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Article

Bending Properties of Finger-Jointed Bamboo Scrimber Composite Beams

by
Chengjian Huang
1,2,
Yongjie Bao
1,2,
Neng Li
1,2 and
Yi Shu
1,2,*
1
China National Bamboo Research Center, Hangzhou 310012, China
2
Key Laboratory of High Efficient Processing of Bamboo of Zhejiang Province, Hangzhou 310012, China
*
Author to whom correspondence should be addressed.
Forests 2024, 15(12), 2116; https://doi.org/10.3390/f15122116
Submission received: 31 October 2024 / Revised: 27 November 2024 / Accepted: 28 November 2024 / Published: 29 November 2024
(This article belongs to the Special Issue Advances in Technology and Solutions for Wood Processing)
Browse Figures
Versions Notes

Abstract

:
The finger-joint technique is an effective and economical method for producing bamboo scrimber composites for structural engineering and construction applications. This study investigates the failure modes and mechanical strength of finger-jointed bamboo scrimber specimens and composite beams loaded parallel and perpendicular to the finger profile orientation. Results indicate that the primary failure mode in finger-jointed bamboo scrimber specimens is damage to the finger-joint area. In V-type composite beams, primary failure was observed as the separation of laminated boards and finger joints, while in H-type beams, large cracks formed and expanded alongside finger joint damage. No statistically significant difference was observed in the modulus of elasticity (MOE) and modulus of rupture (MOR) between the two types of finger-jointed bamboo scrimber. However, the MOR of the finger-jointed bamboo scrimber specimens decreased significantly, by more than 50% compared to the control, while the MOE increased. The ultimate load capacity and displacement of the V-type beams were higher. Under bending, the V-type beams demonstrated elastic deformation, whereas the H-type beams exhibited initial elastic deformation followed by elasto-plastic deformation. Strain distribution along the height of both beam types remained linear, consistent with the plane-section assumption.

