M, JEBBAWY et al: STUDY OF THE FIRST BOULOGNE-SUR-MER CEMENTS USED FOR A HISTORIC AQUEDUCT ...
555–561
STUDY OF THE FIRST BOULOGNE-SUR-MER CEMENTS USED
FOR A HISTORIC AQUEDUCT FROM THE 19
TH
CENTURY
[TUDIJA CEMENTOV BOULOGNE-SUR-MER, UPORABLJENIH V
ZGODOVINSKEM AKVADUKTU IZ 19. STOLETJA
Marwa Jebbawy
1
, Vincent Thiery
1
, Myriam Bouichou
2
, Elisabeth Marie-Victoire
2
,
Catherine Davy
3
, Laurent Izoret
4
, Cyrille Albert-Mercier
5
, Myriam Moreau
6
1
IMT Nord-Europe, Douai, France
2
Pôle "Béton", LRMH, Paris, France
3
Centrale Lille, F-59651 Villeneuve d’Ascq Cedex, France
4
SFIC, Syndicat Français de l’Industrie, Cimentière, Paris-La-Défense Cedex
5
UPHF – Laboratoire des Matériaux Céramiques et Procédés Associés (LMCPA)
6
Univ. Lille, CNRS, UMR 8516 – LASIR, Laboratoire Avancé de Spectroscopie pour les Interactions, la Réactivité et l’Environnement,
Lille, France
Prejem rokopisa – received: 2021-11-11; sprejem za objavo – accepted for publication: 2022-07-11
doi:10.17222/mit.2022.554
Natural and Roman cements are generally considered as the first binders of the 19
th
century concrete but their widespread usage
was short-lived as they were quickly replaced by artificial cements (Portland), still the most important and predominant today.
The Boulogne-Sur-Mer area in the North of France is one of the cradles of the French cement industry where the first French
natural cement was produced in 1802 and the first French Portland cement at around 1850. These cements, natural and artificial,
quickly gained a national and international fame. This paper presents a case study of a 19
th
century aqueduct, still in operation,
with a focus on identifying the binders of concretes and mortars. Several combined techniques – optical microscopy (OM),
scanning electron microscopy coupled with energy dispersive spectroscopy (SEM-EDS) and X-ray diffraction (XRD) – were
carried out to characterize and determine the compositions of the binders present in the aqueduct. Phenolphthalein tests were
carried out in order to evaluate the depth of carbonation in the concrete. Several concrete and mortar samples, from pinkish to
greyish ones, were taken from the outer and inner parts of the aqueduct. Results show several clinker morphologies and compo-
sitions, and different types of hydrates. They also reveal important differences in the microstructure between natural and Port-
land cement, dated from an early period of the cement industry in France. The concomitance of the use of natural and Portland
cement, and good durability of these materials highlight the know-how of the engineers in the 1860s on cement performances
and characteristics.
Keywords: natural cement, Portland cement, optical microscopy, scanning electron microscopy
Naravni in romanski cementi so splo{no znani kot prva veziva v betonu iz 19 stoletja. Njihova {iroka uporaba je bila
kratkotrajna, saj so jih hitro nadomestili umetni portlandski cementi, ki {e danes prevladujejo v betonih. Obmo~je
Boulogne-Sur-Mer v severni Franciji je eno od zibelk francoske cementne industrije, kjer je bil prvi francoski naravni cement
proizveden leta 1802, prvi francoski portlandski cement pa okoli leta 1850. Tako naravni kot umetni cementi iz Boulogne so
hitro pridobili sloves dobrega proizvoda, na nacionalni in mednarodni ravni. Prispevek predstavlja {tudijo primera akvadukta iz
19. stoletja, ki je {e vedno v uporabi, s poudarkom na identifikaciji veziva v betonih in maltah. Za karakterizacijo in dolo~itev
sestave veziv iz akvadukta je bila uporabljena kombinacija razli~nih tehnik opti~ne mikroskopije OM, vrsti~nega elektronskega
mikroskopa sklopljenim z energijsko disperzijsko spektroskopijo SEM-EDS in rentgensko difrackcijo XRD. Globino
karbonizacije smo ocenili s testom s fenolftaleinom. Razli~ne vzorce betona in malte, katerih barva je bila od roza do sive, smo
odvzeli iz notranjih in zunanjih delov akvadukta. Rezultati analiz so pokazali prisotnost razli~nih sestav in morfologij klinkerja
ter razli~ne vrste hidratacijskih faz. Rezultati prikazujejo tudi pomembne razlike v mikrostrukturi hidratacijskih faz med
naravnimi in Portland cementi, ki so bili proizvedeni v zgodnjem ~asu cementne industrije v Franciji. So~asna uporaba
naravnega in portlandskega cementa in dobra obstojnost teh materialov ka`eta na visoko kvaliteto znanja in izku{nje in`enirjev
v 1860-ih letih, o lastnostih in zmogljivosti cementov.
