Mechanical properties of structural bamboo following immersion in water

Abstract Bamboo is widely used as scaffolding for which collapses, often associated with rain events, are not uncommon. The presented study quantifies the degradation of mechanical properties of bamboo samples following immersion in water for 1 and 7 days to simulate the effects of significant rain events. Compression, longitudinal shear and splitting tests were conducted to obtain the respective strengths and moduli. The mechanical properties were observed to degrade significantly with increased moisture content (MC) up to about MC = 30%, a value close to the expected fiber saturation point (FSP). Beyond MC = 30%, further degradation, while apparent, was less significant. Immersion in water for one day was observed to be sufficient to achieve the FSP; under these conditions, compressive strength was observed to be 75% of that obtained from tests conducted at a standard ‘air-dry’ MC = 12%. Accompanying the reduction in strength with increased MC, the bamboo was observed to transition from a relatively brittle behavior to a very ductile behavior. For scaffold applications, degradation of compression capacity is not only critical but also shown to be a conservative indicator for other mechanical properties.

[1]  Shigeyasu Amada,et al.  Fracture properties of bamboo , 2001 .

[2]  Jja Jules Janssen,et al.  Analysis of the critical length of culms of bamboo in four-point bending tests , 1997 .

[3]  A.A.J.F. Van den Dobbelsteen,et al.  An environmental, economic and practical assessment of bamboo as a building material for supporting structures , 2006 .

[4]  Kent A. Harries,et al.  Characterization of Splitting: Behavior of Bamboo Culms , 2010 .

[5]  S. Shen,et al.  The mechanical properties of bamboo and vascular bundles , 2011 .

[6]  Hongzhi Cui,et al.  The effect of fiber density on strength capacity of bamboo , 2004 .

[7]  Shigeyasu Amada,et al.  Fiber texture and mechanical graded structure of bamboo , 1997 .

[8]  Kwok-Fai Chung,et al.  Axial buckling of bamboo columns in bamboo scaffolds , 2005 .

[9]  M R Wakchaure,et al.  EFFECT OF MOISTURE CONTENT ON PHYSICAL AND MECHANICAL PROPERTIES OF BAMBOO , 2012 .

[10]  Jja Jules Janssen,et al.  Bamboo in building structures , 1981 .

[11]  A. A. Griffith.  The Phenomena of Rupture and Flow in Solids , 1921 .

[12]  Kwok-Fai Chung,et al.  Mechanical properties of structural bamboo for bamboo scaffoldings , 2002 .

[13]  C. Hill,et al.  Equilibrium moisture content and volumetric changes of Gigantochloa scortechinii , 2007 .

[14]  Khosrow Ghavami,et al.  BAMBOO: FUNCTIONALLY GRADED COMPOSITE MATERIAL , 2003 .

[15]  Shigeyasu Amada,et al.  The Mechanical Structures of Bamboos in Viewpoint of Functionally Gradient and Composite Materials , 1996 .

[16]  Khosrow Ghavami,et al.  Methods of determining transverse mechanical properties of full-culm bamboo , 2013 .

[17]  Zehui Jiang,et al.  SENSITIVITY OF SEVERAL SELECTED MECHANICAL PROPERTIES OF MOSO BAMBOO TO MOISTURE CONTENT CHANGE UNDER THE FIBRE SATURATION POINT , 2012 .

[18]  Kwok-Fai Chung,et al.  Column buckling of structural bamboo , 2003 .

[19]  K. Ghavami,et al.  Bamboo: Low cost and energy saving construction materials , 2008 .