1. Introduction

Bamboo scrimber is a composite material made from bamboo. It is manufactured by deconstructing the original bamboo structure into fibers or fiber bundles, impregnating them with adhesive, drying, and then forming by cold or hot press process under high pressure [1,2]. This process achieves a bamboo materials utilization rate of approximately 90% [3]. Bamboo scrimber has the potential to be utilized in structural engineering and construction due to its high strength, dimensional stability, and weather resistance [4,5,6,7]. Currently, two common types of bamboo scrimber productions are available in the market. One type, fabricated by the cold molding and hot curing process [8], usually results in finished dimensions of 1850 mm × 150 mm × 140 mm, while another type, fabricated by the hot-pressing process, results in a common flat size of 2440 mm × 1220 mm with a common thickness range from 22 to 50 mm. Apparently, the length of both types of bamboo scrimber can not sufficiently meet the requirement for structural engineering and construction applications. To address this limitation, various length extension techniques, including joint connections, have been explored [9,10,11,12,13]. Although joints can reduce the strength and stiffness of composite materials [14], the finger joint, as a common jointing method in the manufacture of glulam, provides a simple and economical method to produce structural members [15,16,17] with high wood strength retention [18]. The finger-joint technique is mainly used in bamboo processing and utilization for glue-laminated bamboo [19,20,21], bamboo composite materials such as bamboo lumber [20], arc-segment bamboo lumber [22], glue-pressed engineered honeycomb bamboo [23,24], bamboo scrimber, etc. Finger joints are known to have superior mechanical properties compared to butt and scarf joints [25]. During the fabrication of glue-laminated bamboo, the profile orientation and lamination direction had an effect on the flexural strength of finger-jointed laminated bamboo beams, and the finger-jointed bamboo members laminated vertically showed a slightly higher MOR than those laminated horizontally, while the bamboo members with a finger profile on the width face showed a higher MOR than those on the thickness face [11].
Currently, due to bamboo’s abundance and exceptional mechanical strength, research into the utilization of bamboo as a structural beam has attracted significant attention. However, bamboo’s low modulus of elasticity [26] and limited length restrict its application in large-span beams. Consequently, combined beams and reinforced beams with composited materials, like glulam–concrete composite beams [26,27,28,29], steel–bamboo composite beams [30,31,32,33], cross-laminated timber–bamboo (CLTB) composites [34], bamboo composite beams reinforced by carbon fiber-reinforced polymer [35,36,37,38,39,40], glass fiber-reinforced polymer [41], and basalt fiber-reinforced polymer [42], were designed to increase the span of bamboo beams, and their bending properties [43,44] were investigated. Additionally, the long-term creep performance of Moso bamboo (Phyllostachys edulis) beams was investigated to predict the mid-span deflection over a 50-year period, which has a contribution to the evaluation of the full-life-cycle bamboo structure. Typical tension failure was observed in bamboo scrimber beams subjected to bending, which aligns with four typical failure modes identified by Wei [45] in his study on laminated bamboo beam components. For instance, Zhou et al. [36] observed crack formation and tensile failure in the bottom region of bamboo scrimber beams at ultimate load. For the bamboo beams with finger joints, joints reduce the mechanical strength of the beams. Failure at the finger joint caused a reduction of strength in the bending tests on bamboo I-beams conducted by Aschheim [46]. Xiao [20] observed a reduction of approximate 10% in the load-bearing capacity of laminated bamboo beams in bending fatigue tests, due to the finger joints and weak interfaces. Finger joints were employed in Zhao’s study [35] to study the bending performance of CFRP-reinforced bamboo scrimber beams. However, finger joints were not explicitly discussed as an impact factor of bending properties.
In summary, finger joints can effectively reduce the length limitation of bamboo scrimber in structural engineering and construction as a simple and economical method. However, the impact of finger joints on the bending characteristics of bamboo scrimber beams remains an area of insufficient investigation. The objective of this work is to explore the impact of finger joints and loading direction over the side where finger profile orientation is located on the bending characteristic of bamboo scrimber and its composite beam. Bamboo scrimber and its composite beams fabricated by finger-jointing technology was subjected to the four-point bending test in this study.

2. Materials and Methods

2.1. Materials

The bamboo scrimber, produced by Anhui Zhuji New Materials Tech. Co., Ltd. (Huangshan, China) with a density of 1.05 g/cm3, manufactured from 4–5-year-old Moso bamboo (Phyllostachys edulis) by the hot-pressing process, was employed in this study. Phenol resorcinol formaldehyde (PRF) adhesive, supplied by Shanghai Dynea Chemical Industry Co., Ltd. (Shanghai, China), was employed in the preparation of finger-joined bamboo scrimber specimens and finger-joined bamboo scrimber composite beam specimens, which was applied by manual operation with a spread rate of 250 g/m2. Based on Aschheim’s [46] findings, tenons were adopted at both ends in the thickness direction due to the thickness of the hot-pressed bamboo scrimbers being only 22 mm as shown in Figure 1. The factory-original bamboo scrimber boards were divided into two groups; one was used to make finger-jointed bamboo scrimber specimens and control specimens, while the other was used to make finger-jointed bamboo scrimber composite beam specimens. All specimens were in a natural air-dried state in a laboratory environment with a temperature of 25 ± 2 °C and a humidity of 40%–60%, with an average moisture content of 12.06%.

2.1.1. Preparation of Finger-Jointed Bamboo Scrimber Specimens

Specimens of finger-jointed bamboo scrimber were prepared with the finger joint located at the center of the specimen, measuring 300 mm × 20 mm × 20 mm (length, width, height), according to Chinese Standard LY/T 3194-2020 [47]. However, the control specimens were not subjected to a finger-jointing process and still exhibited the intact bamboo scrimber structure, measuring 300 mm × 20 mm × 20 mm (length, width, height). Subsequently, the finger-jointed bamboo scrimber specimens were randomly divided into two groups. Group V was defined as having the loading direction perpendicular to the side where the finger profile orientation was located, while Group H was defined as having the loading direction parallel to the side where the finger profile orientation was located. The control specimens were also randomly divided into two groups according to the same direction of the bamboo fiber orientation as the experimental specimens, into groups Ch and Cv. Over 32 specimens were prepared for each group, giving a total of more than 128 bending test specimens.