Klju~ne besede: naravni cement, portland cement, opti~na mikroskopija, vrsti~na elektronska mikroskopija
1 INTRODUCTION
In 1796, James Parker discovered a clayey limestone
nodule that sets with water after burning at a low temper-
ature (1000 °C) in traditional vertical kilns. He patented
his discovery and sold his cement under the name of
"Roman cement".
1
Parker’s patent activated the research
of chemists in Europe. The French engineer Louis Vicat
was the first to prove, in 1812, that the hydraulic proper-
ties of these binders were the result of a simultaneous
combustion of limestone and clay in very specific pro-
portions, depending on the chemistry of the materials.
However, he published his results without filing a patent.
Historical data indicate that the applications of these
cements were very broad (building constructions and the
industrial field). However, numerous kinds of natural ce-
ments produced during the 19
th
century could also be of
very different qualities, especially due to the variations
in the composition of the original stones.
2
Their colors
generally varied from brown to beige.
3
Materiali in tehnologije / Materials and technology 56 (2022) 5, 555–561 555
UDK 620.187:666.942"19" ISSN 1580-2949
Original scientific article/Izvirni znanstveni ~lanek MTAEC9, 56(5)555(2022)
*Corresponding author's e-mail:
marwa.jebbawy@imt-nord-europe.fr (Marwa Jebbawy)

Vicat’s discovery also facilitated the development of
their industrial production. Thus, following his work,
many cement factories appeared. In France, similar
stones were discovered at Boulogne-sur-Mer, leading to
the first cement production. The product was known as
"plâtre ciment". This expression recalls the properties of
workability of plaster and the setting/resistance of the ce-
ment despite the obvious contradiction between both
binders in the same product.
4
Artificial Portland cement, obtained from a precise
mix of clay and limestone extracted separately appeared
in parallel with the development of natural cements. This
development of artificial Portland cements led to a pro-
gressive decrease in the production of natural cements.
2
Today, Vicat is the only company to produce and market
fast-setting natural cement, "prompt cement".
In France, the Portland cement manufacture began in
1846 in Boulogne-sur-Mer by Mr. Dupont and Mr.
Demarle, and at around 1870 in Genevrey-de-Vif near
Grenoble with vertical shaft kilns directed by Joseph
Vicat (son of Louis Vicat). On May 1853, Mr. Dupont
filed the first patent on the production of natural Portland
cement. A fifteen-kiln factory was opened in 1859, lo-
cated on the banks of Liane close to Boulogne-sur-Mer.
5
The main differences between the two types of ce-
ments lie in the manufacturing process:
Natural cement – its lithology indicates 75–60 % of
carbonates and 25–40 % of clay, which is crushed into
tiny blocks between two temperatures, 800 and 1200 °C.
Early Portland cement – the raw feed, the so-called
"cement stone", containing pure limestone (80–75 %)
and clays (20–25 %) used to be mixed with water in big
pools, and pressed into bricks before being burnt. The
composition of historical PCs always suggests a very
heterogeneous heat distribution (800–1400 °C) during
the firing.
6
Many applications of Boulogne-sur-Mer cements
have been identified in the constructions of buildings
(bridges, aqueducts, etc.). According to old documents,
several military, civil and cultural engineering works
have used these cements, the most famous being the Eif-
fel Tower foundations.
