Search Results (24)

Asbestos is a fibrous variety of certain minerals, some of which occur naturally as an accessory to a wide variety of mineral resources. Although asbestos itself has been historically mined for various useful properties, the negative health effects of asbestos dust have greatly diminished it as a useful earth material, as many countries have banned the use of these fibrous minerals based on those health concerns. Resulting regulations of asbestos have focused primarily on intentionally mined material used in product manufacturing, such as building materials made with beneficiated asbestos and their derivative exposures, e.g., airborne asbestos in schools with asbestos-containing materials. The hazards of asbestos as unintended byproducts have not been as extensively considered, although this “contamination” has been repeatedly observed in common earth materials including talc, vermiculite, sand, and gravel. This study reveals such contamination of ornamental and dimension stone commonly referred to as “marble”. Asbestos types that can be associated with certain Indian marble reserves include asbestiform tremolite, actinolite, anthophyllite, and chrysotile asbestos. This case reveals such contamination in a marble reserve in Rajsamand, Rajasthan. At this location, marble dust in slurry is disposed at waste collection points, unfortunately including a location now open to the public that has become a tourist destination. Using Transmission Electron Microscopy (TEM) in this study, dust from this location revealed abundant tremolite asbestos fibres in the disaggregated dust. This poses potential health risks to the workers, bystanders, and tourists that may be exposed to this recognized carcinogen, a known cause of mesothelioma, lung cancer, and other asbestos-related diseases. Full article

The construction industry plays a crucial role in the global economy but faces significant challenges, including inefficiencies, high costs, and environmental impacts. Although Building Information Modeling (BIM) has been widely adopted as a solution to these issues, its practical impact remains limited. This study investigates how manufacturers can enhance their contributions to improve BIM’s effectiveness, proposing that coopetition practices—combining competition and cooperation—can positively influence these contributions, thereby enhancing the benefits of BIM. To explore this hypothesis, an Experimental Coopetition Network was implemented in the Portuguese ornamental stone (POS) sector, utilizing Industrial IoT technology to facilitate collaboration among selected companies. The study assessed the impact of coopetition practices on key performance indicators related to BIM, including on-time delivery, labor productivity, and CO₂ emissions. The findings demonstrate significant improvements in scheduling, operational efficiency, and environmental sustainability, validating the hypothesis that coopetition practices can enhance manufacturers’ contributions to BIM. These results suggest that coopetition practices contribute to better project outcomes, increased competitiveness, and sustainability within the construction industry. Despite the promising results, the study acknowledges limitations such as the scope of the sample size and observation periods, indicating areas for future research. This research contributes to the theoretical framework of coopetition, aligning with the United Nations Sustainable Development Goals (SDGs), and provides valuable insights for industry practitioners and policymakers seeking to implement more sustainable construction practices. Full article

The construction industry plays a crucial role in the global economy but faces persistent challenges such as inefficiency, high costs, and significant environmental impact. Building Information Modelling (BIM) has been proposed as a solution to enhance efficiency and sustainability through digital representations of construction projects. However, the full potential of BIM has yet to be realized. A contributing factor to this gap is that construction manufacturing companies, which produce upstream parts and products used downstream in construction, are often overlooked in discussions of BIM’s benefits. This study explores the potential of coopetition networks to help manufacturing companies better align with BIM dimensions. Coopetition networks, which integrate competitive and cooperative strategies, present a promising method to enhance the effectiveness of manufacturing companies. Focusing on the Portuguese Ornamental Stone industry, the study employs an experimental pilot network facilitated by the Industrial Internet of Things (IIoT) to assess the effects of competition on labour productivity, on-time delivery, and environmental performance among stone companies. The findings indicate that coopetition networks significantly improve alignment with BIM requirements, enhancing operational efficiency and sustainability. Despite being limited by a small sample size, this research offers valuable insights into the role of manufacturing companies in BIM-enhanced construction projects and the broader applicability of coopetition networks in advancing BIM objectives. These results highlight the potential of coopetition networks as a strategic approach to improving performance in the construction industry. Full article

