Search Results (243)

This study aims to enhance the performance of an innovative steel slag–ceramsite foam concrete (SSCFC) to advance sustainable green building materials. An eco-friendly composite construction material was developed by integrating industrial by-product steel slag (SS) with lightweight ceramsite. Employing a three-factor, three-level orthogonal experimental design at a fixed density of 800 kg/m³, 12 mix proportions (including a control group) were investigated with the variables of water-to-cement (W/C) ratio, steel slag replacement ratio, and ceramsite replacement ratio. The governing mechanisms of the W/C ratio, steel slag replacement level, and ceramsite replacement proportion on the SSCFC’s fluidity and compressive strength (CS) were elucidated. The synergistic application of range analysis and analysis of variance (ANOVA) quantified the significance of factors on target properties, and partial least squares regression (PLSR)-based prediction models were established. The test results indicated the following significance hierarchy: steel slag replacement > W/C ratio > ceramsite replacement for fluidity. In contrast, W/C ratio > ceramsite replacement > steel slag replacement governed the compressive strength. Verification showed R² values exceeding 65% for both fluidity and CS predictions versus experimental data, confirming model reliability. Multi-criteria optimization yielded optimal compressive performance and suitable fluidity at a W/C ratio of 0.4, 10% steel slag replacement, and 25% ceramsite replacement. Full article

To meet the European Green Deal targets, the construction sector must improve building thermal performance via advanced insulation systems. Eco-friendly sandwich panels offer a promising solution. Therefore, this work aims to develop and validate a new eco-friendly composite sandwich panel (basalt fibres and recycled extruded polystyrene) with enhanced multifunctionality for lightweight and energy-efficient building façades. Two panels were produced via vacuum infusion—a reference panel and a multifunctional panel incorporating phase change materials (PCMs) and silica aerogels (AGs). Their performance was evaluated through lab-based thermal and acoustic tests, numerical simulations, and on-site monitoring in a living laboratory. The test results from all methods were consistent. The PCM-AG panel showed 16% lower periodic thermal transmittance (0.16 W/(m²K) vs. 0.19 W/(m²K)) and a 92% longer time shift (4.26 h vs. 2.22 h), indicating improved thermal inertia. It also achieved a single-number sound insulation rating of 38 dB. These findings confirm the panel’s potential to reduce operational energy demand and support long-term climate goals. Full article

This study presents a cost-effective, carbon-negative construction material for affordable housing, developed entirely from locally available agricultural wastes: rice husk ash, wood ash, and rice straw—materials often problematic to dispose of in many African regions. Rice husk ash provides high amorphous silica, acting as a strong pozzolanic agent. Wood ash contributes calcium oxide and alkalis to serve as a reactive binder, while rice straw functions as a lightweight organic filler, enhancing thermal insulation and indoor climate comfort. These materials undergo natural pozzolanic reactions with water, eliminating the need for Portland cement—a major global source of anthropogenic CO₂ emissions (~900 kg CO₂/ton cement). This process is inherently carbon-negative, not only avoiding emissions from cement production but also capturing atmospheric CO₂ during lime carbonation in the hardening phase. Field trials in Kenya confirmed the composite’s sufficient structural strength for low-cost housing, with added benefits including termite resistance and suitability for unskilled laborers. In a collaboration between the University of Tartu and Kenyatta University, a semi-automatic mixing and casting system was developed, enabling fast, low-labor construction of full-scale houses. This innovation aligns with Kenya’s Big Four development agenda and supports sustainable rural development, post-disaster reconstruction, and climate mitigation through scalable, eco-friendly building solutions. Full article

Mycelium-based composites (MBCs) are an emerging category of cost-effective and environmentally sustainable materials that are attracting significant research and commercial interest across various industries, including construction, manufacturing, agriculture, and biomedicine. These materials harness the natural growth of fungi as a low-energy bio-fabrication method, converting abundant agricultural by-products and waste into sustainable alternatives to energy-intensive synthetic construction materials. Their affordability and eco-friendly characteristics make them attractive for both research and commercialisation. Currently, mycelium-based foams and sandwich composites are being actively developed for applications in construction. These materials offer exceptional thermal insulation, excellent acoustic absorption, and superior fire safety compared to conventional building materials like synthetic foams and engineered wood. As a result, MBCs show great potential for applications in thermal and acoustic insulation. However, their foam-like mechanical properties, high water absorption, and limited documentation of material properties restrict their use to non- or semi-structural roles, such as insulation, panelling, and furniture. This paper presents a comprehensive review of the fabrication process and the factors affecting the production and performance properties of MBCs. It addresses key elements such as fungal species selection, substrate choice, optimal growth conditions, dehydration methods, post-processing techniques, mechanical and physical properties, termite resistance, cost comparison, and life cycle assessment. Full article