7
Unlike other historical French
types of cement
8
, these types remain relatively unknown,
and few studies have been devoted to them. In addition,
their compositions and setting mechanisms are not well
known.
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556 Materiali in tehnologije / Materials and technology 56 (2022) 5, 555–561
Figure 2: Section of the historic aqueduct from the 19
th
century (illus-
tration from 1865)
9
Figure 1: Historic aqueduct from the 19
th
century

This paper presents a case study of a historic aque-
duct from the 19
th
century where Boulogne-sur-Mer ce-
ment was used. This study aims at characterizing and
identifying the binder of mortars used in the construction
of the aqueduct from the 19
th
century, with a focus on an-
hydrous-grain characterizations. Such knowledge will al-
low an appropriate restoration of the cement-based mate-
rials that have survived until the present day.
The historic aqueduct from the 19
th
century was built
with Boulogne-sur-Mer cements, from 1863 to 1865 at
the request of Napoleon III (1808–1873) to convey water
from the north-east of the Parisian area to Paris (Fig-
ure 1). The aqueduct is covered with a 10-meter wide
grassy strip and vegetation on both sides, forming a true
ecological corridor. The total length of the aqueduct is
128.61 km. The water circulation is allowed by a natural
slope, using the "siphon" effect with a flow of 230 liters
of water per second. This aqueduct is built of rough
stone blocks. Both the interior and exterior are protected
by cement and concrete linings (Figure 2).
2 EXPERIMENTAL PART
2.1 Sampling
Several representative locations were selected for the
sampling. Three pinkish-colored concretes sampled at
different levels were referred to as:
• sample B1 from the inner section of the vault,
• sample B2 from the intrados (inner curve of an arch)
face,
• sample B3 from the bottom of the aqueduct.
Additional sample B4 (rather grey) was taken from
the external face of the aqueduct vault.
2.2 Analytical methods
In order to characterize the concretes from the se-
lected locations and, in particular, to identify the binders
used, several types of analyses were carried out. Prelimi-
nary phenolphthalein (1 % concentration in ethanol) was
sprayed on freshly fractured samples to distinguish car-
bonated from non-carbonated areas. Then, crystallized
phases were determined with X-ray diffraction, using a
Brucker D8 with long-time acquisition parameters (a
step size of 0.02°, step time of 2 s). The analysis was
carried out on powders of crushed cement paste, ob-
tained after the separation of the cement matrix from the
aggregates by sieving and hand picking (the samples
were gently crushed, then the aggregates were sieved and
separated from the cement paste under the microscope).
Mortar microstructures were observed on polished
sections, using a reflected light optical microscope
(Leica DMRXP) and a scanning electron microscope
equipped with an EDX detector (JEOL IT 300). The pol-
ished plane sections were prepared from the samples im-
pregnated under vacuum with a low-viscosity epoxy
resin.
10
The SEM-EDX analysis in the backscattering
electron (BSE) mode was used on polished sections to
determine their elemental composition at a working dis-
tance of 10 mm.
3 RESULTS
3.1 Macroscopic observations and phenolphthalein
tests
To identify the non-carbonated areas of concrete,
phenolphthalein spraying was performed in situ on the
samples taken. Due to phenolphthalein, the treated sam-
ples became pink. It allowed us to identify the more ba-
sic pH areas corresponding to the non-carbonated do-
mains. The B4 sample is essentially composed of a
sandy fraction completed by large aggregates. On the
other hand, the three pinkish samples (B1, B2 and B3)
show much smaller sandy fractions than the other loca-
M, JEBBAWY et al: STUDY OF THE FIRST BOULOGNE-SUR-MER CEMENTS USED FOR A HISTORIC AQUEDUCT ...
Materiali in tehnologije / Materials and technology 56 (2022) 5, 555–561 557
Figure 4: 3D rendering of the ettringite crystals in the pores
Figure 3: Presentation of the ancient-concrete samples from the his-
toric aqueduct

tions. These samples have a very rich binder with small
quartz grains, compared to the grey cement samples (Er-
ror! Reference source not found.). Ettringite crystals
(Figure 4) were observed in the pores of sample B1.
