Search Results (5,910)

This study investigates the development of sustainable dry-mix shotcrete incorporating fly ash and silica fume as partial cement replacements in order to reduce the environmental impact of cement production. A total of 24 mixtures were systematically evaluated, with 10–30% supplementary cementitious material and 0.9–1.8 kg/m³ polypropylene fiber dosages. This research establishes a quantitative framework for optimizing mechanical performance, durability, and Global Warming Potential. Experimental results reveal that silica fume replacement increases 28-day compressive strength by up to 31.13%, while an optimal polypropylene fiber dosage of 0.9 kg/m³ provides a 15.87% strength enhancement through a matrix-bridging effect. Conversely, excessive fiber content (1.8 kg/m³) increases porosity, leading to a 14.94% reduction in strength. Durability analysis demonstrates that silica fume and fly ash significantly refine the microstructure, reducing sorptivity and limiting freeze–thaw strength loss to a range of 18.13% to 41.03%. Crucially, the 30% by volume of the cement replaced with silica fume mixture was identified as the optimum design, achieving the lowest Global Warming Potential per unit strength at 8.82 kg CO₂-eq/m³/MPa, compared to 18.75 for the high-fiber mixture. These findings provide new, specific evidence that these supplementary cementitious material blends can successfully produce dry-mix shotcrete with significantly lower carbon emissions. Full article

The construction sector remains a major contributor to global energy consumption and greenhouse gas emissions. Heat loss through building envelopes plays a key role, especially in regions with long heating seasons. Hollow building blocks are widely used due to their low cost and structural simplicity, but their inadequate thermal insulation requires additional layers of insulation, increasing costs and complicating installation. The production of cement and traditional insulation materials is associated with a high carbon footprint and disposal issues, which conflict with sustainable development principles and decarbonization goals. In contrast to previous reviews that primarily address bio-based insulation in general building envelopes or focus on bioaggregates in concrete mixes, this paper specifically targets the application of biomaterials in hollow building blocks. It emphasizes how bio-based loose-fill and bound fillers interact with the peculiar thermo-fluid behavior of hollow cavities, including natural convection, conduction and radiation. The effects on thermal performance (thermal conductivity, U-value of walls) are analyzed, along with selected aspects of mechanical strength and durability. Gaps in long-term data on biodegradation are identified. Recommendations for selecting strategies depending on climate and design are offered, as well as directions for future research, including numerical modeling of thermal conditions. The results highlight the potential of biomodified blocks for creating energy-efficient and environmentally friendly wall systems. Full article

Despite its potential to enhance construction quality, efficiency, and sustainability, modular construction continues to experience defects that hinder its broader adoption. Understanding and mitigating defects is essential for maximising the sustainability benefits of modular construction by reducing material waste, minimising rework and improving lifecycle performance. Existing research remains fragmented, with limited synthesis integrating defects with their root causes across the project lifecycle. To address this gap, this study investigates defect types, lifecycle-based causes, and mitigation strategies in modular building projects through a PRISMA-guided systematic literature review of 61 peer-reviewed journal articles published between 2015 and 2025 and retrieved from Scopus and Web of Science. Six major defect categories were identified: geometric and dimensional; material and component; joint and connection integrity; envelope performance and durability; structural; and mechanical, electrical, and plumbing (MEP) defects, with geometric and dimensional defects emerging as the most prevalent, accounting for 26.7% of reported cases. Lifecycle root-cause mapping indicates that poor workmanship during on-site assembly is the dominant contributor, accounting for 44.1% of identified root causes, with manufacturing errors (26.8%) and design limitations (13.4%) acting as critical upstream sources. Mitigation strategies cluster into three groups: general recommendations (39% of reported strategies), mainly focusing on low-cost organisational measures such as logistics coordination and workforce training; structured risk-management frameworks (9.1%), including assembly sequencing and tolerance planning; and digital and data-driven technologies (51.9%), such as laser scanning, AI-based inspection, and digital twins, enabling proactive quality assurance across the lifecycle. The study proposes an integrated lifecycle–defect–mitigation framework to strengthen quality governance and advance sustainable modular delivery. Full article

