Experimental studies on glubam columns under axial compression

Abstract

Glubam is a new type of structural material or bamboo based glulam. Understanding the compressive performance of glubam columns under axial compression is crucial for its application in construction field. Experimental and analytical investigations were conducted to study the mechanical performance of 45 columns fabricated by two types of glubam with different slenderness ratios. The failure modes in terms of various slenderness ratios were reported and evaluated: strength failure was the main failure mode of the short columns while buckling was typically observed for long and slender columns. For the intermediately slender columns, buckling was also accompanied by the material damage. The experimental results were compared with the column design curves specified in Chinese, American and European timber structural design codes for glued laminated timber, showing all the codes can provide adequately conservative prediction to the test results. Euler's equation, Newlin-Gahagan approach, Yoshihara et al.’s approach and tangent modulus theory were adopted to analyze the critical buckling of the columns under both elastic and inelastic conditions. A model is proposed to explain the buckling of intermediate glubam columns with partial splitting.