Search

Highlights • Lime sludge utilization in concrete, mortars, fired bricks, ceramics and cement. • 10–30% cement replacement in concrete and mortars by lime sludge is optimum. • 25–30% replacement of fine aggregates by lime sludge is optimum. • Bricks and ceramic production with lime sludge conserves less energy. • Lime sludge eco clinker synthesizes with less carbon footprint and temperature. Abstract This review paper encompasses the inclusive approach of lime sludge valorization in construction materials. Research studies based on cement and aggregate replacement by lime sludge concludes that 10–30% lime sludge is gainfully utilized in sustainable concrete and mortar. Additional prospect for lime sludge application in construction material is the production of cement and ceramics. Significant use of lime sludge in combination with supplementary cementitious materials such as silica fume, nanosilica and fly ash is recommended for the production of cement components and ceramics. The recommendations are also suggested in accordance with the outcome of the study. [ABSTRACT FROM AUTHOR]

Different grouting and repair mortars were developed and evaluated for the conservation and restoration of fragmented bricks in the walls and floors of the remaining cellars underneath the Aula Magna, the palace's main banqueting hall, and to fill the lacunae and perform edge repairs of red and blue-grey ceramic floor tiles in the remaining cellars underneath the chapel of the former Palace of Coudenberg in Brussels, Belgium. To prevent the deposition of lime bloom at the surface of the masonry and to achieve an acceptable colour match of the grout in harmony with the bricks of the Aula Magna, the effect of brick powder added to natural hydraulic lime was studied. The pozzolanic properties and colour match of several historic and modern powdered bricks were investigated. Surprisingly, ancient bricks do not seem to possess higher pozzolanic properties than the more modern ones, although it is supposed that they were fired at lower temperatures. Additional evidence for the pozzolanic reaction of the different brick powder materials was obtained from a simple visual observation of stored samples. After eight weeks all of the samples containing brick powders, fired at low and high temperatures, added to putty lime had hardened under water and were transformed into a remarkably tough material. These results are important, as modern bricks are readily available in large quantities and different colours, which are hence in favour of being used instead of historical material from the site. For the repair of the ceramic floor tiles different mortars were investigated with mixtures containing talcum, stone or brick powder, pigments, and chalk added to an epoxy binder. The mortars were tested in the laboratory and in situ for their workability and resemblance with the historic floor tiles. The finished mortars showed excellent aesthetic properties with the tiles in situ and good properties to prevent further loss due to human interaction. [ABSTRACT FROM AUTHOR]

This paper analyzes the significant scientific publications worldwide for the last 15years concerning construction ceramics (predominantly brick) made with various inorganic industrial wastes added to the ceramic raw material for the improvement of properties and for eco-friendly disposal. The information gap resulting from the lack of mentions of the Russian publications on this subject in English-language reviews is filled. The paper includes brief summaries of 34 dissertations and 29 patents issued in Russia since 2000. The waste additives described in these summaries are grouped by origin type (mining industry waste, ore enrichment waste, metallurgical waste, sludge, ashes, cullet, large-capacity building wastes and waste from various chemical production processes) with the ceramic mixture compositions, molding and firing conditions, final strength, water absorption and other parameters of the final ceramic samples reported. Russian scientists have expanded the nomenclature of each group of wastes significantly upon addition to the list described in English-language reviews for 2000-2015. References to the recent Russian developments in the field of ecological management in ceramic industry are provided., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Spent adsorbents for oxyanion forming elements and heavy metals are classified as hazardous materials and they are typically treated by stabilization/solidification before landfilling. The use of lime or cement for stabilization/solidification entails a high environmental impact and landfilling costs are high. This paper shows that mixing spent adsorbents in the raw material for the production of ceramic materials is a valuable alternative to stabilize oxyanion forming elements and heavy metals. The produced ceramics can be used as construction material, avoiding the high economic and environmental impact of stabilization/solidification followed by landfilling. To study the stabilization of oxyanion forming elements and heavy metals during the production process, two series of experiments were performed. In the first series of experiments, the main pollutant, Mo was adsorbed onto iron-based adsorbents, which were then mixed with industrial sludge (3 w/w%) and heated at 1100°C for 30 min. Mo was chosen, as this element is easily adsorbed onto iron-based adsorbents and it is the element that is the most difficult to stabilize (i.e. the highest temperatures need to be reached before the concentrations in the leachate are reduced). Leaching concentration from the 97/3 sludge/adsorbent mixture before heating ranged between 85 and 154 mg/kg; after the heating process they were reduced to 0.42-1.48 mg/kg. Mo was actually stabilized, as the total Mo concentration after addition was not affected by the heat treatment. In the second series of experiments, the sludge was spiked with other heavy metals and oxyanion forming elements (Cr, Ni, Cu, Zn, As, Cd and Pb) in concentrations 5 times higher than the initial concentrations; after heat treatment the leachate concentrations were below the regulatory limit values. The incorporation of spent adsorbents in ceramic materials is a valuable and sustainable alternative to the existing treatment methods, saving raw materials in the ceramics production process and avoiding the use of stabilizing agents. Besides, spent adsorbents added to the raw material for ceramic products, may improve their aesthetic and structural properties., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

