Search Results (10,484)

With the increasing global demand for sustainable building materials, coal gangue, as a potential supplementary cementitious material (SCM), has attracted widespread attention. Coal gangue is primarily composed of clay minerals, among which the kaolinite content can significantly enhance its cementitious properties after activation. However, there are various grades of coal gangues, which restrain their application, especially for the low kaolinite content coal gangue. This paper investigates the feasibility of using iron-rich coal gangue with low kaolinite content as a cement substitute through high-temperature activation treatment. In the current study, activated coal gangue replaced cement clinker at proportions of 10%, 15%, and 20%, which was further mixed with limestone powder to form a new cementitious material system. The mechanical attributes of the systems were assessed using compressive strength and microhardness tests. The influence of hydration products and microstructural changes on system performance was further explored through electrochemical impedance spectroscopy (EIS) and quantitative X-ray diffraction (XRD) analysis. The findings suggest that a well-balanced addition of coal gangue can effectively substitute for cement clinker, thereby enhancing both the mechanical properties and microstructure of the systems. These results demonstrate that through appropriate activation treatments, coal gangue can be utilized as an effective SCM. While traditional SCMs like fly ash (FA) and ground granulated blast-furnace slag (GGBFS) have near-zero allocated carbon footprints, their global supply is diminishing and increasingly unreliable. In contrast, our approach valorizes a vast industrial waste stream, aligning with circular economy principles and offering a scalable, sustainable, and low-carbon alternative for the construction industry. Full article

Photovoltaic (PV) energy conversion is expected to contribute to the creation of a clean energy society. For realizing such a vision, various developments such as high-efficiency, low-cost and highly reliable materials, solar cells, modules and systems are necessary. Cooperation with storage batteries is also very important for regulation and self-consumption. The creation of new applications such as building integrated PV, vehicle integrated PV, agriculture PV and floating PV is also very important for further installation of PV and reducing CO₂ emission. The sustainability of material consumption, along with reducing, reusing and recycling are also key issues for widespread deployment of PV. This paper provides an overview of the current status of photovoltaics and discusses future directions for photovoltaics from the view-points of high-efficiency, low-cost, reliability, and importance of integrated photovoltaics and sustainability. Full article

The creep behavior of rigid polyvinyl chloride (PVC) in hydrothermal environments can compromise its long-term stability and load-bearing capacity, potentially leading to deformation or structural failure. Understanding this degradation is critical for ensuring the durability and safety of PVC in engineering applications such as pipelines and building materials. In this study, accelerated hydrothermal aging tests were carried out on PVC under controlled conditions of 60 °C and 90% relative humidity (RH). Short-term tensile creep tests at four different stress levels were conducted both before and after aging. Microstructural changes associated with the PVC’s creep behavior were analyzed using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and other microscopic characterization techniques. These analyses provided a detailed microscopic interpretation of how hydrothermal exposure and applied loads influenced the macroscopic creep performance of the PVC, thereby elucidating the correlation between its macroscopic mechanical behavior and microstructural evolution. By applying the time–stress equivalence principle and the time–aging equivalence principle, the short-term creep behavior was characterized to predict long-term performance. The accelerated characterization curve can effectively predict the creep behavior of PVC under a stress level of 16 MPa over approximately 6.5 years in an environment of 60 °C and 90% RH. At the same time, the master creep modulus curve of PVC under any aging duration and stress level can be established under the specified environmental conditions of 60 °C and 90% RH. Long-term creep curves were fitted using a locally structured derivative Kelvin model, demonstrating that this model can effectively simulate the long-term creep behavior of PVC under hydrothermal conditions. The results indicate that at a stress level of 16 MPa, PVC is expected to undergo creep damage and failure after approximately 15 years in such an environment. These findings provide a critical reference for assessing the long-term performance of PVC in hydrothermal environments. Full article

