Search

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

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

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 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.

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.

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 high levels of atmospheric pollution in cities today are causing the decay of natural building stone, especially due to the formation of gypsum crusts on carbonate stones. For this reason we have assessed the efficacy of using the gypsum crust as an alternative source of calcium in the consolidation of building stone via the formation of calcium phosphates. Samples of Arenisca Ronda (southern Spain) were altered to develop a gypsum crust on the surface for subsequent application of a cellulose poultice with a solution of dibasic ammonium phosphate 3 M (DAP) at different application times. The best results were obtained by the samples treated for 60 min and they have indicated that the application time and the water saturation degree of the poultice affect the amount of gypsum removed and the quantity of fissures on the consolidant film. On the other hand, the DAP concentration of the solution and the pH controlled the calcium phosphate precipitation phases. The habit of the calcium phosphate crystals evolve over the time tending to a homogenization of the consolidant film. This procedure offers an important alternative for the treatment of altered carbonate stones, in which the stone can be cleaned and consolidated in a single application. This study was financially supported by Research Group RNM179 of the Junta de Andalucía and by Research Project MAT2012-34473. E. Ruiz-Agudo acknowledges funding from the Spanish Government (Grant MAT2012-37584) and the Junta de Andalucía (project P11-RNM-7550-ERDF funds), as well as the receipt of a Ramón y Cajal Grant from the Spanish Government (Ministerio de Economía y Competitividad). A. Burgos-Cara acknowledges funding from the Junta de Andalucía (project P11-RNM-7550-ERDF funds).

Thirty-two ceramic fragments dating from the Early Iberian Age were collected in Canto Tortoso, an archaeological site located about 100 km from the city of Granada (Spain). The site is on a hill bordered by two rivers, the Fardes and the Guadiana Menor. The ceramics are divided equally into amphorae and vessels and half of them have black cores. The samples are rich in SiO2 and Al2O3, with varying amounts of CaO, Fe2O3, MgO and K2O. The most common mineral is quartz and almost all the samples have muscovite-type phyllosilicates. Calcite appears as small grains dispersed in the matrix and sometimes also of secondary origin covering the surface of samples or filling the pores. One ceramic was richer in calcite grains than quartz. An incipient decomposition of this carbonate is detected even at low firing temperatures. Samples fired at high temperatures are characterised by the presence of mullite or gehlenite and/or diopside phases. These silicates are also accompanied by a vitreous phase that increases the interlocking between the particles and changes the morphology of the pores from angular to round. The precipitation of phases of secondary origin on the surface of the ceramics may have minimised the chromatic differences between Ca-rich and Ca-poor samples. The combined use of chemical, petrographic and physical techniques allowed us to estimate the firing temperature of the ceramic samples (most samples were well-fired) and to discover the provenance of the raw material (a clayey material found near a kiln located just 3 km away from the settlement has a mineralogical composition compatible with that of the ceramics).