2.1.2. Preparation of Finger-Jointed Bamboo Scrimber Composite Beam Specimens

For the finger-jointed bamboo scrimber composite beams, bamboo scrimbers were made into panels with dimensions of 70 mm × 140 mm or 70 mm × 70 mm (length, width). Beams measuring 2100 mm × 140 mm × 70 mm (length, height, width) were fabricated from horizontally laminated boards with dimensions of 2100 mm × 70 mm and vertically laminated boards with dimensions of 2100 mm × 140 mm. And the boards were made of the panels by the finger-joining technique. As shown in Figure 1, during the composite process, to make sure the finger-joint sections between adjacent boards were staggered, one of the two adjacent boards was constructed with three finger-jointed panels, while the other was constructed with four finger-jointed panels, with a 35 mm cut-off at each end. As illustrated in Figure 1, the specimens with the loading direction perpendicular to the side where the finger profile orientation was located were classified as V-type, while those with the loading direction parallel to the side where the finger profile orientation was located were classified as H-type. Three specimens were prepared for each group, giving a total of six bending test specimens.

2.2. Methods

2.2.1. Bending Test of Finger-Jointed Bamboo Scrimber Specimens

In accordance with Chinese Standard LY/T 3194-2020 [47], the four-point bending method was employed to assess the bending mechanical characteristics of finger-jointed bamboo scrimber through the utilization of a universal testing machine (Model 5969, Instron®, Norwood, MA, USA) loaded at a constant speed, resulting in the specimens being destroyed within 1–2 mins. Variance analysis of the MOR and MOE values of the finger-jointed bamboo scrimber was conducted to assess the effects of finger joint and loading direction on the mechanical strength of bamboo scrimber.

2.2.2. Bending Test of Finger-Jointed Bamboo Scrimber Composite Beams

As depicted in Figure 2a,b, a 300-kN structure testing machine (YJ-IID, Yantai XTD Test Technology Co., Ltd., Yantai, China) was employed for the four-point bending test of finger-jointed bamboo scrimber composite beams, and data acquisition equipment (DH3815N-3, Jiangsu Donghua Testing Technology Co., Ltd., Taizhou, China) was employed to monitor the strain. Electric displacement gauges were positioned directly beneath the loading points and at mid-span to measure and record beam deflection during the experiment. As shown in Figure 2a, the distance between two supports was 1680 mm and the distance between two loading points was 560 mm. The bending test photo of the specimen is shown in Figure 2b. Prior to formal loading, the specimen was preloaded with 5 kN load to check the accuracy of device for proper functioning. The loading speed was 2.5 mm/min [36] for the bending strength test. Strain gauges were attached along the mid-span on one side surface of the finger-jointed bamboo composite beam to measure the strain distribution, as illustrated in Figure 2a,b. Additionally, one strain gauge was attached to both the top and bottom surfaces, respectively.

3. Results and Discussion

3.1. Failure Modes

3.1.1. Failure Modes of Finger-Jointed Bamboo Scrimber

As shown in Figure 3, failure occurred at the mid-span position in both the H-type and the V-type specimens. When the ultimate load of H-type finger-jointed bamboo scrimber specimens had been reached, a significant breakage of bamboo fibers occurred in the tensile area of bottom, which was classified as one of four typical failure modes in Wei’s study [45]. Furthermore, a separation occurred at the finger-joint area, with cracks forming along the upper edges of finger roots. These cracks extended along the bamboo fibers. The finger joint was the weak point of finger-jointed bamboo scrimber specimens due to the stress concentration under load. However, there was no damage observed in the matrix, only separation at the finger joints when the V-type specimens under ultimate load. In contrast, the bamboo fibers in the bottom of the bamboo scrimber in the control group exhibited breakage irregularly, accompanied by deep crack propagation, when both the H-type and V-type specimens were subjected to loading. Notably, the H-type specimens in the control group exhibited more delamination damage during fracture compared with the V-type specimens, as shown in Figure 3. The bamboo scrimber was made of bamboo fiber bundles layer by layer through the hot-pressing process, according to Yu’s research [8]. As a result, once the bamboo fibers fractured, cracks expended along the fiber direction, accompanied by delamination damage.

