Enhancing Fire Resistance Through the Synergy of Gypsum and Fumed Silica Composites: Mechanisms and Performance

Abstract

Fire safety is a critical consideration in modern building design, requiring the development of materials that not only inhibit fire spread but also safeguard occupants and maintain structural integrity during fire incidents. This study investigates the enhancement of fire resistance in gypsum-based composites by incorporating fumed silica, a material with ultra-low thermal conductivity. The objective is to combine the phase-change heat absorption properties of gypsum with the thermal insulation capabilities of fumed silica, creating a composite material with superior fire protection. A multifaceted methodology is employed, encompassing theoretical modeling, experimental investigations, and numerical simulations to systematically assess the influence of fumed silica concentration variations on critical thermal parameters, namely thermal conductivity, density, specific heat capacity, and enthalpy. The research reveals a synergistic mechanism underpinning fire resistance enhancement, where the coupling of diminished thermal conductivity and optimized phase-change behavior extends the crystallization water loss duration, thereby delaying the rate of temperature rise. Optimized fire performance is achieved with a 35% fumed silica gel content, which elevates fire resistance while reducing thickness and surface density compared to the reference material, achieving equivalent fire resistance limits under the ISO 834 standard fire exposure curve. These findings highlight the complex interplay between thermal properties and fire resistance in gypsum-fumed silica composites and provide valuable insights for the development of advanced fire-resistant materials. Furthermore, the principles uncovered in this study can be extended to the design of other fire-resistant composites for construction applications, offering new avenues to improve performance while reducing material usage.

Keywords: Gypsum-fumed silica composite, Fire resistance limit, Phase change enthalpy, Synergistic fire protection mechanism, Thermal conductivity reduction