Search Results (21)

The growing demand for lightweight aggregates (LWAs) in the construction industry is driving the development of sustainable alternatives based on the reuse of solid industrial waste. The aim of this study was to assess the technical feasibility of using red ceramic waste (RCW) as a partial or total substitute for red clay (RC) to produce lightweight expandable aggregates. Six formulations were made with different proportions of RCW and RC and sintered at four temperatures (1100, 1150, 1200 and 1250 °C). They were characterised using physical, thermal, morphological, chemical and mechanical analyses, according to standard protocols. The results showed that almost all the formulations sintered at 1200 and 1250 °C had a positive bloating index (BI > 0), particle density of less than 2.0 g/cm³, low water absorption of less than 2% and mechanical strength of more than 5.4 MPa, revealing strong potential for use in lightweight structural and non-structural concrete. The main conclusion is that RCW, even used in isolation, has physicochemical and mineralogical properties suitable for the production of lightweight aggregates under optimised thermal conditions, contributing to the development of sustainable materials with a competitive technical performance compared to commercial LWAs. Full article

The development of energy-efficient and sustainable construction materials is essential for reducing environmental impact and enhancing building performance. This study investigates the incorporation of coffee grounds and expanded perlite waste—two underutilized industrial byproducts—into clay-based ceramics to improve thermal insulation while maintaining mechanical integrity. Unlike previous studies that explore these additives separately or in impractically high dosages, this research focuses on their combined effect at low, industrially viable ratios to ensure large-scale feasibility. Four clay mixtures were analyzed: a reference clay (TZ), clay with coffee grounds (TZCF), clay with expanded perlite waste (TZPW), and clay with both additives (TZCFPW). Laboratory testing and computational fluid dynamics (CFD) simulations were employed to assess the physical, mechanical, and thermal properties of these formulations. The results indicated that coffee grounds increased plasticity, while expanded perlite waste reduced it, requiring adjustments in processing parameters. Both additives contributed to lower shrinkage and drying sensitivity, improving dimensional stability during production. Although mechanical strength declined due to increased porosity—most notably in the TZPW mixture—the fired bending strength remained within acceptable limits for masonry applications. The most significant finding was the substantial improvement in thermal performance, with all the modified formulations exhibiting reduced thermal conductivity and enhanced insulation. The best performance was observed in the TZPW mixture, which demonstrated the lowest thermal conductivity, highest thermal resistance, and optimal U-values in masonry wall testing, confirming its potential for energy-efficient construction. CFD simulations further validated these enhancements, providing detailed insights into heat transfer mechanisms. These findings demonstrate the feasibility of repurposing industrial waste materials to create scalable, eco-friendly building products. Future research should refine formulation ratios to optimize the balance between strength and insulation, ensuring widespread adoption in sustainable construction. Full article

This paper investigates the potential use of natural materials and elements for stabilizing indoor humidity levels, focusing on creating healthier living environments in buildings. Unstable indoor microclimates, particularly extreme humidity levels, can negatively affect human health by causing issues such as condensation, mold growth, or dry mucous membranes. In this work, we explore how sorptive materials can maintain indoor humidity within the optimal range of 40–50%. The aim is to identify optimal solutions for moisture control using passive elements, such as unfired ceramic components, which demonstrate high sorption activity within the 35–55% relative humidity range. These elements can effectively absorb moisture from, or release it back into, the indoor environment as needed. Five clay types based on different clay minerals were analyzed in the research in order to assess how their structures influence moisture adsorption behavior. These elements can be combined with green/active elements and standard measures, such as ventilation or targeted room air exchange, to improve indoor humidity regulation. The evaluation of the results so far indicates that the use of clay-based elements in the interior offers a sustainable and natural approach to maintaining optimal indoor microclimate conditions. The slab elements from all 5 clay formulations investigated effectively support indoor humidity stabilization. Full article