3.1.2. Failure Modes of Composite Beams

Figure 4 presents the failure modes of the finger-jointed bamboo scrimber composite beams. Similar to the observation of Zhao [35], a cracking sound was heard under loading but no visible damage occurred to the beams. Both types of finger-jointed bamboo scrimber composite beams exhibited brittle failure, with a sudden drop of load.
For the V-type composite beams, delamination damage occurred in the bottom boards after reaching the ultimate load, as shown in Figure 4 (V and Va). In some cases, this delamination resulted from adhesive layer separation between the glued boards, while in a few instances, internal tearing occurred within the matrix, with cracks expending laterally. Furthermore, Figure 4 (Vb) presents a significant separation observed at the finger joints in the bottom of the beams without the damage of finger profile. The distress severity on the side of finger joints exhibited a graded decrease from the bottom to the top of the composite beams. In contrast, the H-type beams exhibited large cracks, which expended towards both ends of the beam, as shown in Figure 4 (H and Ha). The width and extent of cracks on the side increased from the top to the bottom of the composite beams. As shown in Figure 4 (Hb), separation was observed at the finger joint in the bottom which was the tensile region of the beam under loading. Meanwhile, fracture of the bamboo scrimber matrix was observed in the non-jointed areas of the bottom.

3.2. Mechanical Properties

3.2.1. Mechanical Properties of Finger-Jointed Bamboo Scrimber

The load–displacement curve at the mid-span of finger-jointed bamboo scrimber specimens during the bending test is shown in Figure 5. The maximum load-bearing capacity and mid-span displacement of finger-jointed bamboo scrimber decreased compared to the control group. Under the same load, the control group’s V-type specimens exhibited the largest displacement, while the H-type specimens had the smallest displacement. And the displacement values of the experimental group’s V-type and H-type specimens fell in between those of the control group.
As the load increased, the displacement of the H-type specimens in the experimental group increased linearly, forming an almost straight line, indicating elastic deformation. After reaching the ultimate load, the load capacity of the specimen rapidly declined, leading to brittle fracture and failure. In contrast, the V-type specimens exhibited the nonlinear characteristic when the load reached approximately 80% of the ultimate load. Upon continued loading to the maximum load, the load capacity of the V-type specimens dropped rapidly, while failure occurred.
As shown in Figure 5, both elastic and viscoelastic deformation stages were observed during the bending process in the control group based on the load–displacement curves. After reaching the elastic limit, the specimens in the control group entered a longer viscoelastic deformation phase. The load–displacement curves of the control group were similar to the results from Yang’s study [48] on the performance of finger-jointed wood. However, the finger-jointed bamboo scrimber specimens exhibited minimal viscoelastic deformation after reaching the elastic limit, with fracture failure occurring directly, which indicated that the finger joint has a significant impact on the bending performance of bamboo scrimber.
Table 1 and Figure 6 and Figure 7 present the average modulus of elasticity (MOE) and the modulus of rupture (MOR) values of specimens, along with the ratio of change for finger-jointed bamboo scrimber specimens in comparison to the control group. The MOE values for the V-type and H-type finger-jointed bamboo scrimber specimens were found to be 13,216.59 MPa and 13,267.42 MPa, respectively, while the MOR values were 48.27 MPa and 45.23 MPa. Nevertheless, no notable statistic discrepancy in the MOE and MOR values was observed between the two specimen types, as evidenced by the p-values of 0.768 and 0.092 in Table 2. In the control group, the MOE values for the V-type and H-type unjointed bamboo scrimber specimens were 12,577.21 MPa and 11,934.45 MPa, respectively, while the MOR values were 116.44 MPa and 101.61 MPa. In contrast to the experiment group, the statistic discrepancy in the MOE and MOR values between the two specimen types in the control group were significant, as evidenced by the p-value less than 0.05.
The study conducted by Janowiak et al. [49] on three northeastern hardwoods revealed that the orientation of finger profile had no significant impact on the strength characteristic of the three hardwoods. The results of the experiment indicated that the orientation of the finger profile has a minimal effect on the bending performance of finger-jointed bamboo. Conversely, it was found to have a significant impact on the bending performance of unjointed bamboo scrimber.
The statistic discrepancy in the MOE and MOR values between the two specimen types in the control group was extremely significant as shown in Table 2. The MOE value of V-type finger-jointed bamboo scrimber specimens exhibited an increase of 5.08% in comparison to the control group, whereas the MOR value demonstrated a reduction of 58.55%. In contrast, the MOE value of H-type finger-jointed bamboo scrimber specimens exhibited an increase of 11.17%, while the MOR value demonstrated a decline of 55.49%. These findings suggest that finger joint leads to a significant reduction in the MOR values of bamboo scrimber by over 50%, while enhancing the MOE.

