Search Results (259)

The shear strength of rock discontinuities is critical for the stability of deep underground projects. However, its accurate determination is hindered by the discreteness of natural joints and the limitations of conventional direct shear tests, which operate under simplified two-dimensional stress conditions, unlike the true triaxial (σ₁ > σ₂ > σ₃) in situ state. This study introduces and validates a multistage true triaxial direct shear testing method as a practical solution. Through controlled pre-peak unloading, complete failure envelopes were successfully obtained from single specimens of jointed granite and intact marble with minimal strength degradation. The results demonstrate that lateral stress significantly enhances the peak shear strength, characterized by a marked increase in cohesion coupled with a slight decrease in the internal friction angle. For intact marble, increasing the lateral stress from 0 to 20 MPa raised the cohesion by approximately 67% (from 34.9 to 58.4 MPa), while the friction angle decreased from 49.3° to 42.8°. For jointed granite, cohesion showed a more variable but consistently strengthening trend with confinement, accompanied by a minor adjustment in the friction angle. Acoustic emission monitoring confirms that pre-peak unloading confines damage accumulation to microcrack reactivation. From a fracture mechanics perspective, the strength enhancement is attributed to the suppression of tensile crack propagation and the promotion of shear localization under three-dimensional confinement. Collectively, this work establishes a novel experimental framework and elucidates the mechanism by which lateral stress governs the shear behavior of hard rock, offering direct implications for the design and stability assessment of deep excavations and related geo-engineering projects. Full article

Background: Autism spectrum disorder (ASD) is a neurodevelopmental condition characterized by social deficits, repetitive behaviors, and heightened anxiety. Despite extensive research, effective interventions targeting core symptoms remain limited. Gami-Guibitang (GBT), a traditional herbal formula, has been clinically prescribed for anxiety-related symptoms and cognitive complaints, yet its effects on ASD-associated behavioral and molecular abnormalities have not been fully elucidated. Objective: This study aimed to evaluate the anxiolytic and neuroregulatory effects of GBT in a valproic acid (VPA)-induced ASD mouse model, focusing on behavioral outcomes and hippocampal synaptic protein expression. Methods: Pregnant C57BL/6N mice received a single intraperitoneal injection of VPA (500 mg/kg) at embryonic day 12.5. Male offspring were administered GBT (150 mg/kg, p.o.) twice daily for 4 weeks from postnatal day 21 (PND 21). These mice were behaviorally evaluated by the open-field test, elevated plus maze, marble-burying test, Y-maze, three-chamber social interaction test, and Morris water maze. Western blot analysis was conducted to examine hippocampal expression of phosphorylated and total CREB and GluR1, PI3K/Akt signaling components, as well as GABRA1 and GABRB1. Results: VPA-exposed offspring exhibited increased anxiety-like behaviors, altered repetitive behaviors, dysregulated exploratory activity, and impaired spatial learning, and reduced spontaneous alternation performance in the Y-maze. GBT reduced anxiety-like behaviors in the elevated plus maze and marble burying tests, partially improved spatial learning acquisition in the Morris water maze, and normalized excessive locomotor activity, without significantly affecting short-term working memory performance. At the molecular level, GBT significantly attenuated VPA-induced hyperphosphorylation of CREB, GluR1, PI3K, and Akt, indicating suppression of aberrant synaptic signaling rather than global enhancement. In addition, GBT increased GABRA1 expression toward control levels and enhanced GABRB1 expression beyond baseline, suggesting selective modulation of GABAergic receptor subunit composition rather than simple normalization. Conclusions: These findings provide preclinical evidence that GBT alleviates anxiety-like behavior and modulates hippocampal synaptic signaling disrupted by prenatal VPA exposure. By attenuating aberrant excitatory signaling and selectively regulating GABAergic receptor balance, GBT may represent a multi-target herbal candidate for modulating ASD-associated emotional dysregulation and domain-specific cognitive dysfunction, rather than acting as a broad cognitive enhancer. Full article