Magnesium slag (MS) is a solid by-product during magnesium production using the Pidgeon process. Around 5–6 million tons of magnesium slag was produced in China in 2023, which accounted for 83% of the total disposal of magnesium slag worldwide. To explore the innovative and high-end application of MS in building materials, this study investigated the preparation of calcium carbonate cementitious composites produced by high-volume (80%) MS and 20% of traditional ordinary Portland cement (OPC), low-carbon cement–calcium sulfoaluminate cement (CSA), or green cement–alkali-activated materials after CO₂ curing. The effects of OPC, CSA, and AAM on the performance evolution of MS blends before and after carbonation curing were analyzed. The results indicated that AAM contributed to a superior initial strength (7.38 MPa) of MS composites after standard curing compared to OPC (1.18 MPa) and CSA (2.72 MPa). However, the lack of large pores (around 1000 nm) in the AAM-MS binder caused the slowest CO₂ penetration during the carbonation curing period compared to the OPC- and CSA-blended samples. Less than 3 days were required for the full carbonation of the CSA- and OPC-blended MS mortar, while 7 days were required for the AAM blends. After carbonation, the OPC-blended MS exhibited the highest strength performance of 51.58 MPa, while 21.38 MPa and 9.3 MPa were reached by the AAM- and CSA-blended MS mortars, respectively. OPC-blended MS composites exhibited the highest CO₂ uptake of 13.82% compared to the CSA (10.85%) and AAM (9.41%) samples. The leaching of Hg was slightly higher than the limit (<50 µg/L) in all MS mortars, which should be noticed in practical application. Full article

Three-dimensional bioprinting integrating living cells and bioactive materials enables the fabrication of scaffold structures supporting diverse cellular growth and metabolism. Microalgae are among the most promising microbial platforms for the construction of photosynthetic cell factories, while the current industrial-scale cultivation of microalgae remains predominantly dependent on traditional liquid submerged systems, imposing limitations on commercial viability due to both process and economic constraints. Encapsulation of microalgae within bioactive matrices combined with 3D bioprinting to fabricate customized structures has been explored to address the limitations of submerged cultivation, which are expected to expand microalgal applications and establish new research directions in microalgal biotechnology. This review analyzes both matrices and methods of 3D bioprinting, summarizing the advancement of microalgae-based 3D bioprinting into six main domains including living building materials, biophotovoltaics, photosynthetic biosynthesis, bioremediation, tissue engineering, and food engineering. Lastly, synthetic biology-informed perspectives are provided on future developments of 3D bioprinting technologies and their potential in microalgal research. Full article

Quantifying the environmental benefits of designing buildings for disassembly and flexibility (DfD/DfF) remains challenging within current life cycle assessment (LCA) frameworks. This study assesses the climate impact of a two-story Swedish timber multifamily building (377 m²) designed for future transformation and reuse. An LCA covering modules A–D was performed for one linear scenario (S0: demolition without reuse) and three circular scenarios (S1: layout change, S2: relocation, S3: vertical extension), applying three allocation methods: 100:0, 50:50, and system expansion. All circular scenarios reduced climate impact compared to the linear reference, though to varying degrees. Reductions ranged from 8–50% within the system boundary (A–C), depending on scenario and allocation method. While the 50:50 approach attributed significant reductions within A–C, the 100:0 method emphasized benefits primarily in module D. The 50:50 method yielded the lowest impacts within the system boundary, whereas system expansion showed the largest overall reductions but relied on uncertain assumptions. The study concludes that including future scenarios in LCA is more effective in promoting circularity than the specific choice of allocation method. It emphasizes the need for standardized frameworks that account for multiple use cycles and support fair comparisons in policy and procurement. Full article

The sports center is a new type of sports building with high participation and high lighting energy consumption. A typical building model is constructed and analyzed by combining Rhino Grasshopper and Ecotect simulation software, and the passive strategy of placing cavities is used to reduce the lighting energy consumption and improve the lighting coefficient, which is beneficial to the health and visual comfort of users. Data analysis revealed that built-in cavities are effective at increasing the average illuminance of the underlying space. For spaces with glare, using skin cavities significantly reduces the possibility of discomforting glare. In the architectural design of the sports center, the form, size, number, material, and other factors of the cavity should be carefully considered to meet the demand for daylighting and improve the comfort of the indoor light environment, which provides a valuable reference for the architectural design of the sports center. Full article

