Search Results (61)

This study examines a cold-press manufacturing method for laminated bamboo and bamboo–timber composites, together with a cradle-to-gate carbon footprint analysis of the produced materials. The proposed material systems are assessed as alternatives to conventional engineered bamboo and to widely used construction materials such as structural steel, concrete, and aluminum. Existing engineered bamboo products are typically manufactured using hot pressing and formaldehyde-based adhesives, both of which contribute to their environmental burden. The present work therefore considers a more practical and environmentally responsible route based on lower-energy processing and lower-emission adhesive systems. Following a cradle-to-gate carbon footprint analysis of the produced materials, the embodied carbon values obtained for the four systems are 473.3, 322.3, 314.2, and 210.3 kg CO₂e/m³ for the BBE, BPA, CBE, and CPA specimens, respectively. Relative to conventional hot-pressed laminated bamboo, these values correspond to embodied carbon reductions of 26.8%, 50.1%, 51.4%, and 67.5%, respectively. When the biogenic carbon stored in the bamboo and pine biomass is included, the net carbon balances become −415.5, −607.1, −597.0, and −618.6 kg CO₂e/m³, respectively. These results show that the proposed engineered bamboo and bamboo–timber composites offer feasible low-carbon options for construction applications. Full article

This study investigates how key milling parameters influence both cutting noise and surface quality during the machining of laminated bamboo lumber. Using a multifactorial optimal response surface methodology, the effects of fibre orientation (0–135°), spindle speed (7000–10,000 r/min), feed rate (0.5–2.0 m/min) and milling depth (0.5–2.0 mm) were quantified through 25 experimental runs. Cutting noise, measured as peak sound pressure level (SPL), ranged from 86.8 to 95.2 dB, increasing markedly with fibre angle, feed rate, and milling depth, but exhibiting a non-linear response to spindle speed. Surface roughness (S_a) varied from 2.6 to 11.7 µm and was most strongly governed by milling depth, followed by fibre orientation and feed rate, with a significant interaction between fibre orientation and spindle speed. Quadratic regression models demonstrated strong predictive performance (R² = 0.97 for SPL; R² = 0.85 for S_a). Based on the response surfaces, optimal low-noise, high-quality machining was achieved at moderate spindle speeds, low feed rates, and shallow milling depths. These findings provide a mechanistic basis for understanding noise–roughness coupling in bamboo machining and offer practical guidance for computer numerical control processing, tool selection, and industrial noise reduction strategies in bamboo manufacturing. Full article

Laminated bamboo (LB) has emerged as a promising sustainable structural material due to its rapid renewability, high strength-to-weight ratio, and favorable mechanical performance. Drawing on a comprehensive review of over 90 published experimental and analytical studies, this paper provides a critical synthesis of the structural behavior of LB, with emphasis on its compression, tension, flexure, shear, and creep responses. Reported mechanical properties exhibit variability, largely influenced by bamboo species, fiber orientation, processing methods, adhesives, lamination quality, and loading configuration. While LB demonstrates high tensile and flexural strengths comparable to or exceeding conventional timber products, pronounced anisotropy and brittle failure modes are consistently observed, particularly under shear and rolling shear loading. Recent studies on cross-laminated bamboo (CLB) highlight the significant role of interlaminar behavior and adhesive performance in controlling failure mechanisms, indicating that rolling shear capacities often govern the design of planar elements. Beyond mechanical behavior, this review synthesizes available research on thermal and fire performance. Emerging research on LB connections indicates that joint behavior often governs global structural performance, with strength and ductility strongly influenced by fastener type and embedment behavior. Key knowledge gaps are identified, underscoring the need for unified design frameworks to enable broader structural adoption of laminated bamboo systems. Full article

As structural engineers face increasing pressure to minimize the embodied carbon of building components, selecting appropriate materials is critical for sustainable design. Thiemission ts study evaluates the life cycle performance of engineered bamboo beams to determine their viability as a low-carbon alternative to traditional timber in structural framing applications. Utilizing OpenLCA software and the Ecoinvent database, a cradle-to-grave analysis was conducted to inform material selection for the Australian construction context. A parametric design study compared two specific bamboo species, Moso and Asper, against traditional Laminated Veneer Lumber (LVL) to identify the optimal material for minimizing environmental impact. The assessment revealed that Asper bamboo beams represent a superior design choice; a 30.74 kg strand-woven functional unit (FU) achieved net-negative emissions of −13.30 kg CO₂e under 2025 conditions. This offers a significant design advantage over traditional LVL options, which are net-positive emitters, and outperforms Moso bamboo, which yielded higher net emissions (+24.60 kg CO₂e) due to lower sequestration rates. Furthermore, dynamic analysis demonstrated the temporal efficiency of this material in the structural life cycle: in the time required for a single Radiata Pine rotation, Asper bamboo completes five growth cycles, storing a net 103.25 kg of CO₂e per functional unit. Confirmed by a sensitivity analysis for robustness, these findings provide quantitative design criteria supporting the integration of Asper bamboo into sustainable building standards and structural specifications. Full article

