Search Results (2,669)

The objective of this article is to evaluate the viability of implementing the Design for Manufacturing and Assembly (DfMA) methodology in the design and construction of complex wooden structures with non-standard geometry. The present study incorporates an analysis of scientific literature from 2011 to 2024, in addition to selected case studies of buildings constructed using glued laminated timber and engineered wood prefabrication technology. The selection of examples was based on a range of criteria, including geometric complexity, the level of integration of digital tools (BIM, CAM, parametric design), and the efficiency of assembly processes. The implementation of DfMA principles has been shown to result in a reduction in material waste by 15–25% and a reduction in assembly time by approximately 30% when compared to traditional construction methods. The findings of the present study demonstrate that the concurrent integration of design, production, and assembly in the timber construction process enhances energy efficiency, curtails embodied carbon emissions, and fosters the adoption of circular economy principles. The analysis also reveals key implementation barriers, such as insufficient digital skills, lack of standardization, and limited availability of prefabrication facilities. The article under scrutiny places significant emphasis on the pivotal role of DfMA in facilitating the digital transformation of timber architecture and propelling sustainable construction development in the context of the circular economy. The conclusions of the study indicate a necessity for further research to be conducted on quantitative life cycle assessment (LCA, LCC) and on the implementation of DfMA on both a national and international scale. Full article

This article presents the programme for the characterisation of earth mortars stabilised with experimental pozzolanic material from fluid catalytic cracking (FCC). This study aims to establish the optimal ratio for adding pozzolan to stabilise earth mortars. Ash may be used in conservation processes, as it presents suitable pozzolanic properties. Based on the starting premise that its application does not cause chromatic variations in the final mortar and displays resistance to damage from chlorides and extreme temperatures, it can be considered ideal for this purpose. The process of transformation into ash is linked to the production of naphthas and refined petroleum products, where the mineral is a catalyst for the reaction. With use, the mineral tends to shrink, losing the necessary properties for this process. Over the last decade, this process, which is widely used in the petrochemical industry, has generated a volume of waste of up to 3000 tons per day. The amount of waste generated is of interest for its reuse, and a rise is observed in preliminary studies, which confirm that this material is pozzolanic and non-toxic. This offers the possibility of studying this addition to stabilise materials and constructions manufactured with earth. Full article

Concrete is one of the most important and most widely used materials for construction activities around the world. However, it has inherent deficiencies, e.g., brittleness, low impact resistance, low tensile strength, low fire resistance, low durability, and lower resistance to crack formation. Fibers and waste materials of different types are added as partial replacement of cement and aggregates in concrete to improve performance properties and reduce environmental pollution. In the present study, a thorough review of the use of various types of fibers with high and low elastic moduli in concrete to improve mechanical performance and reduce environmental pollution issues has been conducted. This review paper also provides comprehensive information on the different types of waste materials, e.g., biodegradable and non-biodegradable, which are used in concrete. The use of waste materials in concrete reduces the amount of waste sent to landfill and, in addition, improves some mechanical properties of concrete. This review is aimed at evaluating and understanding the strengths and weaknesses of fiber-reinforced concrete by using SWOT (Strengths, Weaknesses, Opportunities, Threats) analysis. Moreover, this study also concluded that carbon fiber-reinforced concrete proves to be stronger and more durable but more expensive than other fibers. An ideal percentage of natural origin fibers used in concrete can greatly improve the mechanical performance. This study also discussed that waste from polymeric materials can be used in concrete as a partial replacement of cement and other components, e.g., coarse aggregates. It can be inferred that the optimum content of fibers that gives effective results is about 1%, and the reinforcement of concrete with different varieties of wastes as a replacement for fine aggregates should not be more than 2%. Parametric optimization of fiber content will be necessary for the best possible combination of performance properties. Full article

Portland cement is widely used in construction, but it contributes significantly to global CO₂ emissions. This study evaluates the potential use of construction and demolition waste (CDW) and marble powder (MP) as supplementary cementitious materials, in line with circular economy goals. Both wastes were ground finer than cement and characterised chemically and physically. Binary and ternary blends with 5% and 10% replacement were tested in pastes and mortars for fresh properties, mechanical performance, and durability. Setting time, soundness, and workability remained within standard limits. Compressive strength decreased moderately, with 28-day activity indices between 82 and 88%, confirming the low reactivity of the supplementary cementitious materials. Sorptivity decreased in all mixes, and chloride resistance improved in the 10CDW and 10MP blends. However, the ternary mix showed increased chloride migration. Carbonation depth increased in all mixes, indicating the need for protective measures in carbonation-prone environments. Replacing 10% of cement with CDW or MP can avoid 70–80 kg of CO₂ per tonne of binder and reduce landfill waste. These materials can be used as low-carbon fillers in cement-based systems, provided that their durability limitations are considered in design. Full article