Asphalt pavements are essential to modern transport infrastructure but remain highly dependent on virgin aggregates and petroleum-based binders, resulting in high energy demand and significant greenhouse gas emissions. In response, research has advanced recycled-material solutions and low-temperature asphalt technologies. However, sustainability is still often inferred from isolated environmental indicators, without consistent consideration of mechanical durability or economic feasibility throughout the life cycle. This review provides an integrated synthesis of sustainable asphalt mixtures by jointly examining recycling strategies, temperature-reduction processes (warm-mix, half-warm-mix, and cold-mix asphalt technologies), and their combined applications through an integrated performance–cost–environment perspective. The literature reveals substantial methodological fragmentation, with limited harmonisation of functional units, system boundaries, and allocation rules, which constrains cross-study comparability. Evidence indicates that reclaimed asphalt, recycled concrete aggregates, and steel slag can maintain or improve rutting resistance, stiffness, and moisture durability while enabling material cost savings of approximately 5–68%. Temperature-reduction technologies further achieve significant energy and GHG reductions in the production phase (20–70%), with integrated recycling–temperature-reduction systems showing the most consistent combined benefits. Overall, this review demonstrates that asphalt sustainability cannot be established through single-dimensional assessments but requires harmonised life-cycle frameworks that explicitly link environmental gains to mechanical performance, durability, and economic viability. Full article

This study investigates the femtosecond laser surface texturing approach to tune the wetting properties of glass substrates applied for photovoltaic panels. Two types of microstructured LIPSS-containing motifs—parallel channels and intersecting (crossing) patterns—were fabricated and evaluated through comprehensive durability tests, including thermal cycling, UV exposure, chemical immersion, mechanical abrasion, and dust retention assessment. Wettability measurements showed that both textures exhibit stable hydrophilicity behavior, with the intersecting patterns exhibiting the fastest wetting dynamics; in many cases, complete surface wetting occurred within the first few minutes, preventing a measurable contact angle at later stages. The durability tests caused only minor smoothing of the textured features, and the overall micro- and nanostructures remained intact. Optical characterization revealed that the laser-induced textures maintained high transmittance with no significant degradation after environmental exposure. Overall, the results demonstrate that femtosecond laser texturing provides a robust, coating-free method for producing stable and tunable wetting behavior on glass, offering a promising pathway for the future creation of durable, highly hydrophilic self-cleaning surfaces in photovoltaic systems. Full article

Natural pumice can reduce the self-weight of concrete, but its high porosity, high water absorption, and weak interfacial bonding tend to limit the strength and durability of lightweight aggregate concrete. To address this issue, this study proposes a method for preparing and applying reinforced pumice lightweight aggregates, namely, using nano-SiO₂-modified fly ash to construct a nanocomposite material at the micro-interface for the reinforcement treatment of natural pumice aggregates, and reveals the mechanism by which this treatment enhances the performance of lightweight aggregate concrete. Through aggregate performance tests, compressive strength tests, XRD, SEM, and freeze–thaw cycle tests, the effects of the reinforced pumice aggregate on the performance of lightweight concrete were systematically investigated. The results show that after the reinforcement treatment, the water absorption of the pumice aggregate decreases by 17.6%, and the cylinder compressive strength increases by 34.3%. As the replacement ratio of reinforced pumice increases, both the early-age and later-age compressive strengths of the concrete continuously improve. When all the pumice aggregate is reinforced, the 3 d and 28 d compressive strengths increase by 35.1% and 33.44%, respectively. Meanwhile, the reinforced pumice effectively improves the interfacial bonding between the aggregate and the cement paste, reducing the width of the interfacial transition zone by 32%, enhancing the matrix compactness, and delaying crack propagation. The study demonstrates that the reinforced pumice aggregate possesses favorable characteristics, not only effectively improving the mechanical properties and freeze–thaw resistance of lightweight concrete but also providing a new technical pathway for the high-performance utilization of porous lightweight aggregates, offering a reference for the resource utilization of industrial solid waste and engineering applications in cold regions. Full article

