Thermal behaviour of fire-resistant ceiling boards in a novel cellular beam structure

Abstract

The thermal behaviour of fire-resistant ceiling boards in a novel cellular beam structure is crucial in ensuring the safety and structural integrity of buildings under fire conditions. Recent studies have revealed that there is a lack of comprehensive understanding regarding the thermal behaviour of fire-resistant ceiling boards, particularly ceiling boards with holes, in a novel cellular beam structure. To address this knowledge gap, this dissertation will conduct experimental tests on fire-resistant ceiling boards with service holes, subjected to standard fire temperatures within a furnace. The experimental tests will be followed up with Finite Element Analysis (FEA) modelling of the same samples and a comparison of the results will be carried out. ABAQUS CAE will be used to develop FEA models, applying boundary conditions and thermal properties to accurately create models for the simulations. Experimental test samples were set up. The samples were prefabricated to 1.2 × 1.2 m to fit onto the testing furnace opening. These samples were instrumented with type K thermocouples (TCs) to measure temperatures at different positions through the ceiling system. The furnace used during the experimental setup was designed in the work of Fourie (2020). This work investigated the influence that service holes in ceiling boards will have on the fire resistance of residential and commercial structures. It was found that the presence of service holes in the ceiling boards increases the rate at which heat is transferred through the system. It was also found that the more holes a sample has, the more heat will be transferred through that system and the more rapidly the sample will fail. Another finding was that concealing the holes with fire-resistant material such as ceramic fibre blanket or Calcium Silicate (CaSi) boards delays the rate of heat transfer through the system. Based on the results analysis, the samples, with the dimensions assigned to them in this work and the sizes of the holes, could achieve a 30-minute rating. Similarities were observed between the FEA-modelled results and the physical test results, wherein the temperature curves followed similar trends for each test. For the four tests, FEA was seen to have underestimated the measured temperatures. The compared temperature curves indicated that for both the physical and simulated tests, the boards behaved similarly and experienced comparable temperature distributions, especially on the unexposed face of the system. The FEA results, therefore, indicate that the FEA model developed predict the heat transfer of such systems and model failure.