In the paper, glass ceramics used as architectural materials were prepared based on lead fuming furnace-slag (LFFS) by a synergistic sinter-crystallization method. The effects of Al2O3 addition on the crystallization phase, crystallization kinetics, and mechanical performance of glass ceramics were investigated. The results showed that the phases of the glass ceramics prepared were composed of gehlenite and wollastonite, and crystallization kinetics analysis showed that bulk crystallization dominated the overall crystallization process in the Al2O3 content range from 2% to 8%. The glass transition temperature and the crystallization peak temperature of the glass ceramics generally increased with the increase in the Al2O3 content. Additionally, the crystalline morphology gradually developed from sheet-like to spherical, while the number of pores increased and the bulk density gradually decreased. When the Al2O3 content was 2%, the bending strength of glass ceramics reached its maximum, 75.1 MPa, corresponding to a bulk density of 2.24 g·cm−3. Owing to the high strength and relatively low bulk density, the sintered glass ceramics appear promising for potential applications in lightweight construction tiles. [ABSTRACT FROM AUTHOR]

In this paper, a brief review on reversible dielectric nonlinearity (RDN) was presented and the mechanism of tunability for ferroelectric ceramics was discussed in several different scale levels, such as atomic level (intrinsic nonlinearity described by ferroelectric thermodynamic theory), nano-meter scale (polar nano-region response), submicron scale (ferroelectric domain and domain wall motion), micron scale (polycrystalline structure of ceramics and surface layer) and macroscopic scale (field induced phase transition). It suggests that RDN is a multi-scale phenomenon and is temperature and frequency-sensitive. The halving field E0 in Roberts' Equation may be a good attempt for the quantitating of RDN. The stability of RDN in paraelectric phase is also mentioned. [ABSTRACT FROM AUTHOR]

Cement-asbestos is the main asbestos containing material still found in most of the European countries such as Italy. Man- and weathering-induced degradation of the cement-asbestos slates makes them a source of dispersion of asbestos fibres and represents a priority cause of concern. This concern is the main prompt for the actual policy of abatement and disposal of asbestos containing materials in controlled wastes. An alternative solution to the disposal in dumping sites is the direct temperature-induced transformation of the cement-asbestos slates into non-hazardous mineral phases. This patented process avoids the stage of mechanical milling of the material before the treatment, which improves the reactivity of the materials but may be critical for the dispersion of asbestos fibres in working and life environment. For the first time, this paper reports the description of the reaction path taking place during the firing of cement-asbestos slates up to the complete transformation temperature, 1200 degrees C. The reaction sequence was investigated using different experimental techniques such as optical and electron microscopy, in situ and ex situ quali-quantitative X-ray powder diffraction. The understanding of the complex reaction path is of basic importance for the optimization of industrial heating processes leading to a safe recycling of the transformed product. For the recycling of asbestos containing materials, the Italian laws require that the product of the crystal chemical transformation of asbestos containing materials must be entirely asbestos-free, and should not contain more than 0.1 wt% fraction of the carcinogenic substances such as cristobalite. Moreover, if fibrous phases other than asbestos (with length to diameter ratio >3) are found, they must have a geometrical diameter larger than 3 microm. We have demonstrated that using an interplay of different experimental techniques, it is possible to safely verify the complete transformation of asbestos minerals in this temperature-induced process. The product of transformation of cement-asbestos (CATP) has a phase composition similar to that of a natural or a low temperature clinker with the exception of having a larger content of aluminium, iron and magnesium. This product can be safely recycled for the production of stoneware tile mixtures. The addition of 3-5 mass% of CATP does not bear significant variations to the standard parameters of white porcelain tile mixtures.

This paper presents the results of the lixiviation of metals from different mixtures of fly and bottom ashes that have been stabilized and solidified in clays used in the manufacture of bricks. The ashes used for this study were obtained from a Hoffmann-type brick furnace adapted for the incineration of municipal solid waste during the manufacturing of ceramic bricks. The ashes were stabilized in clay in different proportions of clay:ash mix (99:1, 95:5, 90:10, 80:20 and 60:40). Such mixes were used to manufacture bricks that were calcined at a temperature ranging from 50 to 1100 degrees C. The clay, ashes and manufactured bricks were characterized using X-ray diffraction, fluorescent X-ray, thermogravimetry, differential thermal analysis, atomic absorption spectroscopy and scanning electronic microscopy. In addition, toxicity characteristic leaching procedure lixiviation tests were performed according to the EPA 1311 method for the determination of heavy metals. The results showed an affinity between clay and ash, and also that the bricks manufactured with these mixtures present low lixiviation levels. The tests also showed the highest decrease in the concentration of arsenic, nickel, chromium, zinc and silver for 99:1 mixtures. The 95:5 mixture was found to be the most favourable for the stabilization (greater concentration decrease) of lead and cadmium. Selenium was the metal with the lowest concentration change whereas arsenic, nickel, chromium, zinc and cadmium showed the greatest concentration change in all mixtures, with the exception of cadmium in the mixture 99:1.