The increasing demand for sustainable polymer composites has driven the development of hybrid laminates that combine natural, recycled, and synthetic reinforcements while maintaining adequate mechanical performance. However, the combined influence of stacking sequence and mineral filler addition on the mechanical behavior of such sustainable hybrid systems remains insufficiently understood. In this study, sustainable hybrid laminated composites based on epoxy reinforced with glass fiber (G), bamboo fiber (B), and flex banner (F) were fabricated with varying stacking sequences and calcium carbonate (CaCO₃) filler contents (0 and 1 wt.%). A total of nine laminate configurations were produced and evaluated through flexural and impact testing. The results demonstrate that mechanical performance is strongly governed by laminate architecture and filler addition. The bamboo-dominant G/B/B/B/G laminate containing 1 wt.% CaCO₃ exhibited the highest flexural strength (191 MPa) and impact resistance (0.766 J/mm²), indicating a synergistic effect between reinforcement arrangement and CaCO₃-induced matrix strengthening. In contrast, the lowest performance was observed for the G/F/B/F/G configuration without filler. Overall, all hybrid composites outperformed neat epoxy, highlighting the potential of bamboo–flex banner hybrid laminates with CaCO₃ filler for sustainable composite applications requiring balanced mechanical properties. This work aligns with SDG 12 by promoting resource-efficient circular-economy practices through the utilization of flex banner material and natural fibers as reinforcements in epoxy-based hybrid composites. Full article

Cross-laminated bamboo (CLB) has gained increasing attention as an emerging structural material combining high mechanical performance with remarkable sustainability potential. This comprehensive review summarizes and critically discusses the main advances and trends in CLB research, drawing on experimental, analytical, and numerical approaches reported in the literature. The review highlights that the mechanical performance of CLB depends on panel architecture, bamboo product type, and adhesive systems. Reported experimental results indicate that CLB panels can achieve competitive or higher mechanical performance than selected cross-laminated timber (CLT) configurations made from specific wood species, particularly in bending, compression, tension, and rolling shear. At the same time, the literature reveals variability associated with manufacturing parameters, adhesive types, and lamella orientation, which affects the comparability of results and highlights current challenges for standardization. Structural applications investigated include floor and wall panels, beams, and rocking walls, especially for seismic-resilient building systems. Despite growing experimental evidence, most investigations remain limited to laboratory-scale elements, with modelling simplifications that constrain predictive accuracy. This review identifies the main challenges and research opportunities towards industrial scalability, standardized testing procedures, and design models adapted to the specific behavior of CLB, paving the way for its consolidation as a reliable and sustainable construction material. Full article

Laminated bamboo (LB) has shown enough exceptional performance to be used in constructions, but the performance of the bolted connections remains to be explored. To meet the criteria of low-carbon construction and fill the research gap in LB dowel embedment performance, this study examined the longitudinal dowel embedment behavior of LB. Failure modes, load–displacement curves, embedment strength, and elastic foundation parameters were examined after four sets of half-hole specimens with dowel diameters (6, 8, 10, and 12 mm) were tested in accordance with ISO 10984-2. The majority of the data was confirmed to follow a normal distribution by the Kolmogorov–Smirnov test. Interlaminar shear failure (dominant in 10 and 12 mm groups) and local crushing (dominant in 6 and 8 mm groups) were the primary failure modes. There were clear linear and nonlinear phases in the load–displacement curves (excellent ductility). The average elastic foundation modulus was 3565.55 MPa (0.39 times the compressive modulus); meanwhile, the average proportional limit, yield, and ultimate strengths were 35.48, 63.08, and 74.44 MPa (0.59, 1.06, and 1.25 times the parallel-to-grain compressive strength). The ultimate strength varied from 72.64 MPa to 76.71 MPa as the diameter rose; however, the elastic foundation beam coefficient dropped significantly. A novel calculation based on LB’s parallel-to-grain compressive strength accorded well with test results, while the existing code formulae (GB 50005, NDS, and CSA O86) overestimated LB embedment strength. The design of LB bolted connections is guided by this study, which also explains LB embedment criteria and offers design parameters and a prediction method. Full article