The construction sector is presently among the most resource-intensive industries, driving a substantial body of research dedicated to the development of more sustainable materials to address these demands. A particularly promising approach within the framework of the circular economy is the repurposing of waste as a principal raw material for the creation of new construction products. Within this context, the primary aim of this study is to engineer ceramic materials for brick production using 100% waste-derived inputs, specifically aggregate washing sludge and manganese mining by-products. To evaluate the potential of these sustainable ceramic materials, an extensive investigation was conducted, encompassing both physical and mechanical testing, as well as a thorough characterisation of the waste inputs. For this purpose, a series of ceramic specimens were fabricated with varying proportions of mining residues and aggregate washing sludge, adhering to the conventional protocols employed in the manufacture of ceramic bricks. The results demonstrate that these sustainable ceramics exhibit a linear shrinkage reduction of up to 5% compared to traditional clay-based ceramics. Furthermore, they show water absorption levels—whether via capillarity, cold water, or hot water absorption—that are up to twice those observed in conventional clay ceramics, while maintaining comparable density values. This increased absorption, however, correlates with a reduction in mechanical strength at higher concentrations of manganese waste, yet the material continues to meet the minimum strength requirements as specified by industry standards for such products. In conclusion, this research introduces a novel, sustainable ceramic material that not only reduces economic and environmental costs but also adheres to the required performance criteria for construction applications. Full article

The world demands suitable design solutions to transition toward a sustainable production system. The concept of sustainability evolves with technology’s ability to understand and replicate nature’s logic. There is a growing need to move beyond punctual solutions towards more intricate and multi-stakeholder considerations, including preemptive assessments of impacts. This article discusses the outcomes of cross-disciplinary material experimentation at Saperi&Co Center, Sapienza University of Rome. This research focuses on enhancing ceramic surfaces through circular economy practices, making them receptive to microorganism colonization—known as bioreceptivity. Through an iterative and repetitive approach, inspired by Research Through Design and material experimentation, several experiments were carried out to study how the innovative use of organic waste in clay-based mixtures can promote bioreceptivity and the design of green surfaces for urban regeneration. The results advance our knowledge on the multiple parameters the designer must consider to transform inert surfaces such as ceramics into “ecological augmentation” devices. The article also aims to raise awareness of bioreceptivity as a practice to educate communities about a symbiotic relationship with nature, promote local economic development and circular production, and prompt reflection on cultural aspects arising from contemporary scientific and technological advancements in line with Responsible Research and Innovation (RRI) principles. Full article

Ceramic slurry wastes have a significant hazardous potential when dumped. Their recycling as raw material is a sustainable approach for the development of nature-friendly applications. The microstructure and mechanical properties play a key role in the success of this sustainable recycling. Ceramic slurry samples resulting from the wall and floor tiles production facility were analyzed. The mineral composition was investigated by XRD combined with mineralogical microscopy and the microstructure was investigated by SEM microscopy coupled with EDX spectroscopy and elemental mapping. The ceramic slurry contains: quartz, kaolinite, mullite and small amounts of lepidocrocite. Quartz and mullite particles have sizes in the range of 5–100 μm and kaolinite has small particles of around 1 to 30 μm. Iron hydroxide crystallized as lepidocrocite is finely distributed among kaolinite aggregates. It makes the slurry unable to be reused in the technological process because of the glaze staining risk, but it does not affect the material cohesion. Thus, the cylindrical samples were prepared at progressive compactions rates as follows: 1808.55; 1853.46; 1930.79 and 2181.24 kg/m³ and dried. Thereafter, were subjected to a compression test with a lower compression strength of 0.75 MPa for lower density and a higher strength of 1.36 MPa for the higher density. Thus, slurry compaction enhances the kaolinite binding ability. The Young’s Modulus slightly decreases with the compaction increasing due to local microstructure rigidizing. This proves the binding ability of kaolinite, which properly embeds quartz and mullite particles into a coherent and resistant structure. The fractography analysis reveals that fracture starts on the internal pores at low compaction rates and throughout the kaolinite layer in the samples with high compactness. The observed properties indicate that the investigated ceramic slurry is proper as a clay-based binder for sustainable ecological buildings, avoiding the exploitation of new clay quarries. Also, it might be utilized for ecological brick production. Full article

