Search Results (262)

Acoustic emission (AE) source localization provides important spatial information for damage characterization and fracture evolution analysis in construction materials, while its accuracy and applicability are strongly dependent on sensor network design. This study proposes an optimization framework for selecting an effective six-sensor network for velocity-free AE source localization in construction materials. The source coordinates are determined by solving a nonlinear inverse problem using the Levenberg–Marquardt algorithm, and candidate sensor subsets are evaluated by combining location error metrics with the number of effective localization results to quantify the effective monitoring range for damage characterization. The framework is investigated through numerical simulations and pencil-lead break tests on a 600 mm × 600 mm ceramic tile. Among different six-sensor configurations, the best-performing layouts place four sensors at the outer corners and two sensors at the horizontal or vertical inner corners. A benchmark comparison with the Fisher-information-based optimized sensor network and sensitivity analyses further show that the optimized sensor network maintains higher effective monitoring ranges under arrival-time noise, velocity uncertainty, and sensor coordinate perturbations. The proposed approach provides a useful reference for robust and cost-effective AE sensor network design in damage monitoring, fracture characterization, and nondestructive evaluation of construction materials. Full article

This study investigates a red pottery eave-end tile (Wadang) from the Minyue Kingdom Imperial City (Western Han Dynasty), a World Heritage Site in Fujian. By integrating quantitative petrography, XRD, and Raman spectroscopy, we systematically characterized its microstructure and production technology. Scientific analyses identify the raw material as local feldspathic–quartz clay, evidenced by angular, ill-sorted quartz inclusions with significant distributional heterogeneity. XRD analysis identified a rigid quartz skeleton, while Raman spectroscopy further revealed a hematite-rich surface formed under an oxidizing atmosphere. While typological analysis confirms a mid-Western Han Cloud Pattern style influenced by the Central Plains, the observed microstructural heterogeneity indicates a production mode characterized by high individual craftsmanship but low overall standardization. These findings highlight the Minyue artisans’ adaptive fusion of imperial aesthetics with indigenous manufacturing techniques, providing material evidence for the center–periphery cultural exchange in the Han Empire. Full article

Tile adhesive mortars are industrialized products used for installing ceramic coverings and are classified according to the Brazilian standard ABNT NBR 14081/2012 on the basis of tensile adhesion performance under different curing conditions. Their formulation directly affects both technical performance and manufacturing competitiveness, while conventional product development remains slow, costly and strongly dependent on trial-and-error laboratory testing. This study evaluates whether historical industrial formulation data can support the retrospective prediction of approval or failure of tile adhesive mortars under ambient, oven, immersed and open-time curing conditions. A dataset comprising 6031 individual pull-off observations collected between 2021 and 2023 by a European multinational company in the construction materials sector was used to train and compare Logistic Regression, Random Forest, Boosted Decision Tree and Support Vector Machine models in R and Azure. The study was designed as an industrial-data modelling investigation rather than as a prospective optimization experiment. The results show that ensemble tree-based models, particularly Boosted Decision Tree and Random Forest, achieved the strongest predictive performance, whereas Logistic Regression remained more suitable for inferential interpretation of formulation variables. Model performance was uneven across curing conditions: prediction was more reliable for oven and immersed curing, whereas ambient curing and open time were affected by strong class imbalance and low failure prevalence. The findings indicate that Machine Learning can support formulation screening and quality-oriented decision-making for tile adhesive mortars, provided that its use remains restricted to the formulation ranges represented in the historical dataset and is complemented by prospective experimental validation before deployment in new product development. Full article

The ceramic tile industry is increasingly required to reduce its environmental impact while maintaining high technological and aesthetic standards. In this context, the use of secondary raw materials (SRMs) represents a promising strategy to decrease the consumption of virgin resources and the energy demand associated with conventional frit production. At the same time, solar-reflective engobes can contribute to passive cooling by limiting solar heat absorption and mitigating the urban heat island effect. In this study, white solar-reflective engobes were developed by incorporating at least 8 wt.% of SRMs, including various recycled glass streams, ceramic wastes, and yttria-stabilized zirconia residues. The results demonstrate that optimized formulations achieve high solar reflectance values (up to 0.79) while maintaining the technological and aesthetic requirements of industrial ceramic tiles. Recycled glasses act as effective fluxing agents, whereas waste zirconia enhances optical performance due to its strong light-scattering capability. The most promising formulations were validated at the industrial scale, confirming their applicability under real production conditions. Overall, the developed engobes represent a scalable alternative to traditional frit-based systems, enabling reduced resource consumption and supporting the development of energy-efficient ceramic surfaces. Full article