This study investigates the Mode II fracture behavior of bamboo–coir–rubber (BCR) hybrid composite panels developed as sustainable alternatives for wood-based panels used in structural applications. The composites were fabricated using alternating bamboo and coir layers within a polypropylene (PP) thermoplastic matrix, with styrene–butadiene rubber (SBR) incorporated as an additive at 0–30 wt.% to enhance interlaminar toughness. Commercial structural plywood was tested as the benchmark. Mode II interlaminar fracture toughness (G_IIc) was evaluated using the ASTM D7905 End-Notched Flexure (ENF) test, supported by optical monitoring to study crack monitoring and Scanning Electron Microscopy (SEM) for microstructural interpretation. Results demonstrated a steady increase in G_IIc from 1.26 kJ/m² for unmodified laminates to a maximum of 1.98 kJ/m² at 30% SBR, representing a 60% improvement over the baseline and nearly double the toughness of plywood (0.7–0.9 kJ/m²). The optimum performance was obtained at 20–25 wt.% SBR, where the laminated retained approximately 85–90% of their initial flexural modulus while exhibiting enhanced energy absorption. Increasing the initial notch ratio (a₀/L) from 0.2 to 0.4 caused a reduction of 20% in G_IIc and a twofold rise in compliance, highlighting the geometric sensitivity of shear fracture to the remaining ligament. Analysis of Variance (ANOVA) confirmed that the increase in G_IIc for the 20–25% SBR laminates relative to plywood and the unmodified composite is significant at p < 0.05. SEM observations revealed rubber-particle cavitation, matrix shear yielding, and coir–fiber bridging as the dominant toughening mechanisms responsible for the transition from abrupt to stable delamination. The measured toughness levels (1.5–2.0 kJ/m²) position the BCR panels within the functional range required for reusable formwork, interior partitions, and transport flooring. The combination of renewable bamboo and coir with a thermoplastic PP matrix and rubber modification hence offers a formaldehyde-free alternative to conventional plywood for shear-dominated applications. Full article

The search for sustainable alternatives to synthetic composites has become increasingly relevant in aerospace engineering education and student rocketry. Fiberglass is widely used for rocket fuselages due to its favorable balance of performance and cost, but it is energy-intensive, non-biodegradable, and environmentally burdensome. This study provides the first demonstration of natural fiber composites applied to student rocket fuselages, evaluating bamboo and jute as sustainable alternatives to fiberglass. Fiberglass, bamboo, and jute laminates were fabricated following the procedures of the RocketWolf team at CEFET/RJ. The fuselages were characterized by parachute ejection tests, surface roughness analysis, and flight simulations using OpenRocket software. Additional data such as laminate mass, wall thickness, fiber–resin ratio, and cost analysis were incorporated to provide a comprehensive assessment. Results revealed contrasting behaviors: untreated bamboo composites showed poor resin impregnation, brittle behavior, and lack of structural stability, confirming their unsuitability without chemical treatment. Jute composites, in contrast, achieved adequate impregnation, cylindrical geometry, and superior surface roughness (Ra = 37 µm) compared to fiberglass with paint (62 µm) or envelopes (52 µm). Both fiberglass and jute fuselages successfully passed parachute ejection tests, while simulations indicated apogees close to 1 km, fulfilling competition requirements. The jute fuselage also presented slightly improved stability margins. Economically, jute was ~492% cheaper than fiberglass in fiber-only comparison but absorbed more resin; nevertheless, real purchase prices favored jute. These findings confirm that jute composites are a technically feasible, cost-effective, and sustainable substitute for fiberglass in student rocket fuselages. Beyond technical validation, this work demonstrates the educational and environmental benefits of integrating natural fibers into academic rocketry, bridging sustainability, performance, and innovation. Full article