Following recent earthquakes in Van, Istanbul, Izmir, and Kahramanmaraş, concerns have once again been raised regarding whether existing buildings possess adequate seismic performance and the necessity of strengthening those that do not. A common theme in all related discussions is how to improve the seismic resilience of the existing building stock most efficiently and cost-effectively. In particular, seismic retrofitting efforts should be accelerated for residential buildings in areas where urban transformation has not been feasible due to low added value, as well as for public buildings in smaller settlements and school or dormitory structures in rural towns and villages. In this study, the seismic performance of a reinforced concrete (RC) frame was evaluated using the nonlinear single-mode pushover analysis method in accordance with the Turkish Building Earthquake Code (TBEC). For frames with inadequate performance, a retrofitting method was proposed using glued laminated timber (glulam), a renewable and sustainable material, as diagonal bracing. This intervention aimed to improve the structural performance to an acceptable level specified by the code. The results indicated that glulam braces can effectively enhance the seismic performance of RC buildings and may be considered a viable solution for this purpose. Full article

Emerging infectious diseases, particularly those of zoonotic origin, often originating from wildlife reservoirs represent a growing threat to global health. Human-driven environmental changes such as habitat fragmentation, climate change, and urban expansion have intensified interactions at the wildlife–domestic animal–human interface, facilitating cross-species viral transmission. Despite their epidemiological importance, systematic virological surveillance of wildlife remains challenging. In this study, we employed shotgun metagenomic sequencing to characterize the virome of wild animals rescued in the Pisa area and hospitalized at the “Mario Modenato” Veterinary Teaching Hospital (VTH) at the University of Pisa. Fecal samples collected from injured wildlife admitted between September 2020 and September 2021 were analyzed to detect both known and novel viruses. This approach builds upon previous PCR-based investigations of the same biological material, enabling a more comprehensive assessment of viral diversity. We adopted a shotgun approach for analyzing six sample pools—four were positive for at least one viral target—identifying diverse viral families, including Astroviridae, Circoviridae, Picornaviridae, Adenoviridae, and Retroviridae, in asymptomatic wildlife admitted to a veterinary hospital, highlighting their potential role as reservoirs. Our findings provide insights into the influence of environmental and anthropogenic factors on wildlife virome composition and highlight the value of hospital-based sampling strategies for urban viral surveillance. The results contribute to the development of integrated monitoring and prevention strategies within a One Health framework. Full article

Masonry construction remains labor-intensive, with current block placement predominantly dependent on workers’ empirical knowledge. Lack of systematic cutting plans induces substantial material waste and rework, adversely affecting sustainability. We propose a two-phase optimization framework to automate and enhance masonry block arrangement efficiency. Phase 1 decomposes masonry structures into optimizable subregions by geometric features, documenting each region’s geometry and position to generate optimization datasets. Phase 2 implements a computational module using the Social Network Search (SNS) algorithm to optimize subregion layouts, recording post-optimization block coordinates and dimensions. Finally, it materializes layout configurations and generates block quantity schedules to provide precise material demand data. An integrated prototype system was implemented in four specialized block arrangement scenarios and one building case study, validating both functionality and efficiency. Full article

Starch and lignin are promising biopolymers for the production of biodegradable biocomposite materials. The possibility of processing starch into thermoplastic materials qualifies it as a starting material for the preparation of thermoplastic packaging films, and the combination with lignin can even out some inherent weak points of starch, such as moisture and water sensitivity, and can add additional features like antioxidant activity. Lignins from herbaceous biomass carry building blocks that are not found in wood lignins and are known for their bioactivity, such as p-coumaric acid or ferulic acid. In this work, a protocol was developed to initially prepare hybrids of wheat starch granules and lignin nanoparticles, which were then plasticized using glycerol in an extrusion process to produce thin films. The lignin-containing thermoplastic starch films showed higher Young’s moduli and less elongation at break compared to neat thermoplastic starch films, while tensile strength remained at the level of the neat films. Thermal stability was slightly increased by lignin addition, and oxygen transmission rates were low for lignin contents as low as 1 wt%. The hydrophobicity of the lignin-containing films increased strongly, and they showed an elevated antioxidant activity over several hours, which was also maintained after 24 h. The preparation of hybrid wheat starch lignin particles was successfully tested for the extrusion of thermoplastic starch films with improved thermomechanical properties, decreased water sensitivity, and prolonged antioxidant activity. Full article