The increasing demand for sustainable construction materials has intensified interest in reusing ceramic waste as a supplementary material in cementitious systems due to its potential to reduce environmental impacts and enhance resource efficiency. Previous studies indicated that ceramic roof tile waste powder (CTP) with a fineness value greater than that of cement did not contribute to an enhancement in the compressive strength of mortar. This study investigates CTP with a higher fineness than cement. Experimental parameters include fineness analysis, mortar flow, setting time, and compressive strength test. The instruments used are the Blaine tools for fineness testing, the flow table for mortar flow testing, the Vicat tools for setting time testing, and the Mortar Compression Machine for compressive strength testing. Mortar specimens (5 × 5 × 5 cm³) were prepared by partially replacing cement with CTP at different substitution levels. The results indicate that the addition of finely ground CTP increases mortar flow, extends setting time, and enhances compressive strength, suggesting its potential as a supplementary cementitious material in mortar applications. Full article

Accelerated industrial development, mass production, economic viability, and environmental sustainability impose new requirements on contemporary materials, positioning basalt as a promising, cost-effective, and abundant environmentally benign raw material. This study explores the influence of sintering temperature on the physical properties of ceramics obtained from andesite basalt aggregate. Relative density, shrinkage, and color changes were monitored to optimize the sintering temperature for the serial production of high-density ceramics. Varying the sintering temperature by 10 °C within the 1040–1080 °C range, while maintaining a constant sintering time of 60 min, leads to significant changes in relative density, shrinkage, and color. Beyond visual appearance, color changes can be quantified with coordinates in color spaces, usually in the CIELAB color space, standardized by the Commission Internationale de l’Eclairage (CIE). The best physical properties were achieved at a sintering temperature of 1060 °C for 60 min with a relative density of 99.501%, shrinkage of 12.811%, and color coordinates L*(32.03), a*(9.25), and b*(7.58) according to the CIELAB analysis. The favorable physical properties and distinctive reddish-brown color of sintered andesite basalt ceramics make them promising for floor and wall tile applications. Full article

The conservation of tuff- and coral rock-built architectural heritage structures (AHS) is challenging because access to original tuff and coral rock has become difficult and severely limited due to urbanization, land reclamation, the depletion of stone quarries, anti-mining and anti-quarrying legislation. An emerging approach to address this issue is to create compatible “replacement” rocks via geopolymerization, a process that is more sustainable and greener than the use of conventional cement and concrete. To explore the potential of geopolymers for AHS conservation strategies, the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were implemented; 103 eligible articles were identified and classified into geopolymers for AHS (34 articles), tuff-built AHS (60 articles), and coral rock-built AHS (9 articles). Tuff substrates in AHSs appear in a variety of colors (yellowish-brown, grayish-cream, reddish-brown, pale greenish-gray and pink hues), densities (1.0–2.5 g/m³), and compressive strengths (3–100 MPa). Meanwhile, coral rock substrates in AHSs appear in whitish-cream color and are coarse-pored (1–5 MPa), fine-grained (8–15 MPa), and calcarenite (50–60 MPa). In terms of geopolymer formulation, metakaolin was reported as the most popular main precursor or admixture, while NaOH and Na₂SiO₃ were used simultaneously as alkaline activators. Aggregates used in geopolymer formulations depended on local availability, including quartz sand, river sand, crushed stones, carbonate stones, volcanic rock, volcanic sand, tuff, brick, ceramic tiles, and waste materials. Aesthetics, chemical composition, physical attributes, and mechanical properties have been identified as key criteria to ensure geopolymer compatibility for AHS conservation application. To date, geopolymers have been applied for AHS conservation as repair mortars, consolidants (i.e., grout and adhesives), and masonry strengthening (i.e., fiber-reinforced mortar). Finally, geopolymers formulated for AHS conservation have similar durability as the original substrate based on accelerated aging tests (i.e., salt mist, wet-dry, and freeze–thaw) and long-term outdoor exposure experiments. Full article

