Silica Aerogel–Glass Fiber Composites As Fire Shield for Steel Frame Structures

Abstract

In this study, glass fiber silica aerogel composites were fabricated and used to protect steel frames against fire. Glass-fiber-coated silica aerogel was synthesized by immersing glass fibers into silica sol. Following gel formation, surface modifications were carried out. Samples were dried carefully at relatively high temperatures and ambient pressure. The samples were then prepared at two different solution pH values and four different aging times. Brunauer-Emmett-Teller (BET) and Barrett-Joyner-Halenda (BJH) techniques have been employed to find the specific surface areas and pore diameters of the silica aerogel, formed as a coating on the glass fibers. Fourier transform infrared spectroscopy (FTIR) was used to investigate the chemical reactions. The coverage of fibers by the aerogel was also verified by scanning electron microscopy (SEM). To examine the composites’ fire resistance, a laboratory turbotorch and infrared thermometer have been used. Fire was applied directly to the composite surface while the temperature was read on the other side. The relationship between the fire resistivity of the composites and physical characteristics of the aerogel such, as porosity and specific surface area, is discussed.