Properties Of Bamboo Research Articles

Combined function of glycerol monolaurate/phytol and carnauba wax for improving the hydrophobic and anti-mildew properties of bamboo

Combined function of glycerol monolaurate/phytol and carnauba wax for improving the hydrophobic and anti-mildew properties of bamboo

Eco-friendly in-situ mineralization of bamboo for flame retardancy

An inorganic-organic structure including calcium carbonate (CaCO3) and bamboo was prepared via in-situ mineralization to improve the flame retardant properties of bamboo. During the mineralization, CaCO3 deposited mostly in parenchyma cells with pits and multilayer cell walls, which contributed to a stable cross-linked structure in bamboo by binding negatively charged calcium ions to carboxyl groups. Also, mineralization reduced the relative content of carbohydrates but promoted the formation of char residue. Cone calorimetry tests demonstrated that the mineralized bamboo had substantially reduced peak heat release rate (pHRR), lower total heat release (THR), lower peak smoke produce rate (pSPR) and total smoke release (TSR) than control bamboo. The improved flame resistance and smoke suppression properties of bamboo were primarily attributed to the even and dense coverage of non-combustible CaCO3.

Construction relationship between a functionally graded structure of bamboo and its strength and toughness: Underlying mechanisms

The special functional gradient structure of bamboo determines its excellent properties of strength and toughness, which make it an excellent candidate for biomimicking purposes in advanced material design. However, the construction relationship and underlying mechanism of the functionally graded structure in the direction of the bamboo wall and its excellent strength and toughness have not been elucidated. Accordingly, this study first conducts a quantitative analysis of the relationship between the directional gradient structure of the bamboo wall layer and its chemical composition and physical and mechanical properties. To this end, in situ scanning electron microscopy (in situ SEM) was used to investigate the mechanical behavior and failure mode of the bamboo wall layer under the effect of external loads, and to investigate the structure–activity relationship between the gradient structure of the bamboo wall layer and its strength and toughness, as well as the potential mechanism of action. From the perspective of structural mechanics, the mechanical model of the bamboo wall direction under the applied load was analyzed, and the mechanism by which the bamboo wall gradient structure improves the strength and toughness of bamboo was further elucidated. The results showed that the uniform gradient distribution of the vascular bundles and their interfaces in the direction of the bamboo wall determines the gradient distribution of its chemical components and physical and mechanical properties. Together, the uneven deformation of parenchyma cells and fibers, multi-path propagation of cracks, fiber bridging, pull-out and fracture constitute the mechanism by which the bamboo gradient structure contributes to its strength and toughness. This study provides a theoretical basis and innovative ideas for the design of biomimetic advanced materials based on the bamboo wall gradient structure by revealing the potential close relationship between the excellent mechanical properties of bamboo of high strength and toughness and its functional gradient structure.

3D characterization of vascular bundle in moso bamboo node and its effect on compressive properties

Abstract The structure of the bamboo node obviously differs from that of the internode and largely affects the mechanical properties of bamboo. However, the node structure of moso bamboo, an important economic and ecologic bamboo species, was still unclear. Thus, in this study, the 3D structural changes of the vascular bundle (VB) in the moso bamboo node were visualized and quantified. The compressive properties and failure mechanisms of the bamboo node were discussed based on the structural changes. The results showed that the horizontal VB in bamboo node was classified into three types: branching, cross-linking, and thickening. The cross-sectional area of the vertical VB in bamboo node increased, and the vertical VBs shifted to the outer side after passing through the node. Due to the “wire hoop” effect of the horizontal VBs, the longitudinal compressive strength of the node was greater than that of the internode. The deflection of VBs caused slippage between VBs and resulted in the decrease of the node’s transversal compressive strength. This research provided key information for a deeper understanding of the structure and mechanical properties of bamboo for potential applications.

