The present work aimed to evaluate non-toxic raw materials that will be part of new hybrid and ecological polymer composite materials, used for fireproof and intumescent treatment of systems and equipment associated with watering of cultivated or uncultivated land surfaces, respectively for land irrigation or for extinguishing vegetation fires, as a feasible, sustainable, efficient and economical alternative to synthesized fireproof and intumescent materials. The possible ecological components of the objective hybrid polymer composite material, which were analyzed, are: Alumina, Liquid starch, Powdered starch, Borax, Zinc borate. The results of the analyses were interpreted by correlation, reporting and comparison with the results obtained from established materials in the field of passive fire protection, which have recognized fire resistance performance, such as: Coroparaffin, Naftoblend ACFR-01, NANO PROTECT - NANO-PROTECT ® for plastics, Nanomagicplastcare, Nanoprotect pre-cleaning and Antimony trioxide. Liquid PVC was analyzed, with the intention of introducing it as an additive during the preparation of hybrid materials, both to improve the physical and mechanical properties and to facilitate subsequent application even in difficult weather conditions, on site, in the field. The research strategy was to choose the component materials so that the resulting hybrid polymer film would not burn, prevent the spread of fire and smoke, maintain its structural integrity and align with the principles of the circular economy. The substances, possibly components of the objective polymer film, were analyzed by Fourier Transform Infrared Spectroscopy (FTIR), in the “pre-burn” phase, respectively before combustion.

This paper presents a detailed and critical review of recycled materials used in the construction industry, with emphasis on sustainability, efficient use of resources, and reduction of environmental impact. The analysis is based on recent studies focused on construction and demolition waste (CDW), including materials such as recycled concrete aggregates (RCA), plastics, metals, glass, and industrial by-products like fly ash and slag. The comparison of multiple research works shows that recycling processes, material composition, and treatment techniques play an important role in determining the mechanical properties, durability, and environmental behavior of recycled construction materials. The results indicate that using recycled materials can lead to lower greenhouse gas emissions, reduced energy consumption, and decreased landfill disposal, while still ensuring acceptable performance in many structural applications. At the same time, several limitations must be considered. These include variations in material properties, higher water absorption in recycled aggregates, and the absence of clear standards for large-scale use. In addition, the study highlights the importance of modern recycling technologies, life cycle assessment (LCA) methods, and circular economy principles in improving the overall efficiency and reliability of these materials. Future research should focus on improving processing techniques, increasing durability, and developing advanced materials such as hybrid and smart systems. Overall, the use of recycled materials in construction can be considered an important step toward a more sustainable and low-carbon built environment.

The C & acirc;ndesti necropolis is currently the largest excavated Bronze Age necropolis in Romania, with approximately 800 graves. Notably, one grave from an earlier phase of the Monteoru culture (c. 2200-1850 BC) contained a remarkable necklace composed of 22 perforated gastropod shells and a metal pendant. Our investigation adopted an integrated approach, including taxonomic identification, taphonomic, technological and functional analyses, experimental studies, and physico-chemical investigations (Fourier Transform Infrared Spectroscopy and Raman spectroscopy) of the pigment traces present on the shells's surface. For the metal pendant, X-Ray Fluorescence analysis was conducted to ascertain its elemental composition. The combined analysis yielded unexpected insights: the shells, belonging to the genus Conus, originated from the Mediterranean region. The perforations were not the result of anthropic intervention; rather, they were the result of natural processes, indicating that the shells were collected from thanatocoenoses. The shells were assembled into the necklace using a thread colored with a red pigment. The perforations show signs of prolonged use, suggesting that the necklace was not only a funerary offering. In conclusion, our study indicated that these exotic shells were collected post-mortem already perforated through a rubbing process in the seashore sediments, transported to the site from a distance, and prior to the death of the owner, had been previously worn as personal adornment before being deposited as grave goods.

