Effects of Moisture Content on the Mechanical Properties of Moso Bamboo at the Macroscopic and Cellular Levels

Abstract

To better understand how moisture content (MC) affects the longitudinal compressive mechanical properties of bamboo, mechanical tests on both the macroscopic and cellular levels were performed on Moso bamboo (Phyllostachys pubescens Mazei ex H. de Lebaie) at different MCs. At the macroscopic level, the compressive modulus of elasticity (CMOE) was determined using a common mechanical tester, while the indentation modulus of elasticity (EIT) and the hardness (HIT) of the bamboo fiber cell walls were obtained using nanoindentation. The results showed that CMOE, EIT, and HIT were all negatively correlated with the change in MC below the fiber saturation point (FSP) with strong linear relationships. However, the CMOE was found to be more sensitive to a change in MC than was EIT, which indicated that the bamboo was more sensitive to MC at the macro level than at the cellular level, at least in terms of longitudinal compression stiffness. Moreover, EIT was found to be much less sensitive to a change in MC than was HIT, which may explain why the longitudinal compression strength of bamboo was much more sensitive to changes in MC than was the compression modulus of elasticity on the macro scale.

Expansión lineal y punto de saturación de las fibras de la Guadua angustifolia Kunth

“…De acuerdo con diversos investigadores (AIS, 2010;Gutiérrez, 2011;Jiang, 2012;Wang, 2013;Xu, et al 2014;Kamiski et al, 2016b), la variación en el contenido de humedad es uno de los factores de mayor afectación en las propiedades mecánicas del bambú. Algunos autores han encontrado que el bambú presenta disminuciones de resistencia de hasta un 30 % cuando se alcanza el PSF (Jiang et al, 2012;Xu, et al 2014).…”

Water vapor sorption behavior of bamboo pertaining to its hierarchical structure

“…On the other hand, water sorption rate is also directly related to the ability to treat bamboo, e.g., mold resistant treatment using borate solution, both in terms of the treatment time and uniformity 33 . In addition, the water sorption responses at different structure levels will have an impact on the multiscale mechanical properties of bamboo 34 – 37 , through the effect of moisture content or EMC 38 , 39 and dynamic moisture diffusivity.…”

Fracture and fatigue behavior of Bambusa Vulgaris-Schrad Bamboo

“…The moisture content of the dry bamboo was determined to be 4.47 ± 0.05% using a method described previously (Onche et al, 2020). Wang et al (Wang et al, 2013) have shown that, for a relative humidity of 15.22%, the corresponding moisture content for the Moso bamboo used in their work was 4.30%, while for 27.19% relative humidity, the corresponding moisture content was 6.04%. Hence, the relative humidity of 18% and corresponding moisture content of 4.52% obtained for the Bambusa Vulgaris-Schrad bamboo that was used in this work are within the range of values reported in an earlier study (Wang et al, 2013).…”