5th International Conference. Youth in Conservation of Cultural Heritage YOCOCU. Book of abstracts.

Depto. de Mineralogía y PetrologíaFac. de Ciencias GeológicasTRUEYouth in Conservation of Cultural Heritage - YOCOCU EspañaMuseo Centro de Arte Reina Sofía MNCARSFundación Reina Sofíapu

Effects of paraffin additives, as phase change materials, on the behavior of a traditional lime mortar

This study refers to the inclusion of phase change materials (PCMs) in porous building materials as an alternative means of improving their thermal behavior, assessing the changes caused in their physical–mechanical and durability properties. Specifically, an organic paraffin wax was selected for direct incorporation into lime mortars using different concentrations by weight. The results show that PCMs improve the thermal properties of the mortar while reducing its accessible porosity. This increases the mortars’ resistance to water and soluble salts. However, excessive PCM content causes stresses within the mortar that can jeopardize its structure

Analytical characterisation of 1st- and 2nd-century Roman mortars at the Utica archaeological site (Tunisia): Construction phases and provenance of the raw materials

The aim of this paper is to characterise the mortars from at the Roman site in Utica, Tunisia. In-depth knowledge of the composition of these Roman mortars is necessary to ensure the proper restoration and preservation of these ancient monuments. Despite the significance of this archaeological site, declared a UNESCO World Heritage Site in 1993, the Roman construction materials used there, particularly the mortars have never been analysed. The findings of this study allowed us to determine the particularities of the Roman mortars in Utica, highlighting the impact that local know-how, geological specificity and the history of the archaeological site had on the end product. The different mortars were analysed using petrographic (optical polarised and electron microscopes), mineralogical (X-ray diffraction), chemical and physical techniques. Three types of joint and coating mortars, associated with two different construction phases and a variety of uses, were identified. The mortars used in the city's first construction phase were low-hydraulicity calcium lime mortars containing inert quartz aggregates. Those related to the city's second phase of construction, are two types of mortar with a greater degree of hydraulicity by virtue of their artificial and natural pozzolanic aggregate content. The lime mortars containing artificial pozzolans (cocciopesto) were coated with lime mortars containing natural volcanic pozzolans. The foreign provenance of the natural and artificial pozzolans may be attributable to the amount of trade that passed through the Roman city’s port in the 1st and 2nd centuries AD.Ministerio de Economía y CompetitividadComunidad de MadridDepto. de Mineralogía y PetrologíaFac. de Ciencias GeológicasTRUEpu

Mortars and plasters—How to characterize aerial mortars and plasters

Aerial mortars and plasters have been widely used in construction throughout history, and their compatibility with historic mortars and plasters has led to their recent re-adoption. This paper reviews the prominent features of aerial mortars and plasters, their main characteristics and the various characterization methods using both traditional and advanced technology. Several techniques are used in physical, hydric, mechanical, petrographic, mineralogical and chemical characterization. A detailed explanation of microscopic characterization techniques is provided, indicating the information that can be obtained with each. Scientific advances in dating and provenance studies are also described

Assessment on the performances of air lime-ceramic mortars with nano-Ca(OH)(2) and nano-SiO2 additions

This research presents a novel approach based on the combination of nanotechnology and Roman technology by investigating how adding nanoCa(OH)(2) and nanoSiO(2) modify the performance of air lime mortars containing Roman ceramics. Microstructural, physico-mechanical properties were periodically controlled until 120 days of curing. XRD and TGA analyses showed that adding nanoSiO(2) either alone or with nanoCa(OH)(2) were more beneficial to improve the pozzolanic activity in the mortars. The less stable hydrated phases generated led to microcracks which eventually impaired compressive strength but enhanced deformability capacity. These results provide insight into the development of highly compatible mortars for cultural heritage

The technology of ancient lime mortars from the Żejtun Roman Villa (Malta)

Studies on original mortars can greatly assist archaeological interpretations, as elucidating the composition of such mortars gives clues on the origin of raw materials, manufacturing technology, and the construction phases of a site. This article presents the multi-analytical characterisation of 24 mortars and plasters from the Żejtun Roman Villa, Malta, to support archaeological hypotheses on the history of the construction of the site. The samples, belonging to at least three distinct phases included in the stratigraphy of the Żejtun archaeological site, were analysed using polarised light microscopy (PLM), scanning electron microscopy (SEM–EDS), X-ray diffraction (XRD), thermogravimetry (TGA/DSC), X-ray fluorescence (XRF), ion chromatography (IC), and stable isotope analysis (13C and 18O). The assessment of the results through correlations with archaeological evidence identifies five types of mortars with varying degrees of hydraulicity. These are associated with different development phases of the site and distinctive uses and were mainly produced using local resources, except in the Early Roman period when natural pozzolanic raw materials started being used. As there are no natural pozzolans on the Maltese Islands, it is hypothesised that the pozzolanic materials used as aggregate in the mortars were imported to the Islands from neighbouring volcanic regions. This volcanic aggregate was especially abundant in one of the mortar types, which was used mainly as a bedding mortar for floors

Microstructural modifications of lime-based mortars induced by ceramics and nanoparticle additives

Lime-based mortars are one of the principal choices for building and restoration projects, owing to their unique qualities and material compatibility. Admixtures have long been incorporated to enhance the performance and durability of mortars, with ceramics being a traditional choice. More recently, the addition of nanoparticles has been explored as a means to further improve these properties. However, the effective optimization of the complex interplay between additives in lime-based mortars, which is crucial for enhancing their sustainability, remains an ongoing area of research. This study investigated the effects of red-clay ceramic aggregates (RCC) and nanoparticle-based solutions of Ca(OH)2 and SiO2 on the mineralogy, hydraulicity, surface properties, pore structure, and mechanical properties of lime-based mortars. The addition of nanoparticle-based solutions increased the carbonation reactivity, whereas the ceramic aggregates caused a more extensive conversion of portlandite to calcite on the external faces, indicating reduced porosity during the carbonation process. Pozzolanic reactions and the formation of new calcium silicate compounds were observed, along with improved compaction, smoother surfaces, and microcrack formation. The porosity increased with the addition of the ceramic aggregates, whereas the addition of nanoparticles significantly increased the number of pores in the mesoporous range. The specific surface area of the mortars increased with the inclusion of ceramic aggregates and nanoparticles, whereas the open porosity increased and the density and compressive strength decreased with the addition of nanoparticles and associated pozzolanic reactions that occurred with the inclusion of ceramic aggregates. These findings lay the groundwork for future improvements in the formulation of lime-based mortars to balance hydraulicity, surface characteristics, and mechanical performance while preserving porosity.Ministerio de Economía y CompetitividadComunidad de MadridEuropean Ceramic SocietyEuropean Union's Horizon 2020Ministry of Culture of the Czech RepublicIGEODepto. de Mineralogía y PetrologíaInstituto de Geociencias (IGEO)TRUEpu