To realize the efficient utilization of biochar and construction solid waste in building materials production, a novel core–shell aggregate concept is proposed, in which artificial aggregates are prepared by encapsulating coarse-particle bamboo biochar (C-BB) with concrete slurry waste (CSW), calcium carbide slag (CCS), and fine-particle bamboo biochar (F-BB). The results showed that the best engineering properties of the artificial aggregates were achieved when the F-BB content was about 6%, with crushing strength, water absorption, and bulk density values of 4.7 MPa, 14.3%, and 796 kg/m³, respectively. In addition, the artificial aggregates have promising potential for CO₂ uptake under a CO₂ curing system and can achieve 5.72% (by mass) uptake when the F-BB content is 6%. This performance is attributed to the formation of well-developed CO₂ transport channels in the shell matrix by the F-BB particles. In summary, the novel core–shell aggregate not only has better engineering properties than commercial lightweight aggregates but also offers significant potential for CO₂ sequestration, opening new opportunities for the efficient application of biochar in construction materials with both engineering and environmental benefits. Full article

Amidst the dual global pressures of plastic pollution and resource scarcity, the transition to a circular economy has become an imperative. The valorization of biomass waste from agricultural, food, and animal processing into biodegradable packaging materials presents a key strategy to address this challenge. This review aims to systematically construct a comprehensive knowledge framework for the field, addressing the thematic fragmentation and methodological limitations of existing literature through integrated cross-stream analysis, combined bibliometric and technological assessment, and identification of emerging research frontiers. We begin with a bibliometric analysis to delineate the field’s evolutionary trajectory since 2008, global collaboration networks, core research themes, and emerging frontiers, revealing a clear progression from environmental impact assessment to functional material innovation. Subsequently, this review delves into the complete technological chain, from the green extraction of bio-based materials from three major waste streams to the comparison of traditional and advanced film fabrication methods. We then elaborate on the critical performance evaluation dimensions, including mechanical, barrier, biodegradable, safety, and functional properties, and summarize current applications in sectors such as food and medicine. Finally, we critically assess the core challenges related to cost, performance stability, and large-scale production, and provide a systematic outlook on future research directions, particularly the development of high-performance, multifunctional, and intelligent materials. This review offers a comprehensive and data-driven reference framework for researchers and industry stakeholders in the field. Full article

This paper examines the sustainability of photovoltaic (PV) panel recycling through a case study in Greece. It traces the evolution of PVs and outlines the main construction characteristics, emphasizing that although PV systems reduce greenhouse gas emissions, they also generate substantial end-of-life (EoL) waste containing both valuable and potentially hazardous materials. The study estimates Greece’s annual PV waste generation and evaluates its environmental, social, and economic impacts. It focuses on advanced disassembly and recycling methods by PV types and calculates material-recovery rates. Using national installation data from 2009–2023, the analysis quantifies the potential mass of recoverable materials and assesses the sustainability of PV recycling in terms of environmental protection, public health, and economic feasibility. Results show high recovery rates: silicon (85%), aluminum (100%), silver (98–100%), glass (95%), copper (97%), and tin (32%). Although current recycling economics remain challenging, the environmental and health benefits are significant. This research contributes to the existing literature by providing the first detailed quantification of recoverable raw materials embedded in Greece’s PV stock and by highlighting the need for technological innovation and supportive policies to enable a circular and sustainable solar economy. Full article

Three-dimensional (3D) concrete printing (3DCP) is an emerging digital construction technology that enables geometrically complex structures with reduced labour, material waste, and formwork. However, the sustainability of 3DCP remains constrained by its heavy reliance on Portland cement, a major source of global CO₂ emissions. This study systematically examines metakaolin (MK) and biochar (BC) as sustainable additives for 3DCP, focusing on their independent effects on mechanical performance, printability, dimensional stability, and environmental impact. A comprehensive literature review (2015 to June 2025) identified 254 publications, of which 21 met the inclusion criteria for quantitative meta-analysis, contributing a total of 95 datasets for compressive and flexural strength. Pooled effect sizes were calculated using a random-effects model, supported by risk-of-bias and heterogeneity analyses. The results indicate statistically significant improvements in mechanical properties, with an overall pooled ratio of means (ROM) of 1.12 (95% CI: 1.06–1.20; I² = 48.9%), representing the overall mechanical performance effect across all datasets, while ROM for compressive and flexural strength was calculated separately in the main analysis. Meta-regression revealed that BC increased compressive and flexural strengths by 7% and 9%, respectively, while MK achieved greater enhancements of 21% and 13.4%. Optimum performance was observed at 15–20% MK for compressive strength and 10–15% for flexural strength, whereas BC performed best at 3–5% and 2–5%, respectively. BC contributed to CO₂ reductions of up to 43% through clinker substitution and biogenic carbon sequestration. These findings demonstrate that MK and BC are complementary eco-efficient modifiers capable of enhancing both structural and environmental performance in 3DCP. Future research should address long-term durability, standardisation of printing parameters, and cradle-to-grave life cycle assessments to strengthen practical implementation. Full article