The global push for sustainable development has intensified the need for innovative tools to assess and enhance sustainability in the built environment. This study explores the role of materials efficiency (ME) within a nature-inspired sustainability assessment framework, focusing on green building projects in South Africa. Using a nature-based (biomimicry) approach, this study identifies and prioritises key ME criteria such as eco-friendly materials, local sourcing, and responsible processing. The methodology employed the Analytic Hierarchy Process (AHP), with input from 38 carefully sampled construction experts, to rank ME criteria through pairwise comparisons. The findings revealed that eco-friendly materials (29.5%) and locally sourced materials (25.1%) were the highest-weighted factors, with strong expert consensus (CR = 0.01). The study highlights how nature-inspired principles like closed-loop systems and minimal waste can guide sustainable construction aligned with global goals such as the UN Sustainable Development Goals. The conclusion advocates for integrating ME criteria into green certification systems, industry collaboration, and further research to scale the framework globally. This study bridges biomimicry theory with practical sustainability assessment, offering actionable insights for the built environment. Full article

The construction industry faces significant challenges such as environmental degradation, resource depletion, waste generation, and pollution, necessitating a shift toward sustainable practices. This study explores the benefits of implementing modular building practices (MBP) as a transformative solution. A quantitative research approach was employed, utilising a structured questionnaire distributed to active and practising construction professionals. Data were analysed using mean item scores and standard deviation, with Cronbach’s alpha confirming the reliability of the research instrument (α = 0.961). The findings reveal that MBPs offer significant benefits, including eco-friendly operations, reduced material wastage, improved safety, and high productivity, among others. The discussion highlights MBPs’ potential to address environmental and economic challenges, aligning with global sustainability goals. The study concludes that MBP is a viable alternative to traditional construction, recommending policy support, industry collaboration, and further research to optimise its adoption and integration into the construction sector. Full article

Studies underscore the significance of coir fibers as a sustainable building material. Based on these insights, this research aims to evaluate coir fiber composite panels of various thicknesses as eco-friendly sound absorbing alternatives to synthetic construction materials like rockwool and fiberglass, aligning its use with the United Nations Sustainable Development Goals. Acoustic absorption was quantified with an impedance tube, and subsequent simulations compared the performance of coir composite panels with that of conventional materials, which constitutes an underexplored evaluation. Using 10 receiver points, the simulations reproduced the acoustic conditions of a multipurpose auditorium before and after the coir covering of parts of the rear and posterior walls. The results indicate that when coir coverings account for approximately 10% of the auditorium surface, reverberation times at 250, 500, 2000, and 4000 Hz are reduced by roughly 1 s. Furthermore, the outcomes reveal that early reflections occur more rapidly in the coir-enhanced model, while the values of the early decay time parameter decrease across all receiver points. Although the original configuration had poor speech clarity, the modified model achieved optimal values at all the measurement locations. These findings underscore the potential of coir fiber panels in enhancing acoustic performance while fostering sustainable construction practices. Full article

Recyclable aluminum-containing industrial solid waste can be used as supplementary cementitious materials (SCMs) to replace cement (30–50%), thereby reducing CO₂ emissions during cement production and improving the mechanical properties and durability of concrete. Therefore, the use of SCMs in building materials presents significant potential. Due to the presence of the aluminum phase in the SCMs, the hydration products of cements blended with SCMs are changed. Compared to the primary hydration product of conventional cement, calcium silicate hydrate (CSH), the main hydration product of cement blended with SCMs is calcium aluminosilicate hydrate (CASH), which exhibits a more complex molecular structure. Understanding the role of Al in C-A-S-H at the atomic scale facilitates mechanistic insights and promotes the sustainable utilization of SCMs in eco-friendly construction. Molecular dynamics enables the rapid and accurate structural analysis and property prediction of materials. Therefore, this paper presents a systematic review of molecular dynamics simulations of CASH and discusses the role of Al in the molecular structure, dynamic, and mechanical behavior of CASH. It also analyzes the interfacial properties of CASH composites, the immobilization and transport of ions in CASH, and the temperature effect on the structure and properties of CASH. Finally, the challenges and perspectives for molecular dynamics simulation of CASH are presented. Full article