This study investigates the effects of artificial plate powders with different compositions on the durability, physical, mechanical, and microstructural properties of self-compacting mortar (SCM). Waste quartz-based composite plate fragments and waste cultured marble pieces were ground into fine powders, and the resulting quartz-based plate powder (WQP) and cultured marble powder (WMP) were used as filler materials to partially replace cement at replacement levels of 0%, 5%, 10%, 15%, 20%, and 25% by mass. The workability of fresh mortars was evaluated using the mini slump flow test in accordance with EFNARC guidelines, while hardened specimens were tested for porosity, capillary water absorption, abrasion resistance, flexural strength, and compressive strength. In addition, specimens with a 25% replacement ratio that were exposed to temperatures of 300 °C, 600 °C, and 900 °C underwent mechanical testing, and their microstructures were analyzed using SEM and XRD. The results indicated that increasing replacement ratios generally reduced workability and mechanical strength, while increasing porosity and water absorption. However, low replacement levels slightly enhanced flexural strength due to the filler effect. SEM and XRD analyses revealed that the quartz in WQP maintained high thermal stability, and mortars containing WQP exhibited a denser, more coherent, and more homogeneous microstructure. Overall, the findings demonstrate that waste-based plate powders can serve as sustainable fillers in SCM, offering environmental benefits while maintaining acceptable mechanical and microstructural performance. Full article

Background/Objectives: Reduced serotonin transporter (SERT) function is associated with increased vulnerability to emotional and metabolic dysregulation, particularly in elderly women. Most preclinical studies relied on young male rodents with complete Sert deficiency; the Western diet (WD) acerbates these abnormalities. However, complete Sert loss does not fully reflect the human condition of partial SERT dysfunction. Here, we examined the effects of WD in aged female Sert^+/− mice on metabolic, biochemical, molecular, and behavioral outcomes. Methods: Wild-type (WT) and Sert^+/− mice were fed WD or a control diet. Emotionality, cognition, glucose tolerance (GT), plasma ¹HNMR spectroscopy metabolome and biochemical parameters were studied. Gene expression analyses of nitric oxide (NO)-related markers were performed in the hypothalamus, dorsal raphe, and liver. Results: WD-exposed WT mice showed impaired GT and reduced plasma lactate and branched-chain amino acid levels; metabolome changes were more pronounced in mutants, while GT was unchanged. Naïve Sert^+/− mice exhibited lower lactate and alanine levels compared with WT controls. WD increased leptin and cholesterol levels in both genotypes, whereas triglyceride concentrations were reduced in Sert^+/− mice. Both WD and Sert deficiency increased Nos expression, while arginase expression was differentially regulated by genotype and diet. Malondialdehyde levels were elevated in the prefrontal cortex of Sert^+/− mice regardless diet. WD also impaired object recognition memory and induced anxiety- and depression-like behaviors, with more pronounced effects in Sert^+/− mice, except marble test behavior. Conclusions: Partial Sert deficiency aggravates some but not all WD-induced metabolic alterations, enhances oxidative stress, dysregulates arginine–NO signaling, and modifies behavior, highlighting the translational relevance of Sert^+/− mice for modeling SERT dysfunction. Full article

This study aimed to evaluate the technical and environmental feasibility of producing concrete paver blocks and pervious concrete paver blocks by incorporating marble waste to evaluate its filler effect within the cementitious matrix. The methodology included the characterization of marble waste, the production of test specimens with the control (0%), 10%, 20%, and 30% of cement replacement, and the execution of performance tests, supplemented by statistical analyses. The results indicated that marble waste replacement significantly impacted the properties. In terms of pervious concrete paver block permeability, the highest rates were observed in the control and 30% treatments. For water absorption, concrete paver blocks showed higher values at a maximum of 20%, while pervious concrete paver blocks maintained statistically analogous values for 10% and 20%. Regarding compressive strength, the concrete paver block formulation with 10% marble waste was statistically compatible with the control. It is concluded that the incorporation of marble waste into concrete and pervious concrete paver blocks is environmentally advantageous as it valorizes an industrial waste. However, mix design optimization is essential, given that excessive replacement (above 10%) resulted in a reduction in compressive strength. Full article

