###### Abstract  
Slim floor systems are very common nowadays and various types are currently being used for the construction of high-rise buildings and car parks. Concrete in slim floor beams encases the steel beam section which helps to improve their fire resistance. Despite their higher fire resistance, several fire protection materials like intunnecent coatings are often used to achieve a higher fire resistance where desired. The thermal properties and behaviour of various intunnecent coating materials were previously studied through experimental investigations. This paper presents finite element analyses to simulate the response of unprotected and protected slim floor beams in fire using different simulation tools. For this purpose, fire tests conducted on unprotected slim floor beams and intunnecent coating materials are modelled using research and commercial software. Results from the analyses are compared and verified with the available test data. These validated models are later combined to study the behaviour of protected slim floor beams in fire. Results from the study show that the research and the commercial software replicate the behaviour of slim floor beams and protection materials with good accuracy. Due to the presence of the intunnecent coating, the protected slim floor beams displayed a better fire resistance as the temperature of the steel part remained below 400 \({}^{\circ}\)C even after 60-min of standard heating. The protected slim floor beams continued to support the external loads even after 120 min of heating. f 2021 24 November 2021 29 November  
of fire research, Netherlands, conducted tests during 1995 to investigate the effect of air-fap between the welded plate and the bottom flange of the steel beam section and to assess the membrane action [6; 7]. These tests were conducted on unprotected slim floor beams. Another fire test on a slim floor beam was conducted at the Polythetic University of Valencia (UPV), Spain on unloaded and unprotected specimens using an electric furnace [8]. Tests on asymmetric slim floor beams were conducted between 2010 and 2012 in the Republic of Korea when 7 asymmetric slim floor assemblies under different loads and variable section properties [9; 10]. Recently during 2029-2021, detailed experimental investigations on slim floor beams have been conducted at Ulster University where the effect of steel reinforcement as an alternative to traditional fire protection methods was investigated [11]. In addition to these fire tests, fire tests on slim floor beams with different web openings were also conducted [12]. In this paper, a finite element modelling (FEM) method is presented to predict the thermal and thermo-mechanical response of slim floors exposed to fire. For this purpose, commercial software, ABAQUS [13] and research software, SAFIR [14], are employed. Both software are used to perform FEM and for computer-aided engineering purposes. In the first part of this study, FE modelling is performed to predict the response of unprotected slim floors in fire. The predicted results are verified against the reported test data. In the later part of this study, the response of intumescent coating applied on a steel member is predicted and verified against the experimental data using a proposed finite element (FE) analysis method. This study is conducted to investigate the response of protected slim floor beams in fire as there is a lack of experimental work. The results from this study will help future researchers to design and plan their experiment work. Finally, the verified models are combined to simulate the behaviour of protected slim floors in fire. Comparative analysis of predictions obtained from both software is performed and the efficiencies and deficiencies associated with each modelling program are highlighted.