Structural properties of Commercial Australian Plantation Hardwood CLT

Significant volumes of plantation hardwood are available in Australia to produce value added engineered wood products such as cross-laminated timber (CLT). To validate the possibility of utilising this available resource, the bending structural properties of plantation Eucalyptus nitens solid board and finger-jointed feedstock were measured. The studied CLT panels produced from finger-jointed lamellas were subjected to bending strength, bending stiffness, rolling shear strength in bending, and pure rolling shear tests to obtain characteristic design values. Solid and finger-jointed timber test results suggested that boards used in longitudinal lamellas have a bending strength of 36.0 MPa and a modulus of elasticity (MOE) of 13,000 MPa. Finger-jointed timber in crossed lamellas presented a declared bending strength of 25.0 MPa. CLT panels showed a bending strength of 24.0 MPa and a rolling shear strength of 2.0 MPa. The experimental results for the CLT panels evidenced that the CLT bending stiffness matches up very well with the modelled results when an MOE of 13,000 MPa is used to describe the stiffness of longitudinal boards. The results presented in this study establish a basis for the commercial use of Australian plantation hardwood CLT in structural applications such as floors and roofs in commercial and residential buildings.