Glass fiber-reinforced polymer matrix composites (GFRPs) constitute a major class of structural engineering materials owing to their advantageous balance of specific mechanical properties, low density, corrosion resistance, and comparatively low production cost. Their increasing adoption in sectors such as automotive, aerospace, civil infrastructure, marine engineering, and renewable energy reflects the need for lightweight materials capable of delivering reliable mechanical performance under diverse service conditions. This review provides a systematic examination of GFRPs, with emphasis on the interdependence between constituent selection, processing methodology, microstructural development, and macroscopic properties. Particular attention is devoted to the classification of polymer matrix composites, the physicochemical characteristics of glass fibers as reinforcement, and the distinct roles of thermosetting and thermoplastic matrices in governing composite behavior. The analysis also addresses fundamental reinforcement mechanisms, stress-transfer efficiency at the fiber–matrix interface, and the influence of critical manufacturing parameters associated with both conventional and advanced fabrication techniques. Furthermore, the review evaluates the mechanical, thermal, and durability-related performance of GFRPs, highlighting the role of fiber architecture, interfacial adhesion, and microstructural heterogeneity on in-service behavior. Representative application areas are presented to demonstrate the technological relevance and multifunctional potential of these materials.

Historical buildings are highly prone to degradation because they are continuously exposed to the external environment, which represents an extremely aggressive factor. Globally, there are so many historical buildings that need urgent restoration. This paper focuses on finding a new consolidant for real oak old wood and presents a new recipe based on multi-walled carbon nanotubes (MWCNTs) decorated with zinc oxide (ZnO) nanoparticles dispersed in PHBHV solution, aimed at improving old wood properties. The research was conducted on Banloc Castle oak wood, which is predominant throughout the castle. The obtained treatment was applied by brushing onto the wood surface, while the retention and uniform application of the consolidation were confirmed by optical microscopy. One major advantage of the treatment is that the natural color of the wood is not affected, with the total color difference being very small. Another advantage gained after consolidation was the enhanced hydrophobic behavior of the old wood confirmed through water absorption, humidity and contact angle tests. In contrast, untreated wood exhibited hydrophilic behavior and high water and moisture absorption capacity, making aged wood extremely vulnerable to environmental degradation over time. Mechanical tests confirmed that the consolidant solution significantly improved the properties of the wooden material, due to the effective impregnation of the treatment into the wood structure. Furthermore, the MWCNT-based consolidant inhibited the growth of the Aspergillus niger strain, providing antifungal protection and preventing the colonization of microorganisms within the wood structure and its subsequent degradation. Through the methods investigated in this work, it was proven that the treatment is suitable for the consolidation of aged and degraded oak wood materials.

Current challenges in the construction field emphasize the need for compatible and durable materials for heritage interventions. Traditional lime-based mortars often exhibit limitations under environmental exposure, particularly in terms of water absorption and freeze-thaw resistance. This article investigates the performance of hydroxyapatite (HAp)-modified lime mortars applied in a real-scale heritage context, namely a student built micro-museum developed within the Apos Architecture Summer School. Following the premature degradation of a conventional lime mortar layer applied at roof level, HAp-modified formulations were introduced as a protective and consolidating solution. The experimental approach combines laboratory testing and in situ evaluation, including compressive strength measurements, water absorption, capillarity tests, chromatic analysis, and freeze-thaw assessment. The results indicate a reduction in water absorption from approximately 22% to 12%, an increase in compressive strength from 6.57 MPa to 19.95 MPa and a significant improvement in freeze-thaw resistance, reflected by a decrease in gelivity from 61.2% to 5.73%, compared to traditional lime mortars. In addition, the contact angle increased from 36 degrees to 82 degrees, indicating enhanced hydrophobic behavior. These improvements are associated with pore structure refinement, reduced capillary uptake, and enhanced interfacial bonding within the mortar matrix. The study also highlights the role of real-scale educational environments in validating sustainable material solutions.