3.2.2. Mechanical Properties of Finger-Jointed Bamboo Scrimber Composite Beams

Load–Displacement Curves

The load–displacement curves of the finger-jointed bamboo scrimber composite beams are shown in Figure 8. The H-type composite beams exhibited distinct elasto-plastic characteristics, with the load–displacement curve remaining nearly linear during the elastic phase. Following the onset of yielding, the slope of the load–deflection curve then decreased gradually as the beam transitioned into the elasto-plastic phase. The load capacity increased gradually until reaching the ultimate load, after which it declined markedly as the specimen failed. In contrast, the V-type finger-jointed bamboo scrimber composite beams exhibited a predominantly linear load–displacement curve prior to reaching the ultimate load. Thereafter, the beams rapidly failed after the ultimate load was reached, as shown in Figure 8, with a rapid decline in the load–displacement curve.
In accordance with Chinese Standard GB/T 26899-2011 [50], the MOR and MOE values of two beam types were calculated and shown in Table 3. The ultimate load of the V-type composite beams was found to be 36.1 kN, which was only 67.98% of that of the H-type composite beams. Furthermore, the displacement of the H-type composite beams was found to be 1.67 times that of the V-type composite beams.

Load–Strain Curves

As shown in Figure 9, throughout the entire loading process of the V-type finger-jointed bamboo scrimber composite beams, the load–strain curve at each measurement point in both the compression and tension zones demonstrated linearity, in accordance with the changes observed in the load–displacement curve. The load–strain curve displayed elastic characteristics and was consistent with Hooke’s Law. In the vicinity of failure, the maximum strain in the tension zone typically ranged from 927.7 to 2822.2, while the maximum strain in the compression zone generally ranged from 1089.1 to 2998.2.
The load–strain curves in both the compression and tension zones for the H-type composite beams exhibited a general linear trend, although nonlinearity was observed in the later stages of loading. In the vicinity of failure, the maximum strain in the tension zone typically ranged from 1725 to 7579.4, and in the compression zone from 2944.6 to 6299.1. In comparison to the V-type beams, the H-type beams exhibited evidence of plastic deformation at the later stages of loading, accompanied by a significantly larger strain generation.
Figure 10 (V and H) presents the strain distribution along the height of the finger-jointed bamboo scrimber composite beams during bending. The strain at the neutral axis across the cross-section was observed to be nearly zero. In contrast to the V-type finger-jointed bamboo scrimber composite beams, the strain distribution of the H-type beams transitioned from linear to nonlinear as the load increased. Subsequently, during the nonlinear phase, the neutral axis commenced a downward shift, exhibiting a slight tendency towards the compression side. Furthermore, the increasing plastic deformation in the compression zone of the beams enhances the load capacity, which is in accordance with the results presented in Table 3. The distribution of the strain along the height of both beam types remained linear, which is consistent with the plane-section assumption. Accordingly, this assumption may be employed in the design calculations.