The growing environmental pollution and the imminent depletion of natural resources highlight the need for alternative building materials derived from renewable sources, including those that promote waste recycling and biodegradability. One promising alternative is biocomposites produced from filamentous fungal mycelium. In Argentina, orange and lemon peels are among the most abundant organic waste generated by the citrus industry. This study explores the development of a sustainable insulating biocomposite using Pleurotus ostreatus mycelium grown on mixtures of citrus peels, paper, and cardboard. The test specimens were prepared using varying concentrations of these components. The resulting fungal biocomposite exhibited a density approximately ten times higher than expanded polystyrene, with drying shrinkage ranging from 28% to 51%, depending on the formulation. Key properties were evaluated, including compressive strength (${\sigma }_{10}$ = 7–33 kPa), bulk density ($\rho$ = 152–181 kg/m${}^3$), and thermal conductivity ($\lambda$ = 0.29–0.36 W/mK), indicating advantageous performance for thermal insulation in construction applications. Specimens containing orange peel also demonstrated repellent activity against Triatoma infestans, main vector of transmission of Chagas’ disease, attributed to the residual limonene content retained from the citrus peels. This fungal biocomposite aligns with principles of green chemistry and circular economy, offering a biodegradable, low-impact solution with potential use in construction. The citrus waste proved to be an effective substrate for mycelial growth, producing a material with desirable mechanical and thermal properties, and added resistance to biodeterioration. Full article

The utilization of waste glass as an aggregate in cement-based materials provides both environmental and economic benefits, but the alkali-silica reaction (ASR) caused by the reactive silica in glass aggregates is a significant challenge for its application. This study investigates the impact of different crushing methods on the ASR of glass aggregate mortar, with a focus on the effect of immersion crushing using calcium chloride (CaCl₂) solution. Glass aggregates were prepared using conventional crushing, water immersion crushing, and CaCl₂ immersion crushing methods. The ASR expansion and compressive strength of the mortar were evaluated through accelerated ASR tests, compressive strength testing, and microstructural analysis using SEM/EDS and mercury intrusion porosimetry (MIP). Results show that immersion crushing significantly mitigated ASR expansion and the associated loss in compressive strength. The CaCl₂ immersion method yielded the most pronounced effect. Compared with conventional crushing, it reduced the ASR expansion by approximately 45% and improved the compressive strengths by approximately 20%. Microstructural analysis revealed that the CaCl₂ treatment led to a higher Ca/Si ratio in the ASR gel, which reduced the gel’s water-absorbing swelling ability and consequently suppressed ASR-induced expansion. Additionally, the CaCl₂ immersion crushing method resulted in the smallest changes in porosity and pore size distribution. These findings provide a theoretical basis for the safe use of waste glass in cement-based materials and contribute to the promotion of resource recycling in the construction industry. Full article

Fine-grained tailings pose significant challenges for direct resource utilization applications such as tailings dam construction and backfill preparation due to their fine particle size, high specific surface area, and extended natural consolidation period. This investigation examined the mechanical properties of cemented fine-grained tailings under varying mix proportions and conditions. The cemented tailings were prepared using raw tailings material containing approximately 95% particles sized 0–74 μm. A comprehensive experimental program comprising 36 flexural tests and uniaxial compressive tests was conducted, with cement–sand ratio (A), curing age (B), and specimen immersion time (C) as controlled variables. The strength development mechanism was characterized through XRD and SEM, while mechanical performance data were systematically analyzed using range analysis, ANOVA, and regression analysis. Key findings demonstrate that ① the flexural strength of cemented tailings ranged from 0.43 to 2.07 MPa, with compressive strength varying between 3.02 and 12.52 MPa; ② both compressive and flexural strengths exhibited positive correlations with factors A and B, while showing negative correlation with factor C; ③ hydration products consisted primarily of C-S-H gels and zeolite-like phases, whose interwoven microstructure collectively ensured specimen integrity; ④ all three factors significantly influenced mechanical strengths with identical hierarchical impact: A > B > C; and ⑤ a comprehensive predictive model based on ternary quadratic polynomial regression was developed and validated. These results provide a scientific foundation for sustainable resource utilization of fine-grained tailings as solid waste materials. Full article