Sulfide-bearing iron oxide deposits consisting of magnetite and silicates are common within the greenstones of north-west Finland and northern Sweden. These iron oxide deposits have variable copper, gold, and uranium content and occur in association with tuffite, black schist, and dolomitic marble. The deposits have a resource size of up to 145 Mt and an iron content of 35%–50% (e.g., Stora Sahavaara). The total sulfur content of these deposits is typically in the range of 1%–5% but can have exceptional values up to 20.8%, and disseminated pyrite, pyrrhotite, and chalcopyrite are commonly present. The prediction of acid rock drainage and metal leaching potential requires a detailed understanding of the site-specific rates and mechanisms of weathering. This has been obtained through geochemical (multi-element analysis and acid–base accounting) and mineralogical characterization testing undertaken on representative materials, including multi-element analysis, acid–base accounting, net acid generation testing, and humidity cell testing. Despite the high sulfide content and low neutralizing potential of most rock types found in these deposits, the humidity cell tests showed a delayed onset to acid generation, which is primarily attributed to sulfide crystallinity and mafic silicate dissolution leading to slow oxidation and reaction rates. The need for long-term kinetic testing is evident from the Hannukainen amphibole and schist rock types. This study provides an overview of the environmental geochemistry of the skarn-hosted sulfide-bearing iron oxide deposits in Scandinavia. These deposits show potential for acid generation but due to the buffering reactivity of mafic silicates and the high crystallinity of the sulfides, the rate of acid generation is slow and the onset of these conditions delayed by mineral buffering. Full article

In the marine environment, numerous factors endanger the preservation of underwater rock surfaces as well as submerged archeological artifacts, including physical, chemical, and biological processes. Limestone and marble are common materials used in artifacts due to their availability and long-term durability. However, such surfaces provide a suitable substrate for the settlement of micro- and macro-organisms, causing so-called biofouling, which significantly contributes to stone deterioration. Previous studies have demonstrated the applicability of antifouling coatings containing ionic liquids (ILs) on marble surfaces and assessed their durability for up to 15 days under submerged environments. To further corroborate these results, additional physical studies (colorimetric, contact angles, capillarity water absorption measurements, and UV aging) were carried out on treated limestone. Washout tests were also performed on both lithotypes to verify the coatings’ stability under medium-term underwater exposures. The results of these investigations are reported here. Our data confirm that the application of IL-based coatings had no effect on the intrinsic properties of the limestone surfaces, as previously reported for marble, including resistance to daily UV irradiation. In addition, laboratory tests demonstrated good coating durability against seawater erosive action for up to 6 months. Full article

This paper examined the effect of marble powder (MP) on air-cured cement-based materials when subjected to sulfuric acid (H₂SO₄) attack. Four MP replacement levels were tested: 0%, 5%, 10%, and 15% by weight of cement. The prepared samples were cured for 90 days prior to being exposed to H₂SO₄. Macroscopic tests for apparent density and compressive strength along with microstructural characterization using X-ray diffraction (XRD) and scanning electron microscopy (SEM) were performed to determine the effect of MP on the properties of the materials. The Rietveld method was used to analyze the amounts of different crystalline phases and amorphous calcium silicate hydrate (C-S-H). The obtained results indicate that 5% MP in air-cured cement -based materials exhibited the best behavior with acceptable resistance to acid attacks. This level of MP replacement was found to optimize the filler effect, improve the hydration process, and enhance the matrix density, which in turn reduces the permeability of the material and increases acid resistance. This is attributed to the balanced contribution of MP to phase formation, particularly calcite, which helps to counteract acid-induced dissolution, while also preserving the stability of C-S-H phases. This study provides a new perspective of the role of MP in influencing phase content (crystalline and amorphous phases) and their possible impacts on macroscopic properties such as apparent density and compressive strength. MP behaved as a filler, to improve hydration and resistance to acid attacks. Additionally, using MP as a replacement for ordinary Portland cement (OPC) offers a sustainable alternative by reducing waste and promoting the recycling of marble industry by-products, thereby contributing to environmental sustainability. It is recommended that, 5% MP is the optimal replacement content to enhance durability and mechanical properties in air-cured cement-based materials in aggressive environments, as it is both practical and achievable for infrastructure to be subjected to the aggressive environment. Full article