Ceramics are commonly used as high-temperature structural materials which are easy to fracture because of the propagation of thermal shock cracks. Characterizing and controlling crack propagation are significant for the improvement of the thermal shock resistance of ceramics. However, observing crack morphology, based on macro and SEM images, costs much time and potentially includes subjective factors. In addition, complex cracks cannot be counted and will be simplified or omitted. Fractals are suitable to describe complex and inhomogeneous structures, and the multifractal spectrum describes this complexity and heterogeneity in more detail. This paper proposes a crack characterization method based on the multifractal spectrum. After thermal shocks, the multifractal spectrum of alumina ceramics was obtained, and the crack fractal features were extracted. Then, a deep learning method was employed to extract features and automatically classify ceramic crack materials with different strengths, with a recognition accuracy of 87.5%. [ABSTRACT FROM AUTHOR]

This document is an editorial introducing a special issue of the journal "Materials" on recent developments in geopolymers and alkali-activated materials (AAMs). The special issue aims to present the latest research findings, methodologies, and insights from leading researchers and practitioners in this field. Geopolymers and AAMs are gaining attention for their potential to replace traditional materials and their eco-friendly properties. The special issue features research papers covering various topics, including the production of geopolymer-based plaster for artwork restoration, the synthesis of low-temperature C-S-H using biomass fly ash, and the prediction of mechanical properties of geopolymer concrete using machine learning. The document emphasizes the need for further research, standardization, and specification improvements in this field. [Extracted from the article]

The corrosion resistance of float glass has been investigated in the course of climatic tests. It is shown that the main surface defects of tempered glass are leaching and “burnt-on paper and sulfurous film.” The properties of various interleaving materials used in the domestic industry are studied. The corrosion resistance of tempered glass depends on the surface of the initial glass and the properties of the interleaving material used for packing the initial as well as the tempered glass. [ABSTRACT FROM AUTHOR]

This paper reports on the use of waste ceramics tiles and waste diatomite in the synthesis of a novel porous ceramics construction material (WRPC) for moisture retention. Experiments were performed to elucidate the impact of sintering temperature (1000 °C–1200 °C) and the proportion of waste ceramics tiles (0 %–40 %) on mechanical properties and water absorption performance. The crystalline phases and constituent minerals were identified using X-ray diffraction and Fourier transform infrared spectroscopy. The proportion of waste ceramic material in the mix was positively correlated with volume shrinkage and inversely correlated with porosity. Sintering temperature was positively correlated with density and compressive strength, and negatively correlated with porosity and water absorption capacity. The primary crystal phase in the WRPC was identified as cristobalite, the intensity of which decreased with an increase in the content of material derived from waste ceramics tile. Under high heating temperatures, all of the quartz in the WRPC samples transformed into cristobalite, resulting in good chemical and thermal stability. The WRPC samples exhibited high compressive strength (>3 MPa), high water absorption capacity (>0.15 g/m2), and slow water-releasing behavior (t 1/2 = 4.1−17.3 h). Experiment results confirmed that waste ceramic tiles and waste diatomite could be transformed into construction materials of practical value. [ABSTRACT FROM AUTHOR]

Microwave radiation is widely utilized in construction practice, especially for drying building materials, remediating damp masonry, or sterilization of biotic pests that have infested building structures. The available scientific and technical literature reports that certain materials exposed to microwave radiation do not change their physical and mechanical properties, although this has not yet been adequately verified. This paper builds on many years of research in the area, adding to and refining existing information, providing new insights into the mechanical and physical properties of commonly available building materials that have been exposed to controlled microwave radiation, and comparing them with reference values. The experimental research on a set of clay brick samples is carried out using tests according to European standards, and it focuses on the effect of microwave radiation on compressive strength and water absorption. The experimental samples were compared to reference samples that had not been subjected to prolonged exposure to moisture and were subsequently treated with microwave radiation for dehumidification. [ABSTRACT FROM AUTHOR]

The presence of moisture in historic buildings, especially from rising damp, is extremely widespread and severe, causing materials' deterioration, internal discomfort and bad thermal insulation of external walls. Although this phenomenon is widely studied in the literature, the available solutions are frequently only partially effective, also due to the lack of reliable and compatible techniques to monitor the amount of moisture inside porous building materials, especially in heritage buildings where multiple restrictions exist. In this paper, a new sensorized ceramic plug was developed, to be inserted in historic masonry walls for the remote monitoring of moisture. The plug includes a moisture sensor that is currently used for soil irrigation purpose in agriculture and a ceramic envelope of tailored properties. The plug was developed in laboratory following a step‐by‐step testing program, which took into account both the specific features of the sensor (requiring a strong research effort to be transferred to building materials) and those of historic walls. After a first set of laboratory tests, the sensorized ceramic plug was validated in small‐scale laboratory walls and in a real historic masonry in the monumental Certosa cemetery in Bologna, Italy. The results are extremely encouraging, as they show how the new plug can provide valuable information about the rising damp evolution, and in fact, the data were correlated with the changes in the concurrent environmental parameters in the area of the cemetery. The results also suggest some possible measures to improve the sensorized ceramic plug in the near future. [ABSTRACT FROM AUTHOR]