The integration of nanotechnology into the food packaging sector has generated a paradigm shift in food preservation, offering superior antimicrobial and barrier properties. However, the transition from conventional materials to nanocomposites raises fundamental questions regarding “nano-safety” and the potential impact on human health. This review paper critically analyzes current scientific literature on the toxicological risk associated with metallic nanoparticles, with a particular focus on zinc oxide (ZnO NPs) and silver (AgNPs). The complex mechanisms through which these submicroscopic entities can interact with biological systems—from inhalation and dermal contact to ingestion through the gastrointestinal tract—are explored. The analysis focuses on the importance of rigorous physicochemical characterization—including morphology, surface charge, and adsorption capacity—as a mandatory prerequisite in toxicity assessment. Furthermore, the paper examines current testing methodologies, drawing a parallel between the efficiency of in vitro models (oxidative stress, apoptosis, genotoxicity) and the complexity of in vivo studies (biodistribution, clearance, histopathology). A significant segment is dedicated to the dynamics of migration from the polymer matrix into food, evaluating influencing factors such as pH, temperature, and contact time. Finally, directives and guidelines issued by the European Food Safety Authority (EFSA) and REACH regulations are reviewed, providing a theoretical perspective on how scientific and political consensus attempts to define safety limits for the modern consumer.

Gypsum has been used as a building material for a long time due to its environmental friendliness, exceptional fire performance, and ease of use. However, it is also known to have poor moisture resistance and lower mechanical performance. Construction and demolition wastes, which can cause many environmental issues if not properly managed, are increasingly recycled as reinforcement materials in gypsum mortar. This study aims to assess the effect of incorporating fine glass waste aggregates into gypsum mortars on their physical, mechanical, and adhesive properties. The effect of replacing sand from 0% to 100% by glass waste in gypsum mortar was investigated using various tests and analyses including scanning electron microscopy (SEM), X-ray diffraction (XRD), thermal analysis (DTA and TGA), setting time, flexural and compressive strengths, adhesive, surface hardness, water absorption, thermal conductivity, and ultrasonic pulse velocity. The results obtained emphasize that glass waste can substitute sand in gypsum mortar, even when used at high replacement levels. Replacing all the sand in mortar with glass waste results in a 11% increase in porosity, a 9% decrease in density, and a 53% decrease in thermal conductivity, while still maintaining acceptable mechanical performances. The adhesive strength shows a great dependence on the nature of the substrate.

Cultural heritage conservation is increasingly affected by environmental degradation, climate change, and intensified human pressures, which accelerate the decay of historic materials and call for more resilient and adaptive conservation approaches. In this context, growing attention is being given to the combined use of sustainable materials and digital technologies.

This study presents an integrated digital and archaeometric investigation of the Roman fortress of Sacidava, located in Dobrogea, Romania. Combining 3D digital reconstruction and advanced material analysis, the research explores both the original architecture and the preserved state of the site. Using Autodesk Fusion 360, a complete 3D model was developed, digitally restoring the fortress as it likely appeared in the 4th century AD and enabling the generation of precise plans, sections, and photogrammetric elevations. Mortar samples from the eight towers of the Sacidava fortress were examined through scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS), atomic force microscopy (AFM), and confocal laser scanning microscopy (CLSM), revealing phyllosilicate-rich matrices, carbonated lime residues, and heterogeneous microstructures. The most severe degradation was found in the towers facing the Danube (E2, F, G), which was strongly influenced by humidity and salt crystallization, while the southern towers (A-C) retained more stable textures. Hydroxyapatite (HAp) treatments visibly improved the surface condition by reducing roughness and sealing active pores. For the first time, chromatic parameters were correlated with environmental factors, such as pH, moisture, and salt content. ImageJ-based pseudo-computed tomography (pseudo-CT), principal component analysis (PCA), and dendrogram analyses confirmed a clear pattern of deterioration near the ancient port area, where increased acidity and moisture coincided with darker surface coloration and deeper microstructural alteration.