Many historic buildings and monuments on the Salento Peninsula (Apulia, southern Italy) were built from locally quarried Miocene calcarenites belonging to the Pietra Leccese Formation (Late Burdigalian–early Messinian). The main facies consists of a homogeneous and porous biomicrite, pale yellow in colour and fine- to medium-grained, very rich in planktonic Foraminifera and massive or thick-bedded in outcrop. Additionally, there are other facies, among which Piromafo stands out for its aesthetic appearance, enhanced by its greenish-brown or greenish-grey colours. Piromafo occurs in the upper part of the Pietra Leccese Fm. and is represented by a fine- to medium-grained glauconitic and phosphatic biomicrite with macrofossils, especially Bivalves and Gastropods. Despite its important historical use as a building and ornamental material, especially in Roman and Baroque architecture, a research gap exists in the scientific literature describing the properties of the stone and their correlation. Therefore, the aim of this paper is to present a wide range of properties useful in explaining the in situ behaviour and damage susceptibility of the stone in monuments and buildings, but also to assist in selecting preservation treatments and strategies. An overall assessment of the main petrophysical and mechanical properties, especially for restoration/conservation purposes, was performed using both standard and unconventional techniques. Starting with rock fabric inspection, particular attention was given to the relationship between the pore size distribution and the hydraulic and thermal properties of the material. Unconfined compressive strength, flexural strength, and indirect tensile strength were also estimated. The findings reveal a significant correlation between the pore size distribution and the hydraulic and thermal properties of Piromafo, impacting its durability and suitability for use in conservation. Specifically, the thermal properties, influenced by the mineral composition and fabric, indicate the potential for using Piromafo as an effective refractory and insulation material, which justifies the origin of its name and confirms what is already stated in the specific literature. Additionally, correlations were proposed among the various mechanical parameters evaluated, including the Schmidt hammer rebound values with compressive strength and tangent modulus. The mechanical analysis shows that the material possesses adequate properties for structural applications. Full article

Marble has been a prominent natural stone exploited since ancient times, commonly employed as a building material and ornamental stone. However, the disposal of waste generated from marble extraction, particularly fine sludge, poses significant environmental challenges for the dimensional stone industry. The difficulty in managing and recovering these materials, exacerbated by local regulations and the absence of suitable recovery protocols, often leads to landfilling. This issue is exemplified by the Carrara Marble Basin in the Apuan Alps (Tuscany, Italy), where more than half of the extracted marble remains as quarry waste or debris. Modern cutting technologies have intensified the production of finer materials and sawing residue, known as “marmettola”, ranging in size from fine sand to silt. The disposal of these materials, commonly through landfilling or abandonment, has profound environmental repercussions. This research primarily aimed to carry out a preliminary physical, mineralogical, and morphological characterization of the fine waste and sludges generated from Carrara Marble exploitation. The findings reveal the high granulometric uniformity of the materials, and a nearly pure carbonate composition, suggesting potential for reuse in various industrial sectors such as paper, plastics, and pharmaceuticals production. Full article

Heritage buildings clad with natural rock endure over time destruction caused by weathering mechanisms, pollution from urban areas, biodeterioration due to organisms, microorganisms, and also the anthropic factor. On the surface of the limestone samples taken from the ornamental natural rock with which the outside of Markovits-Mathéser house, Oradea, Romania, is clad, two species of fungi were inoculated in the laboratory: Aspergillus spp. and Cladosporium spp. Wollastonite was then applied, and from the imaging analysis (SEM), the inhibition of fungi by it is clearly observed (48 h after its application), which was also confirmed using the image segmentation method. It was also noted that the hydrophilicity of the aqueous suspension of wollastonite resulted in the absorption of water in the substrate, which in turn resulted in the drying out and surface breakage of the specimens. X-ray diffraction analysis showed the presence of the two phases (calcite and quartz) as in the starting sample, and also an additional phase assigned to wollastonite in the later phase of the experiment. An amorphous component, due to the applied gel composition, was also reported. This research highlights the fact that there are good premises for aqueous suspension of wollastonite to have a biocidal character for Aspegillus spp. and Cladosporium spp., when applied on natural stone used in the construction of heritage buildings located in temperate climates; due to its easy application, green and ecofriendly properties, and also low cost of acquisition and application. Full article

