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Details of stones before (fresh samples) and after the active sulphuric (SAI) and nitric (NAI) tests
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Atmospheric pollutants are changing due to policies aiming at attenuating climate change. Some of the results of these measures are the current inversion on the SO2/NOx proportion and the pH increase of acid rains to 5 in some areas. The aim of this study was to have a better understanding of the relation between the microstructural and chemical ch...
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... During the collection of typical deterioration phenomena, it is found that exfoliation evolves into fine linear grooves near the bedding plane with the development of deterioration. Moreover, the dissolution and loss of calcareous cement in the rock mass are produced by acid rain, which is a consequence of environmental pollution [43,44]. Surface morphological change is usually considered to be the result of rock weathering, which may include the combination of allochthonous sediment with original rock. ...
Deterioration development is a recognized worldwide threat to rock carvings, especially in humid regions of southern China. Cultural heritage managers thus require precise identification of different deterioration patterns and conduct comprehensive assessments. However, the quantitative analysis of deterioration patterns is limited due to the severe impact of temperature and humidity on rock carvings. Additionally, the current research on the different deterioration patterns is independent, and the corresponding systematic framework is vague. Based on this, the hyperspectral response is constructed to evaluate the various deterioration patterns using spectral index and intelligent model. Firstly, the remarkable correlation between the feldspar content and the deterioration patterns of rock carvings with the influence of environmental factors is investigated by mineralogical analysis. Secondly, combined with microscopic and mineralogical characteristics, the extracted deterioration characteristics are qualitatively screened. Then, a novel spectral index characterizing the correlation between image grayscale and spectral reflectance is proposed by introducing dynamic correction, and the optimal wavelength combination is applied to identify the distribution of deterioration patterns. Consequently, the quantitative screening of deterioration patterns can be realized. After that, the WOA-XGBoost model exhibits better performance in the classification of deterioration patterns. Finally, the influence of different deterioration patterns on rock carvings is quantified by integrating the deterioration index reflected by chemical composition and the proportion of deterioration pattern distribution identified by the spectral response. In the regional deterioration assessment of Dazu Rock Carvings, biological colonization and surface morphological changes have the highest proportion and degree of deterioration, which is worthy of attention in the protection of rock carvings in this region.
... If organic matter is present in the atmosphere, these particles become trapped within the gypsum crystals, leading to unsightly patinas and black crusts [27,32,37,[42][43][44][45]. Wet deposition, on the other hand, occurs when acid rain interacts with the stone surface, causing leaching and mineral dissolution [40,41,46]. ...
... The investigation of salt crystallization effects on cultural heritage requires comprehensive knowledge of salt composition to understand the crystallization conditions specific to each salt or salt association [14,[47][48][49]. Advanced chemical analyses have been employed to determine the composition of damaged areas, including X-ray diffraction (XRD) for salt mineralogy [29,32,34], X-ray fluorescence (XRF) for elemental composition [27,50], ionic chromatography (IC) and inductively coupled plasma spectrometry (ICP) for ionic composition [8,19,27,32,40,46], scanning electron microscope with energy dispersive Xray analyzer (SEM-EDX) for visualization and determination of elemental composition in specific crystals [8,29,32,51], Raman spectroscopy for identifying different hydration and weathering phases [29,52], and X-ray microtomography for locating crystallized salts [41,53]. ...
... The crystallization of gypsum is known to be a slow process [77]. However, in laboratory tests with slightly higher concentrations, gypsum crystals appeared on the surface within one day and formed a stable crust within 5 to 10 days, which remained relatively unchanged regardless of the subsequent exposure time [24,[39][40][41]46,78]. The thermodynamics of gypsum, especially the transition between hydrated and dehydrated phases, are not yet fully understood. ...