4. Conclusions

To explore the impact of finger joints and loading directions over the side where the finger profile orientation was located on the bending characteristic of bamboo scrimber specimens and its composite beams, the bending failure forms and mechanical strength of finger-jointed bamboo scrimber specimens and its composite beams were tested and analyzed in this study. The main findings are summarized as follows:
Finger joints have a significant impact on the bending failure of finger-jointed bamboo scrimber specimens and its composite beams. The main failure mode of finger-jointed bamboo scrimber specimens was damage of finger-joint area. The breakage of bamboo fiber in the bottom and crack extension was observed in Group H for the finger-jointed bamboo scrimber specimens. The primary failure observed in V-type composite beams was the separation of laminated boards and finger joints. In contrast, H-type beams exhibited the formation and expansion of large cracks, accompanied by damage of finger joints.
The mechanical strength of bamboo scrimber was significantly influenced by finger joints, otherwise the mechanical strength of finger-jointed bamboo scrimber specimens was not significantly affected by the loading direction on the side where the finger profile orientation was located, based on the statistical analysis. The MOR values exhibited a significant decrease of over 50% in comparison to the control due to the finger joints, while the MOE was observed to increase. For the finger-jointed bamboo scrimber composite beams, the loading direction on the side where the finger profile orientation was located had a significant impact on the mechanical properties. The ultimate load capacity and displacement of the V-type composite beams were found to be higher than those of the H-type.
According to the load–displacement curves and load–strain curves, the V-type beams demonstrated an elastic deformation under bending, whereas the H-type beams exhibited an elastic deformation in the front phase and an elasto-plastic deformation in the rear phase. The distribution of the strain along the height of both beam types remained linear, which is consistent with the plane-section assumption.
The findings of this study indicate that the bending characteristics of bamboo scrimber specimens and its composite beams are significantly affected by finger joints. Further studies on fracture characteristics, strength enhancement, and reliability would undoubtedly prove beneficial for the application of finger-jointed bamboo scrimber in structural engineering and construction.

Author Contributions

Conceptualization, Y.S.; Methodology, C.H.; Software, N.L.; Validation, Y.B. and N.L.; Formal analysis, C.H. and N.L.; Investigation, N.L.; Resources, Y.B. and Y.S.; Data curation, N.L.; Writing—original draft, C.H.; Writing—review & editing, C.H.; Visualization, Y.B. and N.L.; Supervision, Y.S.; Project administration, Y.S.; Funding acquisition, C.H. All authors have read and agreed to the published version of the manuscript.

Funding

This research was funded by the Fundamental Research Funds for the Central Non-profit Research Institution of Chinese Academy of Forestry (CAFYBB2020MB009).

Data Availability Statement

The original contributions presented in this study are included in the article. Further inquiries can be directed to the corresponding author.

Conflicts of Interest

The authors declare no conflicts of interest.