Resumo Com o intuito de ampliar conhecimentos sobre a deterioracao de materiais construtivos, este trabalho aborda dados e discussoes apresentados em monografia (Master na Universidade de Granada), cuja pesquisa avalia a durabilidade e o grau de deterioracao de tijolos em clima costeiro ou zonas sob a influencia de aerossois marinhos. Foi realizado um ensaio de envelhecimento acelerado com uma câmara de spray salino (pulverizacao de agua do mar). A pesquisa foi executada em tres etapas: 1a) os tijolos saos foram caracterizados atraves de microscopia otica (luz polarizada) e difracao de raios-X (DRX), ensaios fisicos (colorimetricos e ultra-som) e ensaios hidricos (absorcao e dissorcao), porosimetria por injecao de mercurio (PIM) para analisar o sistema poroso e a distribuicao dos poros; 2a) o ensaio de envelhecimento acelerado dos tijolos em câmara de spray salino, onde se aplicou uma variacao da norma ASTM–B–117–73; e, 3a) O grau de deterioracao dos tijolos foi avaliado com algumas tecnicas analiticas utilizadas na primeira etapa, alem da microscopia eletronica de varredura ambiental (ESEM) e a microscopia eletronica de varredura com pressao variavel (VPSEM) para identificar a cristalizacao de sais. Foram identificados cristais de halita nos planos de exfoliacao dos filossilicatos e na superficie dos tijolos, predominando um ataque fisico e nao quimico. Os cristais de halita apresentam habitos cubicos e aciculares, resultantes de diferente umidade do substrato, da concentracao da solucao salina (agua do mar) e da variacao da umidade relativa. A presenca de sais na estrutura dos tijolos contribui para a diminuicao da porosidade (preenchimento de determinados poros), assim como para o aumento nos poros de tamanhos 0,1 a 0,01μm. Com base nos resultados obtidos e aqueles ja discutidos na literatura, conclui-se que: 1) os ensaios de alteracao sob condicoes ambientais controladas sao tecnicas de estudo adequadas para analise dos mecanismos de deterioracao de tijolos, assim como para os materiais petreos; 2) a deterioracao dos tijolos pode depender da disposicao das argilas, da superficie de exposicao do mesmo e do arranjo, vertical ou horizontal, destes, na construcao; e 3) neste caso especifico, os tijolos apresentam boa durabilidade mesmo quando submetidos as intemperies de um clima costeiro. Palavras Chave: tijolos, aerossois marinhos, deterioracao Abstract EVALUATION OF TILES DETERIORATION BY MARINE AEROSOLS. With aim of obtaining deeper knowledge about building materials decay, the present work contains data and discussion presented in a monography (Master Course). The objective of this work is evaluate the durability and damage of bricks in a coastal environment, on areas that can receive the influence of marine spray. The study was realized by using polarized optical microscopy, x-ray diffraction (XRD), colorimetry, ultrasounds, hydric tests, mercury injection porosimetry (MIP), environmental scanning electron microscopy (ESEM) and variable pression scanning electron microscopy (VPSEM), and the salt-spray (sea water) aging test with some variation of the ASTM–B–117–73. Crystals of halite were identified as well in exfoliation planes of the phylosilicates as superficially (physic process preveals the chemical one). The results obtained in this study allow conclude: 1) the aging tests under controlled environmental conditions are suitable techniques for the research of mechanism decay in bricks as well as to stone materials (granites, calcareous rocks); 2) the bricks decay can depend on the clay arrangement, itself superficial exposure and their package (vertical or horizontal) in the building; 3) in this case bricks present a good durability even though when they are in a coastal environmental undergone. Keywords: bricks, marine spray, materials decay

The significance of rip-up clasts as sandstone framework grains is frequently neglected in the literature being considered as accessory components in bulk sandstone composition. However, this study highlights the great value of muddy and dolomitic rip-up clast occurrence as: (a) information source about low preservation potential from floodplain deposits and (b) key element controlling host sandstone diagenetic evolution and thus ultimate reservoir quality. High-resolution petrographic analysis on Triassic fluvial sandstones from Argana Basin (T6 and T7/T8 units) highlights the significance of different types of rip-up clasts as intrabasinal framework components of continental sediments from arid climates. On the basis of their composition and ductility, three main types are distinguished: (a) muddy rip-up clasts, (b) dolomitic muddy rip-up clasts and (c) dolomite crystalline rip-up clasts. Spatial distribution of different types is strongly facies-related according to grain size. Origin of rip-up clasts is related to erosion of coeval phreatic dolocretes, in different development stages, and associated muddy floodplain sediments. Cloudy cores with abundant inclusions and clear outer rims of dolomite crystals suggest a first replacive and a subsequent displacive growth, respectively. Dolomite crystals are almost stoichiometric. This composition is very similar to that of early sandstone dolomite cement, supporting phreatic dolocretes as dolomite origin in both situations. Sandstone diagenesis is dominated by mechanical compaction and dolomite cementation. A direct correlation exists between: (1) muddy rip-up clast abundance and early reduction of primary porosity by compaction with irreversible loss of intergranular volume (IGV); and (2) occurrence of dolomitic rip-up clasts and dolomite cement nucleation in host sandstone, occluding adjacent pores but preserving IGV. Both processes affect reservoir quality by generation of vertical and 3D fluid flow baffles and barriers that compartmentalize the reservoir. These findings may provide quantitative useful data for the better understanding of reservoir quality in analogous hydrocarbon-bearing basins such as the Bay of Fundy, Nova Scotia (Canada)., Funding was provided by research projects CGL2013-43013-R (MINECO-FEDER), CGL2011-22709, CGL2014-52670-P and MAT02012-34473, as well as by the research group RNM369 and RNM179 (JA).

