Thermal Response of Reinforced Concrete Shallow Bin (Bunker) With Protection Coating Under Hydrocarbon Fire: A Finite Element Approach

Abstract

Shallow bins, commonly used for storing material, are typically designed for ambient conditions, overlooking their response under elevated temperatures, such as during fire outbreaks. To illustrate the impact of elevated temperatures on structural performance and signify the necessity of some protection measures, this study examines a reinforced concrete shallow bin (bunker) under Hydrocarbon Fire Curve through a finite element approach. Two fire exposure conditions were considered: bunker heated from one side and heated from the bottom (underside). To improve bunker’s fire resistance, two types of protection coatings were examined: gypsum plaster with sand aggregate and high-density particle board. Different coating thicknesses were analysed to determine their insulation capacity and required thickness to preserve bunker’s structural integrity under fire. The results show that fire magnifies stress and displacement in the bunker, making them beyond the permissible limits set by the Indian Standard IS 456:2000, and induces compression damage in concrete. Different thicknesses (1-10 cm) of the gypsum plaster reduced the temperature by 2.82 to 97.53 %, whereas high-density particle board reduced it by 2.28 to 97.42%. A minimum 8 cm thickness of gypsum plaster and particle board, when applied individually, was required to preserve structural integrity under both fire exposure conditions.