Fire Resistance of Bearing Walls in Light Steel Frame (LSF) Structures Including Various Insulation Filler Materials by Finite Element Method

Abstract

Using prefabricated structure in lightweight construction is the new method in both industry and civil engineering. Lightweight Steel Frame (LSF) becomes more valuable in the construction industry due to low cost, low weight, high speed of installation and resistance to environmental conditions. Cold-rolled form lightweight load-bearing wall is consisting of a thin sheet of steel with C-shaped sections (STUD), thermal insulation filler and cover sheets (Plaster Board). However, regardless of existing plasterboard protection the thin-walled steel sections heat up quickly and lose their strength under fire conditions. The main goal of the current study is an evaluation of thermal capacity and bearing strength of lightweight walls in terms of cellulosic fire condition analytically. The variable parameters are insulation filler materials (polystyrene, polystyrene concrete) and axial load. The Abaqus finite element software was used for modeling and analyzing of fire loads. Lightweight concrete fillers increase the axial bearing capacity of walls sustainably and polystyrene filler improved the fire resistance of walls.

Finite element analysis of lightweight concrete-filled LSF walls exposed to realistic design fire

“…Surface film coefficient values of 25 W/m 2 K and 10 W/m 2 K were considered for exposed and unexposed surfaces, respectively, while an emissivity value of 0.9 was used for surface radiation for both exposed and unexposed surfaces (Perera et al. , 2020; Keerthan and Mahendran, 2012a; Parastesh et al. , 2019; Upasiri et al.…”

“…, 2013; Gunalan and Mahendran, 2014a; Keerthan and Mahendran, 2012b, 2013; Ariyanayagam et al. , 2017; Ariyanayagam and Mahendran, 2014a; Parastesh et al. , 2019).…”

“…, 2020; Keerthan and Mahendran, 2012a, 2014; Ariyanayagam et al. , 2017; Parastesh et al. , 2019; Upasiri et al.…”

“…As a remedy for the above concern, the introduction of cavity insulation materials to LSF, utilisation of optimised LCS, construction of LSF with novel materials and new configurations of LSF are practised in the industry based on the results of previous research studies (Perera et al, 2020;Gunalan et al, 2013;Gunalan and Mahendran, 2014a; Keerthan and Mahendran, 2012b;Keerthan and Mahendran, 2013;Gatheeshgar et al, 2021;Lawson et al, 2020;Roy et al, 2019). It is reported in many studies that cavity insulations in LSF walls have contributed to improving the insulation fire rating and energy performances of LSF (Perera et al, 2020;Gunalan et al, 2013;Gunalan and Mahendran, 2014a;Mahendran, 2012b, 2013;Ariyanayagam et al, 2017;Ariyanayagam and Mahendran, 2014a;Parastesh et al, 2019). Insulation materials such as rockwool, glass fibre, cellulose fibre, silica aerogel insulation blanket, ceramic fibre, vacuum insulation panel, expanded polystyrene and polyethylene foam film are utilised (Perera et al, 2020;Gunalan et al, 2013;Gunalan and Mahendran, 2014a;Keerthan and Mahendran, 2013;Alexander et al, 2019;Martins et al, 2016).…”

“…However, its effect as a filling material in LSF has not been investigated. Fire performance of a structural element is evaluated under insulation, integrity and loadbearing criteria (Perera et al, 2020;Gunalan and Mahendran, 2014a;Dodangoda et al, 2019;Parastesh et al, 2019;Upasiri et al, 2020;Upasiri et al, 2021a;Upasiri et al, 2021b;Upasiri et al, 2021c;European Committee for Standardisation, EN 1991-1-2). Insulation criteria evaluate the heat transfer through the structural element by examining the increment of unexposed surface temperature, whereas integrity criteria check whether fire flame or hot gas could penetrate to the unexposed surface through the structural element.…”