Desertsand concrete (DSC) is a sustainable alternative to natural river sand; however, its application in cold regions is restricted by inadequate crack resistance and freeze–thaw durability. This study investigates the freeze–thaw performance of steel–polypropylene hybrid fiber-reinforced desert sand concrete (SPHF-DSC), with emphasis on durability enhancement and service life prediction. A three-factor, three-level orthogonal experimental design was employed to evaluate the effects of desert sand replacement ratio (DSR), steel fiber (SF) content, and polypropylene fiber (PPF) content on mass loss, relative dynamic elastic modulus, and compressive strength under 25–100 freeze–thaw cycles. The results demonstrate that hybrid fiber reinforcement significantly improves freeze–thaw resistance due to the synergistic interaction between SF and PPF. After 100 cycles, the mass loss of all specimens remained within a narrow range of 0.65% to 0.73%, and the relative dynamic elastic modulus retention stayed above 90%. The optimal mixture (DSR = 30%, SF = 2%, PPF = 0.05%) exhibited superior frost resistance with the lowest deterioration indices among all groups. A freeze–thaw damage model based on damage mechanics was established and validated ($R^2$ > 0.96), enabling prediction of a service life exceeding 38 years under typical cold-region climatic conditions. These findings provide a durability-oriented design reference for the engineering application of DSC in cold-region infrastructure. Furthermore, the utilization of local desert sand reduces transportation energy consumption and promotes the sustainable development of energy infrastructure. Full article

Fatigue failure in scaffolding components poses significant risks to worker safety, particularly in high-altitude construction environments. This study investigates the fatigue behavior of scaffolding stirrups, a critical structural element prone to premature failure. The objective is to analyze the fatigue damage mechanisms in stirrups through a combined experimental and numerical approach. Mechanical characterization and micro-hardness testing were conducted to assess the material properties of the stirrup, while finite element modeling (FEM) was employed to simulate its performance under cyclic loading. The Johnson–Cook material model was utilized to compare experimental hysteresis curves with FEM results, validating the numerical approach. Additionally, the Extended Finite Element Method (XFEM) was applied to model crack initiation and propagation. Results reveal that material hardening and fatigue crack growth are the primary causes of stirrup failure, with distinct fatigue zones and crack paths identified. The study quantifies the relationship between crack growth stages and stirrup bending, providing insights into the failure process. These findings contribute to improving the safety and lifespan of scaffolding systems by identifying key factors influencing stirrup durability. Full article

The growing need for lightweight, multifunctional, and high-performance structures in the automotive, aerospace, electronics, and medical industries has driven the development of advanced joining technologies for polymers and metal-polymer combinations. Among these, ultrasonic welding (USW) and friction stir spot welding (FSSW) have emerged as promising solid-state techniques capable of producing reliable joints with minimal thermal degradation and enhanced interfacial bonding. This review focuses on recent developments in USW and FSSW of thermoplastics, fiber-reinforced composites, and hybrid metal–polymer systems, with a particular emphasis on process mechanics, microstructural evolution, and joint performance. The mechanisms of heat generation, material flow behavior, and consolidation are discussed in relation to key process parameters, including applied pressure, rotational speed, vibration amplitude, plunge depth, and dwell time. Microstructural transformations such as polymer chain orientation, recrystallization, interfacial diffusion, and defect formation are analyzed to establish process–structure–property relationships. Mechanical performance metrics, including lap shear strength, fatigue resistance, impact behavior, and environmental durability, are critically compared across different materials and welding methods. Furthermore, recent advances in numerical and thermo-mechanical modeling, in situ process monitoring, and data-driven optimization are discussed to highlight pathways toward predictive and scalable manufacturing. Current industrial applications and existing limitations such as challenges in automation, thickness constraints, and hybrid material compatibility are also evaluated. Finally, key research gaps and future directions are identified to improve joint reliability, sustainability, and broader industrial adoption of advanced solid-state welding technologies. Full article

Soil-borne diseases pose a severe threat to global agricultural production and food security. Traditional chemical control methods face significant challenges, including environmental pressure, pathogen resistance, and food safety concerns. The rhizosphere microbial community, often termed the plant’s ‘second genome’, plays a pivotal role in maintaining plant health and defending against pathogen invasion. Recent advances in multi-omics technologies, synthetic microbial communities (SynComs) construction, and rhizosphere metabolomics have significantly advanced our understanding of the mechanisms by which rhizosphere microbiomes suppress soil-borne diseases. This review systematically summarizes the following: 1. key drivers of rhizosphere microbial community assembly, particularly plant “cry for help” signaling; 2. core beneficial microbial taxa and their disease-suppressive mechanisms; 3. the critical role of microbial interaction networks; 4. microbiome-based management strategies and their application progress; and 5. current challenges and future research directions. Compared with previous reviews that separately discussed rhizosphere microbiota, disease-suppressive soils, synthetic microbial communities (SynComs), or prebiotics, this review uniquely integrates multiple levels of regulation, from plant genetic determinants (‘M genes’) and root exudate-mediated ‘crying for help’ to microbiome engineering (SynComs and prebiotics) and cross-kingdom interactions (bacteria–fungi–protists–phages). A central conceptual axis of ‘M genes → microbiome engineering → breeding’ is proposed, bridging plant genetics, microbial ecology, and crop improvement for durable disease suppression. Ultimately, this work aims to provide a theoretical foundation for developing efficient and sustainable green control technologies against soil-borne diseases. Full article

