Variation of mechanical properties of P. edulis (Moso) bamboo with moisture content

This study investigates the variation of bamboo mechanical properties under the effects of varying moisture content (MC). Because of some inconsistencies in international standards, this study places emphasis on the effect of MC on bamboo tension parallel to the fibres. A large experimental study is conducted to address tension and other mechanical properties with the aim of confirming, revising and/or refuting the standard-prescribed relationships for normalising mechanical properties of bamboo at MC = 12%. Mechanical property correction factors are reported for a sample of P. edulis bamboo having MC ranging from 5% < MC < 30%. Strength properties, other than tension, exhibit a trend of increasing strength as MC falls below the fibre saturation point (FSP). Tension strength decreases as MC falls and tension modulus is relatively unaffected by MC. The correction factors identified in this study correlate well with the trends implied by similar factors proposed in international standards although two potential revisions are identified and discussed. The large dataset developed in this study also permitted evaluation of test methods and assumptions used in determining characteristic mechanical properties. Taking the approach of correcting mechanical properties to a standard MC supports efforts for grading large populations of bamboo and can be used to promote partial safety factor design of bamboo.