Over the past decade, the physical and mechanical performances of laminated bamboo lumber (LBL)–a bamboo-based structural material, have been extensively studied using experimental, analytical, and ...numerical approaches. This paper presents a review of existing knowledge in the literature about the mechanical properties of LBL. The paper involved the review of the response of LBL to different types of loading such as tension, bending, compression, and shear. Based on results of the literature reviewed, the strength of LBL parallel to grain was 90–124 MPa with MOE of 10700 MPa in tension, 29.55–72.60 MPa, and MOE of 8396–11022 MPa in compression, 63.87–128.4 MPa, and MOE of 8320–10912 MPa in bending, and 7.15–17.5 MPa in shear. The average strength of LBL was similar and in some cases exceeded the average values of bamboo- or wood-based materials, while the variability of its mechanical parameters was lower. The variability in strength values of LBL was affected by bamboo species, density and thickness of bamboo strips, growth portion, type of treatment, strips arrangements, and type of adhesive which in turn calls for classification of LBL by strength grades, degree of hardness, the capability of impregnation and penetration, as well as by areas of application in construction. The study provided and discussed concluding observations, the current research gap, and future research directions on the mechanical properties of LBL.
Wooden packaging boxes and pallets are used in a wide range of applications. In this work, LVL from the same source and batch were used as the base material. After dynamic detection and grading, they ...were divided into two grades (A and B), according to their differences in elastic modulus. The packaging boxes and pallets of the same specifications were designed and manufactured as the research objects. Four mechanical properties studies and related analyses were performed. The three mechanical tests showed different deflection values of the two packaging boxes A and B, and the maximum error was 6.93%. In the rotational edge drop test, the edges of the nether end rails of the two grades of LVL boxes were damaged to varying degrees. Additionally, the nails at the connection between the middle longitudinal beam and the bottom plate also appeared to be pulled out, and the parts made of B-grade LVL were more obvious. The results show that the dynamic detection and quality grading for LVL can effectively distinguish the material grade. The grading results were consistent with the mechanical properties of the LVL packaging boxes and pallets of corresponding grades, which are suitable for use in production lines.
In the light of special attention of world governments to a viable and sustainable decarbonization way of the existing building stock, this article considered the feasibility of using a method of ...Building Information Modeling (BIM)-enabled Life Cycle Assessment (LCA) for the refurbishment in terms of environmental compatibility, energy efficiency, and profitability. An existing residential building in Nanjing was chosen as a case study. The paper investigated the environmental, energy, and economic efficiency of the case building hypothetically refurbished to the Passive House (PH) and “low energy building” (LEB) technologies. The analysis was made based on real construction and energy consumption data, monitored over three years. Also, a comparison of the environmental, energy-efficient, and economic feasibility of two hypothetical models refurbished to the PH and LEB technologies is considered. The results show that BIM-enabled LCA is a powerful tool for refurbishing existing residential buildings due to a comprehensive assessment of environmental compatibility, energy efficiency, and profitability. According to the results, special attention should be paid to reducing cooling loads, using materials with a high recycling rate and low cost, reducing the thickness of the insulation layer, using polyvinyl chloride (PVC) windows with movable sunshades, and setting horizontal and vertical greenery systems.
•BIM-enabled LCA simplifies the workflow of energy-efficient refurbishment.•Energy-efficient refurbishment reduces energy consumption by 22–26%.•The cost of materials exceeds energy savings over 50 years of the building's life.•Passive House is less environmentally friendly than conventional codes of China.•Green roof is energy and environmentally efficient than highly insulated roof with EPS.
Due to the transition of Architecture, Engineering and Construction (AEC) sector to a sustainable development, bamboo turned out to be a suitable option to conventional building materials due to its ...environmental friendliness and distinctive mechanical properties. Initially, it was impossible to use the original bamboo in flat applications due to its round cross-sectional shape, but engineered bamboo, in particular laminated bamboo lumber (LBL), solved this problem. Connections are one of the most important parts of building structures that are responsible for the distribution of loads and energy, ensuring the stability and safety of the structure by avoiding concentration of localized stress that can cause failures at the joints. Over the past decade, a series of experimental studies of connection performance of LBL have been conducted. In order to stimulate the use of laminated bamboo in construction industry, this article reviewed the existing published literature and described the behavior of LBL connections in terms of failure mechanisms and factors affecting the bearing capacity considering three connections categories, namely, LBL sheathing-to-framing connections, LBL dowel-type connections, and glued-in rods (GIROD) in LBL connections. According to the reviewed studies, LBL has great potential and can serve as a worthy alternative for conventional building materials. This work can provide a reference for engineering applications and future research.
