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This study was funded by Junta de Andalucía Research Group RNM179 and by Research Project MAT2016-75889-R. Funding for open access charge: Universidad de Granada/CBUA. I thank Cer´amica Castillo Siles for providing the raw material used to prepare and fire the bricks and the Centro de Instrumentaci´on Científica (CIC, University of Granada) for its assistance with the granulometry, XRF, TG-DSC and FESEM analyses. I am grateful to Nigel Walkington for his assistance in revising the English text of the manuscript., Volcanic ash emissions are responsible for serious damage to buildings. They can also affect vehicle traffic, cause airport closures and may be hazardous for human health. To verify the effects of the potential addition of this residue to the mixture used in the production of bricks, a detailed study of the clayey material, the volcanic ash and the bricks fired at 800, 950 and 1100 ◦C was conducted, assessing chemical, mineralogical, physical, mechanical and durability aspects. The addition of 10–20 wt% of volcanic ash delayed the appearance of new phases during brick firing and made them less porous. The bricks maintained their orange colour and became more compact as the firing temperature increased due to sintering and vitrification processes. The addition of volcanic ash reduced the strength of the bricks although the values were always above the limits recommended for construction work with ceramic materials. Bricks with added volcanic ash increased their resistance to decay due to salt crystallization and the general behaviour of the bricks improved when they were fired at high temperatures., Junta de Andalucía Research Group RNM179, Research Project MAT2016-75889-R, Universidad de Granada/CBUA

The northern slope of Mt. Vesuvius contains some interesting archaeological sites, including the site discovered in the town of Pollena Trocchia, where the remains, dated to between the 79 and 472 CE eruptions, document the transition from the Roman to late Roman cultural and socioeconomic settings. Profound changes occurred in this time interval, which can be inferred from changes in the ceramic manufacturing processes. Common wares, as the most widespread ceramic class in the archaeological record, are a useful example that illustrates this technological transformation. Seventeen samples of tableware, distinguished into three ceramic classes according to the method of slip application (i.e., Slipped Ware, Painted Ware “a straccio,” and Painted Ware), were analyzed. The results highlight the use of high-CaO clayey raw materials compositionally similar to Apennine clayey deposits. The clay bodies were occasionally tempered with sandy-silt materials composed of volcanic grains with lesser amounts of siliciclastic fragments. Firing temperatures ranged from 800 to 950°C, as suggested by quantitative X-ray powder diffraction and microstructural analyses combined with colorimetric measurements of the ceramic bodies. Micro-Raman analyses performed on slips revealed the use of ochre for decorating the vessels; it was applied in a different way, representing an actual technological change.

This paper analyses the effects of the addition of organic (coffee grounds) and inorganic (fly ash) residues to a clayey soil rich in quartz and other silicates used as a raw material in brick production. To this end the mineralogy, texture, durability and physical and mechanical properties of solid bricks fired between 800 and 1100 ºC were studied. The results show that as the firing temperature increased, the phyllosilicate content decreased and mullite appeared. The matrix became less birefringent due to gradual vitrification of the samples, especially after 950 ºC. Vitrification resulted in more compact, less porous samples. The addition of residues did not affect the mineralogy, but it did alter certain physical parameters such as colour and porosity. The largest colour differences were detected after the addition of fly ash, which usually caused a whitish patina to develop on the surface of the fired bricks, while the highest porosity values were detected in bricks with coffee grounds, significantly reducing the bulk density. The increase in firing temperature improved the mechanical resistance and durability of all the bricks regardless of their composition., Grupo de Investigación RNM179 de la Junta de Andalucía

