Improved fire resistance of cold-formed steel walls by using super absorbent polymers

Abstract

Fire resistance is an important concern in the design of steel structures. The fire protection mechanism of traditional methods is to cover the external surface of steel members and delay fire-induced heat transfer. This paper develops an innovative solution to improve the structural fire resistance using super absorbent polymers (SAPs) with an experimental study to successfully demonstrate the effect of SAPs on cold-formed steel (CFS) walls. The SAP insulation material was filled in the cavity of CFS walls to provide thermal insulation and absorb heat. Six 1.1 m × 1.1 m CFS walls with SAP insulation materials inside were prepared and subjected to the ISO 834 time-temperature curve. During the experiments, a large amount of water vapor was observed from the SAP insulation materials, effectively removing heat and providing fire protection. The effects of various combinations of SAP insulation materials and steel studs and different configurations of CFS walls on the fire resistance are discussed. The results show that increasing the stud web depth, using autoclaved lightweight concrete (ALC) boards and SAP insulation materials can substantially improve the fire resistance of CFS walls. An optimal configuration of CFS walls with ALC boards as the face-layer sheathing and SAP insulation materials in the cavity of the rectangle hollow section studs was proposed and showed high heat consumption and low damage during fire exposure, which was supported by the maximum temperature of the steel studs being less than 150 °C after exposure to ISO 834 fire for 2 h. Finally, a possible application scenario for the SAP material was proposed for the fire protection of steel structures.