This study aimed to establish the optimal mix proportions for eco-friendly lightweight boards based on Ground Granulated Blast-furnace Slag (GGBFS) and waste rock wool using Response Surface Methodology (RSM). The investigation focused on optimizing three key properties: flexural failure load (Y₁), moisture content (Y₂), and specific gravity (Y₃). ANOVA results identified Binder and Perlite as the most dominant and statistically significant factors, exhibiting critical conflicting effects necessary for balancing strength and lightweight goals. Wollastonite showed a non-linear effect on flexural strength, peaking at an intermediate level. A Response Optimization simulation, targeting a minimum flexural load of 400 N, moisture content of 2.0%, and specific gravity of 0.80, yielded an optimal mix proportion: Binder 52.12%, Perlite 48.45%, and Wollastonite 7.37%. This blend achieved a high Composite Desirability (D) of 0.8725. Experimental verification confirmed the model’s reliability. The measured flexural load (408.54 N) successfully exceeded the 400 N target, and all measured values exhibited a low error margin (under 7%) compared to the predicted values. This optimized mix proportion provides a reliable foundation for developing high-performance, sustainable lightweight construction materials. Full article

Transportation infrastructure underpins national mobility and economic growth, yet material sourcing for road construction imposes significant environmental and financial costs. As South Africa advances towards road construction, upcycling the reuse of reclaimed materials in higher-value applications offers opportunities to reduce waste and improve circular resource efficiency. This study assesses stakeholders’ perception and adoption of upcycling in the Material Utilisation Plans (MUPs) for road construction. A mixed-methods approach combined nine semi-structured interviews and thirty-two survey responses from professionals involved in the National Route 3 upgrade project. Thematic analysis identified key qualitative themes, while quantituative data from a five-point Likert scale were examined through descriptive statistics, reliability, and correlation analysis. Respondents supported existing downcycling practices (mean = 3.682, SD = 1.088) and expressed readiness to adopt upcycling for pavement surfacing, base, subbase, and subgrade (mean > 3.00, SD < 1.30). Major barriers included client specifications, limited awareness and material cost constraints. Reliability analysis (Cronbach’s α = 0.64–0.88) confirmed internal consistency across qualitative themes. Also, there was a positive correlation between reclaimed materials and cost, design specifications, and optimised cost (r > 0.30, p < 0.05), while downcycling correlated negatively with costs (r = −0.400, p < 0.05). This study provides new empirical evidence on the systemic barriers hindering upcycling adoption in South African road projects and offers a validated mixed-method framework linking perceptual, technical, and economic dimensions of material reuse. It recommends integrating upcycling criteria into design, testing, and procurement processes, shifting from compliance-based recycling to performance-based circular material management in national road infrastructure. Full article

The construction phase of buildings contributes significantly to greenhouse gas (GHG) emissions, yet mitigation strategies within the contractor’s scope—particularly those affecting transport, on-site energy use, and waste—remain underexplored in life cycle assessments (LCAs). This study develops a modelling framework to evaluate 20 mitigation strategies targeting modules A4 and A5 of the LCA, using a generalised business-as-usual (BAU) scenario derived from 15 representative archetypes based on 279 built projects and weighted by national construction statistics. Monte Carlo simulations are applied to capture variability in material composition and component distribution, and marginal abatement cost analysis is used to assess cost-effectiveness. The results show that transport-related strategies offer the highest mitigation potential under Danish conditions with minimal or negative costs, while waste strategies provide moderate reductions and often result in net savings. Energy strategies, though impactful in percentage terms, tend to have lower absolute reductions and higher costs. The applicability of strategies varies across building sizes, with economies of scale influencing feasibility. The modelling framework offers a structured basis for comparing mitigation actions by climate benefit and cost-efficiency, supporting strategic planning for low-carbon construction, while recognising that practical implementation depends on project-specific and organisational factors. Full article

Efforts to reduce greenhouse gas (GHG) emissions across various sectors are on-going to overcome the global climate crisis induced by global warming. The construction sector is a significant contributor of GHG emissions due to the complexity of its diverse processes and the extensive use of various materials. Consequently, simplifying construction processes and adopting low-carbon materials and processes through the rigorous review of material carbon footprints is urgently needed. This study focused on bathrooms (wet areas), which are characterized by complex procedures, the use of diverse materials, and the significant carbon emissions and material waste often resulting from high defect rates. We conducted a comparative analysis of the carbon reduction effects between the conventional wet construction method and the modular construction method specifically for bathroom construction. The analysis involved selecting materials, assessing their suitability against performance standards using a mock-up evaluation, and evaluating the construction applicability of modular bathrooms. Furthermore, through a Life Cycle Assessment, it was confirmed that the selected materials and the modular construction method could significantly reduce carbon emissions compared to the existing wet construction method. The findings of this study provide a crucial direction for the expanded application and use of modular construction methods in future building projects. Full article