Hemp-based composites are eco-friendly building materials as they improve energy efficiency in buildings and entail low waste production and pollutant emissions during their manufacturing process. Nevertheless, the organic nature of hemp enhances the bio-receptivity of the material, with likely negative consequences for its long-term performance in the building. The main purpose of this study was to study the response at macro- and micro-scale of hemp–lime renders subjected to weathering simulations in an environmental cabinet (one year was condensed in twelve days), so as to predict their long-term durability in coastal and inland areas with Mediterranean, Tropical and Semi-arid climates, also in relation with the lime type used. The simulated climatic conditions caused almost unnoticeable mass, volume and colour changes in hemp–lime renders. No efflorescence or physical breakdown was detected in samples subjected to NaCl, because the salt mainly precipitates on the surface of samples and is washed away by the rain. Although there was no visible microbial colonisation, alkaliphilic fungi (mainly Penicillium and Aspergillus) and bacteria (mainly Bacillus and Micrococcus) were isolated in all samples. Microbial growth and diversification were higher under Tropical climate, due to heavier rainfall. The influence of the bacterial activity on the hardening of samples has also been discussed here and related with the formation and stabilisation of vaterite in hemp–lime mixes. This study has demonstrated that hemp–lime renders show good durability towards a wide range of environmental conditions and factors. However, it might be useful to take some specific preventive and maintenance measures to reduce the bio-receptivity of this material, thus ensuring a longer durability on site.

Marble has historically been used as an ornamental stone because of its aesthetic appeal, ease of polishing and ex;cellent physical properties. One of the main factors affecting the durability of marbles is their thermal behaviour. Although marble is used extensively in Spain as a building and decorative material, little research has been done into its thermal behaviour. In this work, the textural and microstructural properties of seven calcitic and dolomitic marbles from Andalusia (southern Spain) were characterized to assess how these properties affect their thermal response. Rock fabric properties (grain morphology, boundaries and micro-crack populations) were studied by polarized microscopy and lattice preferred orientation using X-ray texture goniometry. Elastic properties were measured by ultrasound, thermal properties were determined by a six-rod dilatometer (thermal expansion) and the opening of micro-cracks was observed using environmental scanning electron microscopy. For each marble, thermal coefficients of calcite and dolomite crystals were calculated using thermo-X-ray diffraction, a novel application to characterize historic marbles. The results show that marble thermal expansion coefficients are related to preferred crystallographic orientation, which can help to identify the directions along which decay occurs. The results also show for the first time that the thermal expansion coefficient of the main components of marble,i.e.calcite and dolomite, is specific to each marble, and plays a key role in their different thermal behaviours. Thermal properties also depend on mineral composition, the existence of micro-cracks and hydric properties.

The study of the rheological properties of lime suspensions is a useful means to evaluate the workability of lime mortars. In this work, we studied the flow behaviour of two industrial hydrated limes, one of calcitic and the other of dolomitic composition, by means of two types of rheometer with different geometry and setup mode. The obtained results were interpreted taking into account the differences in microstructure and surface properties of the suspended particles. Calcitic lime dry particles are formed by angular and polydisperse clusters and, once dispersed in water, they behave like thixotropic materials. On the other hand, the dolomitic lime is formed by nanoparticles and small round cluster and it shows a pronounced plastic behaviour in suspension. This fundamental difference between the two materials explains the traditional preference for dolomitic lime mortars for plastering and rendering applications.

