Study On Fire Resistance Performance Of Aluminum Silicate Fiber Aerogel Composite For Steel Structure

Building energy efficiency is becoming increasingly important in building development,reducing energy consumption and reducing pollutant emissions.Among them,steel structure has been recognized as a new energy efficient building,with a small cross-section,easy transportation and installation,recyclable and other characteristics.However,steel structure has characteristics of non-resistant high temperature,it needs to protect against fire and fire protection measures.Compared to conventional building fireproof materials,SiO₂ aerogels has insulation,super-hydrophobic and resistant high temperature properties.In this paper,the washed cotton fiber aerogel composites,glass fiber aerogel composites and aluminum silicate fiber aerogel composites prepared by sol-gel two-step method and atmospheric drying method.The maximum decomposition temperatures were 468 ?,429 ? and 418 ?,respectively,and the maximum decomposition rates were 5.65%/min,0.62%/min and 0.68%/min,respectively,and the maximum decomposition rates were 269 ?,382 ? and 382 ?,respectively,the mass residue were 50.1%,92.2% and 92.2%,respectively.Heating in 800 ? for 1 hour,aerogel of washed cotton fiber aerogel composites was off,glass fiber of glass fiber aerogel composites was melted.Therefore,aluminum silicate fiber aerogel composites had better thermal stability.Secondly,the aluminum silicate fiber aerogel composites were used to protect the rectangular hollow steel and to calculate the fire preotection thickness.With the increase of the thickness of the aerogel composite,the temperature change parameter B of the cross-section protective layer was decreased,and the exponential function curve of the temperature-time of the steel component approached the linear equation.When the temperature of the steel component was 500 ?,the refractory time of 30 min,60 min,90 min,120 min,150 min and 180 min corresponding to the thickness of aluminum silicate fiber aerogel composites were 1.50 mm,2.84 mm,4.21 mm,5.59 mm,6.94 mm and 8.30 mm,respectively.It showed that the thickness of aluminum silicate fiber aerogels was increased with the increase of refractory time at the same steel component temperature.When the refractory time was 3 h,the temperature of steel structure of 300 ?,400 ?,500 ? and 600 ? corresponding to the thickness of aluminum silicate fiber aerogel composites were 17.6 mm,11.81 mm,8.30 mm and 5.84 mm,respectively.It showed that the thickness of aluminum silicate fiber aerogel composites was increased with the decreased of steel component temperature at the same refractory time.Finally,the fire resistance performance of aerogel composites was tested for steel plate.With the increase of the thickness of the aerogel compisites,the amount of heat absorption was increased.The delay time was increased with the increase of temperature of steel component at the same thermal resistance.The delay time was increased with the increase of thermal resistance at the same steel component temperature.Aluminum silicate fiber aerogel composites were tested 1 h to protecte steel plate,3 mm,6 mm and 12 mm thick aerogel composite corresponding to the plate side temperature were 121.6 ?,96.2 ? and 78.2 ?,far lower the softening temperature?550 ??of the steel plate.It indicated that the aluminum silicate fiber aerogel composites had excellent fire resistance performance.Aluminum silicate fiber aerogel composites have excellent fire resistance performance for steel structures and have a wide range of applications in super high-rise buildings,airports,railway stations,and technology venues.