Bamboo surfaces are susceptible to scratches and contamination during service, which limits their durability and aesthetic performance. To address this issue, this study aims to develop a natural self-healing coating based on tung oil microcapsules. Tung oil microcapsules encapsulated within chitosan and gum arabic (TO/CS–GA MCs) were prepared by spray drying at two feed rates (100 and 200 mL h⁻¹) and incorporated into tung oil coatings applied on bamboo substrates. The effects of microcapsule content (1.0–11.0 wt%) and feed rate on the optical performance, mechanical performance, and self-healing performance of the coatings were systematically investigated. The results showed that increasing the microcapsule content gradually increased the color difference (ΔE) and surface roughness of the coatings, while the gloss decreased. The hardness, impact resistance, adhesion grade, and self-healing efficiency of the coatings exhibited a similar trend, initially increasing and then decreasing with increasing microcapsule content. This behavior indicates that an appropriate amount of microcapsules can enhance the coating performance, whereas excessive addition leads to particle agglomeration and structural defects. Under the better condition of 5.0 wt% microcapsule content and a spray-drying feed rate of 100 mL h⁻¹, the coating exhibited the best overall performance, including higher gloss retention, a hardness of 2H, an impact resistance of 3 kg·cm, relatively low surface roughness, and a self-healing efficiency of 28.16 ± 0.63%. These results suggest that the spray-drying feed rate plays an important role in regulating the particle size distribution and encapsulation efficiency of the microcapsules, which in turn affects their dispersion and rupture–release behavior within the coating matrix. Therefore, controlling the spray-drying parameters is crucial for optimizing the performance of microcapsule-based self-healing coatings. Overall, this study provides a sustainable strategy for developing natural polymer-based self-healing coatings and offers useful insights into the design of functional microcapsules for bamboo surface protection. Full article

Ensuring the durability and safety of modern infrastructure critically depends on the quality and strength of concrete. The Ultrasonic Pulse Velocity (UPV) method is a widely used non-destructive testing technique for evaluating concrete properties; however, factors such as aggregate size distribution, compaction methods, and surface quality can significantly influence UPV results and their correlation with compressive strength. This study investigates the effects of different aggregate sizes and an innovative vibration-assisted compaction method—developed using piezoelectric (PZT) transducers—on the mechanical, ultrasonic, and surface properties of concrete. Four distinct aggregate size distributions were employed to produce sixteen concrete specimens with constant mix proportions. Unlike conventional low-frequency, high-power vibration practices, a high-frequency (40 kHz), low-power (120 W) vibration protocol was applied through PZT elements placed within the molds to enhance compaction and reduce entrapped air. Experimental results indicated that the heaviest specimen (7.13 kg) was the medium-aggregate sample compacted using tamping and rodding methods. The highest UPV value (4143 m/s) was obtained from the coarse-aggregate specimen subjected to three minutes of vibration. In contrast, the best compressive strength performance (22.73 MPa) was observed in the medium-aggregate specimen without any vibration treatment. The findings revealed that both aggregate size and advanced vibration techniques have significant effects on the mechanical properties, ultrasonic response, and surface quality of concrete. In addition, a proof-of-concept portable surface-finishing prototype consisting of a steel plate instrumented with multiple PZT transducers was developed, and preliminary trials qualitatively suggested improved surface leveling when applied in contact with the concrete surface. Surface roughness was quantified via image processing (Light Map 150 and Specular Map 150). The rough-area fraction decreased from ~29.8% in the untreated specimen to ~4.3% after ultrasonic application, indicating a marked improvement in surface leveling and overall surface quality. The results indicate that the applied PZT vibration protocol did not improve compressive strength; in several cases, particularly under prolonged excitation, a reduction in strength was observed. In contrast, a significant improvement in surface quality was achieved, with the rough-area fraction decreasing from approximately 29.8% to 4.3%. However, due to the limited number of specimens, the findings should be interpreted as preliminary. Overall, the method appears more promising as a surface enhancement technique rather than a direct alternative to conventional compaction methods. Full article