This research has been supported by the Horizon 2020 Marie Sklodowska-Curie Individual Fellowship Action (grant no. 836122); the Consejeria de Conocimiento, Investigacion y Universidad, Junta de Andalucia, Spain (Research Group RNM179); and the Ministerio de Economia y Competitividad, Spain (grant no. MAT2016-75889-R)., Diverse types of bricks from monuments in the city of Padua (northeastern Italy) were studied using a multi-analytical approach based on spectrophotometry, X-ray fluorescence (XRF), X-ray powder diffraction (XRPD), polarized-light optical microscopy (POM) and/or high-resolution scanning electron microscopy with coupled energy-dispersive X-ray spectroscopy (HRSEM-EDS). The most representative bricks were yellow or beige and in well-preserved condition. The results showed that they were made of Mg- and Ca-rich illitic clays, were fired at high temperatures (from 900 to over 950 C), and achieved an incipient vitrification. Two main processes took place during firing: (i) the development of a Ca-aluminosilicate amorphous phase where very abundant pyroxene-type crystals were nucleated and (ii) the transformation of the pristine Mg-rich clayey grains into Mg-silicate mineral phases. The analyses suggest a firing dynamic within a highly reactive and supersaturated unstable system, particularly rich in calcium and magnesium. There are also signs of the rapid heating and/or soaking of the bricks and the irregular heat distribution and/or different residence times inside the kilns. The formation of zeolite and calcite secondary phases was also observed. The former was largely promoted by the high calcium content of the bodies and the very humid conditions, while the latter was mainly precipitated from Ca-rich solutions. The preservation of the bricks was enhanced by processes that took place both during and after firing. Firstly, the significant development of a Ca-rich amorphous phase and of high-temperature pyroxene-type crystals has provided strength to the bricks. Secondly, the porosity yielded by the firing of the carbonate-rich clays was almost filled by secondary calcite, which acted as a cementing agent. The information attained has increased the knowledge of (i) the mineralogical and microstructural changes that take place during the firing over 900 C of Ca- and Mg-rich illitic clays and (ii) the formation of secondary phases within highly calcareous bricks laid in very humid environments and affected by Ca-rich solutions. The key role of the Ca- and Mg-rich raw clays and of the high firing temperatures, in producing high-quality bricks, and of the secondary calcite, which increased their durability, is highlighted. All these factors have contributed to the better preservation of the built heritage of the city., Horizon 2020 Marie Sklodowska-Curie Individual Fellowship Action 836122, Junta de Andalucia RNM179, Spanish Government MAT2016-75889-R

Mortars are heterogeneous building materials whose raw materials, manufacturing processes and application conditions have evolved continuously throughout history. The fact that apparently small changes in the components or dosages of mortars can affect their overall performance in the masonry makes the study of historic mortars a complex task that needs to be tackled via a multidisciplinary approach, with the support of complementary analytical techniques from the field of chemistry, mineralogy, physics and engineering, among others. This review is intended to be a useful tool for researchers working in the field of archaeology and/or cultural heritage conservation, as it offers a complete overview of the most widely accepted analytical techniques and physical-mechanical tests used in the characterisation of historic mortars and plasters. Although the methods described here are common to both air-hardening and hydraulic mortars, we focus above all on the latter, paying special attention to aspects relating to the chemical, mineralogical and petrographic investigation of the calcium silicate and aluminate hydrated phases that may indicate the use of one or other hydraulic binder in historic mortars, all this taking into account and discussing the practical aspects, drawbacks and limitations of each technique. European standards for the study of mortars are also addressed in this paper.

The limestone used at the Pasargadae World Heritage Site in Iran, an outstanding open-air architectural heritage site dating from the Achaemenid period (sixth century BC), has suffered weathering due to interaction with the environment. It was built out of beige limestone that today shows scaling and pitting decay patterns. Two inorganic consolidating products that are very promising: nanolime and dibasic ammonium phosphate (DAP) were considered for the consolidation of the limestone. Consolidation treatments were conducted on samples from a quarry and applied using a paintbrush with 50% nanolime dispersion in isopropyl alcohol and 1.0 M DAP water solution. Superficial consolidation was evaluated by means of a micro-drilling resistance test, and color changes were assessed by spectrophotometry. The microstructure of the treated samples was observed using FE-SEM. The efficacy of the two consolidation treatments was also assessed by testing their hydric properties and durability (hydric tests, freeze-thaw, and salt crystallization cycles). The compactness in the altered samples was monitored by measuring the ultrasound propagation velocity. We found that the superficial resistance increased in a similar way with both treatments. However, spectrophotometry revealed a yellowish color in the samples treated with DAP. During FE-SEM observations, some diffused microcracks were detected on the surface of DAP treatment. When subjected to accelerated aging tests, both treatments managed to postpone the formation of the first microcrack during the freeze-thaw test and both showed outstanding stability during salt crystallization cycles. In conclusion, the nanolime product seems to be more compatible with beige limestone because it does not affect its aesthetic qualities (color, lightness, and a homogeneous layer formed on the surface of the stone). Moreover, previous research found that lime has a low propensity for biological growth. This supports its use as a consolidating product for the stone used in open-air archeological sites that are prone to microbial growth, such as the beige stone used in the Pasargadae WHS.