Ettringite was predominantly in the form of fibers, but
scattered needles were also identified.
3.2 Crystallized phases determined with the XRD anal-
ysis
The crystallized phases of different samples were
identified with X-ray diffraction. The results of these
analyses are shown in Table 1 below. According to these
analyses, the nature of the identified minerals is almost
identical for all the pinkish concretes (B1, B2 and B3).
All four samples are non-carbonated. The non-carbon-
ated zones of these four samples are composed mainly of
calcite, ettringite and other calcium aluminates, com-
monly found in the B1, B2 and B3 samples. Gypsum
was not detected in the four samples. The anhydrous
phases present in the pinkish samples are rankinite, C
2
S,
C
4
AF and C
3
A with a high Al content. Alite is absent
from the B1, B2 and B3 samples. On the other hand, in
the grey cement concrete (B4), alite and belite crystals
were detected. The B4 sample is characterized by an im-
portant presence of portlandite, which is absent from the
pinkish samples.
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558 Materiali in tehnologije / Materials and technology 56 (2022) 5, 555–561
Table 1: Crystallized phases identified for each sample
B1 B2 B3 B4
Carbonation no no no no
Calcite CC ++ ++ ++ +++
Quartz SiO2
++ ++ ++ +++
Larnite C2S + ++ ++ ++
Alite C3
S ØØØ+ +
Browmillerite C4
A F++++
Hydrocalumite C4
AH
13
+++Ø
Ettringite C6A$3H32
++ ++ ++ +
Portlandite Ca(OH)2 ØØØ+ +
Anorthite CaAl2
Si
2
O
8
+++Ø
Rankinite C3
S
2
+++Ø
Note: significant presence (+++), average presence (++), traces (+),
absence (Ø)
Figure 6: BSE-SEM of B1 sample: a) clinker grains; b) clinker-grain details
Figure 5: OM view using reflected light; anhydrous grains of clinker on a polished section; B1 sample

3.3 Identification of the anhydrous grains
3.3.1 Pinkish-colored concretes
The anhydrous grains shown in Figure 5 are the most
representative of the pinkish-colored concrete. They
measure about 200–500 μm. They are mainly composed
of weakly crystallized calcium silicates, with more or
less visible contours. The binding matrix is a mono-
phase and it is very clear. It is only rich in iron. These
grains present very few binding phases. SEM observa-
tions coupled with EDS (Figure 6) confirm the presence
of C
2
S. The crystallizations of these grains are irregular
and heterogeneous.
Iron-bearing compounds are also noted. The OM ob-
servations showed the presence of red-colored iron ox-
ides, as shown in Figure 7. SEM observations coupled
with the EDS chemical analysis of these compounds
show that they contain mainly iron and calcium oxides
with low contents of Si, Mn and Al (Figure 8).
3.3.2 Grey-colored concrete
Three types of anhydrous grains were observed and
characterized on sample B4.
Type-1 grains are mainly composed of bi- and tri-cal-
cium silicates (Figure 9a). It should be noted that C
2
S
are more or less circular, with parallel striations, thus this
is type II of C
2
S crystals.
11
Type-2 grains are mainly
composed of aluminate phases in platelets and poorly
crystallized calcium silicates. Optical and scanning elec-
tron microscope observations are presented in Figure 9b.
Finally, important amounts of C
3
A and C
4
AF were ob-
served in type-3 grains (Figure 9c).
12
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Materiali in tehnologije / Materials and technology 56 (2022) 5, 555–561 559
Figure 8: BSE-SEM view; iron-bearing compounds; B1 sample
Figure 7: OM view using reflected light; iron-bearing compounds; B1
sample
Figure 9: Photomicrographs of anhydrous grains of clinker on the pol-
ished section, B4 sample: a) OM view, type-1 clinker grains;
b) BSE-SEM view, type-1 clinker grains; c) BSE-SEM view, type-2
clinker grains; d) BSE-SEM view, type-2 clinker-grain details; e) OM
view, type-3 clinker grains, f) BSE-SEM view, type-3 clinker grains

3.4 Hydrated phases
SEM observations of the non-carbonated zone were
carried out on the B1 concrete sample. Numerous
ettringite crystallizations are mainly located in the paste
and in the pores. Figure 10 shows ettringite crystals in
the form of well-crystallized needles, in the pores of the
B1 sample.
