The document describes an experimental study that tested the mechanical properties of cracked round bamboo poles reinforced with fiber-reinforced polymer (FRP) sheets under axial compression loads. Specimens were divided into four groups based on location of the pole, presence/severity of cracks, and whether they were fully or half wrapped with FRP. Results showed that FRP reinforcement increased compressive strength and ductility compared to uncracked and cracked unreinforced specimens. However, the confinement effect of the FRP was not fully utilized. Future work plans to use cement filling and joint reinforcement to prevent inward buckling under loads.

1. The mechanical properties of cracked round bamboo
reinforced with FRP sheets subjected to axial compression
Xinmiao MENG Lecturer
Department of Civil Engineering, Beijing Forestry University, Beijing, China
Peng FENG Professor
Department of Civil Engineering, Tsinghua University, Beijing, China
Youde WU M.S. student (THU)
Qiang DENG M.S. student (BFU)

2. Outline
1. Introduction
2. Experimental research
3. Results and discussion
4. Conclusion
5. Ongoing and future plan

3. Outline
1. Introduction
2. Experimental research
3. Results and discussion
4. Conclusion
5. Ongoing and future plan

4. 1. Introduction
A pavilion in Humble Administrator's Garden
Cracks
almost every poles
Safe or not?
How to deal with?

5. 1. Introduction
Ø Metal hoop
corrosion
Ø FRP reinforcement
FRP sheets
FRP(Fiber-Reinforced
Polymer)
• Anti-corrosion
• Easy to use
• Defend
environmental
impacts

6. Outline
1. Introduction
2. Experimental research
3. Results and discussion
4. Conclusion
5. Ongoing and future plan

7. Experimental research
Specimens
• Cut from a single round pole bamboo
• Each specimen about 200 mm in height
• Divided into four groups
• Two reinforcements: full wrapped and half wrapped
• GFRP: HITEX-G430S ( unidirectional fabric, 430 g/m2 ),
epoxy resin, hand lay-up
Details of specimens
Specimens Location
Height
(cm)
Crack
Reinforce
-ment
A1-B-20-U Bottom 20 Uncrack /
A2-M-20-U Middle 20 Uncrack /
A3-T-20-U Top 20 Uncrack /
B1-B-20-C Bottom 20 Severe crack /
B2-M-20-C Middle 20 Slight crack /
B3-T-20-C Top 20 Slight crack /
C1-B-20-F Bottom 20 Severe crack Full
C2-M-20-F Middle 20 Slight crack Full
C3-T-20-F Top 20 Slight crack Full
D1-B-20-H Bottom 20 Severe crack Half
D2-M-20-H Middle 20 Slight crack Half
D3-T-20-H Top 20 Slight crack Half

8. Experimental research
Compression strength
Height
(mm)
Compression
strength (MPa)
15 63.45
21 64.42
51 65.90
140 61.70
15 mm
21 mm
51 mm 140 mm

9. Experimental research
Experimental observations
A1-B-20-U
Split
B1-B-20-C
Split along
the Initial defect
C1-B-20-F
Local buckling
(inward)
D1-B-20-H
Local buckling (outward)
Split

10. Experimental research
Load-displacement curves
A1-A3 B1-B3 C1-C3
Displacement (mm)
Load(kN)
D1-D3
Displacement (mm)
Load(kN)
Displacement (mm)
Load(kN)
Displacement (mm)
Load(kN)

11. Outline
1. Introduction
2. Experimental research
3. Results and discussion
4. Conclusion
5. Ongoing and future plan

12. 3. Results and discussion
Compressive strength
Group
Strength
(MPa)
Increase
A 57.20 1.25
B 45.76 1
C 57.82 1.26
D 55.69 1.22
Full wrapped
Half wrapped

13. 3. Results and discussion
Ductility
Full wrapped
Half wrapped
• Cracks decreased the ductility
• FRP reinforcement increased
the ductility

14. 3. Results and discussion
Failure modes
• Full wrapped
prevented the
outward split
• Inward deformation
couldn’t avoid
A1-A3 B1-B3 C1-C3 D1-D3

15. 3. Results and discussion
Confinement effect
• The transverse strains were
much little than the ultimate
strain. (5000 me << 15000 me)
• The confinement effect wasn’t
fully used.
Strain (me)
Load(kN)
C1

16. Outline
1. Introduction
2. Experimental research
3. Results and discussion
4. Conclusion
5. Ongoing and future plan

17. 4. Conclusion
• The wrapping method changed the failure modes from
outward split to inward deformation, and improved the peak
loads and markedly improved compression deformation.
• The confinement effect of FRP sheets wasn’t fully used.
• The reinforced cracked round pole bamboos showed better
mechanical behavior, which might promote the development
and application bamboos in constructions and buildings.

18. Outline
1. Introduction
2. Experimental research
3. Results and discussion
4. Conclusion
5. Ongoing and future plan

19. 5. Ongoing and future plan
Fulfill it with cement to
avoid inward buckling
Joint reinforced by
FRP sheets
3D scanning
used in FEA