Serpentinite rocks testify to the ocean-floor metamorphism that took place and transformed the original mineralogy and fabric of previous ultramafic rocks. Due to their tectonic and petrological importance, in recent decades, there has been increasing interest in serpentinites. From the economic point of view, it is worth noting that, due to their beauty and attractiveness, serpentinite rocks have been exploited and traded as building and ornamental stones since prehistorical times worldwide. In this work, we provide a comprehensive report of the petrographic, mineralogical, petrophysical, and geochemical features of the serpentinites cropping out in the northern sector of the Calabria–Peloritani Orogen (Italy), where the historical quarries are located. Since these serpentinite rocks have been traded for a long time and employed as an excellent building material, their detailed knowledge may provide a useful tool to understand their behavior when they are employed as building materials, to predict their performances upon emplacement in monuments, and to plan correct restoration by considering the provenance of the lithotypes employed. Moreover, comprehensive characterization is also particularly important because it has been reported that serpentinites from Calabria may contain asbestiform and other fibrous minerals, as testified by the occurrence of chrysotile, tremolite, and actinolite asbestos located within the veins, which could lead to health problems due to asbestos fiber exposure. Finally, serpentinite may be considered as an important potential CO₂ sequestration sink. Full article

The long-term endurance of building stones must be assured since their longevity has repercussions for their economic and social value. Frequently, slabs for flooring and cladding are installed with polished finishing in outdoor environments for technical and ornamental purposes in cultural heritage sites and modern civil architecture. Compared to any other finishing, glossy surfaces are rather vulnerable to wear, particularly when they interact with slightly acidic rainwater. Several hydrophobic treatments are applied to prevent this damage by preventing contact between rain and stone; such treatments are efficient but sometimes non-durable. Stakeholders and conservation scientists need better methods to anticipate the future behaviour of this building material and hydrophobic solutions. Complying with this demand, a comparison is made between outdoor natural ageing and artificial weathering, reproduced by UVA radiation, moisture and spray accelerated weathering. Artificial weathering is applied to predict the behaviour of stones over time in the real environment. Data obtained through the measurement of gloss and colour parameters, the detection of micro-textures through SEM, and the calculation of micro-roughness using a digital rugosimeter demonstrate that weakly acidic rainwater is the main cause of superficial decay of stone finishing over just six months of outdoor exposure. This period corresponds to 7–14 days of artificial weathering. Furthermore, the loss of efficiency and durability of the hydrophobic coatings is detected by measuring the static contact angle. This highlights that even if a protective treatment was proficient, it could easily deteriorate in normal weathering conditions if applied on polished, low-porosity stone. Additionally, water vapour permeability indicates variations of regular vapour transmission through the stones due to ageing. The first solution to threats is the prevention of pathologies, including aesthetic ones. A careful choice of the most suitable lithotype finish and an environmental study represent an existing solution to the problem. It must be highlighted that aesthetic requirements should not be prioritised to detriment of the technical requirements of architectural quality, performance, durability, and safety. Full article

This study is addressed at the cultural heritage of the UNESCO historical centre of Urbino (Italy) through the focus on a very peculiar building and ornamental carbonate porous (spongy) stone also found in the opus quadratum Roman dry walls. For these rocks, the mathematician and historian Bernardino Baldi (16th century AD) and the mineralogist Francesco Rodolico (middle of the 20th century AD) introduced, respectively, the popular terms of Tufo spugnoso or Pietra Spugna. Physical observations and stable isotope data (δ¹³C and δ¹⁸O) of these rocks allowed, for the first time, their classification as calcareous tufas, thus contributing to the valorization of the stone heritage of the city. This carbonate lithotype was formed by the chemical precipitation of CaCO₃, driven by the CO₂ degassing of supersaturated calcium-bicarbonate-rich waters, coupled with the passive encrustations of organic material in continental environments. Radiocarbon analyses dated these stones mostly between 9100 and 4700 yr. BP when a maximum growth of these carbonate continental deposits occurred in Mediterranean regions and northern Europe, i.e., during the Holocene Atlantic climatic optimum. Work is still in progress on a perched springline of calcareous tufas found along the Metauro Valley (a few km from Urbino), being good candidates for provenance, at least for those blocks exploited by the Romans and successively reused in the architectural framework of Urbino. Full article