The continuous drive for higher efficiency in gas turbines has led to increased combustion temperatures, making the thermal shock resistance of thermal insulation tiles a critical factor limiting performance. Corundum–mullite multiphase ceramics are widely used in such applications; however, their performance is often constrained by an inherent trade-off between mechanical strength and thermal shock resistance. In this work, a synergistic modification strategy based on rare-earth disilicate phases was developed, wherein Y₂O₃ and SiC were incorporated into a corundum–mullite matrix to enable in situ formation and controlled distribution of Y₂Si₂O₇ via gel casting. During sintering, Y₂Si₂O₇ acts as a transient liquid phase, facilitating densification and grain boundary strengthening; upon thermal shock, it migrates to fill and heal grain boundaries and microcracks, thereby significantly enhancing thermal shock resistance. The optimized sample S5, sintered at 1400 °C, exhibited a bulk density of 2.12 g/cm³ and a bending strength of 68.43 MPa. Notably, after 30 thermal shock cycles (air cooling from 1000 °C to RT), its bending strength increased to 79.71 MPa, corresponding to a 16.48% enhancement. This work provides an effective strategy for incorporating rare-earth disilicates into multiphase ceramics and offers valuable guidance for the development of high-performance components for gas turbines. Full article

This paper presents a method for measuring the spatial distribution of surface normal vectors with high angular accuracy. The measured data are visualized using a color-mapping technique and represented as normal maps, which are commonly used in computer graphics. Reliable methods for evaluating material surface properties have long been sought in industrial applications where visual assessments of reflective properties are still widely employed, particularly in appearance-critical fields. Motivated by this need, we introduce an imaging-based technique for measuring the high-resolution spatial distribution of surface normal vectors from specular reflection. A dedicated measurement apparatus was developed to capture surface normal vectors at 1024 × 1024 sampling points with a spatial resolution of 0.02 × 0.02 mm and an angular resolution of approximately 0.1°. Using this apparatus, normal maps were obtained for various materials, including plastic, ceramic tile, inkjet paper, and aluminum sheets. The spatial distribution of surface normal vectors reflects surface roughness, which strongly influences perceived texture. The resulting normal maps enable not only quantitative surface analysis for industrial inspection but also the physical reproduction of gloss in computer graphics. Full article

This study investigates the feasibility of using brick and ceramic tile waste as aluminosilicate precursors for geopolymer synthesis by analyzing the influence of NaOH concentrations, the Na₂SiO₃/NaOH ratio, and curing methods on the physical and mechanical properties of the resulting matrices. Geopolymer pastes were prepared using NaOH concentrations ranging from 5 to 12 mol/L and Na₂SiO₃/NaOH ratios of 2:1 and 2.5:1. Compressive strength, water absorption, density, and void ratio were evaluated. The results indicate that a combined curing method, consisting of initial curing under dry ambient conditions followed by thermal curing at 60 °C, significantly improved the development of mechanical strength. The brick-based geopolymers reached maximum compressive strengths exceeding 55 MPa at intermediate NaOH concentrations, whereas ceramic tile-based geopolymers required higher alkalinity levels and increased soluble silica content. Overall, the findings confirm that an appropriate combination of precursor type, alkaline activator dosage, and curing conditions enables the formation of geopolymers with denser matrices and enhanced mechanical and physical properties, thereby supporting their potential as a sustainable alternative for the construction industry. Full article

This study presents a comparative evaluation of Environmental Product Declarations (EPDs) within the traditional ceramic industry, emphasizing how differences in data structures, reporting formats, and background databases influence the interpretation of environmental performance. Four product categories—ceramic tiles, sanitary ware, clay bricks, and clay roof tiles—were analyzed using datasets from One Click LCA and the International EPD System. Environmental indicators assessed include fossil-based and total Global Warming Potential (GWP), freshwater consumption, and energy demand, standardized per 1 kg of product. The analysis reveals that discrepancies between platforms arise primarily from the limited level of process-specific information required by current EPD formats, rather than from the platforms themselves. Missing details on raw material composition, firing conditions, and energy sources restrict comparability and hinder the development of robust benchmarks. Furthermore, the study highlights the need for harmonized databases, more transparent PCR requirements, and consistent reporting rules to support meaningful cross-platform comparisons. As the first study to examine EPD data structures for ceramic products across two major reporting systems, it highlights the need to expand product-specific benchmarks and enhance disclosure practices to strengthen the role of EPDs in sustainable market design and climate policy. Full article