Effect of temperature on axial compressive mechanical properties of bamboo

To study the axial compressive mechanical properties of bamboo in different temperatures (-60 °C ∼200 °C, 11 temperatures), 264 specimens were designed for experimental research considering the influence of bamboo node and loading direction. This study summarized the failure modes of bamboo under compression load, and the effect of bamboo node and load direction on the compressive strength of bamboo was analyzed. The test results showed that when the temperature rose from −60 °C to 200 °C, the compressive strength of bamboo gradually decreased. The mechanism that the compressive strength of bamboo would decrease under high temperature is that the cell wall of bamboo would become thinner under such environment (>100 °C) and eventually lead to the vanishment of the layered structure of the cell wall, thus losing the bearing capacity. Under any temperatures, the compressive strength of bamboo parallel to fibres was always higher than that perpendicular to fibres. In general, the effect of bamboo node on the compressive strength of bamboo parallel to fibres is more obvious than that of bamboo perpendicular to fibres. An estimation formula was proposed for calculating the compressive strength bamboo under different temperatures.

Experimental research on standardized bamboo culm components for developing prefabricated bamboo building

Bamboo culm structures are useful for areas with limited access to structural wood, especially for remote bamboo forest areas. This study focuses on developing standardized bamboo culm components for the prefabricated bamboo building, which is potential to replace timber components made of dimension lumber used in modern timber buildings. The basic material properties of Moso bamboo and bamboo culm elements were investigated. Test results show that the main mechanical properties of bamboo culm are comparable to some coniferous wood, such as TC-13A grade (in Chinese standard). Several types of simple and reliable connectors were designed for connecting bamboo culms, attempting to provide standardized bamboo culm elements. The prefabricated shear wall elements were designed with bamboo culms as studs and glubam lumber as perimeter frame for regulate the dimension. Three shear wall models were tested under monotonic and cyclic lateral loading. It was found that the lateral resistance capacity of bamboo culm shear wall is about 64% of that of the similar lightweight wood frame shear walls. Three specimens of bamboo culm trusses were also tested to obtain the design capacity of the roof system. Based on the experimental test results, a prototype single-story building was designed and constructed to assess the feasibility of the constructional details. Carbon dioxide emission analysis revealed the environmentally friendly advantages of this type of bamboo building.

Bamboo for producing charcoal and biochar for versatile applications.

Bamboo, the fastest-growing plant, has several unique characteristics that make it appropriate for diverse applications. It is low-cost, high-tensile, lightweight, flexible, durable, and capable of proliferating even in ineffectual areas (e.g., incline). This review discusses the unique properties of bamboo for making charcoal and biochar for diverse applications. To produce bamboo charcoal and biochar, this study reports on the pyrolysis process for the thermal degradation of organic materials in an oxygen-depleted atmosphere under a specific temperature. This is an alternative method for turning waste biomass into products with additional value, such as biochar. Due to various advantages, bamboo charcoal is preferred over regular charcoal as it has four times the absorption rate and ten times more surface area reported. According to the reports, the charcoal yield ranges from 24.60 to 74.27%. Bamboo chopsticks were the most useful source for producing charcoal, with a high yield of 74.27% at 300 °C in nitrogen, but the thorny bamboo species have a tremendous amount of minimal charcoal, i.e., 24.60%. The reported biochar from bamboo yield ranges from 32 to 80%. The most extensive biochar production is produced by the bamboo D. giganteus, which yields 80% biochar at 300 °C. Dry bamboo stalks at 400 °C produced 32% biochar. One of the sections highlights biochar as a sustainable solution for plastic trash management produced during the COVID-19 pandemic. Another section is dedicated to the knowledge enhancement about the broad application spectrum of the charcoal and biochar. The last section highlights the conclusions, future perspectives, and recommendations on the charcoal and biochar derived from bamboo.