Three-dimensional Cementitious materials Printing (3DCP) is a cutting-edge technology for the construction industry. Three-dimensional printed buildings have shown that a well-developed automated technology can foster valuable benefits, such as a freeform architectural design without formworks and reduced human intervention. However, scalability, commercialization and sustainability of the 3DPC technology remain critical issues. The current work presents the ecological fragility, challenges and opportunities inherent in decreasing the 3DCP environmental footprint at a material level (cementitious materials and aggregates). The very demanding performance of printable mixtures, namely in a fresh state, requires high dosages of cement and supplementary cementitious materials (SCM). Besides the heavy carbon footprint of cement production, the standard SCM availability might be an issue, especially in the longer term. One exciting option to decrease the embodied CO₂ of 3DCP is, for example, to incorporate alternative and locally available SCM as partial cement replacements. Those alternative SCM can be wastes or by-products from industries or agriculture, with no added value. Moreover, the partial replacement of natural aggregate can also bring advantages for natural resource preservation. This work has highlighted the enormous potential of 3DCP to contribute to reducing the dependence on Portland cement and to manage the current colossal wastes and by-products with no added value, shifting to a Circular Economy. Though LCA analysis, mixture design revealed a critical parameter in the environmental impact of 3DCP elements or buildings. Even though cement significantly affects the LCA of 3DCP, it is crucial to achieving adequate fresh properties and rheology. From the literature survey, mixtures formulated with alternative SCM (wastes or by-products) are still restricted to rice husk ash, Municipal Solid Waste ashes and recycled powder from construction and demolition wastes. Natural aggregate replacement research has been focused on recycled fine sand, mine tailing, copper tailing, iron tailing, ornamental stone waste, recycled glass, crumb rubber, rubber powder and granules, recycled PET bottles and steel slag. However, flowability loss and mechanical strength decrease are still critical. Research efforts are needed to find low-carbon cement replacements and mix-design optimization, leading to a more sustainable and circular 3DCP while ensuring the final product performance. Full article

Andalusi residential architecture is often described through planimetry or its internal constructive materiality. However, the real architectural vision of those who inhabited or visited Andalusi palaces or houses was completed by an important decorative epidermis that covered the structural materials and gave these Islamic buildings their final visual impact. Traditionally, the three-dimensional stone and plaster ornamentation has been the most analysed; the pictorial decoration that widely covered plinths has rarely been studied as a whole, despite the numerous remnants documented in recent decades. In this work, we propose a holistic and synthetic approach to this decorative architectural element, from its technical elaboration to its role in the three-dimensionality of Andalusi residential spaces. We also address its influences and its aesthetic evolution over the centuries. Full article

Bluish-grey limestones have been extensively used as ornamental stones for decoration purposes in buildings, as well as in works of art, and accordingly, have been the target of intense exploration. In Portugal, the Jurassic limestone massif known as the Maciço Calcário Estremenho (MCE), has been the source of grey-coloured ornamental stones, namely the Azul Valverde (one of the most well-known bluish-grey limestones) and Atlantic Blue varieties, both of which may undergo colour changes in outdoor environments. In this sense, it is important to understand the sudden colour change from bluish-grey to yellow/beige in the same limestone block in a quarry, or even, what happens to the colour when polished limestone is placed outdoors. This study was undertaken using various techniques, namely XRF (X-ray fluorescence spectrometry), XRD (X-ray diffraction), SEM (scanning electron microscopy), DTA–TG (differential thermal analysis/thermogravimetry) and colourimetry. Synchrotron radiation was also used at the European Synchrotron Radiation Facility (ESRF, Grenoble, France) where XANES (X-ray Absorption Near Edge Structure) spectra at Fe K-edge were collected to ascertain the speciation state of Fe in different coloured zones of the limestone, previously checked by EDXRF (energy dispersive X-ray fluorescence). The presence of Fe²⁺ and Fe³⁺ are responsible for the greyish and yellow/brown colour, respectively. On the other hand, the UV radiation from the sun causes a quickened and severe bleaching/fading on the dark blue/grey polished limestone. Full article

