Assessing Delayed Collapse Risks in Load-Bearing Reinforced Concrete Walls Exposed to Parametric Fires: A Numerical Investigation

This study delves into the thermo-mechanical analysis of structures exposed to fire, focusing on the evolution of gas temperatures, thermal distribution in structural members, and mechanical behavior during fire scenarios. Traditional prescriptive approaches assume a monotonically increasing temper...

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Main Authors: Guergah Cherif, Baghdadi Mohamed, Dimia Mohamed Salah, Antonio Marcos de Oliveira Siqueira, Júlio César Costa Campos
Format: Article
Language:English
Published: Universidade Federal de Viçosa (UFV) 2024-08-01
Series:The Journal of Engineering and Exact Sciences
Subjects:
Online Access:https://periodicos.ufv.br/jcec/article/view/19442
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author Guergah Cherif
Baghdadi Mohamed
Dimia Mohamed Salah
Antonio Marcos de Oliveira Siqueira
Júlio César Costa Campos
author_facet Guergah Cherif
Baghdadi Mohamed
Dimia Mohamed Salah
Antonio Marcos de Oliveira Siqueira
Júlio César Costa Campos
author_sort Guergah Cherif
collection DOAJ
description This study delves into the thermo-mechanical analysis of structures exposed to fire, focusing on the evolution of gas temperatures, thermal distribution in structural members, and mechanical behavior during fire scenarios. Traditional prescriptive approaches assume a monotonically increasing temperature, while contemporary performance-based designs incorporate both heating and cooling phases for a more realistic fire resistance assessment. The critical aspect of this research is the modeling of the fire's cooling phase, which, though not commonly practiced in design offices, is essential for evaluating the risk of delayed structural collapse. Utilizing the finite element program SAFIR, numerical simulations were conducted on reinforced concrete walls to investigate their behavior during and post-cooling phase. The findings indicate potential failure not only during the cooling phase but also after the fire has subsided and temperatures have returned to ambient levels. This highlights delayed temperature increases in the core of the element and the consequent loss of concrete strength during cooling as key mechanisms of failure. A parametric study was undertaken, examining various fire scenarios, wall geometries, load levels, wall heights, adjacency, and boundary conditions. The results underscore that short-duration fires pose the most significant risk for delayed failure, particularly for simply supported walls. Additionally, the study scrutinizes the mechanical properties of materials across the heating and cooling phases. This investigation underscores the necessity of incorporating cooling phase analyses in fire resistance evaluations to mitigate the risk of delayed collapses. The insights gained aim to inform safer structural designs and enhance fire safety protocols, emphasizing the importance of realistic fire modeling in performance-based design methodologies.
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spelling doaj-art-6f707000d8a648e29dcba37fb396e90e2025-02-02T19:53:28ZengUniversidade Federal de Viçosa (UFV)The Journal of Engineering and Exact Sciences2527-10752024-08-0110810.18540/jcecvl10iss8pp19442Assessing Delayed Collapse Risks in Load-Bearing Reinforced Concrete Walls Exposed to Parametric Fires: A Numerical InvestigationGuergah Cherif 0Baghdadi Mohamed1Dimia Mohamed Salah2Antonio Marcos de Oliveira Siqueira 3Júlio César Costa Campos 4Department of Civil Engineering, Mohamed-Cherif Messaadia University, Souk Ahras, AlgeriaLGC-ROI Laboratory, Department of Civil Engineering Faculty of Technology University of Batna 2, Batna, AlgeriaLGC-ROI Laboratory, Department of Civil Engineering Faculty of Technology University of Batna 2, Batna, AlgeriaUniversidade Federal de Viçosa, BrazilUniversidade Federal de Viçosa, Brazil This study delves into the thermo-mechanical analysis of structures exposed to fire, focusing on the evolution of gas temperatures, thermal distribution in structural members, and mechanical behavior during fire scenarios. Traditional prescriptive approaches assume a monotonically increasing temperature, while contemporary performance-based designs incorporate both heating and cooling phases for a more realistic fire resistance assessment. The critical aspect of this research is the modeling of the fire's cooling phase, which, though not commonly practiced in design offices, is essential for evaluating the risk of delayed structural collapse. Utilizing the finite element program SAFIR, numerical simulations were conducted on reinforced concrete walls to investigate their behavior during and post-cooling phase. The findings indicate potential failure not only during the cooling phase but also after the fire has subsided and temperatures have returned to ambient levels. This highlights delayed temperature increases in the core of the element and the consequent loss of concrete strength during cooling as key mechanisms of failure. A parametric study was undertaken, examining various fire scenarios, wall geometries, load levels, wall heights, adjacency, and boundary conditions. The results underscore that short-duration fires pose the most significant risk for delayed failure, particularly for simply supported walls. Additionally, the study scrutinizes the mechanical properties of materials across the heating and cooling phases. This investigation underscores the necessity of incorporating cooling phase analyses in fire resistance evaluations to mitigate the risk of delayed collapses. The insights gained aim to inform safer structural designs and enhance fire safety protocols, emphasizing the importance of realistic fire modeling in performance-based design methodologies. https://periodicos.ufv.br/jcec/article/view/19442Concrete wall. Parametric fire. Residual strength. Delayed failure.
spellingShingle Guergah Cherif
Baghdadi Mohamed
Dimia Mohamed Salah
Antonio Marcos de Oliveira Siqueira
Júlio César Costa Campos
Assessing Delayed Collapse Risks in Load-Bearing Reinforced Concrete Walls Exposed to Parametric Fires: A Numerical Investigation
The Journal of Engineering and Exact Sciences
Concrete wall. Parametric fire. Residual strength. Delayed failure.
title Assessing Delayed Collapse Risks in Load-Bearing Reinforced Concrete Walls Exposed to Parametric Fires: A Numerical Investigation
title_full Assessing Delayed Collapse Risks in Load-Bearing Reinforced Concrete Walls Exposed to Parametric Fires: A Numerical Investigation
title_fullStr Assessing Delayed Collapse Risks in Load-Bearing Reinforced Concrete Walls Exposed to Parametric Fires: A Numerical Investigation
title_full_unstemmed Assessing Delayed Collapse Risks in Load-Bearing Reinforced Concrete Walls Exposed to Parametric Fires: A Numerical Investigation
title_short Assessing Delayed Collapse Risks in Load-Bearing Reinforced Concrete Walls Exposed to Parametric Fires: A Numerical Investigation
title_sort assessing delayed collapse risks in load bearing reinforced concrete walls exposed to parametric fires a numerical investigation
topic Concrete wall. Parametric fire. Residual strength. Delayed failure.
url https://periodicos.ufv.br/jcec/article/view/19442
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