The growing demand for fire-safe, sustainable materials has driven extensive research into advanced flame retardants particularly polystyrene (PS), a widely utilized yet inherently flammable polymer. Graphene-derived materials are considered effective flame retardants owing to their higher thermal stability, char-formation, and gas barrier properties. However, despite these advantages, challenges such as agglomeration, high thermal conductivity, poor interfacial compatibility, and processing limitations hinder their full-scale adoption in building insulation and other applications. This review presents an in-depth analysis of recent progress in graphene-enhanced flame-retardant systems for polystyrene applications, focusing on synthesis methods, flame-retardant mechanisms, and material performance. It also discusses strategies to address these challenges, such as surface functionalization, hybrid flame-retardant formulations, optimized graphene loading, and improved dispersion techniques. Furthermore, future research directions are proposed to enhance the effectiveness and commercial viability of graphene-based flame-retardant polystyrene composites. Overcoming these challenges is essential for high-performance, eco-friendly, flame-retardant materials on a larger scale. Full article

Sustainable architectural heritage conservation focuses on preserving historical buildings while promoting environmental sustainability. It involves using eco-friendly materials and methods to ensure that the cultural value of these structures is maintained while minimizing their ecological impact. In this paper, the use of the hydroxyapatite (HAp) in various combinations on masonry samples is presented, with the aim of identifying the ideal solution to be applied to an entire historical building in Banloc monument. The new solution has various advantages: compatibility with historical lime mortars (chemical and physical), increased durability under aggressive environmental conditions, non-invasive and reversible, aligning with conservation ethics, bioinspired material that avoids harmful synthetic additives, preservation of esthetics—minimal visual change to treated surfaces, and nanostructural (determined via SEM and AFM) reinforcement to improve cohesion without altering the porosity. An innovative approach involving hydroxiapatite addition to commercial mortars is developed and presented within this paper. Physico-chemical, mechanical studies, and architectural and economic trends will be addressed in this paper. Some specific tests (reduced water absorption, increased adhesion, high mechanical strength, unchanged chromatic aspect, high contact angle, not dangerous freeze–thaw test, reduced carbonation test), will be presented to evidence the capability of hydroxyapatite to be incorporated into green renovation efforts, strengthen the consolidation layer, and focus on its potential uses as an eco-material in building construction and renovation. The methodology employed in evaluating the comparative performance of hydroxyapatite (HAp)-modified mortar versus standard Baumit MPI25 mortar includes a standard error (SE) analysis computed column-wise across performance indicators. To further substantiate the claim of “optimal performance” at 20% HAp addition, independent samples t-tests were performed. The results of the independent samples t-tests were applied to three performance and cost indicators: Application Cost, Annualized Cost, and Efficiency-Cost-Performance (ECP) Index. This validates the claim that HAp-modified mortar offers superior overall performance when considering efficiency, cost, and durability combined. Full article

The construction industry generates large amounts of waste and high CO₂ emissions, especially from cement production. Sustainable alternatives, such as geopolymers, help reduce these impacts by promoting eco-friendly materials. This study aimed to develop geopolymer mortar using ignimbrite (IG) residues from the Arequipa region, Peru, combined with metakaolin (MK). The raw materials were characterized by X-ray diffraction (XRD), X-ray fluorescence (XRF), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS) to assess the chemical composition, structure, and morphology. Geopolymeric mortars were synthesized with varying MK/IG ratios while maintaining a fixed fine sand proportion. An activating solution of 9 mol/L NaOH was used with different liquid-to-solid ratios. Geopolymers cured at room temperature for 28 days exhibited lower compressive strength than those dried at 50 °C for 48 h or sequentially at 50 °C for 48 h followed by 90 °C for 12 h. The highest IG-content mixture achieved a compressive strength of 18 MPa, while the MK-based geopolymer reached 12 MPa, both under high-temperature curing. An increase in the SiO₂/Al₂O₃ molar ratio was also associated with improved mechanical performance, reinforcing the influence of precursor composition on geopolymerization. These results highlight the potential of regional ignimbrite for the production of geopolymer mortar, promoting sustainable and innovative building materials. Full article