This study explores the potential benefits of incorporating Recycled Demolition Waste (RDF) as an additive in ceramic mass for the brick industry, with a focus on applications such as thermoblocks. The research underscores the significance of sustainable waste management practices and environmental conservation by diverting waste from landfills. RDF, exhibiting combustion properties above 550 °C, emerges as a valuable candidate for enhancing clay-based materials, particularly in the brick production process where firing temperatures exceed 850 °C. Conducted in two phases, the research initially concentrated on RDF preparation, RDF integration with clay materials, and its influence on extrusion and drying phases. Employing innovative techniques involving brick and tile industry machinery coupled with sand incorporation yielded promising results. The grounding of RDF particles to less than 1 mm not only facilitated the mixing process but also ensured stable grinding temperatures within the hammer mill, reducing operational costs. During extrusion, challenges associated with unprocessed RDF material were addressed by utilizing ground RDF, leading to a more efficient and cost-effective process with enhanced plasticity and reduced water requirements. Practical implications for brick plant operations were identified, promoting resource and energy savings. Drying behavior analysis revealed the positive impact of RDF integration, showcasing reduced sensitivity, decreased drying linear shrinkage, and improved density properties. RDF’s role as an inert additive resulted in a 5% reduction in density, enhancing porosity and thermal insulation properties, particularly in thermoblock applications. In the brick industry, where durability, thermal performance, and cost-efficiency are paramount, this study emphasizes the potential benefits of incorporating RDF into clay-based materials. While further research is needed to address the firing procedure of RDF as a brick mass additive, the initial findings underscore the promise of this approach for sustainable and environmentally responsible brick production. This study contributes to the literature by shedding light on the advantages and challenges of integrating RDF into clay-based products, supporting sustainability and waste reduction in construction and manufacturing. The findings provide valuable insights into the performance and feasibility of these mixtures, offering crucial information for industries striving to adopt eco-conscious production methods. This article not only outlines the applied methodology and experimental setup but also presents results related to the behavior of RDF-inclusive clay block mixtures in the production environment. Anticipated to exert considerable influence on future practices and policies, this research contributes to the growing body of knowledge concerning eco-friendly and sustainable manufacturing processes. Full article

The environmental impact of clay mining can be minimized using extractive mineral circularity practices. Combining the available knowledge of the characteristics of different clays with statistical tools was a decisive step for the improved use of mining resources. Through blends, all the mined materials can be incorporated to produce quality ceramic products. This study identified two types of clay from abandoned mining areas in the southern state of Santa Catarina, Brazil. These raw materials were valued together with plastic clay, which is widely used in the region, to develop 10 different formulations using a mixture design method. The clays were characterized using average granulometric distribution, mineralogical composition, and chemical, thermal and plasticity analyses. The specimens were shaped by extrusion, dried in an oven, fired in a muffle furnace and characterized based on their shrinkage, water absorption and compressive strength values. Two clays with varying characteristics—one with low workability and the other with a high silica content—exhibited difficulties (generating defects) in the extrusion shaping process, which compromised the final quality of the ceramic paste. Results showed that incorporating up to 45% by mass of the low-workability clay resulted in an increase in water absorption. The more siliceous clay improved dimensional control; however, its use at high contents (~80%) decreased the mechanical resistance. Nevertheless, when used in controlled amounts, these clays can be beneficial to the production of blocks and bricks because they have the potential to improve some properties of the finished ceramic products. Full article

