Influence of Relative Humidity on Elastic Modulus of Bamboo Bundle

Abstract:

Bamboo can be used for a variety of purposes, whether using the bamboo culm in structures works or using bamboo bundle or bamboo fibers as a reinforcement in composite materials. However, the critical item that should be considered when using bamboo materials is the humidity condition of the environment. The influence of humidity on the mechanical properties of bamboo materials can potentially lead to damage or degradation. The objective of this research is to investigate the influence of relative humidity (RH) on elastic modulus of bamboo bundle. In this research, 3 years old Dendrocalamus bamboo stem at 3-6 m in height without node was used to prepare the bundle samples. The bamboo stem was dried in the oven at 105 °C then hand pulled and cut to get the bamboo bundle with 30 mm in gage length and 0.06-0.09 mm² in cross-section areas. The elastic modulus of bamboo bundles was determined according to ASTM D3379 standard under 8 different relative humidity; 30%, 35%, 50%, 55%, 70%, 75%, 80%, and 85% RH, whereas paper grips technique was applied to prevent damage from the machine clamps. The results indicated that the relative humidity does not affect the value of the loaded or unloaded elastic modulus of bamboo fiber bundle. For the low value of relative humidity, here 35%-55%, the value of elastic modulus of bamboo bundle is quasi-stable with the RH with the average value 25.93 GPa while the elastic modulus was gradually decreased for the high value of RH (>70%) with the minimum value of 24.43 GPa at 85% RH. Implying at high humidity condition, the humidity or the amount of water vapor in the air affects to the bamboo bundle be softened or more flexible, which helps the process of bending or forming bamboo bundles easier.

• Periodical: Key Engineering Materials (Volume 1028)
• Pages: 9-14
• DOI: https://doi.org/10.4028/p-ELH0Wh
• Online since: October 2025
• Authors: Panidpim Sawangbunditkun, Itthichai Preechawuttipong*, Robert Peyroux
• Keywords: Bamboo Bundle, Elastic Modulus, Natural Materials, Relative Humidity

References

[1] Meng, W., Sun, H., & Su, G. (2023). Plastic packaging-associated chemicals and their hazards - An overview of reviews. Chemosphere, 331, 138795.

DOI: 10.1016/j.chemosphere.2023.138795

[2] Verma, R., Vinoda, K. S., Papireddy, M., & Gowda, A. N. S. (2016). Toxic Pollutants from Plastic Waste- A Review. Procedia Environmental Sciences, 35, 701-708.

DOI: 10.1016/j.proenv.2016.07.069

[3] Nkwachukwu, O. I., Chima, C. H., Ikenna, A. O., & Albert, L. (2013). Focus on potential environmental issues on plastic world towards a sustainable plastic recycling in developing countries. International Journal of Industrial Chemistry, 4.

DOI: 10.1186/2228-5547-4-34

[4] Klotz, M., Haupt, M., & Hellweg, S. (2023). Potentials and limits of mechanical plastic recycling. Journal of Industrial Ecology, 27, 1043–1059.

DOI: 10.1111/jiec.13393

[5] Muhammad Shamsuddin, I. (2017). Bioplastics as Better Alternative to Petroplastics and Their Role in National Sustainability: A Review. Advances in Bioscience and Bioengineering, 5(4).

DOI: 10.11648/j.abb.20170504.13

[6] Sun, X., He, M., & Li, Z. (2020). Novel engineered wood and bamboo composites for structural applications: State-of-art of manufacturing technology and mechanical performance evaluation. Construction and Building Materials, 249.

DOI: 10.1016/j.conbuildmat.2020.118751

[7] Ma, X., Luo, Z., Ji, C. H., Cai, L., & Fei, B. (2022). Flexural creep behaviors of bamboo subjected to different gradient variation directions and relative humidity. Industrial Crops and Products, 179.

DOI: 10.1016/j.indcrop.2022.114679

[8] Yuan, J., Fang, C., Chen, Q., & Fei, B. (2021). Observing bamboo dimensional change caused by humidity. Construction and Building Materials, 309.

DOI: 10.1016/j.conbuildmat.2021.124988

[9] Faris M. AL-Oqla, & Salit, M. S. (2017). Materials Selection for Natural Fiber Composites: Woodhead Publishing.

[10] Yiping, L., Li, Y., Buckingham, K., Henley, G., & Guomo, Z. (2010). Bamboo and Climate Change Mitigation (Vol. 32).

[11] Liese, W. (1987). Research on bamboo. Wood Science and Technology, 21(3), 189–209.

[12] Jakovljević,S., Lisjak, D., Alar, Ž., & Penava, F.(2017). The influence of humidity on mechanical properties of bamboo for bicycles. Construction and Building Materials, 150, 35-48.

DOI: 10.1016/j.conbuildmat.2017.05.189

[13] Yuan, J., Chen, Q., & Fei, B. (2021). Investigation of the water vapor sorption behavior of bamboo fibers with different sizes. European Journal of Wood and Wood Products, 79(5), 1131-1139.

DOI: 10.1007/s00107-020-01652-4

[14] Kadivar, M., Gauss, C., Mármol, G., de Sá, A. D., Fioroni, C., Ghavami, K., & Savastano, H. (2019). The influence of the initial moisture content on densification process of D. asper bamboo: Physical-chemical and bending characterization. Construction and Building Materials, 229.

DOI: 10.1016/j.conbuildmat.2019.116896

[15] Chen, G., & Luo, H. (2023). Effects of moisture content and fibrous structure on the uniaxial compression behavior of natural bamboo. Construction and Building Materials, 408.

DOI: 10.1016/j.conbuildmat.2023.133711

[16] Chakkour, M., Ould Moussa, M., Khay, I., Balli, M., & Ben Zineb, T. (2023). Effects of humidity conditions on the physical, morphological and mechanical properties of bamboo fibers composites. Industrial Crops and Products, 192.

DOI: 10.1016/j.indcrop.2022.116085

[17] Lessard, G., & Chouinard, A. (1980). Bamboo research in Asia : proceedings of a workshop held in Singapore, 28-30 May 1980.

[18] Li, X. B., Shupe, T. F., Peter, G. F., Hse, C. Y., & Eberhardt, T. L. (2007). Chemical changes with maturation of the bamboo species phyllostachys pubescens. Journal of Tropical Forest Science, 19, 6-12.

[19] Kaima, J., Preechawuttipong, I., Jongchansitto, P., & Charoenloe, N. (2020). Effect of Chemical Solution on Tensile Strength of Bamboo Fiber. Paper presented at the 10th TSME-International Conference on Mechanical Engineering (TSME-ICOME2019), Pattaya, Thailand.

DOI: 10.1088/1757-899x/886/1/012061

[20] Information on https://www.tmd.go.th

[21] Askarinejad, S., Kotowski, P., Shalchy, F., & Rahbar, N. (2015). Effects of humidity on shear behavior of bamboo. Theoretical and Applied Mechanics Letters, 5(6), 236-243.

DOI: 10.1016/j.taml.2015.11.007

[22] Osorio, L., Trujillo, E., Lens, F., Ivens, J., Verpoest, I., & Van Vuure, A. W. (2018). In-depth study of the microstructure of bamboo fibres and their relation to the mechanical properties. Journal of Reinforced Plastics and Composites, 37(17), 1099-1113.

DOI: 10.1177/0731684418783055