This study focuses on the damage caused by salt crystallization and the associated weathering processes in Crazannes limestone during storage. The main objective was to understand the factors contributing to the limestone’s observed flaking and granular disintegration, which cannot be attributed to frequent salt crystallization cycles experienced in outdoor exposure. Porosity and chemical analyses were performed to identify the salt minerals and their distribution within the stone’s microstructure. Chemical analyses revealed the presence of gypsum on the powdery weathered residues and stone surface, while halite was consistently found throughout the samples, with higher concentrations on the surface. The storage of the blocks in a closed room led to moisture evaporation and an increase in relative humidity (RH) ranging from 60% to 75%. Under these conditions, the gypsum crust remained relatively stable. The threshold for halite crystallization decreased to 65% RH in the presence of other salts. Consequently, even slight fluctuations in RH (%) caused by seasonal variations could induce cycles of NaCl crystallization and dissolution, resulting in damage behind the gypsum crust that protects the surface. Despite gypsum and halite not being the most aggressive salts, the porous nature of Crazannes limestone made it highly susceptible to salt-induced deterioration, leading to significant damage during storage, even with a minimal number of cycles. These results highlight the importance of controlling the storage conditions when stones are contaminated by salts.
... The good pore connection leads to an increase in porosity due to rock dissolution by acid rain. Dissolution occurs mainly on the surface in the case of low connectivity, even if the pore distribution changes (Eyssautier-Chuine et al. 2016). This phenomenon accounts for the difference in the grain size distribution values of the reference samples used in the study and the values after the weathering tests, namely, the increase and decrease in porosity (%). ...
As a building material, limestone is affected salt and acid solutions resulting from intense weather conditions over time. In the present study, variations in capillary water absorption, porosity, physical changes, and internal rock decomposition mechanisms caused by salt crystallization and air pollutants (SOx and NOx) in sedimentary limestone from the Antalya region were explored. The mineralogical–petrographical and geochemical properties of the limestones were determined using polarizing light microscopy, scanning electron microscopy (SEM), and X-ray fluorescence methods. The variations in the capillary water absorption coefficient, weight, and pore distribution and size were also determined by mercury porosimetry (MIP). An increase in weight was observed in the salt and SA (150 ± 10 mL deionized water and 500 ± 10 mL H2SO3 acid) weathering tests, but a reduction in weight was found under the action of NA (150 ± 10 mL deionized water and 500 ± 10 mL HNO3 acid). The reaction of SA with the limestones influenced the presence of calcium sulphite hemihydrate and gypsum on the rock surface, which affected weight gain. A decrease was observed in the weights of the limestones under the action of NA, and the porous structure seen in the microscale examination from SEM analysis supported a loss of material. The values for capillary water absorption increased in the limestones exposed to salt, SA, and NA. According to MIP analysis, the pore size distribution curves became multimodal, and the pore sizes varied in the studied limestones exposed to salt, SA, and NA. The findings of our study serve as an important guide for the use of limestone as a natural stone in regions with severe weather conditions.
... While some materials deposit on the surface, others can penetrate through areas of weakness, leading to their delamination. Likewise, the effect of acid rain can cause constant damage to materials, which acts in the same way by precipitating mineral salts that contribute to the loss of consolidation and the modification of the surface [59][60][61]. Similarly, the emissions produced by proximity to industrial areas [62] can transport compounds that, when deposited on the surface, cause similar Various factors control the adhesion to the surface, mainly of a structural nature. ...
... While some materials deposit on the surface, others can penetrate through areas of weakness, leading to their delamination. Likewise, the effect of acid rain can cause constant damage to materials, which acts in the same way by precipitating mineral salts that contribute to the loss of consolidation and the modification of the surface [59][60][61]. Similarly, the emissions produced by proximity to industrial areas [62] can transport compounds that, when deposited on the surface, cause similar alterations to the surface [63], in addition to the increase in pathological processes such as cardiopulmonary disorders [64]. ...