The development of sustainable and functional nanocomposites has attracted considerable attention in recent years due to their broad spectrum of potential applications, including wood preservation. Also, a global goal is to reuse the large volumes of waste for environmental issues. In this context, the aim of the study was to obtain soda lignin particles, to graft ZnO nanoparticles onto their surface and to apply these hybrids, embedded into a biodegradable polymer matrix, as protection/preservation coating for oak wood. The organic–inorganic hybrids were characterized in terms of compositional, structural, thermal, and morphological properties that confirm the efficacy of soda lignin extraction and ZnO grafting by physical adsorption onto the decorating support and by weak interactions and coordination bonding between the components. The developed solution based on poly(3-hydroxybutyrate-co-3-hydroxyvalerate) and lignin-ZnO was applied to oak wood specimens by brushing, and the improvement in hydrophobicity (evaluated by water absorption that decreased by 48.8% more than wood, humidity tests where the treated sample had a humidity of 4.734% in comparison with 34.911% for control, and contact angle of 97.8° vs. 80.5° for untreated wood) and UV and fungal attack protection, while maintaining the color and aspect of specimens, was sustained. L.ZnO are well dispersed into the polymer matrix, ensuring a smooth and less porous wood surface. According to the results, the obtained wood coating using both a biodegradable polymeric matrix and a waste-based preservative can be applied for protection against weathering degradation factors, with limited water uptake and swelling of the wood, UV shielding, reduced wood discoloration and photo-degradation, effective protection against fungi, and esthetic quality.

The preservation of stone and mortar elements in cultural heritage structures is increasingly challenged by environmental degradation, pollution, and biological fouling. Photocatalytic coatings represent a promising approach for developing self-cleaning and pollutant-degrading surfaces. In this study, a silver-modified ZnAl-layered double hydroxide (Ag@ZnAl-LDH) was synthesized via coprecipitation and applied as a coating on mortar substrates. The structural and compositional characteristics of the prepared materials were investigated using X-ray diffraction (XRD) and wavelength-dispersive X-ray fluorescence (WDXRF). The XRD pattern confirmed the formation of a ZnAl-LDH phase (JCPDS 48-1022) with carbonate as the main interlayer anion, along with additional reflections attributed to ZnO (JCPDS 99-0111) and silver-containing species. The photocatalytic activity was evaluated through the degradation of methylene blue under natural illumination (700 W/m²), monitored via CIELAB colorimetric parameters. The results demonstrated that Ag@ZnAl-LDH coatings promote the photodegradation of organic dyes, indicating potential for developing functional, self-cleaning coatings for the protection of heritage materials.

This paper reports the first evidence of the presence of the mineral tremolite asbestos in Roman building materials from the Micia archaeological site (Romania), thus contributing to the understanding of the implications of ancient building materials. The Micia archaeological site includes both a fort and a civilian Roman military settlement that was inhabited by both civilians and soldiers from various Roman troops. Over time, since the late 2nd century AD, the settlement has undergone significant reconstruction, especially after some fires. Tremolite asbestos is a non-flammable mineral that, due to its fibrous properties, was used in the past in building materials, although it poses health risks when inhaled. To highlight it, several advanced and highly sensitive scientific techniques are used in this work to discover the presence of tremolite asbestos and to examine its structure, composition, and morphology inside the investigated samples. Tremolite asbestos is typically white to gray or greenish in color, characterized by thin, needle-like fibers that can easily become airborne and inhaled. It is a crystalline mineral that usually forms long, straight, sharp fibers. Under high magnification in optical microscopy or in scanning electron microscope images, correlated with other performant analytical techniques (XRD, WDXRF, FTIR, Raman, BET, TGA), tremolite asbestos appears as elongated, slender fibers—often bundled or intertwined—with smooth or slightly striated surfaces.