Bamboo structures are susceptible to natural weathering when exposed to outdoor conditions, making it imperative to comprehend the aging resistance of bamboo. In this paper, the study of Moso bamboo ...exposed to outdoor environment for one year illustrates the discoloration, expansion, mass loss and density reduction of the specimens. The changes of relative crystallinity (CrI) of bamboo were measured by using X-ray diffraction (XRD), the microstructural changes of bamboo were observed by scanning electron microscopy (SEM), and the computed tomography (CT) scanning technology was used to analyze the internal structure of the damaged specimens. Meanwhile, the damage and differences in the mechanical properties of bamboo internodes and nodes were evaluated by the tests of compression parallel to the grain, compression perpendicular to the grain and compressive elastic modulus parallel to the grain, taking into account the bamboo height. The results showed that natural weathering reduces cellulose crystallinity and has a detrimental effect on the cellular structure of bamboo, resulting in a weakening of the interfacial bonding between the vascular bundles and the parenchyma. Consequently, this leads to a decrease in the mechanical properties of bamboo. Compared to the internode specimens, the compressive strength perpendicular to the grain and compressive elastic modulus parallel to the grain are higher in the bamboo node specimens. However, the compressive strength parallel to the grain will be significantly reduced due to the complex fiber structure inside the bamboo nodes. In light of the experimental findings, a constitutive model is proposed to describe the relationship between uniaxial compressive stress and strain in Moso bamboo, both before and after weathering. The numerical results obtained from this model demonstrate a strong correlation with the experimental findings, thereby establishing a solid foundation for conducting finite element analysis on Moso bamboo structures.
•The cellulose crystallinity and microstructural changes of weathered bamboo were analyzed.•Comparative studies were conducted to investigate the mechanical properties of weathered bamboo.•An axial compressive stress-strain constitutive model of weathered bamboo was proposed.
•Relationships between bamboo’s features and properties are investigated.•Improvements of bamboo-inspired materials are separately summarized and analyzed.•Bamboo-inspired structures with good energy ...absorption capabilities are presented and analyzed.
With excellent mechanical properties and structural form, bamboo has attracted more and more scientists’ attention. Biomimetics is a bridge connecting the advantages of organisms with engineering applications that can improve the performance of both materials and structures. This paper aims to guide the design of bamboo-inspired materials, structural members, or structures using bamboo or other renewable materials, and simultaneously guide some designs of nanomaterials at mesoscale to some extent. The characteristics of bamboo at mesoscale and microscale are introduced firstly. And then materials and structures inspired by bamboo are presented and discussed to promote the bamboo-inspired design in engineering. Some points that need to be further researched are proposed afterward. Relevant researches indicated that some functional properties of materials have been improved and the load-bearing capacity and the energy-absorption ability of most structures have been generally improved. And further researches in this area are discussed to give some references for the upcoming work.
•Concrete compressive strength grows at 1.2% of bamboo sticks and decreases at 2.4%•Concrete elastic modulus grows at 1.2% of bamboo sticks and decreases at 2.4%•The lower the bamboo stick diameter ...the higher compressive strength.•Increased length of bamboo sticks increases concrete stiffness.•High bamboo sticks volume ratio decreases bonding strength of concrete aggregates.
Over the past decade, bamboo has received much attention due to its sustainability and strength. The advantages of bamboo over other natural fibres include its abundant existence, high yield, and the ability to quickly reach a maximum height and strength in 3–8 years. Bamboo can be used as an independent structural material and concrete reinforcement in the forms of bamboo culms, bamboo splints, and bamboo composite bars for low-rise and low-cost buildings. In this study, bamboo sticks were adopted as reinforcement for concrete cubes. The following influencing factors were considered: bamboo stick volume ratios of 0.6 %, 1.2 %, and 2.4 %, bamboo stick diameters of 1 mm, 1.5 mm, and 2 mm, and bamboo stick aspect ratios of 10, 20, and 30. The test result shows that with the addition of 0.6 % of sticks, the BSRC compressive strength rose by 3.24 and 17.33 % for length-to-diameter ratios 20 and 30, respectively. The compressive strength of specimens was enhanced by adding 1.2 % and 2.4 % bamboo sticks with a length-to-diameter ratio of 10 by 21.38 and 20.94 %, respectively. The obtained results were compared with the mechanical properties of conventional concrete cubes. Currently, river sand and fresh water are the most often used materials in manufacturing concrete. The widespread use of river sand and freshwater has resulted in major environmental issues. Because many places of the world lack appropriate supplies of fresh water, overuse of this resource is not advised. As a result, saltwater and sea sand were used to create both bamboo stick reinforced concrete and plain concrete specimens. Lastly, a model of strength and stress–strain was proposed.
Fibers are used in many forms in engineering applications–one of the most common being used as reinforcement. Due to its renewable short natural growth cycle and abundance of bamboo resources, bamboo ...fiber has attracted attention over other natural fibers. Bamboo fiber has a complex natural structure but offers excellent mechanical properties, which are utilized in the textile, papermaking, construction, and composites industry. However, bamboo fibers can easily absorb moisture and are prone to corrosion limiting their use in engineering applications. Therefore, a better understanding of bamboo fiber is particularly important. This paper reviews all existing research on the mechanical characterization of bamboo fiber with an emphasis on the extraction and treatment techniques, and their effect on relevant properties. The chemical composition of bamboo fibers has also been thoroughly investigated and presented herein. Current applications and future opportunities for bamboo fibers in various fields have been presented with a focus on research needs. This work can serve as a reference for future research on bamboo fiber.
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