. With the
exception of May and June samples, that exhibited
extremely high sulphate content, concentrations ranged
between 4.1 and 16 mgL-1 in agreement with the range of
values found in wet-only precipitation samples in
Thessaloniki (2.5-30 mgL-1)[26-27]. Nitrate concentrations
were highest in April and May (13 and 17 mgL-1,
respectively), but in most months they were below 4.4
mgL-1, similarly to previous data. Finally, chlorides
exhibited somewhat elevated concentrations (2.4-39 mgL-
1) with highest values in May and June suggesting
possible transport of marine aerosol.
From these results it is evident that there are not
significant amounts of various ions such as chlorides,
nitrates or sulphates (except a period of two months of
rain water samples). This observation is in accordance
with the mentioned absence of crystallized salts on the
surface or inside the pores of the materials (only limited
gypsum was observed).
Figure 5 Concentrations (mgL-1) of sulphates, nitrates and chlorides in surface waters (A: Rillet A, B: Rillet B, C: Vaphyras river) and rainwaters (1:
Dec 2010, 2-12: Jan-Nov 2011)
100 Spathis P., Papanikolaou E., Melfos V. et al: Characterization and Weathering of the Building
Materials of Sanctuaries in the Archaeological Site of Dion, Greece
The results of the IR thermometer in situ measurements
are shown in Figures 6, 7 (sunny conditions) and Figures
8, 9 (wet conditions).
Since a moist porous material presents emittance
variations, moisture detection in porous stones by means
of IR thermometer measurements is feasible. IR
thermometry monitors the water movement in porous
materials and detects its impact by recording temperature
variations on the stones' surfaces. The presence of
moisture (lower temperatures) that arises as a result of the
capillary movement of water causes deterioration of the
building material. In such cases, the optical properties are
altered, the density, specific heat capacity and thermal
conductivity are also affected and so any temperature
changes are much slower in a moist area, as the energy
required to raise the temperature of a moist area would be
much greater than an area that is unaffected by water. In
all cases of IR thermometer in situ measurements, the
recorded temperatures on the side surfaces of the walls
increase with the distance from the ground. The
temperature differences depend mainly on the
environmental conditions (sunny or wet), also on the kind
of the material and the orientation of the wall, being
greater in sunny and smaller in wet conditions. The IR
thermometer measurements correlated with the water and
capillary absorption and desorption results (Table 2) and
also the permanent intensive presence of surface and
underground waters indicate that the main deteriorating
factor of the materials is the moisture penetration due to
capillary action. In sunny conditions, moisture penetrates
into the materials only by capillary absorption (greater
temperature differences, Figures 6, 7), while in wet
conditions rain water and environmental humidity
contribute also to the total moisture absorption (smaller
temperature differences, Figures 8, 9).
Figure 6 IR thermometer measurements, sunny conditions, Asklepios temple, a) north side, b) east side, c) south side, d) west side
Trends Journal of Sciences Research 2015, 2(3): 95-103 101
Figure 7 IR thermometer measurements, sunny conditions, Demeter sanctuary, Altar, a) north side, b) east side, c) south side, d) west side.
Figure 8 IR thermometer measurements, wet conditions, Asklepios temple, a) north side, b) east side, c) south side, d) west side
102 Spathis P., Papanikolaou E., Melfos V. et al: Characterization and Weathering of the Building
Materials of Sanctuaries in the Archaeological Site of Dion, Greece
Figure 9 IR thermometer measurements, wet conditions, Demeter sanctuary, Altar, a) north side, b) east side, c) south side, d) west side.
Conclusions
From the combination of laboratory experiments and in
situ IR thermometer measurements follow safe results
about the deterioration problems of the materials.
The surface of the building materials are partially
covered by the weathering products of the primary
minerals such as secondary calcite and dolomite
precipitated from water solutions, and recrystallized
calcite and dolomite.
Limited presence of crystallized salts on the surface or
inside the pores of the materials is observed.
Absence of significant amounts of various ions such as
chlorides, nitrates or sulphates is observed in the rain and
surface waters.
The main weathering factor of the materials is the
moisture penetration due to capillary action.
In sunny conditions, moisture penetrates into the
materials only by capillary absorption, while in wet
conditions rain water and environmental humidity
contribute also to the total moisture absorption.
The existence of water in the bulk of the materials due to
capillary penetration correlated with an intensive surface
and underground water presence in the whole surrounding
area lead to loss of the structural cohesion and the surface
instability of the building materials.
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