10.6092/issn.1973-9494/12799
Lo studio riguarda le strutture murarie in Italia e si concentra sulle malte storiche, medievali e moderne. Nei contesti regionali oggetto d’indagine (Piemonte e Pianura Padana, Lazio, Umbria-Marche, Puglia e Sardegna) è stata utilizzata una grande varietà di materiali, con caratteristiche chimico-fisiche diverse, e queste differenze determinano anche comportamenti strutturali diversi. Il progetto mira a migliorare la nostra conoscenza delle malte storiche per approfondire il tema della conservazione del patrimonio edilizio italiano, soprattutto nelle zone a rischio sismico. Per ottenere questi risultati, sono stati prelevati campioni sui quali sono state effettuate analisi per indagare quanto le diverse proprietà meccaniche e di coesione incidano sulla vulnerabilità delle strutture in rovina o collassate.
Grazie a queste informazioni è stato possibile contribuire alla prevenzione, manutenzione, protezione e conservazione dell'edilizia storica.
Ulteriori conoscenze hanno riguardato la storia delle tecniche di costruzione, con particolare riguardo al rapporto tra risorse locali e i cantieri. Un altro importante tema è stato il ruolo dei diversi componenti e additivi durante la preparazione delle malte e il loro livello di idraulicità.
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Conservation Science in Cultural Heritage
mortar
An Interdisciplinary Approach for the Historical and Technical Characterization of Medieval and Modern Mortars 
Text.Serial.Journal
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Articles
2021-05-13
2021-04-27
2021-05-13
2021-05-13
197-212
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Elisabetta Giorgi
2020
10.6092/issn.1973-9494/12799
197
ASTRE-LABMAT, Dipartimento di Storia, Disegno e Restauro dell’Architettura, “Sapienza” Università di Roma, Rome, Italy 
1973-9494
mortar
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An Interdisciplinary Approach for the Historical and Technical Characterization of Medieval and Modern Mortars 
https://conservation-science.unibo.it/article/download/12799/12515
20
A     N INTERDISCIPLINARY APPROACH FOR THE
      HISTORICAL AND TECHNICAL CHARACTERIZATION
      OF MEDIEVAL AND MODERN MORTARS

   Daniela Esposito*
   Dipartimento di Storia, Disegno e Restauro dell’Architettura
   “Sapienza” Università di Roma, Rome, Italy

   Aida Maria Conte
   CNR-IGAG-Sede Secondaria di Roma, c/o Dipartimento di Scienze della Terra
   “Sapienza” Università di Roma, Rome, Italy

   Laura Corda
   Dipartimento di Scienze della Terra
   “Sapienza” Università di Roma, Rome, Italy

   Elisabetta Giorgi
   ASTRE-LABMAT, Dipartimento di Storia, Disegno e Restauro dell’Architettura
   “Sapienza” Università di Roma, Rome, Italy


   Keywords: conservation, reconstruction, architecture, seismic risk, mortar



   1. Introduction

     Historical masonries are normally affected by a process of more or less deep natu-
ral weathering, but a further process of mechanical deterioration can occur if the ma-
sonries are located within a geologically seismic context or an area affected by tec-
tonic instability. In this case, great care has to be taken in choosing the most suitable
restoration interventions only after a detailed analysis of the historic materials to be
repaired has been made. It is known that, owing to its geological history, almost all of
Italy has a medium-high level of seismic hazard which may result in severe damage to
its abundant and rich archeological heritage.
     The study, in progress from April 2019, concerns Italian masonries and focuses on
the historical, medieval and modern mortars in the Piedmont region, Po Valley, Latium,
Umbria-Marche areas, and Apulia and Sardinia. The project (Progetto Grande di Ateneo
2018 – Sapienza University of Rome1) aims at improving our understanding of historical
mortars in order to learn more about how to conserve the historical mortars used in built
heritage, especially in seismic risk zones, together with their hydraulic characteristics.
To achieve these results, we will perform analyses on selected samples to investigate
to what extent different mechanical and cohesion properties affect the vulnerability of
the ruined or collapsed structures.
     Thanks to this information it will be possible to make advances in preventive mea-
sures, maintenance, protection and the preservation of historical buildings by:


   * Corresponding author: daniela.esposito@uniroma1.it
                                                                                                                                 1. Improving the study of historical technical know-how on how to build complex struc-
                                                                                                                                     tures, and on their vulnerability and maintenance.
                                                                                                                                 2. Discerning material deterioration processes and instabilities caused by the ma-
D. Esposito, A.M. Conte, L. Corda, E. Giorgi - An interdisciplinary approach for the historical and technical characterization




                                                                                                                                     sonry itself.
                                                                                                                                 3. Identifying suitable tests and procedures for verifying statics.
                                                                                                                                 4. Recognizing effective techniques for consolidation and conservation, prevention and
                                                                                                                                     degradation deceleration.
                                                                                                                                 5. Planning a multidisciplinary analytical protocol for the characterization of mason-
                                                                                                                                     ries and mortars.
                                                                                                                                 6. Organizing survey-derived information and other results in an open GIS database
                                                                                                                                     system.
                                                                                                                                     Further details will concern the history of construction techniques, with particular
                                                                                                                                 regard to the relationship between local resources and construction sites. Another im-
                                                                                                                                 portant topic will be the role of different components and additives used in the prepara-
                                                                                                                                 tion of the mortars and their level of hydraulicity.
                                                                                                                                     The materials will be studied both in situ and in laboratory, on different observation
                                                                                                                                 scales: the territory, the buildings, and the materials. All the information will be aimed
                                                                                                                                 at studying the construction materials and their areas of provenance, analyzing differ-
                                                                                                                                 ent building and executing techniques, including different degradation processes in
                                                                                                                                 historical structures. These mechanical and chemical-physical analyses, combined
                                                                                                                                 with an aesthetic and conservative assessment of surface finishes, are fundamental in
                                                                                                                                 identifying the mechanical properties of masonries and mortars in order to carry out
                                                                                                                                 their conservation and restoration.