The identification of calcareous foraminifera and nannofossils in archaeological ceramics (tiles and bricks from the Archaic to Roman ages) of Naxos and Taormina (Sicily) has, along with other evidence and archaeometric analyses, addressed aspects of technology and raw material source areas. Microfossils, like the other aplastic inclusions, help to interpret ceramic pastes. This paper provides, for northeastern Sicily, a contribution demonstrating the importance of an integrated approach in the study of archaeological ceramics; micropaleontological analysis supports mineralogical, petrographic and chemical data to constrain interpretations of provenance and technology. The preservation of foraminifera calcitic tests and coccoliths is an additional key to identifying errors, failures and strategies during the ancient ceramic firing process. Comparisons with the micropaleontological content of locally outcropping clay deposits have allowed for the unambiguous identification of the clay sources used for ancient ceramic production in the region. Full article

Municipal solid waste incineration (MSWI) fly ash is classified as hazardous waste due to its enrichment of heavy metals and dioxins. This article systematically reviews its generation pathways, physicochemical characteristics, and potential environmental risks, based on the literature from 2010 to 2025 sourced from Web of Science, Scopus, ScienceDirect and China National Knowledge Infrastructure. Emphasis is placed on heavy metal stabilization, dioxin degradation and resource recovery from MSWI fly ash. The mechanisms, technical advantages, and application limitations of three mainstream detoxification, including solidification/stabilization, extraction and thermal treatment, were emphasized. For instance, geopolymer achieves >99.6% Pb immobilization and electrodialytic removal rates of Cd up to 98%, while vitrification reduces the MSWI fly ash volume by >50%. A comprehensive exploration of MSWI fly ash resource utilization was conducted, covering the preparation of ceramic tiles, synthesis of glass ceramic and glass ceramic foams, processing of road substrates, and modification of cement-based composite materials. The current technological system still faces challenges such as high costs, excessive energy consumption, and secondary pollution. Future research should focus on developing green, low-carbon, and low-cost processes, improving long-term environmental stability of products and strengthening pollution source reduction control. Full article

In the high Andean regions of Peru, above 3500 m a.s.l., selecting a roofing system requires balancing budgetary constraints, technical performance, and environmental impacts under severe frost and demanding climatic conditions. This study compared several roofing alternatives from a comprehensive perspective to determine the most suitable solution by simultaneously considering economic, environmental, and social criteria. For this purpose, the Integrated Value Model for Sustainable Assessment (MIVES)—a multi-criteria decision-making methodology—was employed to evaluate five systems: traditional ichu thatched roof (ITR), ceramic tile (CT-II), corrugated galvanized steel with insulation (CGS-II), fiber cement with insulation (FC-II), and sandwich panel with an insulating core (PIR-SP). The model was implemented using a requirements tree with 11 indicators and its stability was assessed through a sensitivity analysis involving five weighting configurations. The overall sustainability indices ranked ITR first (0.697), primarily due to its low carbon footprint and favorable thermal performance. It was followed by CT-II (0.632), due to its superior landscape integration; CGS-II (0.602), owing to its cost-effectiveness; FC-II (0.586), for its balanced environmental profile; and finally, PIR-SP (0.504), which excelled in industrial efficiency and construction speed despite a higher environmental impact. In summary, the results indicated that vernacular solutions minimized environmental impacts and optimized local resources, whereas industrialized options were preferable when durability and assembly times were prioritized. The sensitivity analysis, with variations below 5%, supported the model’s consistency as a decision-support tool and its potential to guide policies for sustainable social housing in high-mountain contexts. Full article

The increasing demand for sustainable construction materials has intensified research on supplementary cementitious materials capable of reducing Portland cement consumption and associated CO₂ emissions. In this context, porcelain polishing residue (PPR), a fine ceramic waste generated by the tile industry, presents potential for valorization in cement-based composites. This study investigates the use of PPR as a supplementary cementitious material in self-compacting concrete (SCC), focusing on its pozzolanic activity and its influence on fresh, physical, and mechanical properties. Pozzolanic behavior was evaluated using strength-based indices with lime and Portland cement, as well as the modified Chapelle method. SCC mixtures were produced with partial replacement of cement by PPR at different levels and assessed in terms of self-compactability, compressive strength, elastic modulus, water absorption, and void index. The results showed that, although PPR did not meet strength-based pozzolanicity criteria at early ages, it exhibited significant calcium hydroxide consumption, indicating latent pozzolanic potential. Fresh-state properties were preserved in all mixtures, and an optimal replacement level of 20% resulted in improved long-term mechanical performance, reduced void content, and enhanced matrix compactness. These findings demonstrate that PPR can be effectively used as a functional supplementary cementitious material in SCC, contributing to more sustainable and eco-efficient concrete production. Full article