This article offers a thorough review of recent scientific research on the synthesis, characterization, and performance of epoxy-based composite materials reinforced with organic components. It critically evaluates progress made in the past decade in development of composites that incorporate natural fibers, agricultural byproducts, biodegradable polymers, and other bio-derived fillers. By analyzing the existing literature, the review discusses various processing techniques, structural features, and the mechanical, thermal, and chemical properties of these composites. It highlights how organic reinforcements affect the performance of epoxy matrices. The primary objective is to provide an updated overview of current knowledge in epoxy-organic composites, highlighting emerging trends, key challenges, and opportunities for sustainable innovation. The article also compares findings from multiple studies to clarify the relationships between reinforcement types, interfacial interactions, and composite behavior. Furthermore, it underscores the potential of bio-based and hybrid epoxy composites as eco-friendly alternatives to traditional synthetic materials, supporting the global shift toward circular and low-carbon material engineering.

The aim of this work was to determine the mineralogical, physicochemical, and mechanical properties of Bangoua clay materials in order to evaluate their potential for the manufacture of ceramic wares. Six representative clay materials were collected in the study area and were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR), X-ray fluorescence (XRF) and physical analyses (particle size distributions and consistency limits). The fired properties of the specimens made from clay materials were determined. Results show that the clay materials are composed of kaolinite (18.95-36.45 wt%), quartz (18.26-22.02 wt%) with variable proportions of microcline, muscovite, rutile, illite, goethite, hematite and anatase. These materials contain a significant amount of flux, which makes it possible to lower firing temperatures. SiO2 (40.56-53.06 wt%), Al2O3 (38.45-45.29 wt%) and Fe2O3 (3.23-15.1 wt%) are the main major oxides. Particle size analysis reveals that the clay materials are suitable for common brick production (B1, B3, B6), vertically perforated bricks (B2), hollow bricks (B5). Bricks were fired at 900 degrees, 1000 degrees, 1100 degrees and 1200 degrees C. Ceramic properties of fired products show good performances at 1000 and 1200 degrees C mostly for samples B1, B2 and B5. The most relevant are water absorption: 2.21-17.84 wt%, bulk density: 1.41-1.82 g/cm3, compressive strength: 4.17-20 MPa, metallic sound and good cohesion. This good performance makes them ideal for firing these materials on an industrial and semi-industrial scale.

Replacing virgin raw materials with recycled waste in construction products is a key strategy for advancing sustainable development. This study explores the partial substitution of commercial gypsum with powdered waste brick (WB) in gypsum mortars, assessing its impact on mechanical performance, water absorption, and environmental footprint. Mortars were prepared with 0%, 5%, 10%, 20%, and 30% WB by weight. Results indicate that a 20% replacement level enhances flexural strength by 56% and compressive strength by 33% at 28 days, compared to the reference mix. SEM and XRD analyses revealed no formation of new crystalline phases, suggesting that the performance improvement is primarily due to physical interactions and microstructural effects. However, at 30% WB, a significant reduction in adhesion strength was observed, falling below the typical threshold for gypsum-based coatings, which may constrain practical application at higher replacement levels. Environmental assessment showed that both CO2 emissions and energy consumption decreased by up to 20% with a 30% substitution. A 20% WB content is therefore proposed as the optimal compromise between mechanical performance and environmental benefit. This approach supports circular economy principles by promoting the reuse of ceramic construction waste in the development of new sustainable materials.

Increased concern for human health and the environment has pushed various industries to adopt new approaches towards satisfying modern regulations. Strategies to achieve these approaches include utilizing lightweight materials, repurposing waste materials, and substituting synthetic polymers with bio-based counterparts. This study investigates the effects of treated fly ash (C) and bio-based polyamide 10.10 (PA10) on the thermal, morphological, and mechanical properties of glass fiber (GF)-reinforced polyamide 6 (PA6). Our main objective was to develop a composite that would allow for the partial replacement of glass fiber in reinforced polyamide 6 composites (PA6-30G) while maintaining a favorable balance of mechanical properties. Composites processed via melt processing demonstrated enhanced mechanical properties compared to PA6-30G. Notably, significant improvements were observed in impact strength and tensile strain at break. The addition of PA10 resulted in increases of 18% in impact strength and 35% in tensile strain relative to PA6-30G. Complementary, structural and morphological analyses confirmed strong interfacial interactions within the composite matrix. These findings indicate that a PA6/PA10 hybrid composite may represent a viable alternative material for potential automotive applications.