Load and resistance factor design for bamboo reinforced concrete beam in ultimate flexural limit state

Building sustainable infrastructure brings back the idea of using environmentally friendly materials, such as bamboo, for reinforcing concrete structures. However, a design framework for bamboo reinforced concrete (BRC) structures is still in its early stages due to the inherent uncertainties in the properties of bamboo. The present work focuses on developing a load and resistance factor design (LRFD) framework for BRC beams subjected to flexure. Before developing the design framework, the major variables affecting the behaviour of BRC beams are identified — the tensile properties of bamboo, the compressive properties of concrete, the bond strength between them, and the load. BRC beams, with various reinforcement percentages, are investigated through real-life experiments and finite element (FE) based numerical experiments. We show that the FE models provide good agreement with the real-life experiments if the major variables are chosen as per their descriptive statistics. The FE model is used to generate a synthetic dataset, using which Monte Carlo simulations are performed. The BRC beam is assumed to be governed by the limit state of collapse in flexure. The partial safety factors for bamboo with different dead and live load combinations are calibrated to different target reliability. Designers can make use of the proposed partial safety factors for designing BRC flexural members.

Physical and Mechanical Properties of Bamboo Fiber/Glass Fiber Mesh Reinforced Epoxy Resin Hybrid Composites: Effect of Fiber Stacking Sequence

ABSTRACT To further improve the preparation efficiency and properties of bamboo fiber reinforced polymer composites (BFRPs) fabricated by the vacuum-assisted resin transfer molding (VARTM) process. Here, the bamboo fiber/glass fiber mesh reinforced polymer hybrid composites (BGRPs) were fabricated by VARTM to determine the effects of three fiber stacking sequences (namely, GBBGBBG, BGBGBGB, and BBGGGBB; B: bamboo fiber, G: glass fiber mesh) on the physical and mechanical properties, as well as void characteristics of BGRPs (i.e. BGRP-1, BGRP-2, and BGRP-3). The results showed that the incorporation of glass fiber meshes could shorten the injection time of epoxy resin and improve the mechanical properties of BFRPs. BGRP-1 exhibited the lowest water absorption (1.31%) and the highest shear strength (15.55 MPa). Glass fiber meshes on the surface and bottom of BGRP-1, respectively, served as buffer layers to retard mechanical damage, so that BGRP-1 had the best drop hammer impact properties. BGRP-2 represented the highest flexural strength and flexural modulus of 92.22 MPa and 6.69 GPa, respectively. The mechanical properties of BGRP-3 were inferior to those of BGRP-1 and BGRP-2, and more voids were observed in the middle of BGRP-3 in micro-CT slices induced by inadequate epoxy resin impregnation on bamboo fibers.

Physical and Mechanical Properties of Bamboo Oriented Strand Board Prepared fromAlkali-Immersed Strands

In this work, the physical and mechanical properties of bamboo oriented strand board (BOSB) prepared from alkali-immersed strands were examined. The Dendrocalamus asper strands were modified with alkali treatment by immersing them in 1% sodium hydroxide solution for 1, 2, and 3 hours. Three-layers BOSBs (30 x 30 x 0.9 cm3) were prepared using phenol-formaldehyde (PF) adhesive of 8% concentration and 1% paraffin. According to JIS A 5908:2003 Standard, the physical and mechanical characteristics of BOSB were evaluated (JSA, 2003). The study showed that alkali treatment improved the dimensional stability of BOSB. Immersion in 1% sodium hydroxide solutions enhanced internal bonding (IB). The longer the immersion time, the better the WA, TS, and IB values. However, alkali treatment decreased the bending strength, i.e., modulus of elasticity (MOE) and modulus of rupture (MOR). The physical and mechanical properties of all BOSBs met the commercial standard, except the BOSBs prepared from strand with alkali immersion treatment by 1% sodium hydroxide solution for 3 hours. Alkali immersion treatment of D. asper strands for producing BOSB for 1-2 hours was still acceptable. The results could provide an alternative method to produce high-performance oriented strand board using bamboo as the raw materials.

Research on the Change in Chemical Composition and Fungal Resistance of Moso Bamboo with Heat Treatment

Bamboo, as a potential alternative to biomass materials, has gained more attention from the bamboo manufacturing industry in China. However, the drawbacks, such as the dimensional instability, and low antifungal and hydrophilic properties of bamboo, inhibit its application and shorten its service life. The objective of this work was to analyze the change in chemical components and fungal resistance of moso bamboo with heat treatment. For this objective, moso bamboo specimens were thermally modified in an oven at different temperatures for a fixed duration. The results showed that the parenchymal cells distorted and deformed in comparison to the control after thermal modification. After thermal modification in an oven, the crystallinity index increased from 39% to 53%. Owing to the thermal modification, the hemicellulose and cellulose relative content decreased, as confirmed by FTIR and XPS analysis. Thus, the dimensional stability and antifungal properties of the thermally modified bamboo specimens improved.