                                                                                                                                    2. The aim of the project

                                                                                                                                      The project consists in collecting, producing, organizing and disseminating – through
                                                                                                                                 scientifically controlled sharing – the data related to the multiple components which
                                                                                                                                 characterize traditional medieval and modern mortars. The aim is to highlight the differ-
                                                                                                                                 ences between the ways of crafting and using mortars depending on the raw materials
                                                                                                                                 available. The study will be carried out on both poor and rich architectures belonging
                                                                                                                                 to different regional areas. The comparison will allow – also through scientific investi-
                                                                                                                                 gations – to better recognize the specificities and the different features that have sig-
                                                                                                                                 nificant consequences, firstly on structural behaviour, with reference to the tensile
                                                                                                                                 strength, and secondly, on the cohesion capacity of the mortar [1-5].
                                                                                                                                      Special attention will be given to samples taken from ruins which were damaged or
                                                                                                                                 collapsed after the seismic events of 2012 and 2016, in order to contribute to further the
                                                                                                                                 study of mortars in areas of risk and to test if and how the different characteristics and
                                                                                                                                 mechanical properties of the aggregates and binders (by controlling their performance)
                                                                                                                                 could influence the vulnerability of structures located within the same geological setting.
                                                                                                                                      This operation will make it possible to identify specific chronological indicators use-
                                                                                                                                 ful for recognizing masonry techniques and will have obvious repercussions on the
                                                                                                                                 history of construction techniques, local resources, and construction sites. This research
                                                                                                                                 will contribute to better define the history of the territory, to clarify the role of organic
                                                                                                                                 additives (proteins, fats, etc.) and to assess the hydraulic characteristics of mortars
                                                                                                                                 according to the different components (fillers, lime, etc.) [6-14]. On a practical and op-
                                                                                                                                 erational level, the research will provide useful information for the prevention, mainte-
                                                                                                                                 nance, protection and conservation of historic buildings.


                                                                                          198
     The methodological structure of the project is laid out primarily in the bibliographic
and documentary research and metric and material survey with analyses of the ma-
sonries of specific study cases to be performed with direct and indirect surveys. The
surveys will allow the reading of components, size and position of the elements and
wall-unit organization; the ingredients and meshes of the mortars; potential re-used
parts; surface treatments and decay. The study will focus mainly on the interaction be-
tween organic and inorganic materials, with particular attention given to the presence
of additives and mortar composition.
     The innovative features of the research consist in providing and sharing informa-
tion of a highly scientific and historical content. Decoding the information contained in the
buildings – in their constitutive materials and executive techniques – is a fundamental
process that broadens the historical-technical knowledge itself and leads to the aware-
ness that every element, such as a fragment of plaster or trace of colouring, will pro-
vide further knowledge about building techniques and a guide to conservation and res-
toration actions both in prevention and in intervention. The acquired knowledge will
subsequently be collected in guidelines or in a compendium of the consolidation and
preventive restoration interventions, according to an analysis of the damage and the
definition of a list of priorities. Firstly, the design of compatible materials for the reha-
bilitation or improvement of performance, and subsequently, the development of new
‘sustainable’ mortars, produced with low energy impact and high performance.
     Although a vast historical and contemporary bibliography exists, it can be added to
and improved, both in the field of historical technical literature, regarding the most recent
updates in archaeometry and in understanding different ways of processing, disseminat-
ing and exploiting the specific technical knowledge in the territories under examination.


   3. Description of the project in progress




                                                                                                  Conservation science in Cultural Heritage
    In the Umbria and Marche regions, we started by classifying the types of masonries
with low lime mortars and earthen-clay components. The study includes the late-medi-
eval brick structures recently excavated in the archaeological area of the abbey of Santa
Croce di Sassovivo in Foligno and the masonries of the crypt and basement of the
church of Santa Maria di Plestia in Colfiorito. Other case studies have been identified in
the cities of Assisi, Foligno, Gubbio, Narni, Sangemini, Spello and Spoleto and in the
localities of Massa Martana and Montecastrilli, in Umbria. In the Marche region, near
Ascoli Piceno (Arquata del Tronto and hamlets), the samples show a low-lime mortar
with components of terrigenous and/or clayey origin, which degrades over time, losing
cohesion and binding capability. In the regions of Lazio and Apulia (Salento area), the
study will focus on mortars with aggregates made mostly of pozzolana, cocciopesto and
bolo (‘red soil’), and mortars with aggregates deriving from the grinding of local stone.


   3.1. A case study: the mortars of the abbey of Santa Maria di Cerrate
        (Lecce, Apulia)

    The interdisciplinary study on the Cerrate complex masonry structures represents
a tentative analytical approach which could become a standard procedure for the
knowledge, restoration and conservation of historic buildings (Figure 1)2. The study
includes techniques ranging from a macroscopic reading of the type of masonry, and


                                                                                                199
                                                                                                                                 architectonic and construction characteristics, to a microscopic, petrographic, and chem-
                                                                                                                                 ical reading of the composition of the mortars.
D. Esposito, A.M. Conte, L. Corda, E. Giorgi - An interdisciplinary approach for the historical and technical characterization




                                                                                                                                                        Figure 1. The Santa Maria di Cerrate complex.




                                                                                                                                          Figure 2. Topographic sketch map of the complex of Santa Maria di Cerrate.


                                                                               200
   3.1.1 Macroscopic reading

    A macroscopic reading may contribute to the scientific knowledge of ancient mor-
tars in terms of mechanical characteristics and the historical background of their pro-
duction. Analyzing mortars from different historical periods helps to identify the various
types of mixture and production techniques, and to evaluate their state of preservation.
    The masonry of the medieval buildings of Cerrate is characterized by the use of
square blocks of local limestone of different quality (calcarenite). The medieval mortars
display a predominantly carbonate binder with aggregates consisting mostly of carbon-
ate bioclasts and lithoclasts.
    The mortars that make up the wall structures of the church (12th and 13th century)
and of the masseria (16th century) are generally composed of lime and red siliceous soil
or bolo. Therefore, the composition and the mixtures used for the mortars often consti-
tute important chronological indicators (Figure 2).


   3.1.2. Optical microscopy

     Optical microscopy is the preliminary approach to studying historic mortars. It is used
to observe the texture and structure of the binder (i.e. drying, shrinkage, cracks), the
mineralogical composition and character of the aggregate, the binder-to-aggregate
ratios and the possible occurrence of fragments of brick, re-used mortar or pozzolanic
additives.
     Based on the proportion of aggregate and binder, the analyzed mortars were gath-
ered into two main groups which were further split into sub-groups based on the com-
position and character of the aggregate. The aggregate constituents are represented by
silicate grains (mostly quartz and K-feldspar) or carbonate grains (bioclasts, benthonic
and planktonic foraminifera, fragments of underburned limestones and occasionally
re-used mortar fragments); lime lumps also occur that have been related to either in-




                                                                                                 Conservation science in Cultural Heritage
correct slaking or incomplete calcination, or poor mixing of lime binder and aggregates
(Figure 3).




             a)                              b)                             c)

Figure 3. Microphotographs of some analyzed mortars. a) mortar showing siliciclastic
aggregate (crossed polars, scale bar 1 mm); b) mortar showing carbonate aggregate
(plane polars, scale bar 1 mm.); c) small-sized lumps of silicate material (plane polars,
scale bar 1 mm).