Environmental stressors, such as freeze–thaw (F–T) cycling and acid rain, affect the durability of carbonate rocks used in engineering and cultural heritage structures. This study investigates the mechanical degradation and strain evolution of Carrara marble subjected to 10 F–T cycles and immersion in a simulated sulfuric acid solution (pH 5) for 3, 7, and 28 days. The mechanical strength of the samples was tested under uniaxial compression using a displacement-controlled loading rate, while full-field deformation and fracture evolution were analyzed with Digital Image Correlation (DIC). Results show that F–T cycling led to a substantial reduction in uniaxial compressive strength (UCS) and a very large decrease in tangent Young’s modulus. Acid exposure also caused progressive degradation, with both UCS and stiffness continuing to decline as exposure time increased, reaching their greatest reduction at the longest treatment duration. Additionally, DIC strain maps revealed a change in deformation response as a function of the treatment. The findings provide the integrated assessment of Carrara marble mechanical response under both F–T and acid weathering, linking bulk strength loss with changes in strain localization behavior, highlighting the vulnerability of marble to environmental stressors, and providing mechanical insights relevant to infrastructure resilience and heritage conservation. Full article

Portland cement is widely used in construction, but it contributes significantly to global CO₂ emissions. This study evaluates the potential use of construction and demolition waste (CDW) and marble powder (MP) as supplementary cementitious materials, in line with circular economy goals. Both wastes were ground finer than cement and characterised chemically and physically. Binary and ternary blends with 5% and 10% replacement were tested in pastes and mortars for fresh properties, mechanical performance, and durability. Setting time, soundness, and workability remained within standard limits. Compressive strength decreased moderately, with 28-day activity indices between 82 and 88%, confirming the low reactivity of the supplementary cementitious materials. Sorptivity decreased in all mixes, and chloride resistance improved in the 10CDW and 10MP blends. However, the ternary mix showed increased chloride migration. Carbonation depth increased in all mixes, indicating the need for protective measures in carbonation-prone environments. Replacing 10% of cement with CDW or MP can avoid 70–80 kg of CO₂ per tonne of binder and reduce landfill waste. These materials can be used as low-carbon fillers in cement-based systems, provided that their durability limitations are considered in design. Full article

In assessing the strength properties of stone materials, especially in historic structures, ultrasonic measurements are widely used as a non-destructive testing (NDT) method. Actual stone degradation in situ is estimated based on various laboratory tests which allow researchers to correlate the number of artificial ageing cycles of stone specimens with ultrasonic wave velocity measured on these specimens. This paper presents the results obtained for granite, marble, limestone, travertine and sandstone which underwent various cyclic ageing tests including freezing and thawing, high temperature and salt crystallization. Analysis of the obtained results shows that, independent of the stone type tested and independent of the ageing test applied, a rate of change in the stone elastic properties is described by an ordinary differential equation whose solution is an exponential law analogue to the Newton’s law of cooling. The degradation function model can be used for further research on expected residual strength and dynamics of the heritage materials degradation processes. Full article

One of the environmental concerns today is the increasing amount of waste generated from marble quarrying and processing. This study evaluates the mechanical and durability properties of marble waste-modified rigid pavement material. A series of laboratory tests was conducted to obtain the properties of marble waste-modified rigid pavement material. The slump value decreases as the percentage of marble waste increases. As the percentage of marble waste increases, the dry density gradually decreases from 2770 kg/m³ to 2590 kg/m³. Comparison of the 7-day and 28-day compressive strength indicates that replacing the gravel with marble waste resulted in early strength gain, making it suitable for use in conditions that require early strength gain. The scanning electron microscopy results indicated higher calcium content for the 10% marble waste sample, which is responsible for the cementation and supports the higher compressive strength obtained for the sample at 7 days of curing, due to early strength gain. The study is the first to show the synergistic effect of marble waste on early strength and durability in rigid pavements. These findings showed that marble waste can be used as a modifier in rigid pavement materials. The study contributes to Sustainable Development Goals 9 and 11. Full article

