PSI - Issue 37

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Procedia Structural Integrity 37 (2022) 811–819

ICSI 2021 The 4th International Conference on Structural Integrity A risk-based approach for timber building decay prediction ICSI 2021 The 4th International Conference on Structural Integrity A risk-based approach for timber building decay prediction

Andrea Gaspari a,b , Ivan Giongo a,c *, Maurizio Piazza a,d a University of Trento (IT), Department of Civil, Environmental and Mechanical Engineering b andrea.gaspari.1@unitn.it c ivan.giongo@unitn.it d maurizio.piazza@unitn.it Andrea Gaspari a,b , Ivan Giongo a,c *, Maurizio Piazza a,d a University of Trento (IT), Department of Civil, Environmental and Mechanical Engineering b andrea.gaspari.1@unitn.it c ivan. iongo@unit .it d maurizio.piazza@unitn.it

© 2022 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of Pedro Miguel Guimaraes Pires Moreira Abstract The durability of timber structures subjected to biotic attacks is becoming of increasing concern due to several recent examples of failures caused by early degradation. Therefore, the design process of a timber building cannot prescind from accounting for the possible degradation due to biotic attack, especially in light of the recent spread of high-rise timber buildings. Furthermore, it is of extreme importance that reliable models to foresee possible sources of degradation in existing buildings are made available so that retrofit interventions can be programmed before it is too late. In the work presented herein, the decay due to fungal attack was predicted through a risk-based approach where decision trees were created to address all the possible scenarios where water or moisture can intrude within the construction details that most affect the durability. These decision trees allow to assign a risk class, defined based on a thorough review of the major European standards addressing timber “use - classes”. The trees also lead to the selection of a proper prediction function for estimating the decay depth, chosen among suitable functions available in the literature. The proposed methodology was applied to selected case studies where a good correlation was found between the decay level detected onsite and the results from the prediction model. To facilitate the application of the methodology to both the design of new durable timber buildings and the assessment of existing timber structures, an ad hoc software tool named TSafe was developed. In the present paper, due to the length limit, the focus is on the decision trees and the risk classes, while just a brief description of the case study used for the procedure validation is given. © 2022 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of Pedro Miguel Guimaraes Pires Moreira Keywords: Timber structures; Decay prediction; TSafe project Abstract The durability of timber structures subjected to biotic attacks is becoming of increasing concern due to several recent examples of failures caused by early degradation. Ther fore, the design process of a timber building cannot pr scind from a counting for the possible degradation due to biotic attack, especially in light of th recent spread of high-rise timbe bu l ings. Furthermore, it is of extrem import nce that reliable models to foresee poss ble sources of degrad ti n in existing buildings are made availabl so that ret ofit interventions c n be programmed befor it is too late. In the work prese ted herein, the ecay due to funga attack w s predic ed through a risk-based approach where dec ion trees were created to address all the possible scenarios where water or moisture can intrude within the constru tion details that most affect the durability. The e decision trees allow to a sign a risk class, def ned based on a thorough r view of he major European standards address ng timb r “use - class ”. The ree also lead to the s lection of a proper prediction functi n for estimating th dec y epth, chosen among suitabl functions available in the literature. Th pr p sed methodology was applied to elected cas studies w ere a good correlation was fou d between the decay lev l det cted nsite and the results from th prediction model. To facilitate the appli ation of the methodology to bo the design of n w durable timber buildings and the assessment f existing timber s ructur s, an ad h c s tware tool named TSafe was developed. In the pres nt paper, due to the length limit, the f cus is on he d cision t es d the ri k class s, while just a brief descripti n of the case study used for the procedure validation is given. © 2022 The A thors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review u der re ponsibility of Pedro Miguel Guimara s Pires Moreira K ywords: Timber structures; Deca prediction; TSaf project

* Corresponding author. Tel.: +39-0461-282543. E-mail address: ivan.giongo@unitn.it * Corresponding author. Tel.: +39-0461-282543. E-mail address: ivan.giongo@unitn.it

2452-3216 © 2022 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of Pedro Miguel Guimaraes Pires Moreira 2452-3216 © 2022 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review u der responsibility of Pedro Miguel Guimara s Pires Moreira

2452-3216 © 2022 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of Pedro Miguel Guimaraes Pires Moreira 10.1016/j.prostr.2022.02.013