A review on the mechanical properties of aged wood and salvaged timber

• Effect of aging on the mechanical properties of wood and timber.
• Aging is a complex phenomenon including load history and chemical composition change.
• Contrasting results reported due to the difficulty to test old wood/timber.
• Majority of works agree on the fact that MOR and MOE are slightly affected by aging.
• Needs to standardize tests on old wood/timber to allow a reliable comparison process.

The effect of time on the mechanical properties of wood is of interest for structural engineers, wood technologists and conservators; for the old timber structure assessment, for the potential reuse of salvaged timbers and poles and for the conservation of wooden artefacts as well. The topic was investigated since the 50’s, but the results reported in literature are not always concordant. This is a consequence of the fact that this kind of research works are quite difficult, as a consequence of the material characteristics itself: mechanical properties variability, low availability of material, uncertainty about the “history” of the tested material, unknown original mechanical properties. Another source of uncertainty between the research works is a consequence of the different research approaches: some have investigated only the effect of the time passing (therefore, aging), others consider the aging effect together with other effects, like the state of conservation and the duration of load. The main interest of the researchers was in the bending properties variation, while for other mechanical properties less information is available. In this paper, the results of several research works are presented and analysed regarding the differences in the mechanical properties for elements with different age levels. Moreover, recommendations for future research are included attending to the conclusions drawn from the analysed literature.