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Figure 1. Schematic diagram of the finger-jointed bamboo scrimber and composite beams.
Figure 1. Schematic diagram of the finger-jointed bamboo scrimber and composite beams.
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Figure 2. Bending test of the finger-jointed bamboo scrimber beams: (a) schematic diagram; (b) photo of bending test.
Figure 2. Bending test of the finger-jointed bamboo scrimber beams: (a) schematic diagram; (b) photo of bending test.
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Figure 3. Failure modes of the finger-jointed bamboo scrimber specimens.
Figure 3. Failure modes of the finger-jointed bamboo scrimber specimens.
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Figure 4. Failure modes of composite beams: V—Type V; Va—failure modes on the side; Vb—failure modes in the button; H—Type H; Ha—failure modes on the side; Hb—failure modes in the button.
Figure 4. Failure modes of composite beams: V—Type V; Va—failure modes on the side; Vb—failure modes in the button; H—Type H; Ha—failure modes on the side; Hb—failure modes in the button.
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Figure 5. Load–displacement curves of specimens.
Figure 5. Load–displacement curves of specimens.
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Figure 6. MOE of finger-jointed bamboo scrimber specimens.
Figure 6. MOE of finger-jointed bamboo scrimber specimens.
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Figure 7. MOR of finger-jointed bamboo scrimber specimens.
Figure 7. MOR of finger-jointed bamboo scrimber specimens.
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Figure 8. Load–displacement curves of beams specimens.
Figure 8. Load–displacement curves of beams specimens.
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Figure 9. Load–strain curves of six detection points on the mid-span cross-section of beams: V—strain distribution of V beam; H—strain distribution of H beam.
Figure 9. Load–strain curves of six detection points on the mid-span cross-section of beams: V—strain distribution of V beam; H—strain distribution of H beam.
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Figure 10. Load–strain curves of six detection points on the mid-span cross-section of beams: V—strain distribution of V beam; H—strain distribution of H beam.
Figure 10. Load–strain curves of six detection points on the mid-span cross-section of beams: V—strain distribution of V beam; H—strain distribution of H beam.
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Table 1. The MOE and MOR of finger-jointed bamboo scrimber specimens.
Table 1. The MOE and MOR of finger-jointed bamboo scrimber specimens.
SpecimensMOE/MPaRatio/%MOR/MPaRatio/%
Cv12,577.21 116.44
V13,216.595.0848.2758.55
Ch11,934.45 101.61
H13,267.4211.1745.2355.49
Table 2. MOE and MOR variance analysis for the finger-jointed bamboo scrimber specimens.
Table 2. MOE and MOR variance analysis for the finger-jointed bamboo scrimber specimens.
CharacteristicSource of VarianceSum of SquaresDegrees of FreedomMean SquaresF-Statisticp-ValueSignificance Level
MOE *Cv and Ch7,436,416.32017,436,416.32015.9380.000***
Cv and V6,925,798.61216,925,798.61216.3990.000***
Ch and H31,531,905.50131,531,905.5059.0490.000***
V and H43,180.814143,180.8140.0880.768*
MORCv and Ch3955.20613955.20654.9950.000***
Cv and V78,720.503178,720.5031698.2370.000***
Ch and H56,418.307156,418.307719.8550.000***
V and H154.5351154.5352.9260.092*
Note: *** denotes highly significant, * denotes not significant.
Table 3. The mechanical properties of the bending test of finger-jointed bamboo scrimber specimens.
Table 3. The mechanical properties of the bending test of finger-jointed bamboo scrimber specimens.
SpecimensUltimate Load/kNMax Displacement/mmMOR/MPaMOE/MPa
V36.111.265.0226,228.57
H53.118.744.3327,308.57
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Huang, C.; Bao, Y.; Li, N.; Shu, Y. Bending Properties of Finger-Jointed Bamboo Scrimber Composite Beams. Forests 2024, 15, 2116. https://doi.org/10.3390/f15122116

AMA Style

Huang C, Bao Y, Li N, Shu Y. Bending Properties of Finger-Jointed Bamboo Scrimber Composite Beams. Forests. 2024; 15(12):2116. https://doi.org/10.3390/f15122116

Chicago/Turabian Style

Huang, Chengjian, Yongjie Bao, Neng Li, and Yi Shu. 2024. "Bending Properties of Finger-Jointed Bamboo Scrimber Composite Beams" Forests 15, no. 12: 2116. https://doi.org/10.3390/f15122116

APA Style

Huang, C., Bao, Y., Li, N., & Shu, Y. (2024). Bending Properties of Finger-Jointed Bamboo Scrimber Composite Beams. Forests, 15(12), 2116. https://doi.org/10.3390/f15122116

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