The conservation of heritage buildings requires non-invasive tools that can predict material performance while maintaining historical integrity and structural safety. This study introduces a multivariate statistical framework that integrates regression analysis, Principal Component Analysis (PCA), and Hierarchical Cluster Analysis (HCA) to classify seven traditional materials adobe, lime mortar, limestone, sandstone, marble, volcanic stone, and wood based on their mechanical, thermal, and moisture-related properties. This study aims to develop a validated multivariate framework for classifying traditional heritage materials based on their mechanical, thermal, and moisture-related properties to support sustainable restoration and retrofit design for classifying traditional materials based on their mechanical, thermal, and moisture-related properties to support sustainable restoration and retrofit design. Unlike prior research limited to single-material assessments, this study standardizes and analyzes data from fourteen peer-reviewed sources using regression models, Principal Component Analysis (PCA), and Hierarchical Cluster Analysis (HCA), Principal Component Analysis (PCA), and Hierarchical Cluster Analysis (HCA), complemented by pilot non-destructive validation tests on lime mortar, sandstone, limestone, and marble. The framework compiles and standardizes datasets from fourteen peer-reviewed sources into a unified predictive model. The framework was validated through pilot testing using non-invasive methods (density, ultrasonic pulse velocity, rebound hardness), which confirmed the statistical predictions of robustness versus moisture vulnerability. Advanced cluster solutions identified conservation-relevant subgroups, enabling engineers to distinguish between moisture-sensitive low-density materials and durable lithic stones, with direct implications for sustainable restoration and retrofit practices. The originality of this study lies in transforming fragmented datasets into a validated, decision-support tool that can be embedded into Historic Building Information Modeling (HBIM) platforms for predictive diagnostics, compatibility assessment, and energy-efficient retrofit planning in heritage structures. This study provides the first validated cross-material statistical framework linking traditional conservation materials with predictive digital-modeling tools. This framework further demonstrates that the application of regression, Principal Component Analysis (PCA), and Hierarchical Cluster Analysis (HCA) enables quantitative prediction of material performance through non-destructive parameters. The integration of these techniques provides interpretive value beyond descriptive classification, facilitating preventive diagnostics, compatibility assessments, and energy-oriented retrofit planning within HBIM systems. Full article

Biodeterioration represents a major threat to cultural heritage, as microbial colonization can cause both esthetic and structural damage. The use of conventional chemical biocides raises concerns due to environmental and health risks, potential substrate deterioration, and the emergence of resistant strains. In this study, an ozone-loaded bacterial cellulose (OBC) hydrogel was investigated as an eco-friendly, broad-spectrum antimicrobial treatment in the case study of the Cryptoporticus of the Baths of Trajan (Rome, Italy), a hypogean archeological site where some structures are severely affected by phototrophic biofilms. Microorganisms isolated from a colonized wall were employed in laboratory assays. OBC hydrogel exhibited strong antimicrobial activity, with >90% bacterial mortality within 10 min, complete inhibition of fungal spore germination after 24 h, and a marked reduction in microalgal chlorophyll fluorescence comparable to heat-killed controls. Furthermore, tests on Carrara marble and brick specimens artificially contaminated with microalgae confirmed the removal of green staining, restoring surface chromatic parameters (ΔE* < 5) comparable to those obtained with a commercial biocide. In situ applications demonstrated significant suppression of green biofilm for at least two months. These findings support OBC hydrogel as a sustainable, effective, and non-toxic alternative to conventional biocides for controlling microbial and microalgal colonization on cultural heritage surfaces. Full article

Autism spectrum disorder (ASD) is a group of neurodevelopmental dysfunctions characterized by a heterogeneous etiology that involves gene–environment interactions. Early postnatal lead (Pb) exposure has been found to be associated with the etiology of ASD, but the mechanisms remain unclear. The present study aims to investigate the effects of early Pb exposure on the emergence of ASD-like behaviors in offspring and to evaluate its potential relationship with morphological changes and underlying mechanisms in the cerebellum. The study established a mouse model to study early postnatal Pb exposure and examined ASD-like behaviors through the open field test, novel object recognition test, marble burying test, and three-chamber social test. Quantification of Pb levels was performed in cerebellar tissue, examination of Purkinje cell morphology was carried out, and identification of differential protein expression was conducted using TMT-based quantitative proteomics. The study revealed that the offspring of Pb-exposed mice showed significant social deficits, increased repetitive behaviors, and cognitive impairments. The cerebellum showed both elevated Pb levels and a reduction in Purkinje cells. Proteomic analysis identified 45 proteins that were differentially expressed, showing disruption in the retinoid signaling pathway. These findings demonstrate that early postnatal Pb exposure leads to ASD traits and that retinoid signaling may be a key pathway in the cerebellum, at least in part. Full article