Noise barriers are commonly used to reduce the adverse effects of traffic noise in both urban and suburban settings. While conventional systems constructed from concrete and steel provide reliable acoustic and structural performance, they raise sustainability concerns due to high embodied energy and carbon emissions. Glued-laminated (glulam) timber has emerged as a sustainable alternative, offering a reduced carbon footprint, aesthetic appeal, and effective acoustic performance. However, the crashworthiness of timber-based noise wall systems remains under investigated, particularly with respect to the safety criteria established in the 2016 edition of the American Association of State Highway and Transportation Officials (AASHTO) Manual for Assessing Safety Hardware (MASH). This study presents the full-scale crash testing and evaluation of glulam rubrail and noise wall systems under MASH Test Level 3 (TL-3) impact conditions. Building on a previously tested system compliant with National Cooperative Highway Research Program (NCHRP) Report 350, modifications were made to increase rubrail dimensions to meet higher lateral design loads. Three full-scale vehicle crash tests were conducted using 1100C and 2270P vehicles at 100 km/h and 25 degrees, covering both front- and back-mounted wall configurations. All tested systems demonstrated acceptable structural performance, effective vehicle redirection, and compliance with MASH 2016 occupant risk criteria. There was no penetration or potential for debris intrusion into the occupant compartment, and all measured occupant risk values remained well below allowable thresholds. Minimal damage to structural components was observed. The results confirm that the modified glulam noise wall system meets current impact safety standards and is suitable for use along high-speed roadways. This work supports the integration of sustainable materials into roadside safety infrastructure without compromising crash performance. Full article

As operational emissions decrease due to improved energy efficiency, reducing embodied carbon in buildings has become increasingly important. Life cycle assessment (LCA) is a widely used method to quantify these impacts. However, its implementation often remains data-intensive and time-consuming due to the need for detailed material inventories. This study analyzes 100 LCA reports submitted for G-SEED certification in South Korea to identify a core set of construction materials that accounts for most of the total material mass. Unlike previous approaches that relied on 99% cumulative mass thresholds, this study introduces a function-based classification framework considering both material roles and environmental impact intensity, offering a novel pathway for simplifying LCA. The findings reveal 12 key material categories, such as ready-mixed concrete, cement-based products, structural steel, wood, and interior finishes, that dominate embodied carbon contributions, with concrete alone composing over 85% of the total mass based on the analyzed G-SEED dataset. A material classification framework is then developed, organized by functional role and carbon impact. By focusing on these high-impact materials, future LCA efforts can be significantly streamlined without compromising accuracy. This approach offers data-driven guidance for LCA practitioners, designers, and green building certification bodies aiming for efficient and reliable carbon assessments. Full article

A homogenisation procedure for energy-buffering structural layers with integrated electrical energy storage systems (capacitors) is described with the aim of calculating their shielding effectiveness to the electromagnetic waves when they are installed inside building walls. In fact, these storage systems may attenuate electromagnetic fields in the frequency ranges employed by mobile telephony, radio broadcasting, and wireless data transmission, thus impairing the operation of Internet of Things infrastructures. The capacitors inside the individual energy-buffering modules have a multilayered structure, in which the layers have very small thicknesses, making an analytical solution of the electromagnetic field for this kind of object practically impossible. Similarly, numerical solutions may not be practical due to the very small thickness of the layers compared to the overall object size. Therefore, this paper presents a simple and effective analytical method to model multilayered structures consisting of homogenising the whole capacitor, which can then be treated as a unique block of material with fictitious (but effective) electric and magnetic parameters. The method is based on multi-section transmission lines, and a quick and reliable analytical methodology is proposed to evaluate the shielding capabilities using the homogenised capacitor’s effective parameters. Moreover, experimental measurements on a real prototype have also been carried out to validate the methodology. Results show that the trend of the simulated and measured SE is the same, proving that the method can be employed to obtain a conservative estimation of the SE from numerical simulations. Full article