20.500.12556/DiRROS-21196 Predicting the effective char depth in timber elements exposed to natural fires, including the cooling phase This paper presents a numerical study on the effect of the heating and cooling phases on the reduction of the effective cross-section of timber elements, in particular on the evolution of the char depth (300°C isotherm) and zero- strength layer. An advanced calculation method based a finite-difference heat transfer model is compared to the simplified approach suggested by Eurocode 5. For the heating phase, defined as the standard fire curve (ISO 834), the simplified Eurocode 5 method generally provides more conservative char depths, while the zero-strength layer is under-predicted. Nevertheless, the values of effective char depth are comparable. Including the cooling phase evidences that, during this phase, the heat wave penetration leads to a significant increase in the char depth and zero-strength layer. Particularly, this increase directly depends on the fire cooling rate: a slower cooling phase further reduces the effective cross-section of timber members. As a result, this research highlights how the heat wave penetration during the fire cooling phase can significantly reduce the load-bearing capacity of timber elements. timber structures fire safety heat transfer charring zero-strength layer cooling lesene konstrukcije požarna varnost prenos toplote zoglenitev sloj ničelne trdnosti hlajenje true false true World Conference on Timber Engineering Angleški jezik Slovenski jezik © (2023) WORLD CONFERENCE ON TIMBER ENGINEERING 2023 (WCTE 2023) All rights reserved. Neznano 2025-01-14 11:46:20 2025-01-14 11:53:35 2025-01-15 03:37:23 0000-00-00 00:00:00 2023 0 0 Nasl. z nasl. zaslona; Opis vira z dne 10. 7. 2023; Str. 1681-1690 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 2023-01-01 624 10.52202/069179-0226 158332931 156463107 https://www.proceedings.com/069179-0226.html 1 cc294c66-d264-11ef-ba3f-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=30075 RAZ_Lucherini_Andrea_2023.pdf RAZ_Lucherini_Andrea_2023.pdf 1 63C8458DF5725EADE7A91A30722AF513 cc64ef72ecbaed503025a1f53667f84b3745ae9e3e94f920c514f7ca4c33ab24 48599450-d266-11ef-ba3f-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=30077 Zavod za gradbeništvo Slovenije 0 0 0