4 DISCUSSION
Microstructural and physical characterizations of
these concretes from the selected locations were carried
out. The main phases identified with the XRD analyses
for the pinkish samples (B1, B2 and B3) of the historical
aqueduct are similar.
Indeed, the XRD analyses indicated the presence of
rankinite, C
2
S, C
3
Aa n dC
4
AF in the three concretes
(samples B1, B2 and B3). Alite was not detected. Ac-
cording to Rankin and Wright
13
, rankinite is formed at
temperatures below 1200 °C. Hydrocalumite C
4
AH
13
was
also identified through XRD in the pinkish-colored con-
cretes (samples B1, B2 and B3). In terms of hydrated
phases, the XRD analysis and SEM observations re-
vealed the presence of ettringite in samples B1, B2 and
B3. Ettringite is localized in the paste and in the pores.
Optical microscopic observations and scanning electron
microscopic analyses identified anhydrous grains mainly
composed of C
2
S, C
3
Aa n dC
4
AF. Their structure is
poorly crystallized. Alite crystals were not detected. The
shape of C
2
S is very irregular. During firing, dicalcium
silicate (C
2
S) crystallizes between 900 °C and 1200 °C.
13
All these analyses showed that the pinkish-colored con-
cretes were based on fast-setting natural cement.
The grey concrete (B4) is poorer in aluminium
(hydrocalumite was not detected) than the concretes
based on natural types of cements (B1, B2 and B3). In
the B4 concrete, the anhydrous phases are mainly com-
posed of C
3
S, C
3
A, C
4
AF and some C
2
S whereas in the
natural-cement concretes (B1, B2 and B3), C
2
S, C
3
A and
C
4
AF were mainly observed. Concerning the hydrated
phases, the presence of portlandite was mainly detected
with the XRD analysis in sample B4 and few ettringite
crystals were identified. On the contrary, the hydrated
phases observed in natural cements (B1, B2 and B3) cor-
respond to the ettringite crystallization while portlandite
was not detected. So, according to these analyses, the ce-
ment used in the B4 concrete corresponds to Portland ce-
ment.
5 CONCLUSION
This article provides new findings on the micro-
structural and physical characterization of the cements
produced in the first French plants during the 19
th
cen-
tury. The structures were built with Boulogne-sur-Mer
cement. The location and identification of these build-
ings were identified with the help of the indications
given in old documents. This article presents a case study
of a historic aqueduct from the 19
th
century using this ce-
ment. Samples were taken from the interior (B1, B2 and
B3, pinkish-colored concretes) and exterior of this aque-
duct (B4, grey-colored concretes). Microstructural and
physical analyses of the concretes from selected loca-
tions were presented. Several characterization techniques
were used: SEM observations, optical microscopy and
X-ray diffraction. These analyses revealed mainly two
categories of the binder: natural cements and cements
close to the Portland type.
The absence of portlandite, a strong presence of the
ettringite zone, the presence of rankinite, limited pres-
ence of alite and poorly crystallized anhydrous grains
clearly indicated that the binder used in the pinkish-col-
ored concretes (B1, B2 and B3) was a natural cement,
rich in aluminates, and the calcination temperature was
lower than 1200 °C.
In the case of the B4 concrete, the co-existence of
three types of anhydrous grains, as well as the presence
M, JEBBAWY et al: STUDY OF THE FIRST BOULOGNE-SUR-MER CEMENTS USED FOR A HISTORIC AQUEDUCT ...
560 Materiali in tehnologije / Materials and technology 56 (2022) 5, 555–561
Figure 10: BSE-SEM view, ettringite, B1 sample

of portlandite and alite confirmed that the binder used in
this concrete was close to Portland cement.
Acknowledgments
This study is a part of the CASSIS project. The
CASSIS project is funded by the I-Site of the University
of Lille-Nord-Europe, Laboratoire de Recherche des
Monuments Historiques, SFIC and Optics Concepts.
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