Stepwise modification with 2,3-epoxypropyltrimethylammonium chloride cationization and rosin acid impregnation to improve water repellency and mold-proof property of bamboo

As its abundant reserves and good physical properties, bamboo is deemed to be a promising feedstock material for construction and home furnishing. However, the hydrophilicity of bamboo and its rich nutrients make it susceptible to mold infection. In this study, bamboo firstly reacted with 0, 3, 6, 9, and 12 wt times of 2,3-epoxy-propyltrimethylammonium chloride (EPTAC) in NaOH/Urea solution, respectively, and then impregnated with rosin acid. Effects of modification on structure, thermal stability and water repellency of bamboo were identified by FT-IR, XRD, XPS, SEM, TGA, contact angle measurement and water absorption coefficient, respectively. A comparative study of mold-proof properties of original and modified bamboo was conducted as inoculation of Aspergillus niger, Penicillium citrinum and Trichoderma viride on samples. The results indicated that the sample obtained from a mass ratio (EPTAC to bamboo) of 9 had the highest substitution degree, charge content and ion exchange capacity as compared to samples obtained from other EPTAC dosages. After modification, the density of bamboo increased by 43.3%, which exhibited considerable thermal stability. Impregnating this sample with rosin acid improved its water-repelling and anti-swelling efficiency to 10.91% and 27.83%, respectively. Compared with the original bamboo, anti-mold property of EPTAC modified bamboo to three fungi was notably improved and achieved rate 1 mold coverings. Impregnation-modified bamboo with rosin acid enhanced the anti-mold property, achieving a rate of 0 mold covering. The research provides a feasible way to improve the mildew resistance of bamboo and promote the utilization of rosin.

Thermal treatment of bamboo with flame: influence on the mechanical characteristics

The mechanical properties of bamboo are susceptible to degradation due to both physical and biological agents. Among the non-chemical treatments, we studied the influence of a short-time heat treatment, using an LPG-gas torch, on the mechanical properties of a bamboo (Phyllostachys viridiglaucescens) growing in Italy. The response was very encouraging as we found no significant reduction in either elastic modulus or tensile, compressive and bending strength.Several samples were subject to tension, compression and bending tests to compare the responses of the treated and untreated culms. The average tensile elastic modulus was slightly greater for the untreated culms. The average tensile strength of the untreated culms was only slightly greater, and the differences can be assumed to be insignificant from a structural point of view. The average value of the treated culms compressive elastic modulus was slightly greater than that of the untreated ones. The compressive strength was essentially the same. The bending mechanical behaviour was barely influenced by the thermal treatment.A microscopic investigation (optical and electron microscopy) was undertaken to investigate the possible deterioration of the bamboo microstructure due to the heat treatment. No appreciable damage was detectable in the treated material.The proposed heat treatments can be considered as a reliable and sustainable protection practice for bamboo culms.

A Review of Experimental Research on the Mode I Fracture Behavior of Bamboo

Bamboo is an eco-friendly material with light weight, high strength, short growth cycle and high sustainability, which is widely used in building structures. Engineered bamboo has further promoted the development of modern bamboo structures due to its unrestricted size and shape. However, as a fiber-reinforced material, fracture damage, especially Mode I fracture damage, becomes the most likely damage mode of its structure, so Mode I fracture characteristics are an important subject in the research of mechanical properties of bamboo. This paper summarizes the current status of experimental research on the Mode I fracture properties of bamboo based on the three-point bending (TPB) method, the single-edge notched beam (SENB) method, the compact tension (CT) method and the double cantilever beam (DCB) method, compares the fracture toughness of different species of bamboo, analyzes the toughening mechanisms and fracture damage modes, discusses the applicability of different theoretical calculation methods, and makes suggestions for future research priorities, aiming to provide a reference for future research and engineering applications in related fields.