Sustainable architectural heritage conservation focuses on preserving historical buildings while promoting environmental sustainability. It involves using eco-friendly materials and methods to ensure that the cultural value of these structures is maintained while minimizing their ecological impact. In this paper, the use of the hydroxyapatite (HAp) in various combinations on masonry samples is presented, with the aim of identifying the ideal solution to be applied to an entire historical building in Banloc monument. The new solution has various advantages: compatibility with historical lime mortars (chemical and physical), increased durability under aggressive environmental conditions, non-invasive and reversible, aligning with conservation ethics, bioinspired material that avoids harmful synthetic additives, preservation of esthetics—minimal visual change to treated surfaces, and nanostructural (determined via SEM and AFM) reinforcement to improve cohesion without altering the porosity. An innovative approach involving hydroxiapatite addition to commercial mortars is developed and presented within this paper. Physico-chemical, mechanical studies, and architectural and economic trends will be addressed in this paper. Some specific tests (reduced water absorption, increased adhesion, high mechanical strength, unchanged chromatic aspect, high contact angle, not dangerous freeze–thaw test, reduced carbonation test), will be presented to evidence the capability of hydroxyapatite to be incorporated into green renovation efforts, strengthen the consolidation layer, and focus on its potential uses as an eco-material in building construction and renovation. The methodology employed in evaluating the comparative performance of hydroxyapatite (HAp)-modified mortar versus standard Baumit MPI25 mortar includes a standard error (SE) analysis computed column-wise across performance indicators. To further substantiate the claim of “optimal performance” at 20% HAp addition, independent samples t-tests were performed. The results of the independent samples t-tests were applied to three performance and cost indicators: Application Cost, Annualized Cost, and Efficiency-Cost-Performance (ECP) Index. This validates the claim that HAp-modified mortar offers superior overall performance when considering efficiency, cost, and durability combined.

This study investigates the potential of Layered Double Hydroxides (LDH) as additives to improve the durability and physical properties of cement-based mortars, with a focus on freeze-thaw resistance. Three LDH types—MgAl-LDH, CaAl-LDH, and ZnAl-LDH—were synthesized and incorporated into mortar at a 1/1000 w/w ratio. X-ray diffraction (XRD) and wavelength dispersive X-ray fluorescence spectroscopy (WDXRF) were used to characterize the LDHs, and the effects of the additives on mortar density, water absorption, and durability under 30 freeze-thaw cycles were examined. Results revealed that MgAl-LDH provided the best freeze-thaw resistance, likely due to its smaller crystallite size and enhanced cement hydration. CaAl-LDH offered moderate improvements, while ZnAl-LDH negatively impacted the mortar’s mechanical integrity, leading to higher degradation. The study demonstrates the potential of LDH additives—particularly MgAl-LDH—in improving the durability of cementitious materials, although further optimization is required to enhance long-term performance and resistance to environmental stresses.

The paper aims to conduct a novel investigation of ceramic samples from the Trophaeum Traiani Monument in Romania using various nuclear analytical techniques such as WDXRF, XRD, neutron diffraction, and neutron tomography, which will be complemented by FTIR and Raman spectroscopy data. The experimental data gathered revealed the mineral and chemical composition of the object’s surface, identifying quartz, hematite, calcite, and graphite. The employment of non-destructive techniques with high penetration capabilities is adequate in examining the spatial distribution and phase composition of the samples, providing valuable insights into their composition and structure without altering their integrity.