Copyright of Eastern-European Journal of Enterprise Technologies is the property of PC TECHNOLOGY CENTER and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Bulletin of the Chinese Ceramic Society is the property of Bulletin of the Chinese Ceramic Society Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper takes into consideration the performance of traditional bricks as part of a building exterior wall finish. Exterior wall materials change their properties when exposed to external environment. This process is extended over time and its intensity is closely related to microstructure, moisture and freeze–thaw cycles. Two methods of freeze–thaw durability tests were used in this study: standard and defined by the authors. The authors' method incorporated the actual conditions of masonry unit function in exterior wall finish, i.e., cyclical effects of precipitation water, changes in temperature and air humidity. The laboratory test study included 50 freeze–thaw cycles. Three characteristic ranges of pore dimensions were indicated in the analysis: below 0.1 µm, between 0.1 and 3.0 µm and above 3 µm. Based on the method of freeze–thaw durability testing, the areas of microstructure changes were determined. The obtained results were related to the absorption of ceramic building materials. The authors' method confirms the usage of traditional ceramic building materials designed for use in protected walls against water penetration in unprotected exterior wall finish. The critical water saturation method of masonry units (standard) based on extreme environmental conditions generates significant changes in porosity distribution that do not reflect real, i.e., moderate, conditions. This method is appropriate for masonry units operating in severe conditions, i.e., F2. The aim of this study is to suggest a methodology for durability tests of traditional ceramic masonry units to cyclic freezing and thawing, which are only exposed to F1 (moderate) conditions during operation. Changes in the microstructure of the ceramic building materials were used as the primary evaluation criterion. In order to determine the effect of cyclic temperature changes, the freeze–thaw durability test was performed according to generally accepted standard procedures and in-house methodology. The purpose of the study is to point out the individual approach for the analysis of the material–environment system. At the same time, it should inspire researchers to innovative methods which use external conditions in a laboratory environment. [ABSTRACT FROM AUTHOR]

Ultra-high-temperature ceramics (UHTCs) is a kind of material that is in a rapidly evolving technical field, with a very wide range of applications across the aerospace, defense, energy, and civilian as a result of its excellent physical and chemical properties. Within this family, the ZrC-based composites are the most attractive. ZrC has excellent mechanical and physical properties such as high melting point, excellent fire resistance, high hardness, high elastic modulus, and good electrical conductivity. Moreover, compared with other ultra-high-temperature materials, the price of ZrC is lower, and it is a potential non-oxide high-temperature structural material. However, problems pertaining to sintering and moderate fracture toughness have limited its widespread applications. Second-phase toughening is considered to be a promising reinforcement method for ceramic materials. This paper comprehensively reviews the various routes/techniques, including the advanced ones, as adopted for the synthesis and densification of the ZrC-based composites. The research status of ZrC-based composites toughened by particles, fibers, flake graphene, and layered structure is introduced, and the toughening mechanism of ZrC-based composites is summarized. Some of the existing and futuristic applications of ZrC-based composites have also been discussed. Finally, the existing problems and future development direction of ZrC-based composites are also pointed out. [ABSTRACT FROM AUTHOR]

Dislocations are commonly present and important in metals but their effects have not been fully recognized in oxide ceramics. The large strain energy raised by the rigid ionic/covalent bonding in oxide ceramics leads to dislocations with low density (∼106 mm−2), thermodynamic instability and spatial inhomogeneity. In this paper, we report ultrahigh density (∼109 mm−2) of edge dislocations that are uniformly distributed in oxide ceramics with large compositional complexity. We demonstrate the dislocations are progressively and thermodynamically stabilized with increasing complexity of the composition, in which the entropy gain can compensate the strain energy of dislocations. We also find cracks are deflected and bridged with ∼70% enhancement of fracture toughness in the pyrochlore ceramics with multiple valence cations, due to the interaction with enlarged strain field around the immobile dislocations. This research provides a controllable approach to establish ultra-dense dislocations in oxide ceramics, which may open up another dimension to tune their properties. Dislocation engineering is important for designing structural materials. Here the authors demonstrate that a high-entropy oxide ceramic with a high density of edge dislocations can be stabilized by increasing the compositional complexity, resulting in enhanced fracture toughness. [ABSTRACT FROM AUTHOR]

Because of its excellent properties, mullite porous ceramics are widely used in thermal insulation materials, catalyst carriers, gas-liquid filtration, separation materials, etc. At the same time, zirconia not only has the advantages of high melting point, good chemical stability, and high strength but also can significantly improve the strength of ceramics through phase transformation and particle dispersion in the matrix and is widely used in the reinforcement of ceramics. In this paper, using mullite powder as the raw material, Al2O3 and SiO2/ZrSiO4 as the starting material for the mullite self-bonding phase, and AlF3·3H2O, ZrO2, and Y2O3 as additives, the zirconia-reinforced mullite was prepared by the foaming-injection method. The volume density, linear shrinkage rate, microstructure, room temperature, etc. of nanozirconia-reinforced mullite porous ceramics were studied by the amount of the foaming agent, the amount of mullite self-bonding phase powder, the type and amount of additives, etc. Effects of mechanical properties and thermal conductivity were also analyzed. The research results show that zirconia-reinforced mullite porous ceramics were prepared with mullite powder and 6 wt% AlF3·3H2O as raw materials, and ZrO2 and Y2O3 as additives. Adding an appropriate amount of ZrO2 and Y2O3 can significantly improve the mechanical properties of porous ceramics. When ZrO2 is 6 wt% and Y2O3 is 8 wt%, the porosity is 66.4% and the flexural strength and compressive strength of porous ceramics with a large pore size of 168 μm can reach 14.3 MPa and 36.3 MPa, respectively, which are obviously better than the strength of mullite porous ceramics without adding Y2O3 (flexural strength 11.3 MPa, nanocompressive strength 29.4 MPa). [ABSTRACT FROM AUTHOR]