    An interesting feature is the occurrence of lumps of silicate material on which fur-
ther investigations are still in progress. The formation of lumps is probably due to an


                                                                                               201
                                                                                                                                 incomplete or incorrect mixture of lime binder and fine-grained silicate phases; their
                                                                                                                                 characterization could shed light on the important problem of the hydraulic properties
                                                                                                                                 of the mortars.
D. Esposito, A.M. Conte, L. Corda, E. Giorgi - An interdisciplinary approach for the historical and technical characterization




                                                                                                                                     Based on the chemical-mineralogical composition of aggregates and binder, it was
                                                                                                                                 possible to discriminate the medieval mortars (12th-13th centuries) from the post-medi-
                                                                                                                                 eval ones.


                                                                                                                                    3.1.3. Scanning electron microscopy and energy-dispersive spectrometry

                                                                                                                                      Scanning electron microscopy (SEM) coupled with energy dispersive spectroscopy
                                                                                                                                 (EDS) provides details on morphologies, microstructures and aggregate components.
                                                                                                                                 Moreover, the acquisition of X-ray maps contributes to a better understanding of the
                                                                                                                                 elemental composition of the mortar, making it possible to evaluate the more or less
                                                                                                                                 homogeneous elemental distribution and abundance, both of binder and aggregate
                                                                                                                                 components.
                                                                                                                                      Based on the SEM analyses, it was possible to discriminate a first group of mortars,
                                                                                                                                 represented by the medieval mortars, which were characterized by a homogeneous,
                                                                                                                                 predominantly carbonate binder, well mixed with a clay-sized silicate fraction and an
                                                                                                                                 overall well-distributed carbonate aggregate. The second group, including the post-
                                                                                                                                 medieval mortars, was characterized by a prevalently carbonate binder containing a
                                                                                                                                 more or less abundant clay-sized silicate component mostly represented by Al-silicates
                                                                                                                                 (Figure 4a). This second group, by elemental abundance (Cavs Si) and elemental distri-
                                                                                                                                 bution (Al-silicate material scattered within the binder vs gathered as lumps), observable
                                                                                                                                 on the X-ray maps, was further subdivided into two sub-groups. The first sub-group in-
                                                                                                                                 cludes mortars dated between the 16th and 17thcenturies and exhibits a mixed siliciclas-
                                                                                                                                 tic-carbonate binder containing a scattered clay-sized Al-silicate component whereas
                                                                                                                                 the second, represented by mortars dated approximately to the 19th and 20th centuries,
                                                                                                                                 displays a predominantly carbonate binder with the subordinate Al-silicate fraction most-
                                                                                                                                 ly gathered as lumps (Figures 4b and 4c). Our findings suggest that this unusual ana-
                                                                                                                                 lytical technique should represent a further discriminating tool.




                                                                                                                                              Figure 4. Image and X-ray maps showing elemental distribution.


                                                                                                                                      Figure 4 shows: a) medieval mortars with aggregates composed mostly by calcar-
                                                                                                                                 eous bioclasts (bright turquoise) and a siliciclastic component, definitely subordinate,
                                                                                                                                 consisting of fine to very fine grains (mostly represented by quartz) and a clay-sized
                                                                                                                                 silicate fraction mixed within the binder (the yellow color represents Si and bright ma-
                                                                                                                                 genta represents Al);  b) mortars of the 16th and 17th centuries with the aggregates
                                                                                                                                 mostly represented by quartz (bright yellow) and Al-silicates (bright magenta) and sub-


                                                                                     202
ordinate carbonate fragments (bright turquoise color represents Ca). The binder appears
to be predominantly carbonate (light turquoise) with a clay-sized silicate fraction, scat-
tered within the binder, mostly constituted by Al-silicates (light magenta color); c) mor-
tars of the 19th and 20th centuries with the aggregates dominantly composed by quartz
(bright yellow) and Al-silicates; carbonate fragments (bright turquoise color represents Ca)
are subordinate. The binder appears to be predominantly carbonate (light turquoise)
with a clay-sized silicate fraction, gathered as lumps, mostly constituted by Al-silicates
(light magenta color).


   3.1.4. X-ray diffraction

     This technique allows the identification of crystalline material on powdered sam-
ples; it is essentially used to interpret the mineralogical composition of mortar binders.
The choice of Cerrate mortars to be analyzed by XRD technique focused on mortars
with a higher silicate content and a more evident reddish coloring, in order to character-
ize the mineral composition of the red silicate component. However, one difficulty we
encountered was the dominance of the carbonate component which almost complete-
ly obscured the other phases, as well as the presence of amorphous or non-crystalline
materials which can obscure small peaks in certain ranges of the scan. To highlight the
detection of silicate material, the carbonate component was first removed from the se-
lected samples by dissolution with hydrochloric acid.
     This allowed the small peaks to stand out, making them faintly visible in a certain
range of the scan, referable to phyllosilicates of the illite-smectite group and occasion-
ally chlorite. Such a subordinate silicate component probably represents the part of the
silicate that was added to the lime binder, together with the aggregate particles, in or-
der to enhance mortar performance. This last assumption is consistent with the qualita-
tive composition shown by the SEM-EDS spectra of the mixed carbonate-silicate bind-




                                                                                                 Conservation science in Cultural Heritage
er and of the silicate lumps we frequently observed in the mortars.
     Although the XRD method does not allow aggregates and binder to be differentiated,
by coupling the OM and SEM observations with the XRD analyses it is possible to make
the distinction.
     As regards the aggregate composition, XRD data supported our petrographic inter-
pretation showing the strongest peaks for quartz and K-feldspar.


   3.1.5. X-ray fluorescence

    X-ray fluorescence, historically used in the study of mortars, consists of the quan-
titative chemical analysis of major and minor elements on pellets of pressed pow-
dered samples to create a more homogeneous representation of the mortar com-
positions.
    Chemical data resulting from the Cerrate mortars are in general agreement with
petrographic and diffractometric data. Mortars with silicate, or mixed silicate-carbonate
aggregate, display a higher content of SiO2 and K2O (chemical formulas are SiO2 and
KAlSi3O8 respectively). A high content of CaO, on the contrary, was detected in mortars
with a predominantly carbonate binder and in mortars with carbonate aggregate in which,
as expected, the highest concentration of CaO was detected (about 95 wt%), due both
to the aggregate grains and to the predominantly carbonate binder as well.