Nanotechnology has allowed for significant progress in architectural, artistic, archaeological, or museum heritage conservation for repairing and preventing damages produced by deterioration agents (weathering, contaminants, or biological actions). This review analyzes the current treatments using nanomaterials, including consolidants, biocides, hydrophobic protectives, mechanical resistance improvers, flame-retardants, and multifunctional nanocomposites. Unfortunately, nanomaterials can affect human and animal health, altering the environment. Right now, it is a priority to stop to analyze its advantages and disadvantages. Therefore, the aims are to raise awareness about the nanotoxicity risks during handling and the subsequent environmental exposure to all those directly or indirectly involved in conservation processes. It reports the human–body interaction mechanisms and provides guidelines for preventing or controlling its toxicity, mentioning the current toxicity research of main compounds and emphasizing the need to provide more information about morphological, structural, and specific features that ultimately contribute to understanding their toxicity. It provides information about the current documents of international organizations (European Commission, NIOSH, OECD, Countries Normative) about worker protection, isolation, laboratory ventilation control, and debris management. Furthermore, it reports the qualitative risk assessment methods, management strategies, dose control, and focus/receptor relationship, besides the latest trends of using nanomaterials in masks and gas emissions control devices, discussing their risk of toxicity.
... As shown in Table 5, redness and decreased lightness were observed in the weathered specimens. Previous studies indicated that the precipitation and oxidation of metal elements, such as Fe, exposed to an acidic atmosphere may account for such phenomena [11,24,39]. Color changes of stones will show different patterns depending on the material's characteristics, including pore connectivity and initial color, as well as the distribution and oxidation state of Fe. ...
The Yungang Grottoes, with over 1500 years of history, have been subjected to air pollution since the last century. Field investigations have indicated that acid gases, particularly sulfur dioxide (SO2), have accumulated on the surface of the sculptures and caused various types of decay that reduce their artistic value. To shed new light on the gas–stone interaction process, artificially accelerated weathering was performed on local sandstone in the laboratory. In a specially developed test device, fresh specimens were exposed to gaseous SO2 under different relative humidity and temperature conditions. The physical, mineralogical, and chemical changes of Yungang sandstone were evaluated conjointly using destructive and non-destructive methods. The results show that after weathering, the luminosity of all specimens changed, with a slight alteration in hue toward yellow. The weight increased to various degrees during the aging cycles, which depended on both the accumulation of matter and the detachment of particles. Higher relative humidity and cyclic temperature fluctuations favored the dissolution of carbonates and the hydrolysis of feldspar in sandstone. The concentration of ions, especially dissolved Ca2+ and SO42-, increased considerably over time in the near-surface region of the specimens. A trace of newly formed gypsum was detected in some specimens at the end of the test. Knowing the synergistic impact of different climatic variables will make it possible to identify the mechanisms of the deterioration of sandstone in complex environments.
... Experimental studies show that pyrite oxidation rate only slightly depend on the pH value of water (Moses et al., 1987;Kohl and Bao, 2011). However, the high rainfall with low pH values in monsoon season would lead to an increase in weathering rate of carbonate (Eyssautier-Chuine et al., 2016;Huang et al., 2019;Zhu et al., 2019). The dissolved CO 2 produced by this weathering promotes the dissolution of iron monosulfide, which is often appeared in the fractured surface of pyrite (Kameia and Ohmotob, 2000). ...
CO2 is released to the atmosphere via sulfuric acid weathering of carbonate rocks, affecting the flux of CO2 drawdown via silicate weathering. Precisely quantifying the proportion of oxidative weathering of sulfide minerals to riverine sulfate is critical to improving the estimation of the global carbon budge. Chemical and sulfur and oxygen isotopic compositions of river water samples collected monthly at 12 sampling sites from a small typical karstic catchment of Southwest China were analyzed, in order to quantify the relative contribution of sulfide oxidation to riverine sulfate and elucidate the factors affecting its changes. Results show that the sulfate concentration and its δ³⁴S and δ¹⁸O values at most sampling sites have obvious seasonal changes, with low values in the monsoon season and high values in the non-monsoon season, suggesting that the relative contributions of different sulfur sources are seasonally variable throughout of the year. Results from the Beyesian isotope mixing model show that overall, the fraction of sulfide-derived sulfate to riverine sulfate ranges from 44.3 ± 13.7% to 53.3 ± 10.5%, although it has a wide range for different sampling sites. In addition, the relative contribution of sulfide weathering displays a seasonal variation and is higher in the monsoon season, which is mainly attributed to the influence of high rainfall in wet season. This study indicates that an increase in rainfall intensity under climate change may lead to a raised sulfide oxidation rate in the karstic catchment, which is important for assessment of global carbonate and silicate weathering in future.