Utilization of wastes for the preparation of ceramic foams has gradually become a major direction in the development of new building materials. In this paper, all wastes-based ceramic foams based on electrical insulators waste (EIW) and red mud (RM) were prepared through the high-temperature foaming method. The factors affecting the increase in pore size under different preparation conditions (RM content, temperature and time) were investigated separately by studying the changes in pore size. With the increase of RM content, sintering temperature and sintering time, the pore morphology gradually evolved from a regular spherical shape to a polygonal or irregular shape with a corresponding increase in pore size, albeit at different rates. The pore size enhancement ascribed to changes in RM content was primarily attributed to the synergistic influences of a plurality of factors including glass phase content, viscosity, and gas phase content. Sintering temperature mainly affected the balance between the forces acting inside and outside the pores and the gas phase solubility in the liquid phase to adjust the size of pores. The influence of sintering time on pore size and morphology emanated from the glass phase viscosity and the resulting changes in the release rate of gas phase. In summary, the study will help to investigate the actual controlling factors of composition and process on the pore structure, and provides significant insights into the optimization and adjustment of pore structure for samples obtained by high-temperature sintering. [ABSTRACT FROM AUTHOR]

This Special Issue presents a series of research papers and reviews about the second-phase enhancement, surface coating technology, high-temperature corrosion, wear, erosion, and protection of high-temperature structural materials. The effects of alloying and surface coating technology on the microstructure, mechanical properties, and oxidation resistance of materials were systematically introduced. In addition, this Special Issue also summarizes the strengthening mechanism of the second relatively refractory metal alloy and carbonized ceramic materials, compares the advantages and disadvantages of different surface coating technologies, and analyzes the oxidation behavior and failure mechanism of the coating in order to provide valuable research references for related fields. [ABSTRACT FROM AUTHOR]

Ceramic foam prepared from steel slag particles in colloidal suspension was stabilized with propyl gallate and after drying was sintered by direct electromagnetic wave radiation at successive thermal regimes within the limits of 980-1200 °C. The microwave heat treatment is the originality of the work. The heating rate reached very high values of up to 40 °C/min without affecting the microstructural configuration of the foam. The peculiarities of ceramic foam include reduced heat conductivity (in the range of 0.060-0.085 W·m-1·K-1), high compression resistance (about 9.8 MPa) and extremely low pore size (between 20-160 µm). [ABSTRACT FROM AUTHOR]

Quaternary carbide Ti3NiAl2C ceramics has been investigated as a potential nuclear fusion structural material, and it has advantages in certain aspects compared with Ti2AlC, Ti3AlC2, and Ti3SiC2 structural materials. In this paper, quaternary carbide Ti3NiAl2C ceramics is pressurized to investigate its structural, mechanical, electronic properties, and Debye temperature. Quaternary carbide Ti3NiAl2C ceramics still maintains a cubic structure under pressure (0–110 GPa). At zero pressure, quaternary carbide Ti3NiAl2C ceramics only has three bonds: Ti–Al, Ni–Al, and Ti–C. However, at pressures of 20 GPa, 30 GPa, 40 GPa, 60 GPa, and 70 GPa, new Ti–Ni, Ti–Ti, Al–Al, Ti–Al, and Ti–Ti bonds form. When the pressure reaches 20 GPa, the covalent bonds change to metallic bonds. The volume of quaternary carbide Ti3NiAl2C ceramics can be compressed to 72% of its original volume at most. Pressurization can improve the mechanical strength and ductility of quaternary carbide Ti3NiAl2C ceramics. At 50–60 GPa, its mechanical strength can be comparable to pure tungsten, and the material changes from brittleness to ductility. However, the degree of anisotropy of quaternary carbide Ti3NiAl2C ceramics increases with the increasing pressure. In addition, we also investigated the Debye temperature, density, melting point, hardness, and wear resistance of quaternary carbide Ti3NiAl2C ceramics under pressure. [ABSTRACT FROM AUTHOR]

Copyright of Bulletin of the Chinese Ceramic Society is the property of Bulletin of the Chinese Ceramic Society Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this paper, the authors present a technology that allows the manufacture of ceramic blocks using refractory waste at the raw material recipe. The research was carried out within the Refractory Design and Production Research Center in Alba Iulia. In these researches we studied various types of possible raw materials used for the preparation of recipes that include different proportions of refractory waste. Several manufacturing recipes were studied which led to the obtaining of heat--resistant ceramic blocks, determining the physical and chemical properties of the finished products obtained, which can be accepted by beneficiaries in the construction materials industry. The comparative analysis of the manufacturing recipes and of the characteristics of the heat--resistant ceramic blocks obtained, determined the optimal recipe. [ABSTRACT FROM AUTHOR]

This paper introduces a novel method for defect detection in homogeneous flat surface products. The coefficient of variation is used as a homogeneity measure for approximate defect localization and features extracted from the Log – Gabor filter bank response are used to accurately localize and detect the defect while reducing the complexity of Gabor based inspection approaches. The scanning window size and threshold parameter are the two major factors that affect the system performance. An adaptive technique is proposed for selecting the size of the scanning window and automating the selection of the threshold level. Compared to the Log-Gabor filters, the proposed combination resulted in speeding up the defect detection process by about ten times. The experimental results show that the proposed system gives promising results and is applicable for defect detection in homogeneous surfaces like paper, steel plates, ceramic tiles and foils. [ABSTRACT FROM AUTHOR]

