STRUCTURAL FIRE DESIGN WITH AGED RECLAIMED TIMBER: SMALL-SCALE CHARRING PERFORMANCE ASSESSMENT

Timber can play a vital role in the circular economy when reusing materials from deconstruction in new 
buildings, but modern design constraints hinder its widespread use. Despite efforts to promote reuse of reclaimed timber in construction, its fire performance is not well understood. Current Eurocode 5-1-2 guidelines do not specifically address aged timber of the same species, posing challenges for structural fire design. Limited research indicates that heritage timber chars faster than new timber, influenced by factors like radial cracks. This paper presents an assessment of reclaimed timber's charring performance compared to contemporary timber, using a systematic approach across different origins and age groups. Small-scale fire testing and thermogravimetric analysis evaluated the charring rates and thermal decomposition of wood species. The test results indicate that the age of timber does not show a clear correlation with its charring rate. However, older timber appears to exhibit a significantly greater degree of variability in charring rates withinspecies when compared to new timber. It was observed that factors beyond age, such as the annual ring orientation in relation to heat exposure, may have a comparable or even more substantial influence on the charring characteristics of timber. By integrating results from previous studies, this research enhances the understanding of the charring behaviour of aged timber, thereby providing valuable data that can inform the design of structural applications involving aged timber