In this paper, we studied building materials from the Nigde-Kinik Hoyuk archaeological site (Southern Cappadocia, Turkey) with the support of historical, architectural, and geological research. The samples were collected within the framework of the Kinik Hoyuk Archaeological Project, which began excavations at the site in 2011 in a bid to conserve the ancient buildings that would be discovered there. The objective was to characterize the fine-grained building materials as a means of understanding the structural stability they offered, in order to explain how the remains had managed to survive for such a long time. Samples were taken from the coating on different walls, from mud bricks and rendering, and from soil-beaten floors from the different buildings in the settlement. Samples were first observed using a video microscope and then studied by means X-ray diffraction and optical and scanning electron and transmission microscopies. The materials studied were composed of volcanic sands coming from the materials that outcrop in the area. In general, the samples were porous and fissured and minerals of volcanic origin were identified such as quartz, plagioclases, cristobalite, pyroxenes, micas, amphiboles, and olivine together with others of sedimentary origin, such as calcite, and small amounts of clays. The possible presence of hydrated calcium silicates was closely investigated due to their important role in the preservation of ancient building materials, but although we searched for them with a range of different techniques, none was found. This indicates that the long-term conservation of the Nigde-Kinik Hoyuk archaeological site may be due to the fact that it was buried at constant temperature and humidity conditions and so protected from the weather conditions, which are milder in this area than in any other region of Central Anatolia.

Representative and very uneven texturally bricks having yellow/beige or pale or dark red colors from the Renaissance walls (16th century) of Padua, Northeast Italy, were studied by means of colorimetric, petrographic (MOP), chemical (XRF), mineralogical (PXRD) and microstructural analysis (FESEM-EDS). Starting from the color measurements of the ceramic bodies, the manufacturing technologies and their influence on the physical behavior and durability of the bricks were established. The porous system was characterized by means of hygric tests and mercury intrusion porosimetry; the compactness and structural anisotropy were defined through ultrasound velocity; the uniaxial compressive strength was determined; and durability to salt crystallization and frost action of the bricks was assessed. Mg- and Ca-rich illitic clays fired at temperatures ≥900 ◦C were used to manufacture the beige hue bodies, while the pale red bricks were made out with Ca- and Fe-rich illitic clays fired at 850–900 ◦C. A lower carbonate content on the base clays and a lower firing temperature were the main causes responsible for the changing colors from beige to red hue. The increase of the red color was associated to higher silicate inclusions content and lower development of reaction rims around grains. The low sintering degree achieved yielded highly porous bodies with diverse porous systems, leading to differential physical performance and durability of the bricks that may turn out beneficial for the conservation of the historic walls., Marie Sklodowska-Curie grant agreement No 836122, CLAYONRISK Project, Research Group of the Junta de Andalucía RNM179, MSC Action

The history of brick manufacturing in Madagascar dates back to the early 1800 s when European colonisers imparted to the local population the basic knowledge for firing clayey sediment to obtain a more durable construction material. The evaluation of the entire production cycle accounting for the involved natural resources such as raw materials, fuels and derived bricks, represents the aim of this research started in 2015 and focused on both rural and urban contexts. Clayey raw materials from lateritic soils widely occur in central Madagascar whereas, in southern coastal sites, carbonate-bearing clays definitely prevail since their composition are influenced by the reef. Bricks are prepared on site with no additional manipulation of the base clay and, depending on the climatic conditions, the bricks are dried and fired from one week up to ten days. Furnaces are powered by rice husk in south-western part of the island whereas in central Madagascar the use of peat and wood was also recorded. The calorific performances of these common fuels allow achieving temperatures of 800–900 °C; however, the huge loss of heat due to the poor quality of the furnaces determine low equivalent firing temperatures (EFT) that negatively affect the quality of the bricks. The above described ceramic process has remained unchanged for more than 200 years and even if new social and economic opportunities arose, this unvirtuous system slowly (but inexorably) contributed to the impoverishment of important energy sources and, above all, of natural resources.

The archaeological site of the Anahita Temple in Kangavar is one of the best-known stone monuments in western Iran and dates back to the Persian Empire period of Iranian history (about 550 BC to 650 AD). The Temple was constructed on a semi-artificial hill out of large stone blocks, many of which are cubic in shape, and short thick columns. In the Kangavar area (basin) there are various sites in which there is evidence of stone extraction. The aim of this paper is to characterize the stones used in the Anahita Temple of Kangavar and their correlations with the quarrying activities observed in the Kangavar regions. In fact, we tried to find out which of these quarries may have been the source of the stone blocks used in the construction of the Anahita Temple. To this end the stones used in the Temple have been characterized by conducting a multi-analytical study involving chemical, mineralogical and textural analyses including XRF, XRD and thin section petrography. The results show that although all the quarries could have provided the stone used in the construction of the Temple, the largest, most probable source was the Chel Maran quarry. It is due to the more similarity of stones used in the Anahita Temple and the samples from this quarry from geochemical point of view as well as the archaeological evidences present in this quarry. The results are also useful for conservators to select appropriate materials for reconstruction of the decayed parts of the Anahita Temple.