The construction sector is increasingly seeking sustainable alternatives in its processes worldwide, with a particular focus on the production of eco-friendly materials. Additionally, the improper disposal of solid waste is rapidly increasing, particularly in the agro-industry, including the waste generated from beer processing such as malt bagasse. Therefore, the objective of this study was to incorporate malt bagasse residue into ceramic materials at varying proportions (0, 2.5, 5, 10, and 15%) as a partial substitute for clay, submitted to different sintering temperatures (750, 850, 950, and 1050 °C). The raw materials, namely ceramic mass and malt bagasse, were characterized based on their chemical properties (XRF, loss of fire, and elemental analysis), physical properties (grain size, Atterberg limits), and mineralogical properties (XRD) characteristics. The properties of the ceramics, both with and without the incorporation of waste, were evaluated using dilatometry, apparent density, apparent porosity, water absorption, linear shrinkage, and tensile strength. The compositions that exhibited the best sintering temperatures were subjected to microstructural characterization using optical microscopy and X-ray diffraction (XRD). Significant differences were observed in the properties of the ceramic material, particularly in terms of linear shrinkage and apparent porosity. It was concluded that as the amount of malt bagasse residue incorporated increased, the mechanical properties of the pieces decreased. The incorporation of 15% residue resulted in the lowest performance, primarily due to a greater loss of mass. However, it should be noted that the incorporation of up to 5% malt bagasse for all the studied temperatures can still be considered acceptable, as it meets the minimum recommended value of 1.5 MPa for masonry ceramic components. This incorporation of malt bagasse contributes to both the technological and environmental aspects of civil construction. Full article

Soils contaminated by mining activities are a major environmental concern, and to avoid this type of environmental impact, carrying out high-cost processes is necessary. For this reason, a solution is proposed in this study in order to eliminate the soils contaminated by mining activities and, in turn, prevent the soil’s contaminating elements from causing harm. All this is achieved by using contaminated soils as raw materials for the production of ceramics for bricks. For this purpose, the materials were initially characterized physically and chemically, and different ceramic test pieces were manufactured with different percentages of clay and contaminated soil, subsequently determining the physical properties and the leaching of toxic elements. In this way, it was possible to evaluate, via innovative data mining and fuzzy logic techniques, the influence of the contaminated soil's contribution on the properties of ceramics. Based on this, it was possible to affirm that the contaminated soil incorporation negatively affects the physical properties of ceramics as well as the leaching of polluting elements. The ceramic formed by contaminated soil and clay has a lower compressive strength, and it is associated with lower linear shrinkage and lower density, as well as higher porosity and cold-water absorption. However, the addition of different percentages of contaminated soil (up to 70%) to clay created a ceramic that complied with regulation restrictions. Therefore, it was possible to obtain a sustainable material that eliminates environmental problems at a lower cost and that fits within the new circular mining concept thanks to fuzzy logic techniques. Full article

Mycelium-based composites (MBCs) are alternative biopolymers for designing sustainable furniture and other interior elements. These innovative biocomposites have many ecological advantages but present a new challenge in aesthetics and human product acceptance. Grown products, made using living mycelium and lignocellulosic substrates, are porous, have irregular surfaces and have irregular coloring. The natural origin of these types of materials and the fear of fungus can be a challenge. This research investigated the level of human acceptance of the new material. Respondents were students of architecture who can be considered as people involved in interior design and competent in the design field. Research has been performed on the authors’ prototype products made from MBCs. Three complementary consumer tests were performed. The obtained results measured the human reactions and demonstrated to which extents products made of MBCs were “likeable” and their nonobvious aesthetics were acceptable to the public. The results showed that MBC materials generally had a positive or not-negative assessment. The responses after the pairwise comparison of the MBC with wall cladding samples pointed out the advantage of ceramic reference material above the MBC based on an overall assessment. The respondents also believed that the chamotte clay cladding would be easier to fit into the aesthetics of a modern interior and would in better accordance with its style. Although the MBC was less visually appealing, the respondents nevertheless found it more interesting, original, and environmentally friendly. The experiments suggested that the respondents had double standards regarding MBCs. MBCs were generally accepted as ecological, but not in their own homes. All of these results support current and future applications of MBCs for manufacturing items where enhanced aesthetics are required. Full article