We studied the pore system of six different types of sedimentary stone (two limestones, two sandstones, one dolostone and one travertine). Techniques based on the direct observation of the pore system (optical and scanning electron microscopes, digital image analysis) were combined with others used for indirect characterization (mercury intrusion porosimetry, N2 adsorption, hydric tests, and vapour permeability). In addition, we performed accelerated decay tests to determine the durability of the stones and to check the consistency of the results obtained in the pore system study. Digital image analysis allowed us to calculate the pore size distribution and the total porosity. Digital image analysis always gave higher values for total porosity than those determined by porosimetry and hydric tests, which only measure open porosity. The density values were congruent with the mineralogy of the stones. The stone that obtained the best results in the various tests in terms of its petrophysical parameters was dolostone, while the worst performance was by one of the two limestones. These results were confirmed by the decay tests. The combined use of these different techniques gave us an accurate interpretation of the pore systems of the six different stones, and also enabled us to correct misleading interpretations caused by the limitations of using one single technique. Our findings also provide useful information to help prevent the decay of these stones.

We performed an archaeometric study of the ceramic materials from the façade of the church of Santa Maria del Carmine in Pavia (Italy). We obtained useful information about the firing temperatures, the provenance of raw materials and the type of oven used. The ceramics used in the façade are mineralogically rich in quartz, feldspar and phyllosilicates, and newly formed calcium silicate phases were detected in some samples. Microtextural observations revealed the presence of incipient reaction rims, phyllosilicate sintering and partial vitrification of the matrix. Ceramics show high porosity (32 to 45%) and pore sizes of between 0.4 and 1.3 µm. Our study of the different types of decay collected on the façade of the church (green and black patinas and efflorescences) revealed the presence of gypsum, whewellite, thenardite and moolooite.Se ha llevado a cabo un estudio arqueométrico de los materiales cerámicos de la fachada de la iglesia de Santa Maria del Carmine en Pavía (Italia). Se han obtenido valiosas informaciones sobre las temperaturas de cocción, la procedencia de las materias primas arcillosas y el tipo de hornos utilizados. Mineralógicamente, las cerámicas utilizadas en la iglesia son ricas en cuarzo, feldespato y filosilicatos y en algunas muestras se han detectado silicatos de calcio de neoformación. Las observaciones microtexturales han revelado la presencia de incipientes bordes de reacción, la sinterización de los filosilicatos y la parcial vitrificación de la matriz. Las cerámicas poseen una porosidad elevada (del 32 al 45%) y radio de poros comprendido entre 0,4 y 1,3 μm. El estudio de los diferentes tipos de deterioro muestreados en la fachada de la iglesia (pátinas verdes y negras y eflorescencias) ha revelado la presencia de yeso, whewellita, thenardita e moolooita.

One of the properties that makes marble such an excellent construction and ornamental material is its low porosity. It is very difficult for water or decay agents to penetrate the internal structure of materials with no or few pores, so enhancing the durability of these materials. However, environmental temperature fluctuations bring about significant physical changes in marbles that result in an increase in porosity, due to the appearance of new microcracks and the expansion of existing ones. These cracks offer new paths into the marble which make it easier for solutions containing pollutants to penetrate the material. Thermal expansion tests were performed on three different types of marble known as White, Tranco, and Yellow Macael (Almeria, Spain), after which an increase in porosity (from 17 to 73% depending on marble type) was observed, mainly due to crack formation. The structural changes occurring during thermal expansion tests were more significant in the case of White Macael samples, a fact that is not only related to its mineralogical composition but also to the morphology of the grains, grain boundaries and crystal size. Our research suggests that thermally weathered White Macael marble could be more susceptible to decay by other contaminant agents than Tranco or Yellow Macael. The use of hot-stage environmental scanning electron microscopy is proposed as a valid tool for observing, both in situ and at high magnification, changes in the fracture system of building stones induced by thermal stress. peerReviewed