Soluble salts are compounds found inside ornamental rocks and building stones exposed to atmospheric agents in environments rich in alkaline metal ions, such as sodium and potassium. The damage induced by their crystallization in those materials, used to build monuments and architectural structures of great importance, is an unsolved problem. Sodium sulfate is one of the most common and harmful salt found in these constructions. In this work, we studied the resistance through time to the wet-drying cycles of some natural stones (calcarenites, marbles, and sandstones) that have been utilized in the historical architecture in Italy. Samples were freshly cut and thermally aged to simulate increasing decay. Induced porosity in the thermally degraded samples was high in calcarenites, medium in marbles, and low in sandstones. Specimens subjected to artificial thermal aging lost a major percentage of mass compared to the non-weathered ones, when affected by the crystallization of soluble salts. With this study, we have observed that samples subjected to different wetting and drying cycles degrade faster due to the action of soluble salts, compared to samples that are not subjected to these cycles. Full article

The ornamental stones industry has grown progressively in Egypt as the demand has increased for Egyptian decorative stones in indoor and outdoor building spaces. Choosing the most suitable ornamental stone for each purpose and taking the right decisions related to aesthetic and practical performance can be a challenge causing a lot of confusion for homeowners and contractors. Thus, there is a need to define what decorative style you are trying to achieve in order to properly choose the most suitable decorative stone. In this research, some Egyptian ornamental stones were evaluated by combining the analytic hierarchy process (AHP) and the technique for order preference by similarity to ideal solution (TOPSIS). The optimized AHP–TOPSIS comprehensive decision model was implemented on natural materials relevant to ornaments and the finishing purposes of indoor and outdoor buildings. Ten rock types from four Egyptian sites were studied, examined, and analyzed. According to the quality index scheme, grey granite is an ideal ornamental stone that meets indoor and outdoor purposes. Grey granite and black marble have a performance score (Pi) of 0.78 and 0.71, respectively. Serpentine and pink granite were ranked third with a Pi = 0.68. These results provide stakeholders with strategic indicators to select different natural ornamental stones based on the total points assigned to all rock specifications and costs. Full article

The present study aimed to assess the radiological hazards associated with applying the investigated granite in the building materials and the infrastructures applications. The investigated granites are classified into four categories: El-Urf, barren, colourful and opaque. El Urf monzogranite intrudes metagabbro diorite complex with sharp contacts. Based on the activity concentrations, the environmental parameters such as absorbed dose rate (D_air), annual effective dose (AED), radium equivalent activity (Ra_eq), external (H_ex) and internal (H_in) hazard indices were measured. The mineralized pegmatite is located in the southwestern foothill of the Gabal El Urf younger granite. It displays well-defined zonation of three zones: outer, middle and inner zones represented by potash feldspar, quartz and mica, respectively. The isorad map showed that El Urf monzogranite is barren (Up to 100 cps) surrounding an excavation of the studied pegmatite that exhibits moderate colorful mineralization (phase-I = 500–1500 cps) and anomalous opaque mineralization (phase-II = 1500–3500 cps) pegmatites. The obtained results of radionuclides activity concentrations illustrated that the Opaque granites have the highest values of ²³⁸U (561 ± 127 Bq kg⁻¹), ²³²Th (4289 ± 891 Bq kg⁻¹) and ⁴⁰K (3002 ± 446 Bq kg⁻¹) in the granites, which are higher than the recommended worldwide average. Many of the radiological hazard parameters were lesser than the international limits in the younger granites and barren pegmatites. All of these parameters were higher in the colorful and opaque mineralized pegmatites. The high activity and the elevated radiological hazard parameters in the mineralized pegmatites are revised to the presence of radioactive and radioelements bearing minerals, such as thorite, meta-autunite, kasolite, phurcalite, columbite, fergusonite, Xenotime and fluorapatite. Other instances of mineralization were also recorded as cassiterite, atacamite, galena, pyrite and iron oxide minerals. Thus, the granites with high radioactivity concentration cannot be applied in the different applications of building materials and ornamental stones. Full article