                                                                                               203
                                                                                                                                     3.1.6. Mössbauer spectrometry

                                                                                                                                     57
                                                                                                                                       FeMössbauer spectrometry provides quantitative information on the magnetic and
D. Esposito, A.M. Conte, L. Corda, E. Giorgi - An interdisciplinary approach for the historical and technical characterization




                                                                                                                                 structural properties of Fe-bearing materials. Mössbauer spectra are useful for quanti-
                                                                                                                                 tative phase analyses or determination of the Fe2+/Fe3+ ratio in different phases, even
                                                                                                                                 when the phases are nanostructured or amorphous [15 -17].
                                                                                                                                     Using this technique, quite unusual for the characterization of historical mortars, a
                                                                                                                                 considerable amount of amorphous and/or nanostructured material was detected with-
                                                                                                                                 in the studied mortars and is probably responsible for the hydraulic properties. In order
                                                                                                                                 to investigate the origin of this amorphous material, the bauxite from local red soils
                                                                                                                                 cropping out as lenses and horizons within the local sedimentary successions, and the
                                                                                                                                 bauxite from the Otranto quarry (Apulia) were analyzed and compared. Preliminary
                                                                                                                                 results suggest a significant similarity between the studied mortars and the local red
                                                                                                                                 soils (G.B. Andreozzi, personal communication).


                                                                                                                                     3.1.7. Thermal analysis

                                                                                                                                      This analysis includes a variety of techniques providing information about the prop-
                                                                                                                                 erties of materials measured through a predetermined temperature profile.
                                                                                                                                      In the case of our study, thermal analysis – differential scanning colorimetry (DSC),
                                                                                                                                 was additionally performed. This technique is ongoing and is currently being employed
                                                                                                                                 to determine the chemical character of the studied mortars and to assess the possible
                                                                                                                                 presence of hydraulic compounds within the mortars and so learn more about their
                                                                                                                                 nature and characteristics. This technique should enable us to discriminate the presum-
                                                                                                                                 able source area of the clay-sized fraction which was artificially added and mixed to give
                                                                                                                                 it the proper hydraulicity.


                                                                                                                                     3.1.8. Remarks

                                                                                                                                     Study of the Cerrate masonries:
                                                                                                                                 -   petrographic results showed a possible discrimination between mortars of different
                                                                                                                                     production periods, based on textural features and the mineralogical composition
                                                                                                                                     of binder and aggregate;
                                                                                                                                 - SEM-EDS analyses coupled with X-ray diffraction provided information about the
                                                                                                                                     texture and composition of the binder, aggregates and the artificially added clay-
                                                                                                                                     sized fraction; further discrimination between mortars dated between the 16th and
                                                                                                                                     17th centuries and mortars dated approximately to the 19th and 20th centuries was
                                                                                                                                     made possible through X-ray maps, on the basis of elemental abundance and the
                                                                                                                                     different degree of mixing of the clay-sized silicate component within the binder;
                                                                                                                                 - the ongoing Mössbauer and thermal analyses are currently providing interesting
                                                                                                                                     results about the properties of the original mortars and the possible raw materials
                                                                                                                                     used in their production.
                                                                                                                                     Considering the complexity and the difficulties in studying mortars and, in general,
                                                                                                                                 historical buildings, the significant results reached in our study of the Cerrate complex
                                                                                                                                 have allowed us to delineate a preliminary analysis protocol. The protocol consists of
                                                                                                                                 analytical procedures which will help gain further knowledge of historical masonries and
                                                                                                                                 their characterization. More in general the systematic physico-chemical characterization


                                                                                 204
of the original historical mortars is essential for conservative and repair purposes and
useful in selecting the most compatible restoration materials. This methodology, veri-
fied on Cerrate, is also applicable to other sites.
    It is important to emphasize that this framework of analyses should be considered
only a preliminary step and, as yet, incomplete. Further testing needs to be carried out
in other contexts for it to be fine-tuned.
    Table 1 shows the samples examined and the analytical investigations carried out.

Table 1.
Summary of the macroscopic-microscopic observations (texture, type and composition of aggre-
gate, total elemental composition, binder composition) and of the analyses performed on the stud-
ied mortars. In the XRD column, minerals are listed in order of abundance. Plain-type = more
abundant minerals; bold-type = minor abundance; bold italic type = minerals in traces. Kf = K-feldspar;
plg = plagioclase. XRF chemical composition is given in wt% oxides.


                                                                Aggregate more than 50 %


 AGGREGATE            SAMPLE        CENTURY     COLOUR          OPTICAL MICROSCOPE ANALYSIS:
 COMPOSITION                                                    AGGREGATE COMPOSITION AND
                                                                TEXTURE


 silicate aggregate   M24           20th        pinkish red     Medium to very fine-grained silicate
                                                                grains, 0.05-0.5 mm, mostly quartz
                                                                and K-feldspar, subordinate bioclasts,
                                                                carbonate lithoclast and a reused
                                                                mortar fragment containing quartz.


                      MUR42-01     12th-17th    pinkish red     Medium to very fine-grained silicate
                                                                grains, 0.05-0.4 mm, mostly quartz
                                                                and K-feldspar, rare bioclasts and




                                                                                                             Conservation science in Cultural Heritage
                                                                lithoclasts including crystalline
                                                                limestone and fragments of
                                                                pietraleccese, presence of lime lumps.


                      MUR62-02      (≤ 16th)    pinkish white   Inhomogeneously distributed
                                    ???                         aggregate represented by medium
                                                                to very fine grains, 0.05-0.35 mm of
                                                                quartz and K-feldspar and Na-feldspar,
                                                                sub-angular to sub-rounded in shape.
                                                                Subordinate bioclasts (red algae,
                                                                planktonic and benthonic foraminifera
                                                                with phosphate filling) are concentrated
                                                                in a small sector of the mortar.


                      MUR58-04      20th        pinkish white   Poorly sorted aggregate consisting
                                                                of fine to very fine grains, 0.05-0.25
                                                                mm of quartz and K-feldspar, sub-
                                                                angular to sub-rounded in shape
                                                                and subordinate bioclasts (red algae
                                                                and echinoids). A fragment of a
                                                                reused mortar, about 2 mm in size,
                                                                was detected, displaying a mixed
                                                                carbonate and silicate aggregate in a
                                                                carbonate binder. A large lime lump is
                                                                also present.