Hyblean limestone of Oligo-Miocene age was widely used as a construction material in the architectural heritage of Eastern Sicily (Italy). Among them, the so-called Pietra Bianca di Melilli (Melilli limestone) and Calcare di Siracusa (Syracuse limestone) were prized for their attractive appearance, ease of quarrying, and workability. Syracuse limestone shows general weathering, whereas Melilli limestone is better preserved, and only differential erosion or superficial exfoliation can be detected in monuments. The cause of the different behavior of these two limestones was investigated from the petrographic and petrophysical points of view. The saturation coefficient is higher in Melilli limestone, and ultrasound measurements indicate that it is less compact than Syracuse limestone, so that Melilli limestone could deteriorate more easily than Syracuse limestone. However, pore interconnections and the size of very small pores play the main role in the durability of both materials. The “irregularity” of the Syracuse pore system and its greater number of micropores hinder water flow through the exterior, promote stress in pore structure, and favor the development of scaling, as confirmed by salt crystallization tests. In Melilli limestone, the low concentration of micropores and fast water evaporation allow solutions to reach the surface more easily, resulting in less damaging efflorescence.

The benefits of using sustainable building materials are linked not only to the adoption of manufacturing processes that entail reduced pollution, CO2 emissions and energy consumption, but also to the onset of improved performance in the building. In particular, hemp-lime composite shows low shrinkage and high thermal and acoustic insulating properties. However, this material also shows a great ability to absorb water, an aspect that can turn out to be negative for the long-term durability of the building. For this reason, the hygric properties of hemp-based composites need to be studied to ensure the correct use of this material in construction and repair works. The water absorption, drying and transpirability of hemp composites made with aerial (in the form of dry powder and putty) and hydraulic limes were investigated here and related to the microbial growth induced by the water movements within the material. Results show that hemp-natural hydraulic lime mixes exhibit the highest transpirability and drying rate, the lowest water absorption by immersion and capillary uptake and the least intense microbial attack and chromatic change. A microscopical study of the hemp shives also related their great ability to absorb water to the near-irreversible swelling of their structure under dry-wet conditions., The research leading to these results has received funding from the European Union's Seventh Framework Programme (FP7/2007-2013) under grant agreement n° 326983 (NaturALiMe), and the Spanish project MAT-2012-34473 of the Ministerio de Ciencia y Competitividad. Author MB, owner of the CANNABRIC company, had some role in the design and preparation of mortar samples and in the preparation of this manuscript, but did not have any additional role in data collection and analysis.

The fountain of Bibatauin, in Granada (Spain), is in a poor state of conservation, and biodeterioration is occurring. Colonization by microalgae and its effects on the fountain were investigated. The microorganisms from representative sampling areas were identified by optical microscopy, and the biogenic carbonate crusts they formed analysed by X-ray diffraction and field emission scanning electronic microscopy. The most representative genera found were Cosmarium, Phormidium and Symploca, and the main mineral was calcite.

We have studied the physical-mechanical behaviour of solid bricks treated with consolidants and/or water-repellents in accelerated aging tests to determine their durability. The bricks were manufactured with a quartz-rich clay lacking in carbonates to which was added small amounts of different additives (calcite, dolomite or sodium chloride). During the manufacturing process, we attempted to replicate solid bricks similar to those used in many Cultural Heritage buildings. We have concluded that silicon resin gives the best results, whatever the additive used, whereas acrylic resin gives the least satisfactory results.