Research on the Bending Impact Resistance and Transverse Fracture Characteristics of Bamboo under the Action of Falling Weight

Drop weight impact tester was used to accurately measure the bending impact resistance of various parts of Phyllostachys edulis, commonly known as moso bamboo, with a growth cycle of 3–8 years. Cellulose crystallinity in the bottom (B), middle (M) and top (T) of bamboo at different ages was calculated using peak height analysis in X-ray diffraction. Heatmap of Spearman correlation analysis was used to represent the correlation between chemical composition and impact mechanics. The breaking load (BL), fracture energy (FE) and impact deflection (ID) of 3–8-yearold bamboo were found to be in the range of ~670–2120 N, ~5.17–15.55 J, and ~3.60–~17.76 mm, respectively. As the growth period of bamboo rises, the cellulose crystallinity at the B and T decreases first and then increases, while that for the M increases first and then remains stable. Similarly, the bending impact performance of bamboo was found to become stable with its growth and age. The flexural impact and toughness of the 4-year-old bamboo base material were better than other specimens. The enhancement in the bending impact properties of bamboo at different growth periods was influenced by the lignin content, while the value of FE was mainly positively correlated with ash, cold and hot water extracts and benzyl alcohol content. However the content of holocellulose and pentosan, air-dry density and, base density negatively influenced the FE. With the change in the height of the bamboo, the correlation between its impact mechanical properties and chemical composition gradually decreased. This study provides data support and theoretical basis for the age-appropriate thinning and application of moso bamboo.

Photodegradation of Bamboo: A Study on Changes in Mechanical Performances.

One of the main concerns in using natural materials in construction, such as bamboo, regards their durability. Ultra violet (UV)irradiation is claimed as a damaging agent; therefore, it is important to study its effect. Several studies have shown that bamboo components such as lignin are subjected to photochemical degradation, but it is not well understood how this affects the mechanical properties of bamboo. The aim of this paper is to explore the correlation between photodegradation and bamboo mechanical performance. Bamboo samples were exposed to accelerated UV ageing for different times (from 6 to 360 h) and then subjected to a four-point bending test. Since one of the ways to stabilize bamboo is to thermally treat it, the tests were conducted on natural untreated bamboo and treated bamboo with a traditional flame treatment. Modifications of the chemical features of the material were analyzed with Fourier Trasform Infra Red (FTIR) spectroscopy, while modifications of the morphological features were analyzed byEnvironmental Scanning Electron Microscopy ESEM and optical microscopy observations. The results show that the bending behavior of bamboo is not compromised by UV exposure up to 360 h. In fact, although a progressive degradation of lignin is reported and cracks in the fiber walls are highlighted from micrographs, no effects were found on the fiber length.

Improving Biomass-Degradation Properties and Nano-Mechanics of Moso Bamboo via a Simple Nitrogen Heat Treatment

Nitrogen is generally used as a protective gas to provide an oxygen-free environment for the heat treatment of biomaterials. In order to indicate the effect of nitrogen heat treatment of bamboo, the changes in terms of the chemical composition, chemical functional groups, cellulose crystallinity index, surface color, micro-mechanics and anti-mildew properties of bamboo, and the interaction relationship among the properties, were analyzed. The mass loss ratio of treated bamboo samples increased significantly during the process of thermal modification. In detail, the hemicellulose exhibited a decreasing tendency from 23.7% to 16.6%, while the lignin content presented an increasing tendency. The decreased hemicellulose and cellulose contents are a benefit to enhancing lignin content and crystallinity degree, thus increasing the modulus of elasticity and hardness of treated bamboo cell walls. The obtained bamboo sample treated at 190 °C/3 h displayed the best micro-mechanical properties. It presented a maximum modulus of elasticity of 22.1 GPa and a hardness of 0.97 GPa. Meanwhile, the lignin and cellulose content was proven to increase in the bamboo surface in chemical composition analysis, resulting in lower free-hydroxyl groups on the bamboo surface. Thus, the contact angle value of bamboo increased. Furthermore, nitrogen thermal modification positively contributed to the mildew resistance of bamboo specimens.