                                                                                                           205
                                                                                                                                 MUR29-11   19th-20th   red             Inhomogeneously distributed aggregate
                                                                                                                                                                        with silicate grains, mostly quartz and
                                                                                                                                                                        K-feldspar, medium to very fine in size.
D. Esposito, A.M. Conte, L. Corda, E. Giorgi - An interdisciplinary approach for the historical and technical characterization




                                                                                                                                                                        A large lime lump is present displaying
                                                                                                                                                                        typical shrinkage fractures.

                                                                                                                                 M16        19th        pinkish white   Silicate grains, very fine to medium
                                                                                                                                                                        in size, predominantly represented
                                                                                                                                                                        by quartz, K-felspar and silicate of Al,
                                                                                                                                                                        Mg, and Fe, from sub-angular to sub-
                                                                                                                                                                        rounded in shape; K-feldspar appear
                                                                                                                                                                        more rounded. Rare bioclasts (red
                                                                                                                                                                        algae).
                                                                                                                                 M23        16th-18th   pinkish red     Silicate grains, 0.05-0.7 mm,
                                                                                                                                                                        subordinate bioclasts (red algae,
                                                                                                                                                                        bryozoans, bivalves, benthonic
                                                                                                                                                                        foraminifera, worm tubes (> 1mm),
                                                                                                                                                                        underburned carbonate lithoclasts.
                                                                                                                                 M19        16th-18th   red             Aggregate mostly represented by
                                                                                                                                                                        grains of quartz and K-feldspar, 0.05-
                                                                                                                                                                        0.5 mm, and subordinate silicates
                                                                                                                                                                        rich in Fe. A large lime lump (up to
                                                                                                                                                                        1 cm) was detected, with shrinkage
                                                                                                                                                                        fractures containing very small angular
                                                                                                                                                                        fragments of quartz.
                                                                                                                                 M18        16th        red             Inhomogeneously distributed aggregate
                                                                                                                                                                        with silicate grains, mostly quartz,
                                                                                                                                                                        K-feldspar and Na-felspar, medium
                                                                                                                                                                        to very fine in size (0.05-0.35 mm);
                                                                                                                                                                        sub-angular to sub-rounded in shape.
                                                                                                                                                                        A fragment of a previous mortar was
                                                                                                                                                                        observed, displaying a mixed bioclastic
                                                                                                                                                                        and subordinately silicate aggregate
                                                                                                                                                                        scattered in a carbonate binder.
                                                                                                                                 M27        19th        red             Poorly sorted and inhomogeneously
                                                                                                                                                                        distributed aggregate with predominant
                                                                                                                                                                        silicate grains of quartz and
                                                                                                                                                                        K-feldspar,0.05-0.35 mm in size,
                                                                                                                                                                        from angular to sub-rounded and
                                                                                                                                                                        subordinate bioclasts. A large lime
                                                                                                                                                                        lump is also present.
                                                                                                                                 MUR29-08
                                                                                                                                            19th-20th   red             Scialbo + mortar finishing: bioclastic
                                                                                                                                                                        calcarenite with abundant fragments
                                                                                                                                                                        of red algae (rhodoliths ≥ 2mm),
                                                                                                                                                                        echinoids, worm tubes, benthonic
                                                                                                                                                                        foraminifera and rare planktonic
                                                                                                                                                                        foraminifera. Subordinate grains of
                                                                                                                                                                        quartz and K-feldspar. The finishing
                                                                                                                                                                        mortar exhibits a silicate aggregate
                                                                                                                                                                        consisting of quartz and K-feldspar
                                                                                                                                                                        grains (grainsize: 0.06-0.25 mm) from
                                                                                                                                                                        sub-rounded to sub-angular and rare
                                                                                                                                                                        bioclasts.
                                                                                                                                 M9-1A      17th-18th   pinkish white   This sample is represented by a very
                                                                                                                                                                        thin layer of mortar on lithoid material.
                                                                                                                                                                        Aggregate consists of quartz and
                                                                                                                                                                        K-felspar grains of 0.05-0.3 mm, sub-
                                                                                                                                                                        angular in shape.



                                                                                  206
carbonate            M22        16th   pinkish white   Aggregate dominated by carbonate
aggregate                                              bioclasts, variable in size up to 1
                                                       mm. The subordinate silicate fraction,
                                                       absolute, consists of rare grains of
                                                       quartz and K-feldspar, 0.05-0.25 mm.
                                                       A thin superficial layer with a silicate
                                                       composition was observed.

                     MUR30-07   19th   pinkish white   Bioclasts (mostly red algae) and
                                                       lithoclasts), rare silicate grains of
                                                       quartz. K-feldspar and Na-feldspar,
                                                       0.08-0.2 mm, commonly sub-angular
                                                       in shape. A thin external layer (about
                                                       1 mm) of silicate material containing
                                                       abundant grains of quartz and
                                                       K-felspar) was also observed.

                     M02        12th   pinkish white   Abundant medium to coarse-grained
                                                       bioclasts, up to1.5 mm (red algae and
                                                       worm tubes); dolomitic lithoclasts are
                                                       also present. The subordinate silicate
                                                       fraction is mostly represented by quartz
                                                       grains (<0.1 mm in size) and silicates
                                                       of Mg, Al, K and Fe

                     MPSX       12th   pinkish white   Abundant medium to coarse-grained
                                                       bioclasts, up to 2 mm (red algae,
                                                       benthonic foraminifera and echinoids).
                                                       The subordinate silicate fraction mainly
                                                       consists of quartz grains, 0.05-0.2 mm.

                     M10-2A     19th   pinkish white   Abundant medium to coarse-grained
                                                       bioclasts, up to 1 mm (red algae,
                                                       benthonic foraminifera and echinoids,
                                                       bryozoans, bivalves). The fine-grained,




                                                                                                     Conservation science in Cultural Heritage
                                                       0.01-0.3, silicate fraction is very poor
                                                       and mostly represented by quartz.
                                                       Irregular and unusual porosity and
                                                       fractures (10-15%) are also present.

                     M13        13th   pinkish white   Abundant medium to coarse-grained
                                                       bioclasts (red algae, serpulids,
                                                       balanids, bryozoans, echinoids). The
                                                       subordinate silicate fraction (0.02 - 0.2
                                                       mm) mostly consists of quartz.

                     M10-2B     19th   pinkish white   Sample very similar to M10-2A.




mixed carbonate-
silicate aggregate                                     Abundant medium to coarse-grained
                                                       bioclasts (red algae, echinoids,
                     M01        12th   pinkish white   bivalves and benthic foraminifera).
                                                       The subordinate silicate fraction is
                                                       represented by quartz, subordinate
                                                       K-Feldspar and rare apatite grains.
                                                       Silicate grains (less than 0.25 mm in
                                                       size) are sub-angular to sub-rounded
                                                       in shape.