Many industrial by-products contain Naturally Occurring Radioactive Materials (NORM) that normally represent a cost in terms of monitoring, risk management and storage. When included in new mix designs of bricks, these materials may become a valuable sustainable resource. Before marketing, companies involved in development and commercialization of these new building materials ensure safety related to radiation, usually by assessing radon-related risk. According to the Council Directive 2013/59/Euratom, both raw materials and final products used in building constructions need to be tested for activity concentration. The present work explores the radionuclide concentration and the radon exhalation of bricks obtained recycling different types of potentially radioactive wastes: i) trachyte as by-product resulting from quarrying operations, and ii) two different types of industrial sludge derived from ceramic tiles industry. Raw materials were studied to foresee any potential radioactive risk derived from their use as secondary raw materials, while bricks were investigated to assess the influence of mineralogy and texture on their radioactive properties and their effective radon-risk. The results obtained here show that, although radon emanation in bricks is primarily determined by radionuclide concentration in the raw materials, textural features significantly affect radon mobility and exhalation.

Natural stone has long been used as a building material because of its physical-mechanical resistance and its esthetic appeal. However, over the last century increasing industrial activity has produced more acidic environments, such as polluted urban areas, that can cause serious damage to many buildings and historic monuments, and in particular those made with carbonate rocks, which are most prone to decay. In order to mitigate the physicochemical processes that degrade these buildings, a number of phosphate-based consolidants have been developed, which are highly compatible with the carbonated substrate. Research about the role of the surface and its different possible finishes in the transmission of the agents that damage or protect the stone would therefore be very useful, both when choosing the most suitable stone for new constructions and when restoring historic buildings. The main objective of this research was to determine whether the roughness of three types of surface finish (sawcut, honed and bush-hammered) influences the durability of four types of natural stone (two calcarenites, one travertine and one sandstone) widely used in Andalusia (Spain). The efficacy of a calcium phosphate-based consolidant as a mitigator of deterioration in polluted urban environments was also studied and to this end the physical properties of untreated and treated samples were measured and compared. The samples were exposed to artificial atmospheres with SO2 pollution in order to assess the damage caused to each surface finish. The results indicate that all the surface finishes were vulnerable to the decay caused by acidic atmospheres, although the saw-cut finish was less affected, perhaps because it did not require additional industrial processing. The mineral composition and texture of the rocks were critical factors in terms of the amount and type of decay they suffered, and the travertine and sandstone were more resistant to deterioration than the calcarenites. Similarly, the pore system of each rock was decisive in the penetration of the consolidant. Application of the consolidant improved the behavior of the treated samples by making them more resistant to acid attack without significantly altering the water vapor permeability, the color or the roughness of the surface., Junta de Andalucia RNM179, MAT2016-75889-R

Research Project MAT2016-75889-R Junta de Andalucía Research Group RNM179 Departamento de Mineralogía y Petrología (Universidad de Granada) Departamento de Didáctica de las Ciencias Experimentales (Universidad de Granada) Instituto Andaluz de Ciencias de la Tierra (CSIC-UGR) Grupo de Investigación HUM613 (Didáctica de las Ciencias Experimentales y de la Sostenibilidad), We thank Cerámica Castillo Siles for providing the raw material used to prepare and fire the bricks and Cervezas Alhambra S.L. (Granada) for providing the calcined diatomite sludge with yeast. We are grateful to Nigel Walkington for his assistance in translating the original text., Mineralogical and textural changes experienced by solid bricks made without additives and others made with added halite or with added calcined diatomite sludge, and fired in an electric oven at 800, 950 and 1100°C have been studied. Different analytical techniques (x-ray fluorescence, thermogravimetric analysis, x-ray diffraction, polarized optical microscopy and scanning electron microscopy) were used to reconstruct the changes that took place inside the bricks from a mineralogical and textural point of view. These changes are similar to those that take place in nature during pyrometamorphism. Carbonates decompose and react with silicates to form gehlenite, diopside and wollastonite. Plagioclase enriches in calcium and quartz concentration diminishes. Clay minerals favour the melting of matrix and the appearance of mullite. K-Feldspar changes from microcline to sanidine. The extent of vitrification increases in line with the increase in the firing temperature. When halite is added, new silicates appear earlier at lower firing temperatures and molysite is formed. Calcined diatomite sludge contains cristobalite, which becomes part of the mineralogy of the bricks. The newly-formed phases contain certain chemical elements that are not normally found in their standard chemical composition., This study was funded by Junta de Andalucía Research Group RNM179 and by the Research Project MAT2016-75889-R.

