This paper briefly presents and discusses the results of experimental tests undertaken to resolve an issue regarding theviability of multi-storey prestressed timber structures, specifically the reduction in prestress load over time. The testprogramme included full-scale specimens, reduced scale specimens and small blocks of laminated veneer lumber(LVL). Based on the experimental data, the creep functions of LVL in bending and compression parallel andperpendicular to the grain were evaluated. The creep perpendicular to the grain was found to be significantly larger(about four times) than the creep parallel to the grain. The prestress losses were found to be relatively low (around 10%)when timber is loaded parallel to grain only, such as a beam. However, the losses markedly increased and reached a34% value when 11% of the frame’s length was loaded perpendicular to grain. An attempt has been made to separatethe contributions made to prestress losses by key factors, namely creep and mechano-sorption parallel andperpendicular to the grain of the LVL. Lastly, an analytical solution is proposed, developed and compared with theexperimental values.
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