Volume effects in glued laminated timber beams

Abstract

This paper discusses several aspects related to volume effects on glued laminated timber (GLT) beams, with focus on the combined effects of height and length on the bending strength. Challenges related to the prediction of the mechanical properties of very large GLT beams using numerical models are discussed. If the exact lay-up of a GLT beam is not known (i.e. if there is no knowledge aboutlocal and global timber properties along boards and about finger joints), a large number of test results are needed to ensure a reliable validation of numerical models. A review of experimental research shows that the variability of bending strength and stiffness properties is significantly smaller for larger GLT beams. A simplified study on the effect of reduced material properties on the structural reliability of GLT beams is also presented.