Towards modular composite wall systems: thermal properties and boundary conditions for fire resistance simulation

This article investigates the fire resistance performance of composite walls, focusing on the thermal properties of wall materials and the critical boundary conditions for heat transfer numerical simulations. As the construction industry increasingly adopts modular and light-gauge steel frame structures, evaluating the fire resistance of composite walls under high-temperature conditions has become essential. This study consolidates the thermal properties of widely used wall materials such as fiber cement boards, calcium silicate boards, rock wool, and autoclaved aerated concrete, with particular attention to the temperature dependency of these properties. Notably, an equivalent area method was applied to optimize the temperature-dependent specific heat capacity of ALC boards, preserving the original thermal response characteristics while ensuring positive values across the temperature range. Given the limitations and high costs associated with full-scale fire resistance testing, numerical simulation has emerged as an effective alternative. This article provides optimal parameter recommendations based on a comprehensive literature analysis, aiming to enhance the accuracy of thermal simulations and support future fire safety research.