Mineralogical, textural and chemical analyses of clay-rich materials following firing, evidence that initial mineralogical differences between two raw materials (one with carbonates and the other without) influence the tex- tural and mineralogical evolution of the ceramics as T increases from 700 to 1100° C. Mineralogical and textural changes are interpreted considering local marked disequilibria in a system that resembles a small-scale high- T meta- morphic process ( e.g., contact aureoles in pyrometamorphism). In such conditions, rapid heating induces significant overstepping in mineral reaction, preventing stable phase formation and favoring metastable ones. High- T transfor- mations in non-carbonate materials include microcline structure collapse and/or partial transformation into sanidine; and mullite plus sanidine formation at the expenses of muscovite and/or illite at T ‡ 800° C. Mullite forms by mus- covite-out topotactic replacement, following the orientation of mica crystals: i.e., former (001) muscovite are ^ to (001)mullite. This reaction is favored by minimization of free energy during phase transition. Partial melting followed by fingered structure development at the carbonate-silicate reaction interface enhanced high- T Ca (and Mg) silicates formation in carbonate-rich materials. Gehlenite, wollastonite, diopside, and anorthite form at carbonate-silicate interfaces by combined mass transport (viscous flow) and reaction-diffusion processes. These results may add to a better understanding of the complex high- T transformations of silicate phases in both natural ( e.g., pyrometamor- phism) and artificial ( e.g., ceramic processing) systems. This information is important to elucidate technological achievements and raw material sources of ancient civilizations and, it can also be used to select appropriate clay com- position and firing temperatures for new bricks used in cultural heritage conservation interventions.

Lime mortar has been used throughout history despite current substitution by hydraulic mortars (cements). The chemical composition of the lime used in its manufacture, however, is determined by local geology. In addition, the type of slaking, which depends on the amount of water used, gives rise to different types of lime. The result is that the behavior of lime mortar can vary depending on the composition and type of lime used. A three-way ANOVA analysis was carried out to determine the composition, type, and temporal evolution and the interactions of these three variables for evaluation of the characteristics of air lime mortars for their use in cultural heritage conservation projects.

It is a common practice to test building stones against an isolated decay factor when assessing the durability of building stones. Accordingly, the interpretation of results is often driven by the considerations of a limited number of properties thought as relevant to the action of that specific decay factor. In this way, the role of the synergies of decay processes and agents is often neglected. Contrarily, when different decay factors are included in the same experiment and the stone properties are examined conjunctly, the difficulties of isolating the effects of a specific decay factor or of isolating the contribution of “relevant” stone properties become apparent. The aim of this paper is to assess the combined contribution of mineralogical, hygric and thermal properties to the durability of different stones after exposure to laboratory-simulated cyclic decay combining wetness and temperature variations. For this purpose, 10 stone types were selected to emphasize the impact of the mineralogical heterogeneity on stone decay, in particular the coexistence of calcareous and siliceous grains and the occurrence of clays. The results emphasize the importance of considering the relations between decay factors and highlight how stone properties must be considered as a whole in order to assess and understand the durability of building stones. This study was funded by the Generalitat Valenciana (Spain) through the Research Project GV05/129.

La “Piedra de Sierra Elvira” constituye una de las piedras ornamentales más significativas del Patrimonio Arquitectónico de Andalucía Oriental. Es una roca caliza del Lias que aflora en el Subbético Medio del sector central de las Cordilleras Béticas. El litotipo más explotado es una caliza con crinoides, en bastante menor importancia se ha extraído también otra caliza micrítica de la misma edad. Los bancos son muy potentes, en algunos casos de más de 5 m, con un paralelismo constante y un buzamiento que favorece su explotación en los frentes de cantera. Sus características petrográficas y físico-mecánicas le confieren una calidad técnica y durabilidad muy notables para su utilización como material de construcción estructural y ornamental. Los principales parámetros que determinan estas cualidades son su mínima porosidad eficaz y asociado a ello sus excelentes propiedades hídricas, así como sus elevadas resistencias mecánicas y el bajo coeficiente de anisotropía textural, tanto elástico como mecánico. Este conjunto de características ha permitido su utilización en muy diversas funciones constructivas., “Sierra Elvira stone” is one of the ornamental building stones most widely used in the historical monuments of eastern Andalusia. A Liassic age limestone, it appears in the central section of the Baetic Mountains and more specifically in the Middle Subbaetic domain. While the most common variety is a crinoid limestone, a micritic limestone of the same age has also been quarried, albeit in much smaller quantities. These stones form very thick beds, up to nearly 5 m deep, that run in consistently parallel lines and have a dip angle that facilitates quarrying. With petrographic, physical and mechanical properties that ensure stone strength and durability, it is a high quality building material suitable for both structural and ornamental purposes. These properties can be attributed to the minimal open porosity and concomitant excellent water resistance that characterize the stone, as well as to its high mechanical strength and low textural anisotropy, both elastic and mechanical. With such attributes, the stone can be successfully used for any number of purposes, including decorative stonework (portals, fountains, plinths), structural members (column shafts and bases) or urban curbing and paving. Intervention on Sierra de Elvira limestone structures should be limited to cleaning or repair, for consolidating or protective materials are scantly effective., Los autores agradecen la financiación del Proyecto de investigación MEC MAT2004-6804 y el Grupo de Investigación RNM179 de la Junta de Andalucía.