Engineered wood products have become key sustainable alternatives to conventional building materials, offering strong potential for reducing climate impacts in the construction sector. This review systematically assesses recent life cycle assessment studies on engineered wood products to compare their environmental performance and support low-carbon building practices. The peer-reviewed literature published over the past decade was analyzed for publication trends, geographic focus, and methodological approaches, including goal and scope definition, life cycle inventory, and life cycle impact assessment. Comparative analyses examined climate change impact and key parameters influencing environmental outcomes. Results indicate a steady growth of research in this field, led by China, the United States, and Europe. Volume-based functional units (e.g., 1 m³) are predominant in structural wood studies, while mass-based units are more common for composites. Cradle-to-gate boundaries are most frequently used, and data are primarily drawn from Ecoinvent, Environmental Product Declarations, and regional databases such as GaBi and CLCD. Common impact assessment methods include CML-IA, ReCiPe, and TRACI, with climate change identified as the core impact category. Cross-laminated timber and glue-laminated timber consistently show lower and more stable climate change impacts, while fiberboards exhibit higher and more variable results due to adhesive content and energy-intensive manufacturing. Key factors influencing environmental outcomes include service life, wood species, and material sourcing. The review highlights the need for standardized methodologies and further exploration of emerging products, such as nail-laminated and dowel-laminated timber and laminated bamboo, to improve comparability and inform sustainable design practices. Full article

Natural arc-shaped bamboo laminated lumber (ABLL) represents an eco-friendly advanced material. This study introduces an innovative preparation method and manufacturing process to enhance production efficiency and reduce costs. Full-scale processing experiments were conducted to evaluate the feasibility and performance of the innovative integrated fixed-arc and drying process. Bonding integrity was assessed through glue-line shear strength and soak-delamination resistance. The maximum dry glue-line shear strength and delamination length achieved were 8.19 MPa (>traditional value of 3.5 MPa) and 21.8 mm (<traditional value of 25 mm), respectively. Comparative analysis of material utilization of eight-layer natural arc-shaped bamboo laminated lumber demonstrated a rate of 77.9% (<traditional value of 60%). This optimized process significantly contributes to elevated production efficiency and material yield in natural arc-shaped laminated lumber manufacturing. Full article

As an innovative advancement beyond cross-laminated timber (CLT), cross-laminated bamboo and timber (CLBT) combines sustainability with enhanced structural performance. This review critically assesses the current state of CLBT research, focusing on its failure mechanisms, mechanical properties, and predictive theoretical models. Key findings indicate that CLBT exhibits superior rolling shear strength, bending stiffness, and stability compared to conventional CLT, achieved through optimized hybrid layering and manufacturing techniques. The integration of bamboo not only improves mechanical performance but also promotes diversification of raw materials and more efficient use of regional biomass. This paper highlights the potential of CLBT as a high-performance, eco-friendly construction material and identifies key research gaps and future directions to facilitate its standardized application. Full article

This study proposes an approach to design and develop a prosthetic foot using bamboo laminate, a sustainable and cost-effective material. The proposed design method is an alternative to the current prosthetic foot design methods developed mainly for carbon-fiber reinforced polymer. This design solution entails significant economic and environmental costs. The research is structured into three main phases: an experimental campaign to characterize the reference prosthesis and select materials for the prototype; a dimensional design and prototyping phase using the new materials; and finally, a phase dedicated to testing and comparative evaluation of the results. Static tests, conducted in accordance with ISO 22675 on both the bamboo prototype and a commercial reference model, revealed comparable static performance between the two solutions. The laminated bamboo prosthetic foot exhibits a strength-to-weight ratio comparable to that of carbon fiber laminates. Its stiffness deviates by less than 15%, with an 8% reduction in weight and a 7% increase in volume compared to the carbon fiber counterpart. Therefore, these results confirm the feasibility of laminated bamboo as a viable material for prosthetic foot design. Full article

Natural arc-shaped bamboo laminated lumber (ABLL) is an engineering material made from recyclable and rapidly renewable bamboo. Objectives: to enhance processing mechanization by (i) establishing a fixed-arc dimensional model for bamboo splits, (ii) designing an integrated mold capable of simultaneous shaping and drying, and (iii) validating its performance through simulation and experiment. Methods: numerical modeling simulated the operational process, and physical tests measured split length, thickness, inner and outer chord lengths, and moisture content. Results: after the mold completes the arc-fixing and drying of bamboo splits, parameters including the splits’ length, chord length, thickness, and moisture content are suitable for subsequent processing. Based on simulation results, the working mechanism of load application and deformation of bamboo during the equipment’s arc-fixing process was analyzed. The cylindrical arc geometry causes uneven material deformation and stress distribution during arc-fixing. Arc-fixing of bamboo splits results in irreversible edge densification. Thus, gluing should be performed promptly to prevent warping. Evaluation metrics for arc length data—including RE ≤ 8.46%, R² ≥ 0.71, and RMSE ≤ 3.61—confirm the reliability of the dimensional model and virtual prototype simulation model. The proposed method was expected to provide a reference for the development of devices specifically designed for ABLL. Full article