The European TBM (Test Blanket Module) program under development will test two alternative concepts for tritium generation and extraction in ITER: a helium cooled / ceramic pebble breeder concept and a water cooled / lithium lead breeder concept. The former implements Advanced Ceramic Breeder pebbles that act as tritium breeding material, and Beryllium pebbles as neutron multiplier. A Reduced Activation Ferritic Martensitic steel, the EUROFER-97 (X10CrWVTa9-1), is used as structural material and pressurized Helium technology is implemented for efficient heat extraction (300-500°C, 8 MPa). The design of the TBM box involves challenges that must be tackled with a holistic approach to simultaneously consider a variety of aspects. Some of these challenges include: the thermal performance and the structural integrity of the TBM under ITER normal operations and accidental conditions, the implementation of pressurized equipment regulation(s), the convergence with manufacturing activities being developed in parallel and the high congestion in the reduced TBM volume –especially when considering instrumentation integration– without affecting too much the tritium breeding capability. It is also key to develop advanced methodologies based on design by analysis to virtually test alternative design solutions in an agile manner. These should be linked to the applicable nuclear design code (RCC-MRx) to consolidate design choices. In this way, a traceable evolution of the TBM design process can be built where alternatives are tested, compared and either discarded or selected in a consistent and comprehensive framework. This paper presents an overview of the very significant progress achieved in the design of the helium cooled concept TBM over the last two years, a period that corresponds to the first steps of the preliminary design phase towards the Preliminary Design Review (PDR) gate. This includes a significant change in the design of the back manifold area and the connection with the rest of the TBM-Set that solves long-standing historical problems inherited from pre-conceptual design stage. An update on the latest and most relevant methodological developments achieved is also provided in this paper, since these have been key to progress with the design evolutions in a sound and traceable manner. To end, the paper also presents some examples of the instrumentation definition and its complex integration within and outside the TBM box. [ABSTRACT FROM AUTHOR]

Reusing waste as raw materials to produce other materials can entail a decrease in production costs and in the abusive use of natural resources. Furthermore, it can even improve the properties of the end product or material. In this sense, a review of the most relevant literature published in recent decades shows that numerous solutions have been proposed or implemented, such as its use to produce construction materials, catalysts, pigments, pozzolana, refractory materials, glass-ceramic products, etc. Our research group has verified the viability of using different types of waste as secondary raw materials to obtain several types of ceramic, glassy and glassceramic materials, as well as frits. This article highlights several types of industrial waste that have both non-toxic (Li, Ca and Mn) and highly toxic (Cr VI) differentiating elements that can be used in sintering and vitrification industrial processes to immobilise them or render them inert. We studied the compositions and characterised the various materials obtained, conducting toxicity and leaching tests on waste/materials designed with high amounts of chromium. A suggestion for future lines of research has been proposed. [ABSTRACT FROM AUTHOR]

Due to its ability to evaporate completely at room temperature, menthol has recently been proposed for use as a new kind of temporary consolidant at the excavation site of Qin Shihuang's Terracotta Army. Compared to cyclododecane (CDD), the most widely used temporary consolidant, menthol has the advantages of a longer working time, a well‐established safety profile and easy local availability. In this paper, in order to better understand the temporary consolidation behaviour of menthol and to guide its optimal use in the field, laboratory experiments are carried out on ISO standard sand substrate in conditions mimicking the situation of an archaeological excavation. Basic and important knowledge about menthol, which is related to its effectiveness in temporary consolidation, such as penetration into the substrates, the solidification process and the degradation of the efficiency of consolidation over the sublimation time, are systematically studied. The results show that the penetration of menthol is notably affected by the substrate's temperature, particle size, particle‐size distribution and water content. The solidification of melted menthol is an obvious volume shrinkage process, and the shrinkage extent is greatly affected by the application protocol. The consolidated samples experience a dramatic promotion in compressive strength, and as menthol volatilizes, the consolidated samples will eventually become loose and finally collapse. [ABSTRACT FROM AUTHOR]

The paper is devoted to the analysis of two genetically related groups of medieval traditional moulded ceramics, which in historical studies of the polyethnic Middle Volga and Kama region fulfil the function of an ethnocultural and chronological marker. Based on the data from Mössbauer studies of clays and archaeological ceramics, the identity of the raw materials and the constancy of ethnographic handicraft traditions in the production of artisanal moulded ceramics over the 9th–15th centuries are shown. [ABSTRACT FROM AUTHOR]

Huge amounts of waste are being generated, and even though the incineration process reduces the mass and volume of waste to a large extent, massive amounts of residues still remain. On average, out of 1.3 billion tons of municipal solid wastes generated per year, around 130 and 2.1 million tons are incinerated in the world and in Belgium, respectively. Around 400 kT of bottom ash residues are generated in Flanders, out of which only 102 kT are utilized here, and the rest is exported or landfilled due to non-conformity to environmental regulations. Landfilling makes the valuable resources in the residues unavailable and results in more primary raw materials being used, increasing mining and related hazards. Identifying and employing the right pre-treatment technique for the highest value application is the key to attaining a circular economy. We reviewed the present pre-treatment and utilization scenarios in Belgium, and the advancements in research around the world for realization of maximum utilization are reported in this paper. Uses of the material in the cement industry as a binder and cement raw meal replacement are identified as possible effective utilization options for large quantities of bottom ash. Pre-treatment techniques that could facilitate this use are also discussed. With all the research evidence available, there is now a need for combined efforts from incineration and the cement industry for technical and economic optimization of the process flow. [ABSTRACT FROM AUTHOR]