La calcarenita de Santa Pudia es uno de los materiales rocosos de construcción más empleados en las edificaciones monumentales de la ciudad de Granada (España). Se ha evaluado la compatibilidad de diversos productos de tratamiento (de consolidación y/o hidrofugación) con esta calcarenita y como son capaces de mejorar su durabilidad. Para ello, se han realizado dos fases de envejecimiento acelerado: la primera tenía el objetivo de acercar el material de cantera sin alterar (“sano”) a las condiciones reales del material puesto en obra y actualmente deteriorado; la segunda, efectuada después de aplicar los tratamientos sobre la calcarenita deteriorada, con el fin de determinar su grado de eficacia. Se ha podido comprobar que aunque, en general, todos los productos de tratamiento seleccionados (Tegosivin HL100, Silo 111, Estel 1100 y Tegovakon V) mejoran las propiedades del material frente al deterioro y apenas modifican sus parámetros cromáticos, el más eficaz es el Tegovakon V ya que es el que proporciona mejores resultados frente a los ensayos hídricos en este litotipo calcáreo., Santa Pudia limestone, a biocalcarenite highly sensitive to decay, is one of the most commonly used building materials in historical monuments in the city of Granada, Spain. The compatibility between a variety of stone treatments (consolidants and/or water repellents) and this calcarenite was analyzed and the resulting improvement in durability assessed. To this end, a two-stage accelerated ageing process was implemented. In the first, freshly quarried, undamaged specimens were altered to resemble the weathered stone in buildings. The second was conducted after applying the various treatments to the artificially aged stone to test their effectiveness. While all the treatments studied (Tegosivin HL100, Silo 111, Estel 1100 and Tegovakon V) enhanced stone resistance to decay while barely affecting chromatic parameters, the most effective was Tegowakon V, as it provided the best results in the hydric tests on the limestone., Este trabajo ha sido financiado por el Grupo RNM179 de la Junta de Andalucía y del Proyecto de Investigación MEC MAT2004-6804.

This work focuses on the chemical-mineralogical, textural and physical-mechanical properties of hydraulic lime mortars made with siliceous and calcareous aggregate. Mortars were cured at 60% and 90% of relative humidity, so as to assess the variability of mortar petrophysical properties in the hardened state due to the moisture conditions. The final aim was to determine the most adequate moisture conditions to be maintained during application and hardening of hydraulic mortars intended for repair interventions. We found out that using a calcareous aggregate and curing mortar at 90% of relative humidity give place to better textural and mechanical properties. However, these characteristics mostly depend on the maximum size of the aggregate grains, which should be smaller than 6 mm, in order to avoid the occurrence of mechanical discontinuities in the mortar. En este trabajo se han estudiado las propiedades químico-mineralógicas, texturales y físico-mecánicas de morteros de cal hidráulica elaborados con áridos silíceo y calcítico. Estos morteros se han curado al 60% y 90% de humedad relativa, con el fin de evaluar las eventuales diferencias en las propiedades petrofísicas de los morteros una vez endurecidos y así establecer cuál de los dos ambientes es recomendable durante la aplicación y fraguado de morteros de cal hidráulica destinados a obras de restauración. Se ha encontrado que el uso de un árido de composición calcítica y el curado al 90% de humedad relativa dan lugar a morteros hidráulicos con mejores características texturales y propiedades mecánicas. De todas formas, estas características dependen principalmente del tamaño máximo del árido empleado, que debería ser inferior a 6 mm para evitar discontinuidades mecánicas en el mortero. This study was financially supported by the Spanish research group RNM179 of the Junta de Andalucía, by the research project MAT-2012-34473 and by the Institute of Conservation and Restoration of Cultural Heritage of the CICOP foundation (ICON-CICOP).