Fired-clay bricks are frequently object of conservative actions aimed at the preservation of cultural heritage. Information on firing conditions is relevant for the production of custom made replacement bricks, since, as a widely accepted principle, they should be close match to the pre-existing ones. In this work, the mineralogical and microstructural evolution of fired-clay bodies is described using a combination of analytical techniques, and an approach for the assessment of firing temperature using calibration curves built from the results of X-ray powder diffraction quantitative phase analysis with the Rietveld method, is presented. The weight fractions of hematite, mullite and the amorphous fraction, from two raw clays fired in the laboratory at different temperatures, have been used to assess the firing temperature of two industrially produced bricks. The values derived applying these three methods were in good agreement with the nominal temperatures of the industrial cycles. This approach might be of interest for the assessment of the firing conditions of a broader range of historical/archaeological fired-clay materials.

We investigated the viability of a fluid catalytic cracking catalyst residue (FC3R) as an alternative sustainable pozzolanic additive in aerial lime mortars. The pozzolanic activity of FC3R was compared to that of metakaolin (MK) by chemical-mineralogical, petrographic and physical investigations. The FC3R showed lower pozzolanic activity than MK when added to aerial lime mortars, owed to the size of FC3R particles that generate less hydrated phases and give place to lower mechanical resistances in mortars. We also demonstrated that FC3R is not a compatible material for use in repair mortars, due to the formation of the harmful soluble salt ettringite.

The architectural remains at Pasargadae were built of three different stones classified according to their colors (beige, dark-gray, and green-gray). The stones show different macroscopic features,...

Mineralogical, chemical and physical characterization of archaeological lime mortars from different structures at Amaiur Castle (Navarre, Spain) was accomplished in order to comprehend their durability. Mortars from the south-west of the 16th century filling and bastion, and the south-east mortars of the17th century bastion are the most susceptible to deterioration due to their textural features. The high porosity and water absorption capacity, the poor interconnection of pores and slow drying are the main factors contributing to deterioration of mortar at Amaiur Castle. The mineralogical study enabled an approach to the technological knowledge used in the lime mortar manufacturing process at Amaiur Castle. Hydrotalcite and hydromagnesite identified in the mortar binder support the use of the traditional hot-mixing method during mortar manufacturing. This work provides valuable references for the formulation of compatible repair mortars to ensure suitable conservation of the castle as well as of other ancient structures built with similar materials.

Glazed ceramics -both original and replacement- from Chamberí Metro Station (built in 1919) in Madrid (Spain) were studied using a multidisciplinary approach aimed at finding out more about the materials and technologies used to make them. The original white tiles, which help illuminate these underground spaces, were manufactured in Onda, Castellón (Spain) with very calcareous clays fired at ≈950 °C and coated with lead alkali-glazes. The original decorative pieces, with a metallic sheen, were made in Triana, Seville (Spain) with calcareous and illite clays fired at temperatures of between 850 and 950 °C and treated with transparent lead glazes. The replacement pieces had the same appearance as the originals but were more resistant. The white tiles were made out of quartz-rich, illite-kaolinite and calcareous clays fired at temperatures of >950 °C with an alkali-glaze that was very rich in zircon and aluminium. The decorative pieces were made from illite-kaolinite clays very rich in aluminium and fired at, This work was supported by the Madrid Region Geomaterials Programme 2 [S2013/MIT_2914], the UCM research group in Petrology Applied to Heritage Conservation [921349] and by Project [MAT2016-75889-R] of the Spanish Ministry of the Economy and Competitiveness.

Archaeological lime mortars from the Tower Keep andWest perimeter wall of Irulegi Castle (Navarre, Spain) were analysed to determine susceptibility to deterioration. Chemical, mineralogical, textural and physical characterisation was performed by different tests and multianalysis techniques in order to determine the intrinsic features of the original historical mortars at the castle. Samples from the Tower Keep are more prone to deteriorate compared with theWest perimeter wall due to high water absorption capacity and high porosity. A high degree of pore interconnection, high desorption index and the presence of high pore volume in the 0.01 to 1 um size range affect the mortar durability since pores retain water longer inside the mortar. Local environment conditions with persistent annual rainfall, high humidity and temperature variations contribute to the decay process of the original mortar. Characterisation of historical mortars not only allows better understanding of susceptibility to deterioration but also helps the design of compatible and durable repair mortar for future interventions on historical heritage. Compatibility of new materials with the historical mortar will be ensured by studying mortar characteristics and properties., This study was possible thanks to the financial support of Junta de Andalucía Research Group RNM179 and Research Project MAT2016-75889-R.