Big narratives on the role of metallurgy in social change and technological innovations are common in archaeology. However, informed discussion of these issues requires a contextualised characterisation of metallurgical technology at the local level in its specific social and technological contexts. This paper approaches early metallurgy in Iberia from a technological perspective. We focus on the site of Las Pilas in the Vera Basin (Mojácar, Almería, Spain), where the whole metallurgical chaîne opératoire has been documented in situ through archaeological excavation of a third millennium bc context. The study includes microstructural, mineralogical and chemical analyses of ores, slag, technical ceramics and finished artefacts, as well as domestic pottery used for comparative purposes. These results are discussed with reference to the archaeological context and evidence for other domestic activities and crafts. Our aim is to contribute to better characterise the early metallurgical tradition of Southeast Iberia, paying particular attention to specific technological tools, knowledge and recipes that may allow future comparative approaches to knowledge transmission or independent innovation debates. For this particular case, we demonstrate the direct production of arsenical copper in a low-scale, low-specialisation, low-efficiency set up that involved the crucible smelting of complex oxidic ores in a context that suggests associations with cereal roasting and, indirectly, with basket and pottery making. [ABSTRACT FROM AUTHOR]

This paper deals with Ca and Zr co-doped BaTiO (BCTZ) ( x = 0.1, 0.13, 0.2 and y = 0.05, 0.1, 0.15). These ceramics were prepared using the conventional solid state method. The symmetry, dielectric properties, Raman spectroscopy, ferroelectric behavior and piezoelectric effect were examined. X-ray diffraction (XRD) results display that morphotropic boundary occurs from tetragonal to orthorhombic region of BCZT and polymorphic phase transitions from tetragonal to orthorhombic, orthorhombic to rhombohedral regions of BCZT. The evolution of the Raman spectra was investigated as a function of compositions at room temperature, in correlation with XRD analysis and dielectric measurements. We note that the substitution of Ca in Ba site and Zr ions in Ti site slightly decreased the cubic-tetragonal temperature transition ( T ) and increased the orthorhombic-tetragonal ( T ) and rhombohedral-orthorhombic ( T ) temperatures transitions. The ferroelectric properties were examined by a P- E hysteresis loop. The two parameters Δ T and Δ T are defined as Δ T = T − T and Δ T = T − T , they come close to T for x = 0.13, y = 0.1, which reveals that this composition is around the polymorphic phase. The excellent piezoelectric coefficient of d = 288 pC N, the electromechanical coupling factor k = 40%, high constant dielectric 9105, coercive field E = 0.32 (KV mm) and remanent polarization P = 0.1 (µc mm) were obtained for composition x = 0.13, y = 0.1. [ABSTRACT FROM AUTHOR]

The recent quest for developing new low carbon footprint construction materials to lower the environmental emissions and implications of infrastructure has imposed many challenges and has created many opportunities for research and development in academia and industrial sectors. The present paper, discusses and summaries these challenges and opportunities and provides a synopsis of the ideas presented in the Infrastructure sessions of the Fourth International Congress on Ceramics ( ICC4). This paper also discusses recent advances in the development of sustainable infrastructure materials. [ABSTRACT FROM AUTHOR]

Purpose - Double pressing systems have recently been introduced to speed up and improve the pressing step of porcelain stoneware tiles. This paper aims to analyze double pressing systems using discontinuous pre-compaction, both technically and economically. Two operative conditions are considered: the traditional forming of tiles during pressing is compared with the innovative production of a unique large-sized slab, subsequently customized according to market requirements. Furthermore, manufacturing conditions are explored with infrequent or frequent production runs, due to increasingly smaller production batches, in order to evaluate which production process is more suitable when changing operative conditions are managed. Design/methodology/approach - The analysis is carried out experimentally, by collecting data in existing pilot plants, producing batches of products of different size and colour. Details are provided concerning the technical characteristics of the systems, along with costs per manufactured square metre for investments, personnel, maintenance, spare parts and electric power. A case in which some production days are reserved for each manufactured batch is compared to a case in which production runs are repeated more frequently in a day. Findings - Manufacturing large-sized slabs and customization has shown to be an efficient solution for companies operating in changing markets. Research limitations/implications - Further research should study double pressing systems using continuous pre-compaction. Originality/value - The proposed analysis, by presenting an evaluation process and sharing data collected experimentally, provides innovative support for addressing decision makers when new pressing systems for porcelain stoneware tiles are selected. [ABSTRACT FROM AUTHOR]

This paper develops a new multilayered wide-passband bandpass filter with the assistance of low-temperature co-fired ceramic technology. The mutually inductive coupling between the input and output port of a low- and high-pass filter cascaded in the proposed filter is utilized as well. The results show that in the passband of 3.1-4.9 GHz, the measured insertion loss and return loss of this filter are less than 1.1 dB and greater than 18 dB, respectively. In addition, the insertion loss from dc to 2.76 GHz is greater than 20 dB, and the one from 5.8 to 12 GHz is greater than 30 dB. [ABSTRACT FROM AUTHOR]