In 2026, sustainable construction materials research is focused on optimization of the resources’ circularity, carbon reduction, and performance improvements through advanced materials. Biochar, nanomaterials, and recycled aggregates (RA) are enhancing concrete by improving strength, durability, and carbon capture, while supporting low-carbon, circular practices. When used in low-carbon alkali-activated materials (AAMs), these materials reduce greenhouse gas emissions by approximately 30–60% compared to Portland cement (PC). Despite challenges in cost, standardization, and large-scale production, these innovations are advancing the construction industry towards sustainable, carbon-neutral solutions. RA helps reduce landfill waste and converse resources, though issues like quality variability and potential contaminants must be addressed. Biochar’s (0.5–2 wt.% of binder) adoption is limited by inconsistent properties, while nanomaterials (0.01 to 3 wt.% of binder) offer improved mechanical properties (5–20%) but face high production costs and limited long-term data. In the coming years, efforts will focus on standardizing production, improving nanoparticle dispersion, and refining RA processing. The integration of AI and machine learning may further optimize material design, leading to greener, low-carbon materials for large-scale, sustainable infrastructure by 2036. Full article

Solar-driven interfacial evaporation is a promising strategy for alleviating freshwater scarcity and water pollution. However, developing efficient evaporators using eco-friendly, renewable biomass remains a significant challenge. Herein, we report a bio-derived solar-driven interfacial evaporator (CSIE) based on iron–tannin modified collagen, further enhanced via mechanical micro-perforations to induce the Marangoni effect (EN-CSIE). The influence of pore size and open-area ratio on the Marangoni-driven flow was systematically investigated. The optimized EN-CSIE (with 1.2 mm pore size and 6.1% open-area ratio) achieved a superior evaporation rate of 2.5 kg m⁻² h⁻¹ with an energy conversion efficiency of 93.5% under 1 sun illumination. Furthermore, the system demonstrated exceptional purification capabilities, removing over 99.9% of metal ions and organic impurities. Long-term durability tests in 3.5 wt% saline water confirmed a stable evaporation rate of 2.3 kg m⁻² h⁻¹ over 15 continuous cycles. This low-cost and sustainable collagen-based evaporator presents a robust solution for solar-powered water desalination, particularly for decentralized clean water production in sun-rich regions. Full article

Silane-based hydrophobic coatings are widely used to improve the durability of cement-based materials in aggressive environments such as marine and hydraulic structures. However, their long-term effectiveness is strongly influenced by interfacial adhesion degradation under humid conditions, which remains a critical challenge in engineering applications. From a scientific perspective, the fundamental mechanisms governing how silane-based coatings interact with cement hydration products, particularly under varying moisture conditions, are still not fully understood. In particular, the role of interfacial water in regulating bonding strength and intermolecular force transfer at the nanoscale has not been quantitatively clarified. To address these issues, this study investigates the interfacial debonding behavior of polydimethylsiloxane (PDMS), a representative silane-based hydrophobic component, on calcium silicate hydrate (C–S–H) substrates using molecular dynamics simulations under controlled hydration states. The results show that the interfacial interaction is dominated by van der Waals forces, with a calculated binding energy of approximately 357 kcal/m². As the interfacial water content increases from dry to high-humidity conditions, the maximum debonding force (F_max) decreases from approximately 1.6 × 10³ pN to 1.3 × 10³ pN, corresponding to a reduction of about 18–20%. Similarly, the debonding work (W_max) shows a consistent decreasing trend, indicating reduced energy required for interface separation. This reduction is attributed to the formation of a continuous water film, which increases the interfacial separation distance and reduces the efficiency of intermolecular force transfer. These findings demonstrate the humidity-dependent weakening of interfacial adhesion and provide new insights into the nanoscale mechanisms governing the performance of silane-based coatings. The results offer a theoretical basis for optimizing the durability and reliability of hydrophobic treatments in cement-based materials under realistic service conditions. Full article