Mechanical evaluation on BFRP laminated bamboo lumber columns under eccentric compression

Bamboo has been studied and utilized quite significantly in recent years because of its advantages such as short growth period, good appearance, environmental protection and superior mechanical properties. Bamboo is processed into profiles to address inherent issues with size limitation and self-defects and use of BFRP can enhance the mechanical properties of bamboo for widespread application. In this paper, the mechanical properties of BFRP strengthened chamfered laminated bamboo lumber (LBL) columns with four eccentricity e0 of 30 mm, 60 mm, 90 mm, and 120 mm were tested. The strengthening effect of BFRP on the performance of LBL columns subjected to eccentric loading was compared with the specimens without any reinforcement. Several analytical models to capture the mechanical performance of BFRP reinforced LBL columns with different eccentricities have been proposed in the current study.

Physical, Chemical, and Mechanical Properties of Six Bamboo from Sumatera Island Indonesia and Its Potential Applications for Composite Materials.

The suitability of bamboo's basic characteristics is very important for more specific purposes, such as composite raw materials. Anatomical, physical, mechanical, and chemical characteristics are some of bamboo's fundamental characteristics. This study analyses the basic properties, such as physical, mechanical, and chemical properties of bamboo from the Forest Area with Special Purpose (FASP) Pondok Buluh Sumatera Island, Indonesia (I); analyses the relationship between the properties of each type of bamboo (II); and chooses the type of bamboo with the best properties that have the potential to be applied to composite materials, such as laminated bamboo (III). This study used materials consisting of six species of bamboo from the FASP Pondok Buluh. The manufacture of physical and mechanical test samples refers to the ISO 22157 standard, 2004, while the chemical properties test refers to the TAPPI 1999 standard. The chemical, physical, and mechanical properties of bamboo vary widely among species. The lowest holocellulose and α-cellulose content were found in the Kuning Bamboo (B. vulgaris var. vittata). The content of holocellulose and α-cellulose causes the lowest density in Kuning Bamboo (B. vulgaris var. vittata). The Dasar Bamboo (Bambusa vulgaris) has the highest levels of lignin. The substances have an impact on moisture content, T/R ratio, and shear strength. The Dasar Bamboo (Bambusa vulgaris) has the lowest moisture content, the highest T/R ratio, and the highest shear strength. However, Betung Bamboo (Dendrocalamus asper) has the highest density in this study. The compressive strength of the Betung Bamboo (Dendrocalamus asper) has the highest value. Therefore, Betung bamboo and Dasar Bamboo in this study were potentially utilized for composite materials, such as laminated bamboo.

Physical and Mechanical Properties of Novel Multilayer Bamboo Laminated Composites Derived from Bamboo Veneer.

Compared with wood, bamboo has a special fiber gradient structure. Bamboo fibers have attracted attention as reinforced polymer composites. This study investigated the effects of lamination and fiber volume on the physical and mechanical properties of bamboo laminated composites (BLCs). Six types of BLC were derived by parallel and cross laminating bamboo veneers with high, middle, and low fiber volumes. The results indicated that the laminated structure and fiber volume significantly influenced the BLC properties. Microstructural analysis showed that parallel lamination and low fiber volume were more conducive to resin penetration and enhanced the bonding strength. Both the bending and tensile strengths of the cross lamination were lower than those of the parallel lamination. BLCs made of veneers with high and middle fiber volumes and parallel lamination had the maximum bending and tensile strengths (145.1 and 101.53 MPa, respectively). When tested for water resistance, parallel and cross lamination inhibited expansion in the thickness (TSR, 0.56-2.14%) and width (WSR, 0.07-1.61%) directions, respectively. Laminated structures and veneers with varying fiber volume contents should be chosen according to the specific application scenarios. This study provides a reference for selecting an appropriate BLC structure and fiber volume based on application.