The durability of a rock when exposed to decay agents is an important criterion when assessing its quality as a building material. Our study focuses on six varieties of natural stone (two limestones, one dolostone, one travertine and two sandstones) that are widely used in both new and historical buildings. In order to assess their quality, we measured and characterized their dynamic elastic properties using ultrasounds, we measured their compressive strength using the uniaxial compression test and we evaluated their durability by means of accelerated aging tests (freeze-thaw and salt crystallization). In order to get a full picture of the decay suffered by the different stones, we determined the composition and amount of the clay fraction of the six stones. We also observed small fragments subjected to the salt crystallization test under an environmental scanning electron microscope to study any textural change and measured the changes of colour on the surface with a spectrophotometer. Finally, we analysed the pore system of the stones before and after their deterioration using mercury injection porosimetry. We then compared the results for the different stones and found that dolostone obtained the best results, while the two limestones proved to be the least durable and had the lowest compressive strength.

El artículo presenta un estudio en el que se ha medido mediante colorimetría la modificación de luminosidad y cromaticidad de ladrillos macizos cocidos a distintas temperaturas. Tierras arcillosas de diferente composición generan piezas de diferentes colores porque reflejan el desarrollo de distintas fases minerales. Se ha demostrado también la utilidad de la colorimetría en la elección de la cantidad más idónea de aditivo a añadir a la materia prima arcillosa sin que se verifiquen cambios sustanciales en el color de las piezas cerámicas.

Mullite (Mul) formation after high-T muscovite (Ms) breakdown has been studied in phyllosilicate-rich bricks. At T 900 °C Ms dehydroxylation is followed by partial melting that triggers the nucleation and growth of Mul acicular crystals. An analytical electron microscopy study reveals that the Mul is a 3:2-type with a [6](Al1.686Ti0.031Fe0.159Mg0.134)[4](Al2.360Si1.649)O9.82 formula and an O atom vacancy of x = 0.18. This is consistent with X-ray diffraction results [i.e., unit-cell parameters: a = 7.553(7), b = 7.694(7), and c = 2.881(1) Å, V = 167.45 Å3]. The initial stage of the process resulting in Mul growth followed the balanced reaction Ms 0.275Mul + 0.667Melt + 0.244K2O + 0.01Na2O + 0.125H2O, yielding an alkali-poor peraluminous melt. H2O with K (and Na), which are lost along the (001) planes of dehydroxylated Ms, play a significant role as melting agents. The c-axes of the Mul crystals are oriented parallel to [010]ms or to the symmetrically equivalent ms zone axis, while the (120)mul or (210)mul planes are subparallel to (001)ms (TEM results). These systematic orientations point to epitaxial Mul nucleation and growth on the remaining Ms substrate, which acts as a template for Mul heterogeneous nucleation. Randomly oriented Mul growth is also observed during the late stages of the process (i.e., melt cooling). The epitaxial nature of Mul growth after dehydroxylated Ms melting minimizes the energy requirement for nucleation. In addition, the water released after Ms breakdown and the multicomponent nature of the melt enable this high-T aluminum silicate to grow at T ~ 900 °C, almost 100 °C below the SiO2-Al2O3-K2O ternary system eutectic (after a melt with an end-member Ms composition).