Solid bricks manufactured out of clayey earth from a quarry near the city of Granada (Spain) were studied and compared with others to which two additives were added during the kneading of the raw material: Calcined diatomite sludge and sodium chloride. Samples with and without additives were fired at 800 &deg, C, 950 &deg, C, and 1100 &deg, C. New mineral phases were formed in the bricks after firing. These included gehlenite, diopside, and plagioclase, which is gradually enriched in calcium, and microcline, which is transformed into sanidine. Mullite and molysite also appeared in the bricks made with added salt. Porosity increased substantially in the bricks that contained diatomite sludge, while the addition of sodium chloride accelerated the mineralogical transformations and caused sintering at relatively low temperatures of 800 &deg, C. The bricks became more compact and less anisotropic as the firing temperature increased. This behaviour was less evident in the bricks with added diatomite sludge, which alters the orientation of the phyllosilicates. The bricks fired at 1100 &deg, C had the best physical parameters. However, the bricks with added sodium chloride fired at 800 &deg, C reached hygric and compactness values that were at least similar to bricks from the other groups fired at 950 &deg, C.

Most brick companies nowadays focus their research on the recycling of waste, in order to be able to market new types of bricks. In this work, we explored the possibility of using ceramic sludge in brick production, aiming to find an alternative eco-friendly additive to produce “eco-bricks” characterised by suitable mechanical and aesthetic properties and durability. For this purpose, two types of bricks produced by an Italian factory (SanMarco-Terreal) were compared with a newly designed brick obtained from the same starting clay, with the addition of ceramic sludge in place of the traditionally used siliceous sand. Bricks and raw materials were investigated with a multivariate approach, consisting in the mineralogical and chemical analysis, and the final products microstructurally investigated and their physical-mechanical properties determined. Results show that bricks produced with added ceramic sludge can substitute traditional bricks well, fulfilling aesthetic requirements and maintaining sufficient mechanical properties. However, one drawback was that these new materials did not respond to freeze-thaw cycles, highlighting their potential vulnerability in cold climates.

This paper studies the influence of sawdust on the petrophysical properties of solid bricks. Brick samples without additives were handmade using a clayey earth that is rich in quartz and phyllosilicates and has some carbonate content. Similar bricks were made with added sawdust at 2.5%, 5% and 10% weight. The bricks were fired in an electric kiln at 800 °C, 950 °C and 1100 °C. The addition of sawdust did not change the mineralogy of the fired bricks. As the firing temperature increased, the quartz content fell and carbonates and phyllosilicates disappeared causing new silicates (gehlenite, wollastonite, anorthite and diopside) to develop. There was an increase in the vitrification of bricks, which also became more compact. At high firing temperature, the bricks had a higher water absorption capacity and worse interconnection between the pores. The high level of vitrification reached at 1100 °C enabled greater transmission of heat inside the bricks. The most refractory bricks were those fired at 800 °C with a 10% sawdust content. When subjected to the salt crystallization test, the most resistant bricks were those with the lowest sawdust content and the highest firing temperature.

Archaeological excavations performed in a funerary complex in Cuma (Campania region, Italy) unearthed excellently preserved common wares dated to the third century A.D. Archaeometric analyses were focused on Campanian pitchers, Aegean like cooking pots, and pyriform pitchers, the latter recorded for the first time in an Italian context. The local pitchers were manufactured with a high‐CaO clay (CaO = ca. 12 wt.%) and local volcanic temper, fired at ca. 800–850°C, as suggested by the presence of calcite. The Aegean‐like pots and the pyriform pitchers were made with low‐CaO clay (CaO ≤ 4.0 wt.%) mixed with a calcite‐bearing temper, along with volcanic and siliciclastic grains, and fired at 800–950°C. The comparison with raw materials inferred that local vessels were made with low‐CaO basinal clays which outcrop in the northern Campania region, and sands from the shoreline north of Cuma where carbonate, siliciclastic and volcanic phases mix together. Our results suggest that the Phlegraean Late Roman workshops produced their traditional vases along with imitations of Aegean‐like pottery. Thus, microregional production responded to a market demand requiring shapes and styles similar to imports from the eastern Mediterranean, with which commercial trade was still quite active.