This study investigated the use of organic compound waste (OCW) contaminated magnesium silicate/diatomite in ceramics. Substituting part of the clay (between 5 and 20 wt.%) with OCW modifies a pore structure and enhances the ceramic product’s thermal conductivity, density, and frost resistance. Prepared samples were tested at 1000–1060 °C temperatures and their structural parameters and Maage factor, useful for frost resistance prediction, were evaluated. Results show that OCW modifies the porous structure and improves the insulating properties of the ceramic body. Increasing OCW content up to 15% in the ceramic body decreases density by up to 15.0%, and thermal conductivity by up to 42.5%, because of the modified pore structure. According to structural parameters calculation, the higher frost resistance can be predicted for ceramic bodies containing 5–10% of OCW, according to Maage factor calculation ceramic bodies containing 5–20% of OCW are frost resistant. Designed ceramic products can be attractive for use in construction due to improved energy efficiency and reduced energy consumption in buildings due to their low thermal conductivity, satisfactory mechanical strength, and sustainability based on predicted frost resistance. Full article

This study aims to optimize the composition (body formulation) and firing temperature of sustainable ceramic clay-based ceramics incorporated with electric arc furnace (EAF) steel slag waste using general full factorial design (GFFD). The optimization is necessary to minimize drawbacks of high iron oxide’s fluxing agent (originated from electric arc furnace, EAF steel slag waste), which led to severe surface defects and high closed porosity issue of the ceramics. Statistical analysis of GFFD including model adequacy checking, analysis of variance (ANOVA), interaction plots, regression model, contour plot and response optimizer were conducted in the study. The responses (final properties of ceramics) investigated were firing shrinkage, water absorption, apparent porosity, bulk density and modulus of rupture (MOR). Meanwhile, the factors employed in experimental parameters were weight percentage (wt.%) of EAF slag added and firing temperature. Upon statistical analysis, GFFD has deduced that wt.% amount of EAF slag added and firing temperatures are proven to significantly influence the final properties of the clay-based ceramic incorporated with EAF slag. The results of conducted statistical analysis were also highly significant and proven valid for the ceramics. Optimized properties (maximum MOR, minimum water absorption and apparent porosity) of the ceramic were attained at 50 wt.% of EAF slag added and firing temperature of 1180 °C. Full article

The interest of the construction industry in alkali-activated materials has increased to the extent that these materials are recognized as alternatives to ordinary Portland cement-based materials in the quest for sustainable construction. This article presents the design and construction of a prototype of an eco-friendly house built from concrete blocks produced using alkali activation technology or geopolymerization. The prototype meets the requirements of the current Colombian Regulations for Earthquake Resistant Buildings (NSR-10) and includes standards related to the performance of the materials, design, and construction method for earthquake-resistant confined masonry of one- or two-story buildings. The alkali-activated blocks were obtained from different precursors (aluminosilicates), including a natural volcanic pozzolan, ground granulated blast furnace slag, fly ash, construction and demolition waste (concrete, ceramic, brick, and mortar), and red clay brick waste. The physical-mechanical characterization of the alkali-activated blocks allowed their classification according to the structural specifications of the Colombian Technical Standard NTC 4026 (equivalent to ASTM C90). The global warming potential (GWP) or “carbon footprint” attributed to the raw materials of alkali-activated blocks was lower (25.4–54.7%) than that of the reference blocks (ordinary Portland cement concrete blocks). These results demonstrate the potential of alkali-activated materials for application in the construction of eco-friendly houses. Full article

In this study, we develop ceramic formulations based on quartzite and scheelite tailings collected from mining companies in the northeast of Brazil (Rio Grande do Norte State). New ceramic samples (27 wt% of kaolin, 29 wt% of plastic clay, 11 wt% of quartzite tailing, and 0–8 wt% scheelite tailing) were uniaxially pressed in two steps (20 MPa and 50 Mpa for 20 s); dried at 110 °C for 24 h; and sintered at 1150 °C, 1200 °C, and 1250 °C. The main mineralogical phases (mullite, quartz, calcite, and anorthite) of the sintered samples were identified using X-ray diffraction (XRD). After evaluation of the physical-mechanical properties (water absorption, linear shrinkage, apparent porosity, and flexural strength), it was observed that the incorporation of scheelite tailing by up to 8 wt% did not significantly alter the properties of samples sintered at all temperatures. Our results indicate that the new ceramics formulations developed have strong potentials in manufacturing sustainable materials such as ceramic tiles and porcelain stoneware. Full article