This paper reports processing of lithium ion-conducting, composite membranes comprised of 14Li2O·9Al2O3·38 TiO2·39P2O5 glass–ceramic and polyethylene. The processing involved tape casting of 14Li2O·9Al2O3·38TiO2·39P2O5 glass powder with organic additives into tapes, subjecting the green tape to binder burnout and thermal soaking in the temperature range of 950°–1100°C, and finally infiltrating the porous tape with polyethylene solution. The ionic conductivity and microstructure of 150–350 μm thick membranes were characterized and are discussed in this paper. The crystallites of the glass–ceramic show liquid-like conductivity at ambient temperature, whereas the grain boundary conductivity is lower by a factor of five. The lower grain boundary conductivity is explained on the basis of crystallographic mismatch and the existence of AlPO4 at the grain boundary. The polyethylene infiltration in the porous membrane improved mechanical resilience with a minor adverse effect on conductivity. [ABSTRACT FROM AUTHOR]

The disposal of coal fl y ash obtained in thermal power plants presents the general problem all over the world. Significant research on the utilization of fl y ash has been carried out in the area of construction materials. The aim of this study was to develop porous ceramics based on coal fl y ash and clay (60wt.%clay and 40wt.% fl y ash). Three types of pore creators: two types of wood cutting (Quercus and Facus sylvatica) and C-powder were used for creating of the porous ceramics. The mixtures based on fl y ash and clay and different content of pore creators (2, 5, 10 and 20wt.%) were consolidated (P=45 MPa, T = 900, 1000, 1050 and 1100oC/1h) to obtain porous ceramic (PC). The results indicate that the properties of the porous ceramics depend on the type and content of the pore creators. Furthermore, the sintering temperature was found to be main factor affecting the properties of the sintered products. The maximal bending strength (26 MPa) was achieved by using 2wt% P3 (C-powder) and the porous ceramics has the density and porosity of 1.90g/cm3 and 22%, respectively. By using the highest content (20wt.%) of each pore creator (P1, P2 and P3) the lowest bending strength cca 5 MPa was achieved and the variation of the density and porosity was in the range from 1.22 to 1.32 g/cm3 and 44 to 48%, respectively. Water absorption, durability and the microstructure of the obtained porous ceramics are also reported in this paper. [ABSTRACT FROM AUTHOR]

High-entropy diboride-based (MeB2-based) ceramics are promising high-temperature structural materials because of their excellent mechanical properties, high-temperature stability, and oxidation resistance. In order to achieve low-temperature sintering of the high-entropy ceramics, a novel preparation method of high-entropy (Ti,Zr,Nb,Mo,W)B2-SiC ceramics based on reactive sintering of pre-alloyed solid-solution metals and nonmetals of Si, C, B4C was conducted in the current work. Mechanical alloying behavior of the mixed metal powders, as well as the phase composition, microstructure, mechanical properties, and oxidation behavior of the as-sintered MeB2-SiC ceramic were investigated. The XRD, SEM, and EPMA results indicated that the primary MeB2 solid-solution and SiC phases could be successfully formed during reactive sintering at a relatively low temperature of 1650 °C. The as-sintered MeB2-SiC ceramics had a high relative density of 97.8% and high mechanical properties (hardness of 19.74 ± 0.8 GPa, flexure strength of 533 ± 38 MPa, and fracture toughness of 6.01 ± 0.77 MPa·m1/2). Combining the oxidation behavior and microstructure evolution of the oxidation layer, a continuous and relatively dense MeOx-SiO2 oxidation layer was gradually formed and covered on the external surface, leading to decelerating oxidation behavior after an oxidation exposure time of 10 min. [ABSTRACT FROM AUTHOR]

Rare earth zirconates (RE2Zr2O7) are considered as a class of potential high-temperature structural materials. In this paper, a series of Y2O3 and Ta2O5 co-doped Gd2Zr2O7 [(Gd1−xYx)2(Zr1−xTax)2O7+x, x = 0, 0.1, 0.2, 0.3, 0.4] ceramics were prepared by solid-state reaction sintering in order to clarify the influence of Y2O3 and Ta2O5 co-doped on microstructure, Young's modulus and thermal conductivity. The results showed that Y2O3 and Ta2O5 co-doped Gd2Zr2O7 exhibited a single pyrochlore structure, and a small amount of Y3+ ions were doped into the Zr4+ ions lattice. The Young's moduli of doped Gd2Zr2O7 ceramics slightly change with the increase in Y2O3 and Ta2O5 doping concentration. The minimum thermal conductivities of the specimens were obtained at 800 °C. The thermal conductivity of doped Gd2Zr2O7 with x = 0.3 is lower than that of others among the doped specimens, which is around 1.41 W m−1 K−1 at 800 °C. In addition, (Gd0.7Y0.3)2(Zr0.7Ta0.3)2O7.3 ceramic exhibits excellent phase stability from room temperature to 1550 °C. [ABSTRACT FROM AUTHOR]

• Building ceramics were prepared at 700–900 °C using industrial side streams. • Sodium hydroxide performed better that sodium carbonate as fluxing agent. • The materials achieved max compressive and flexural strength of 55 and 14 MPa. • The results are of interest for waste management and sustainable use of resources. This paper deals with the valorization of quartz and felspar rich lithium mine tailings (QFS) in the development of construction materials. Ladle slag was used as green strength increasing agent. Sodium hydroxide and carbonate were used as fluxing agents to allow sintering at 700–900 °C. Of these, sodium hydroxide was found to be the more efficient. The sintered ceramics were characterized by X-ray diffraction, scanning electron microscopy, compressive test, water absorption, apparent density and dilatometry; the results were found to comply with ASTM C62-99 specifications for building brick, and interesting for a sustainable use of resources. [ABSTRACT FROM AUTHOR]