We performed a comparative study of the effectiveness of ethyl silicate (TEOS) and dibasic ammonium phosphate (DAP) on two varieties of natural stone used in the architectural heritage of Andalusia (Spain): Arenisca Ronda (calcarenite) and Molinaza Roja (arkose). The consolidants were applied on healthy samples with a paintbrush, a method frequently used in real building works, and the study was divided into three phases: (a) petrophysical analysis and analysis of the porous system prior to application of the consolidants; (b) evaluation of the changes that have taken place after each application; (c) evaluation of the durability of the two varieties of treated rock when subjected to the salt crystallization ageing test. The results obtained show that there is a compositional affinity between the consolidant and the rock and that this affinity has an influence on the efficacy of the product. This explains why DAP performed better in Arenisca Ronda, which is rich in carbonates, while TEOS was more effective for Molinaza Roja, which is rich in silicates. The change in the porous system was not important, although it showed positive aspects such as an improvement in the drainage of the water during the drying process. We also measured the level of penetration of both products, which reached a depth of 3–5 mm depending on the product applied. We also noticed a negative result, namely the change in the colour of both rocks after treatment with the consolidants, especially in the case of DAP. Finally, the stones were subjected to a salt crystallization test, the results of which show that the consolidants increased the durability of the materials.

This paper reports the results of an archaeometric characterisation carried out on nineteen samples of Late Roman table and cooking ware by means of the combined use of spectroscopic techniques (colorimetry, FT-IR and μ-Raman). The study attempts at defining the technology adopted in the manufacturing of these ceramics, unearthed during archaeological surveys carried out within the “Ancient Appia Landscapes” project. Successful results were achieved and the reconstruction of the productive process was carried out. Second derivative profiles of IR spectra and μ-Raman analyses allowed defining the mineralogy of ceramic pastes, inferring the local provenance of raw materials and the low attention paid in their manufacturing. If good technological standards were achieved in the production of tableware, cooking ware shows colorimetric and mineralogical evidences of uncontrolled firing conditions, testifying a not-well standardized technological process.

This work examined the possibility of recycling trachyte waste as temper for preparing new types of bricks, thus reducing disposal costs and requirements for increasingly vulnerable raw materials, ultimately reducing production costs. The influence of the waste addition was studied by determining the petrographic and physical characteristics of fired bricks, in order to assess their aesthetic and mechanical features. Alkali feldspars in trachyte turned out act as fluxing agents, favoring partial melting of the matrix. Textural and mineralogical analyses revealed a considerable increase in the number of connections among minerals, extensive re-crystallization of the matrix, and an overall increase in compactness, not only with increasing firing temperatures but also increasing trachyte contents. The physical and mechanical properties of all samples were comparable with those of traditional bricks, showing that the addition of trachyte confers sufficient technical features already at 900 °C, allowing further reduction of production costs by lowering firing temperatures.

Natural stone has been a popular and reliable building material throughout history appearing in many historic monuments and in more recent buildings. Research into the intrinsic properties of specific stones is important because it gives us a greater understanding of the factors that limit and act on them. This can help prevent serious problems from occurring in our buildings bringing both esthetic benefits and financial savings. To this end, the main objective of this research has been to study the influence of the fabric and the mineral composition of two types of sandstone on their durability. The first is a red continental sandstone from the Buntsandstein Age called “Molinaza Roja”, which is quarried in Montoro (Cordoba). The second is quarried in Ronda (Malaga) and is sold under the trade name of “Arenisca Ronda”. It is a light pink-whitish calcarenite deposited during the Late Tortonian to Late Messinian. We characterized their petrological and petrophysical properties by studying their rock fabrics, porous systems and mechanical properties. In order to obtain a complete vision of the behavior of their rock fabrics, we also carried out two decay tests, the salt crystallization and the freeze–thaw tests. We then measured the effects on the textures of the altered samples during and after the decay tests and we evaluated the changes in the porous system. By comparing the results between intact and altered samples, we found that Arenisca Ronda is less durable because it has a high quantity of expandable clays (smectites) and a high percentage of pores in the 0.1–1 μm range, in which the pressure produced by salt crystallization is strongest. In Molinaza Roja the decay agents caused significant sanding due to loss of cohesion between the clasts, especially during the salt crystallization test. In both stones, the anisotropies (oriented textures) have an important role in their hydric and dynamic behavior and also affect their mechanical properties (especially in the compression resistance). No changes in color were detected. This study was financially supported by Research Group RNM179 of the Junta de Andalucía and by Research Project MAT2012-34473.