                                                                                                   207
                                                                                                                                                      M32         13th       pinkish red     Inhomogeneously distributed aggregate
                                                                                                                                                                                             with portions characterized by bioclasts
                                                                                                                                                                                             (mostly red algae) more than 1.5 mm
D. Esposito, A.M. Conte, L. Corda, E. Giorgi - An interdisciplinary approach for the historical and technical characterization




                                                                                                                                                                                             in size mixed with medium to very fine
                                                                                                                                                                                             silicate grains (quartz and subordinate
                                                                                                                                                                                             K-Feldspar). Other portions of the
                                                                                                                                                                                             sample exhibit rare silicate grains.

                                                                                                                                                      L13                    pinkish white   Very abundant aggregate consisting
                                                                                                                                                                                             of medium to coarse-grained bioclasts
                                                                                                                                                                                             (mostly echinoids and red algae),
                                                                                                                                                                                             benthonic foraminifera (locally
                                                                                                                                                                                             phosphatized) and rare planktonic
                                                                                                                                                                                             foraminifera. The silicate fraction is
                                                                                                                                                                                             mostly represented by fine-grained, 0.1
                                                                                                                                                                                             mm in size, quartz (sub-rounded to
                                                                                                                                                                                             sub-angular in shape) and subordinate
                                                                                                                                                                                             K-Feldspar and micas).

                                                                                                                                                                                             Aggregate less than 50 %

                                                                                                                                 silicate aggregate

                                                                                                                                                      MUR62-03    pre-16th   pinkish white   Medium to fine-grained grains of
                                                                                                                                                                                             quartz and K-feldspar, 0.05-0.5 mm,
                                                                                                                                                                                             and silicate lumps. Rare bioclasts and
                                                                                                                                                                                             fragments of underburned crystalline
                                                                                                                                                                                             limestone are also present.

                                                                                                                                                      MUR28-12    16th       pinkish red     This sample is an extremely weathered
                                                                                                                                                                                             mortar consisting of reddish powder
                                                                                                                                                                                             containing a limestone fragment
                                                                                                                                                                                             (corresponding to sample Mur 28A-06).



                                                                                                                                                      MUR28A-06   16th       pinkish red     Limestone fragment included within
                                                                                                                                                                                             the sample MUR28-12. It consists of
                                                                                                                                                                                             bioclastic calcarenite with red algae
                                                                                                                                                                                             and echinoids (even more than 1.5
                                                                                                                                                                                             mm in size), serpulids and bivalves,
                                                                                                                                                                                             surrounded by a film of reddish dust.


                                                                                                                                 carbonate
                                                                                                                                 aggregate
                                                                                                                                                      FN 44-M20   17th       pinkish red     Aggregate constituted by bioclasts,
                                                                                                                                                                                             up to more than 1 mm, of red algae,
                                                                                                                                                                                             bryozoans, echinoids. Underburned
                                                                                                                                                                                             limestone particles are also present.
                                                                                                                                                                                             The silicate fraction, consisting of
                                                                                                                                                                                             quartz and K-feldspar grains, 0.1 mm in
                                                                                                                                                                                             size, is scarce.

                                                                                                                                                      M05         12th       pinkish red     Aggregate mostly constituted by
                                                                                                                                                                                             bioclasts, up to more than 1 mm, (red
                                                                                                                                                                                             algae, echinoids, benthonic and rare
                                                                                                                                                                                             planktonic foraminifera). Underburned
                                                                                                                                                                                             lithoclasts are also present. The silicate
                                                                                                                                                                                             fraction, showing a mostly bimodal
                                                                                                                                                                                             particle-size distribution, around 0.5-0.7
                                                                                                                                                                                             mm and 0.1-0.2 mm, consists of Qz
                                                                                                                                                                                             and more rarely Al-silicate



                                                                                 208
 mixed carbonate-
 silicate aggregate
                      M15       16th or     pinkish white   Aggregate constituted by quartz and
                                19th                        feldspar grains, less than 0.25 mm in
                                                            size, phosphates and bioclasts (red
                                                            algae). Underburned lithic fragments,
                                                            around 1 mm in size were detected. A
                                                            large silicate lump, more than 2 mm in
                                                            size, containing quartz grains, is also
                                                            present.



    4. Conclusions

     As part of a wider ongoing project, the study on the Santa Maria di Cerrate complex
offers a framework of analyses and methodologies which are relevant and promising
for studying historic masonries. These methodologies, presented here as a case study,
will be tested on other samples from different archeological contexts with the purpose
of creating a background of knowledge useful for evaluating technical properties and
the performance of historical mortars also in relation to local construction techniques.
     In detail, studies will be carried out on the history of construction techniques and
the relationship between local resources and construction sites, thus contributing to a
more accurate history of the territory. The analytical aspect, specific analyses on or-
ganic additives (proteins, lipids, etc.) and the use of quicklime will contribute to under-
standing their role in the properties of the mortars.
     The path the project will follow, starting from the experiences of the single research-
ers, aims to integrate historical, technical and scientific knowledge at international level,
also through bibliographic research, for a better understanding of cultural heritage [18-21].


    Notes




                                                                                                        Conservation science in Cultural Heritage
    1
       The “Progetto Grande di Ateneo” (2018), Historical and technical characterization
of medieval and modern mortars. Methods for study and conservation (scientific coor-
dinator Prof. Daniela Esposito) is being carried out by the interdisciplinary research
group composed of Professors M. Asciutti, L. Barelli, F. De Cesaris, R. Mancini, M.L.
Santarelli, L. Sorrentino with the collaboration of L. Corda of the Sapienza University
of Rome, the Laboratory AStRe-LabMat (Architettura Storica e Restauro-Laboratorio
Materiali) (E. Giorgi) and the CNR of Milan, Rome and Lecce (A. Sansonetti, A. M.
Conte, E. Scopinaro, A. Monte), the Politecnico of Milan (G. Landi), the Università di
Roma Tre (S. Passigli), the University of Camerino (E. Petrucci), Pavia (M.P. Riccardi),
Parma (F. Ottoni), the Politecnico of Turin (C. Tosco) and Ph.Ds of the Sapienza Uni-
versity of Rome (S. Cirulli, V. Montanari, L. Ninarello, M.G. Putzu)
     2
       The abbey (founded in the12th century) became a masseria (‘manor farm’) from
the 16th century and the church was gradually abandoned. The manor farm carried out
its agricultural activity until the postwar period, when it was purchased by the Biancos.
In 1965, they ceded the complex to the Province of Lecce. In the 1970s, restoration
interventions of the complex were started, designed by Franco Minissi. Some adapta-
tions were made in 1986, and other interventions followed in 2006, on the initiative of
the provincial administration. The restoration project is supported by FAI (Fondo Ambi-
ente Italiano) and its technical office (and architects Paola Candiani, Roberto Segattini,
Giacomo Sosio et al.) in 2012-2014.