... In addition to the content of the staining agent exposed in the dissolution of the calcite mineral, it is thought to be effective in the pore structure of the mineral. Furthermore, Eyssautier-Chuine et al. [58] stated that the interpore connection was significantly effective in dissolving natural stone minerals. When the EDS spectra of the unstained natural stone samples were examined, it was determined that they were composed of significant elements such as Ca and O and minor elements such as Al, Si, and Cl. ...
Marmara White (MW), Bursa Beige (BB), Emprador (EM), and Kütahya Black (KB) natural stones are widely used as kitchen countertops and wet floor covering materials in our country. This study investigated the changes in these natural stones' gloss, roughness, and total color change properties due to the spillage of eight different food, beverage, and cleaning materials. Staining-cleaning cycles were applied to natural stones for 1, 3, and 7 days. In addition, with the help of field emission scanning electron microscopy (FESEM) analysis, the damage caused by these stain effects on the internal structures of these natural stones was investigated. According to the results obtained from the study, after three staining-cleaning cycles, the highest gloss loss was observed in the KB sample at the rate of 97.15% after the descaler effect, while the minor gloss loss was obtained in the MW sample at the rate of 82.16%. Furthermore, the highest roughness increase was observed in the KB sample at the rate of 555.1% after the effect of descaler, while the slightest increase in roughness was obtained in the MW sample at the rate of 395%. In addition, cooking oil has the most negative effect on natural stones' total color change (ΔE) properties. After three staining-cleaning cycles of the cooking oil effect, ΔE =20.86 was obtained in the MW sample, while this value was 3.25 in the KB sample.
... [1] In recent years, especially since the industrial revolution, with the rapid development of productivity and the intensification of human activities, air pollution has caused great damage to cultural relics. [2][3][4] The destruction of cultural relics caused by air pollution in the past 100 years is much more serious than the environmental damage to cultural relics in the past few thousand years. ...
... In the ground-state silica(L) 3 complexes, there are pores between methylsiloxane and silica, and the horizontal size of the two pores are 3.645 Å and 3.948 Å, respectively. Comparing the structures of silica(L) 2 and silica(L) 3 , the main structure of silica is not destroyed by these organic molecules. ...
... In the ground-state silica(L) 3 complexes, there are pores between methylsiloxane and silica, and the horizontal size of the two pores are 3.645 Å and 3.948 Å, respectively. Comparing the structures of silica(L) 2 and silica(L) 3 , the main structure of silica is not destroyed by these organic molecules. The structural parameters of pores did not change significantly, and the representative bond angle difference in the figure is within 2°. ...
The interaction between organosiloxane materials and siloxane species has attracted extensive attention in the protection of cultural relics due to their bonding characteristics. In this context, detailed studies of the complexation between siloxane species and methylsiloxane were explored using various computational methods. The complex molecular structures and their electronic excitation characteristics were predicted. The strong covalent interactions of Si−O bond between siloxane and methylsiloxane are checked by topological analysis of electron density and obvious charge transfer. Thermodynamic results show that these types of complexes are considerable stability. The energy barrier of oxygen molecules to pass through the pores between methylsiloxane and silica close to 19 eV, indicating that this type of coating does not peel off easily. Moreover, IR and UV‐vis spectrum were predicted. The microscopic mechanism will give theoretical direction for theoretical guidance for practical applications of the coating in the protection of stone artifacts.
... The absorption of the acid solution caused the proton to diffuse with the voids of the bricks leading to a chemical reaction that aids the decrease in alkalinity of the bricks leaving them venerable to low compression strength. In furtherance, the internal hydration of calcium silicate and the calcium aluminate hydration lost their stability and accelerated their hydrolysis, destroying the internal microstructure of the clay bricks leading to low compressive strengths as reported elsewhere by (Eyssautier-Chuine et al., 2016;. The moisture absorption capacity of the PWBs is very low compared to fired clay bricks. ...