Mycelium-based composites (MBCs) have emerged as eco-friendly alternatives, utilizing fungal mycelium as a natural binder for agro-industrial residues. This study focuses on developing an MBC based on abundant waste in Colombia, pith Arboloco (A) (Montanoa quadrangularis), a plant endemic to the Colombian–Venezuelan Andes with outstanding insulating properties, and natural fiber of Kikuyu grass (G) (Cenchrus clandestinus), utilizing Ganoderma lucidum as an agent to form a mycelium network in the MBC. Three formulations, T (100% A), F1 (70% A/30% G), and F2 (30% A/70% G), were evaluated under two different Arboloco particle size ranges (1.0 to 5.6 mm) for their physical, mechanical, and thermal properties. The Arboloco particle sizes did not show significant differences in the MBC properties. An increase in Kikuyu grass proportion (F2) demonstrated superior density (60.4 ± 4.5 kg/m³), lower water absorption (56.6 ± 18.4%), and better compressive strength (0.1686 MPa at 50% deformation). Both mixing formulations (F1–F2) achieved promising average thermal conductivity and specific heat capacity values of 0.047 ± 0.002 W m⁻¹ K⁻¹ and 1714 ± 105 J kg⁻¹ K⁻¹, comparable to commercial insulation materials. However, significant shrinkage (up to 53.6%) and high water absorption limit their scalability for broader applications. These findings enhance the understanding of MBC’s potential for non-structural building materials made of regional lignocellulosic waste, promoting a circular economy in waste management for developing countries. Full article

The development of sustainable insulation materials plays a crucial role in creating energy-efficient and environmentally responsible buildings. This study investigates eco-friendly composite materials based on plaster and wood shavings for insulation purposes. Incorporating wood shavings into plaster improves thermal insulation and mechanical behavior by enhancing porosity, reducing density, and improving bonding. As the wood shaving content increases from 5% to 15%, the thermal conductivity decreases from 0.252 W/mK to 0.099 W/mK, reflecting superior insulating performance. Concurrently, thermal resistance rises, showcasing enhanced insulation. The material also demonstrates increased flexibility, with the Young’s modulus decreasing at higher wood shaving proportions. Numerical simulations confirm these observations, indicating a 12 K temperature drop for composites with 15% wood shavings compared to a 6 K drop for pure plaster. This study suggests that an insulation thickness of 6–7 cm for the 15% composite strikes the optimal balance between performance and cost-efficiency. The findings underscore the potential of wood shavings to significantly enhance the thermal efficiency and mechanical adaptability of plaster composites, promoting sustainable and effective building insulation solutions. Full article

The construction sector faces growing pressure to adopt sustainable alternatives amid the global plastic-waste crisis. This study presents a novel use of mechanically recycled high-density polyethylene (HDPE) and polypropylene (PP) to manufacture full-scale plastic rebars for mortar-free, light-load construction applications. A total of 48 samples, plain and ribbed, across three diameters (12 mm, 19 mm, and 25 mm) were fabricated and tested. Due to the absence of standardized protocols for recycled plastic rebars, tensile testing was conducted in reference to ASTM A615. Characterization techniques such as X-ray diffraction (XRD), and Scanning Electron Microscopy (SEM) confirmed the material’s structural features and polymer integrity. XRD confirmed the crystalline phases of HDPE and PP, while SEM revealed ductile fracture in HDPE and brittle failure in PP. The 25 mm ribbed PP rebars demonstrated superior performance, achieving a maximum load capacity of 12.2 ± 0.6 kN, a toughness index of 19.3 ± 1.0, and energy absorption of 101.6 ± 5.0 N-m × 10. These results affirm their suitability for lightweight structural components such as boundary walls, partition panels, and mortar-free interlocking systems. Unlike prior studies that confined recycled plastics to filler roles in composites, this work validates their direct application as full-section, load-bearing members. Additionally, a polynomial-based empirical model was formulated to predict the tensile behavior of the recycled rebars. The findings underscore the potential of mechanical extrusion as a low-emission, scalable solution to convert plastic waste into durable construction materials that support circular economic principles. Full article

This study presents a comprehensive review of various advanced methodologies that have been used to enhance the structural and thermal performance of masonry walls through innovative and sustainable retrofitting/upgrading techniques. Focusing on three primary approaches—mechanical/structural retrofitting, thermal retrofitting, and integrated (structural and thermal) retrofitting, this paper critically examines various masonry-strengthening strategies. Retrofitting techniques are categorized by material use and objectives. Fiber-based solutions include insulation materials, fiber composite mortar for strength, FRP for high-strength reinforcement, and TRM for durability. According to the relevant objectives, retrofitting can enhance structural stability (FRP, TRM), improve thermal insulation, or combine both for integrated performance. Particular emphasis is placed on the effectiveness of TRM systems, with a comparative analysis of man-made (glass, steel textile) and natural fiber-based TRM solutions. Regarding integrating natural fibers into TRM systems, this study highlights their potential as eco-friendly alternatives that reduce environmental impact while maintaining or improving structural integrity. Furthermore, it highlights and examines techniques for testing masonry walls. In this context, this review highlights the applicability of natural fiber as a sustainable building material in various retrofitting/upgrading solutions. Full article