                                                                                                      209
                                                                                                                                       References

                                                                                                                                 [1]    Chiari, G., Santarelli, M.L., Torraca, G. (1992), Caratterizzazione delle malte an-
D. Esposito, A.M. Conte, L. Corda, E. Giorgi - An interdisciplinary approach for the historical and technical characterization




                                                                                                                                        tiche mediante l’analisi di campioni non frazionati, in Materiali e strutture, proble-
                                                                                                                                        mi di conservazione, II, 3, pp. 111-137.
                                                                                                                                 [2]    Azeredo, G., Morel, J.C., Lamarque, C. (2008), Applicability of rheometers to
                                                                                                                                        characterizing earth mortar behavior. Part I: experimental device and validation,
                                                                                                                                        Materials and structures, vol. 41, 1465-1472.
                                                                                                                                 [3]    Bei, G.E. (1996), Raw earth, an ancient and modern building material, Master
                                                                                                                                        thesis, KatholickeUniversiteite Leuven
                                                                                                                                 [4]    Guillaud, H. (2008), Characterization of Earthen Materials, Terra Literature Re-
                                                                                                                                        view, Los Angeles, 21-31.
                                                                                                                                 [5]    Marino, L. (2007), Cave storiche e risorse lapidee. Documentazione e restauro,
                                                                                                                                        Firenze.
                                                                                                                                 [6]    Bayat, A., Hassani, A., Yousefi, A.A. (2018), Effects of red mud on the properties
                                                                                                                                        of fresh and hardened alkali-activated slag paste and mortar, Construction and
                                                                                                                                        Building Materials, 167, 775-790.
                                                                                                                                 [7]    Conte, A.M., Corda, L., Esposito, D., Giorgi, E. (2017) Characterization of mor-
                                                                                                                                        tars from the medieval Abbey of Cerrate (southern Italy). Journal of Archaeologi-
                                                                                                                                        cal Science: Reports 12, 463-479.
                                                                                                                                 [8]    Fieni, L (1999), Approfondimenti metodologici e tecnologici per lo studio delle malte
                                                                                                                                        di terra: l’esempio dei manufatti cremonesi, Archeologia dell’Architettura, IV, 9-28.
                                                                                                                                 [9]    Galdieri, A. (1913), Sul bolo di terra d’Otranto, Annali della Reale Scuola supe-
                                                                                                                                        riore d’Agricoltura di Portici, v. 11, Portici: Premiato stab. tip. Vesuviano di E. Del-
                                                                                                                                        la Torre.
                                                                                                                                 [10]   Galdieri, A. (1913), L’origine della terra rossa, Annali R. Scuola Sup. d’Agricoltura
                                                                                                                                        di Portici, Portici, Premiato stab. tip. Vesuviano di E. Della Torre
                                                                                                                                 [11]   Lekshmi, M.S. et al. (2016), Experimental studies on the physical properties of
                                                                                                                                        mud mortar in comparison with the conventional mortars, Civil Engineering and
                                                                                                                                        Urban Planning: an International Journal, 2, 127-135
                                                                                                                                 [12]   Rampazzi, L. et al., Technology of medieval mortars: an investigation into the use
                                                                                                                                        of organic additives (2015), Archaeometry
                                                                                                                                 [13]   Scarzella, P., Zerbinatti, M. (ed), (2000), Malte a vista con sabbie locali nella
                                                                                                                                        conservazione degli edifici storici, Torino
                                                                                                                                 [14]   Leslie, A.B. and Hughes, J.J., 2002. Binder microstructure in lime mortars: impli-
                                                                                                                                        cation for the interpretation of analysis results. Quarterly journal of Eng. Geol.,
                                                                                                                                        35, 257-263.
                                                                                                                                 [15]   Fierro, G., Moretti, G., Ferraris, G., Andreozzi, G.B. (2011). AMössbauer and
                                                                                                                                        structural investigation of Fe-ZSM-5 catalysts: Influence of Fe oxide nanoparti-
                                                                                                                                        cles size on the catalytic behaviour for the NO-SCR by C3H8. AppliedCatalysis
                                                                                                                                        B: Environmental, 102, 215-223.
                                                                                                                                 [16]   Andreozzi, G, (2007) Spettroscopia Mössbauer, 6° Forum della FIST, Rimini 11
                                                                                                                                        settembre 2007.
                                                                                                                                 [17]   Andreozzi, G.B., Pollastri, S. (2017). Bulk spectroscopy of mineral fibres. In Min-
                                                                                                                                        eral fibres: Crystal chemistry, chemical-physical properties, biological interactions
                                                                                                                                        and toxicity (Gualtieri Editor). EMU Notes in Mineralogy, 18, 111-134.
                                                                                                                                        ISBN:9780903056656 DOI: 10.1180/EMU-notes.18.4.
                                                                                                                                 [18]   De Giorgi, C., La chiesa di S. Maria di Cerrate: note archeologiche, Firenze,
                                                                                                                                        1888.


                                                                                           210
[19] Barletta R., Santa Maria di Cerrate, Lecce, Ed. del Grifo, 2003.
[20] Arthur, P., Limoncelli, M., (2004) Abbazia di S. Maria di Cerrate – Squinzano (LE),
     Campagna di rilievo archeologico. Laboratorio di Archeologia medievale, Univer-
     sità di Lecce, Dipartimento di Beni Culturali, 2004.
[21] Bruno, B., Gravili, G., Lo scavo di S. Maria di Cerrate, resp. P. Arthur. Laboratorio
     di Archeologia medievale, Università di Lecce, Dipartimento di Beni Culturali
     (ottobre-dicembre 2005).