Waste utilization as an alternative for masonry bricks has proven to compensate for
the dwindling natural construction materials particularly clay. Currently, South African
municipalities are struggling to update their effective waste management techniques.
Improper waste management is one of the major constraints affecting the natural
environment due to the associated environmental waste pollution. This constraint
fostered the motivation to the present study, which reported on the findings obtained
from the masonry bricks produced from blends of recycled crushed glass (RCG) and fly
ash (α-FA) with the inclusion of ordinary Portland cement (OPC) at varying percentages.
The masonry bricks were produced with 5%, 10%, and 15% inclusion of OPC to the
combined weight of α-FA and RCG. The produced bricks rendered significant
compression strength resistance compared to the fired clay bricks that are 3.8% higher
on average. However, the compressive strength of all the produced bricks in this study
satisfied the South African National Standard SANS 227 Code requirements (i.e., ≥7
MPa) for individual load-bearing masonry brick. The scanning electron microscopy
(SEM) analysis confirmed that the identified void spaces within the microstructure of the
brick specimens with 5% OPC were the major cause of the low strength resulting from
the incomplete pozzolanic reaction. Also, the effects of sulphate salt were significantly
resisted on the surface of all the tested bricks incorporating α-FA and RCG, due to the
presents of aluminosilicates compounds that triggered pozzolanic reactions within the
brick’s matrix. The stiffness of the investigated bricks portrayed brittle characteristics
due to the developed strength after production. This revealed the existence of a great
proportionality between the dynamic modulus and ultrasonic pulse velocity (UPV)
revealed a coefficient of determination (R2
) equivalent to 90% because of the percentages
of RCG particles.
... Monumentos y esculturas son testimonios de la historia y pertenecen a nuestro patrimonio cultural; fueron construidos para desafiar el tiempo, no obstante, la degradación progresiva asociada a la problemática ambiental por diferentes fuentes antrópicas genera pérdida irreparable (Eyssautier-Chuine, et al., 2016). La decadencia no se puede evitar, pero se puede limitar. ...
Este proyecto evalúo la caracterización fisicoquímica de las precipitaciones en el área de influencia del parque arqueológico San Agustín ubicado en el departamento del Huila, Colombia. Además, de las posibles fuentes antropogénicas asociadas que pueden generar variación en las características fisicoquímicas de las precipitaciones y el posible efecto de las precipitaciones en la estatuaria. Se determinó los parámetros fisicoquímicos: pH, conductividad, nitratos, sulfatos, acidez, temperatura en cuatro puntos de muestreo (mesita A, B, C, D). Se realizo análisis de correlación de Pearson, componentes principales (ACP) y cluster (CA) para verificar relaciones significativas entre los parámetros en las muestras de agua lluvia y el origen común entre parámetros. Las variables conductividad, acidez y sulfatos presentan diferencias estadísticamente significativas en función del tiempo y estaciones de muestreo. El análisis estadístico multivariados, componente principal y conglomerados sugieren que las variaciones de los parámetros fisicoquímicos provienen generalmente de fuentes antropogénicas mixtas, industria de fabricación de ladrillos – agroindustria de la panela. La composición de piedra volcánica de la estatuaria rico en compuestos de calcita influye en los procesos de deterioro causados por precipitaciones. Los resultados de este proyecto permiten presentar un diagnóstico inicial espacial comparativo en cuatro puntos de muestreo de la zona de estudio, evaluar el nivel de impacto que están soportando la estatuaria por acción de las precipitaciones y serán útiles para seguir desarrollando estrategias de mitigación ambiental; respondiendo a la necesidad en el manejo y conservación de los recursos. Asimismo, permitieron obtener un mejor conocimiento de la dinámica de parámetros fisicoquímicos y la relación con las diferentes fuentes antropogénicas aledañas.