This paper analyses the efficacy of dispersions of nanoparticles of calcium hydroxide for consolidating lime mortars, according to three variables: the type of dispersion (three consolidating compounds—CaLoSil ® , Nanorestore ® and Merck ® —with different-sized calcium hydroxide particles); the concentration of the dispersion (5 and 25 g/L of Ca(OH) 2 in isopropyl alcohol); and the state of the sample (comparison of saturated and non-saturated samples). The outcome of the consolidation process was studied in terms of improved carbonation of the mortar, mineralogy (by means of X-ray diffraction and thermogravimetric analyses), texture (study of the porosity by mercury intrusion porosimetry) and compactness (measurement of ultrasonic velocity propagation through samples). To ensure that the treatment had no negative effects on the physical characteristics of the mortars, we performed microstructural (phase morphology studied by means of scanning electron microscopy) and aesthetic (colour and lightness measured by spectrophotometry) analyses. Of the different dispersions, CaLoSil ® at 5 g/L produced the most significant improvement in the degree of carbonation and in the compactness of the mortar, thanks to the precipitation of small crystals of calcite and aragonite in the pores located between the matrix and the aggregate grains. This product also caused the least significant chromatic changes (slight decrease in lightness and yellowing) and the greatest increase in ultrasonic propagation velocity through the mortar samples. This research has specific application in restoration work that involves consolidation of lime mortars, especially in tropical climates or in confined environments with high humidity levels (such as deep hypogea).

The excavations at Mount San Paolillo (Catania, Italy) led to the discovery of a Prehistoric site that still represents the most important evidence of Middle and Late Bronze Age settlement in this area. During the excavations, archeologists located a hut, a store for ceramic storage vessels, and a pottery workshop, all of which provided a large quantity of heterogeneous ceramics with apparent typological parallels in other areas of Sicily, such as Syracuse, Augusta, and Messina. A large number of specimens were selected in order to cover all the macroscopic types and the main classes. The results identified four petrographic fabrics. Most of the ceramics are characterized by abundant tempers consisting of volcanic rock fragments and occasionally of grog. Only a few samples contained common fine-grained quartz. The groundmass ranges from non-micaceous to very micaceous. In some cases, there is evidence of mixed clays. Analysis of the chemical composition of the ceramics revealed the existence of two groups with low and high CaO contents. The high Fe2O3 content (more than 8.7 wt%) is probably due to the use of temper from altered pyroclastic rocks which are of local provenance as SEM-EDX data suggest, even if petrographic and chemical results suggest that different raw materials may have been used. The data provided by these archeometric analyses have made a significant contribution to the study of Middle and Late Bronze Age pottery from the Catania area, by offering insights into the methods, production processes, and high technical level of the prehistoric craftsmen.

This study gives an example of the steps that a repair work must include to be successful. It deals with a specific building, repair material (lime mortar) and application (render), but also with the study of the repair mortar in the laboratory and on site. Firstly, the original materials of the wall were characterized to ensure compatibility with the new repair mortars. Secondly, the suitability of different mortar mixes, made with lime and calcareous aggregate, was assessed by characterizing their properties after 15 months. At the same time, the repair mortars were applied in testing panels, and their behaviour under environmental conditions was studied and compared with that of the laboratory mortars. Mortar properties (shrinkage, adhesion, mineralogy, microstructure and texture) developed differently according to the curing conditions. The carbonation degree was higher in mortars cured on site (especially those with higher aggregate content), although in both cases it depended on mortar porosity. Testing the type of application on site was helpful to define the best performance of the designed mixes and to choose the most suitable one among them, which was found to be the 1:6 binder-to-sand ratio mortar applied in both layers of the render.

Mixing hemp with aerial or natural hydraulic lime gives rise to mortars with improved flexibility and insulation but with peculiar microstructure compared to lime-aggregate mortars. The chemical–mineralogical and morphological investigation carried out here shows that hemp absorbs most of the water present in the matrix, causing superficial deposition and scarce adhesion of the lime to the hemp. This also delays the hardening process, as demonstrated by the high content of portlandite, vaterite and calcium silicates found after three months of curing. Some modifications to the production and curing procedures are suggested to improve the microstructure and final performance of hemp-lime mortars.

Different techniques (X-ray diffraction, field emission scanning electron microscope, colorimetry, visible-near infrared reflectance spectroscopy) were carried out to investigate the cause of colour changes of traditional ceramic materials. Two clayey materials of different composition, collected in the Bay of Naples, were fired in oxidising atmosphere at different temperatures resulting in different shades of red colour. Hematite is responsible of the reddish hue of ceramics and its nucleation is strictly related to firing temperature and chemical composition of the raw materials. A low CaO concentration allowed hematite to form in higher amounts providing a more intense reddish hue at high firing temperatures (over 950 °C). At the highest temperature (1100 °C) all samples showed darker colour due to increased size of iron oxide particles. Black core developed in Ca-rich ceramics fired at low temperatures as the short time of firing is insufficient to complete iron oxidation within the matrix, except in those containing high temper amounts. Indeed, microstructural modification occurs due to the presence of discontinuities among temper grains and matrix, which improves the circulation of oxygen in the core of ceramics.