   Biographical notes

     Daniela Esposito is an architect with a degree in Monument Conservation and a
full professor in restoration. She works in the Faculty of Achitecture of the Sapienza
University of Rome, in the Dept. of History, Representation and Restoration of Archi-
tecture. She is a “Chercheur associé” of the Laboratoire de médiévistique occidentale
de Paris (LAMOP, UMR 8589), CNRS-Université Paris I-Sorbonne.
     She holds the chair of the Architectural Restoration Laboratory in the Master de-
gree course of Architecture (Restoration). From 2013 she is chairperson of the Didactic
Area 2, “Sciences of Architecture and Landscape” in the Faculty of Architecture, Sa-
pienza University of Rome and from 2013 to 2019 of the post-graduate School in Ar-
chitectural Heritage and Landscape (Scuola di Specializzaizone in Beniarchitettonici e
del Paesaggio) of the Sapienza University of Rome. She was a member of the re-
search committee of the Sapienza University from 2011 to 2014. She is at present a
member of the validation committee for PhD courses, at the same University.

    Aida Maria Conte is a researcher at the National Research Council (C.N. R.), Isti-
tuto di Geologia Ambientale e Geoingegneria (I.G.A.G.). She has also been a member
of the Scientific Board of the C.N.R.- CSESMR (1998-2001); Lab Manager for the




                                                                                               Conservation science in Cultural Heritage
C.N.R. - XRF laboratory (1992-2017); Lab manager for the C.N.R - FTIR laboratory
(2010-2018) and head of the “Sapienza” branch office of the C.N.R.- I.G.G. (2007-2017).
Her teaching activities include petrography (Bachelor’s degree in ”Scienze Naturali”) at
the Sapienza University of Rome (2012-2015); research fields include geomaterials in
geological processes (magmatism and tectonics) and in cultural heritage (character-
ization through a multi-analytical approach of archaeological and architectural materi-
als for the purposes of origin and restoration).

    Laura Corda is full professor of Stratigraphic Geology at the Sapienza University
of Rome, Dept. of Earth Sciences; chairman of the Geology Museum of the University
of Rome (2010-2016); coordinator of the Earth Sciences scientific areas within the
“Polo Museale” of the Sapienza University (2011-2016); coordinator of the Ph.D. in
Earth Sciences (2009-2016); chairman of the “Professor-Student Joint Committee” of
the Faculty of “Scienze Matematiche, Fisiche e Naturali”. Teaching activities: Geology
I (Bachelor’s degree ”Scienze Geologiche”); main current research fields are facies
analysis and sedimentology of carbonate systems; oceanic tectonic islands: facies and
depositional architecture of related carbonate platforms; archaeometry: geological char-
acterization and provenance of used materials.

   Elisabetta Giorgi is an architect and expert in conservation of historical-building
materials, surfaces and finishes. A consultant and teacher at ICCROM for the conser-


                                                                                             211
                                                                                                                                 vation of mural painting and historical constructions; a researcher in many worksites
                                                                                                                                 for testing hydraulic mortar for conservation plaster and mural painting (Pompei, and
                                                                                                                                 other sites with the scientific support of Prof. G. Torraca). A consultant for IsCR (Istituto
D. Esposito, A.M. Conte, L. Corda, E. Giorgi - An interdisciplinary approach for the historical and technical characterization




                                                                                                                                 Superiore per la Conservazione ed il Restauro, formerly ICR) in didactic worksites with
                                                                                                                                 the coordination of data and lectures on graphic documentation. She is currently the
                                                                                                                                 Technical-Head of AsTRE-LabMat, Architettura Storica e Restauro-Laboratorio Materi-
                                                                                                                                 ali at the Sapienza University of Rome, Department for Architectural History, Design
                                                                                                                                 and Restoration. As an architect Elisabetta Giorgi is involved in many research activi-
                                                                                                                                 ties and provides didactic support for post-graduates and thesis preparation on the
                                                                                                                                 Restoration of Architecture and history of Architecture.


                                                                                                                                    Summary

                                                                                                                                     The study concerns Italian masonries and focuses on historical, medieval and mod-
                                                                                                                                 ern mortars. Within the context of the different regions under examination (Piedmont,
                                                                                                                                 the Po Valley area, Latium, the Umbria-Marche region, and Apulia and Sardinia) a wide
                                                                                                                                 variety of materials with different chemical-physical characteristics were used in ma-
                                                                                                                                 sonry work, determining different structural behaviors. The project aims at improving
                                                                                                                                 our knowledge about historical mortars in order to further the conservation of Italian
                                                                                                                                 built heritage, especially in zones with seismic risk. To achieve these results, we took
                                                                                                                                 samples and carried out analyses to investigate the different mechanical and cohesion
                                                                                                                                 properties that influence the vulnerability of ruined or collapsed structures.
                                                                                                                                     This information has enabled advances to be made in the prevention, maintenance,
                                                                                                                                 protection and preservation of historical buildings.
                                                                                                                                     Further details will concern the history of construction techniques, with particular
                                                                                                                                 regard to the relationship between local resources and construction sites. Another im-
                                                                                                                                 portant topic is the role of different components and additives during the preparation of
                                                                                                                                 the mortars and their level of hydraulicity.


                                                                                                                                    Riassunto

                                                                                                                                     Lo studio riguarda le strutture murarie in Italia e si concentra sulle malte storiche,
                                                                                                                                 medievali e moderne. Nei contesti regionali oggetto d’indagine (Piemonte e Pianura
                                                                                                                                 Padana, Lazio, Umbria-Marche, Puglia e Sardegna) è stata utilizzata una grande va-
                                                                                                                                 rietà di materiali, con caratteristiche chimico-fisiche diverse, e queste differenze deter-
                                                                                                                                 minano anche comportamenti strutturali diversi. Il progetto mira a migliorare la nostra
                                                                                                                                 conoscenza delle malte storiche per approfondire il tema della conservazione del pa-
                                                                                                                                 trimonio edilizio italiano, soprattutto nelle zone a rischio sismico. Per ottenere questi
                                                                                                                                 risultati, sono stati prelevati campioni sui quali sono state effettuate analisi per indaga-
                                                                                                                                 re quanto le diverse proprietà meccaniche e di coesione incidano sulla vulnerabilità
                                                                                                                                 delle strutture in rovina o collassate.
                                                                                                                                     Grazie a queste informazioni è stato possibile contribuire alla prevenzione, manu-
                                                                                                                                 tenzione, protezione e conservazione dell’edilizia storica.
                                                                                                                                     Ulteriori conoscenze hanno riguardato la storia delle tecniche di costruzione, con
                                                                                                                                 particolare riguardo al rapporto tra risorse locali e i cantieri. Un altro importante tema è
                                                                                                                                 stato il ruolo dei diversi componenti e additivi durante la preparazione delle malte e il
                                                                                                                                 loro livello di idraulicità.


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