Fire Spread in Insulation Materials in the Ceiling of a Piloti-Type Structure

Abstract

In piloti-type structures, large-scale fires frequently occur because insulation materials in the ceiling are ignited. However, the spread of fire in these cases is not well known. Therefore, this study conducted small-scale (1.0 m × 1.0 m) tests and real-scale model tests. According to the results, we clarified the fire spread, temperature variation over time, and the effects of insulation materials in fire sites. For the small-scale tests, the internal structure of the ceiling was extruded polystyrene (XPS) + sheet molding compound (SMC), retardant expanded polystyrene (Retardant EPS) + sheet molding compound (SMC), and extruded polystyrene (XPS) + design metal ceiling (DMC). From the small-scale and large-scale tests that simulated a fire in a piloti-type structure, the flow of heat in the interior space and the cause of a large fire were identified. The tests were conducted with EPS+DMC, defined as the best-case scenario, and XPS+SMC, defined as the worst-case scenario during a fire accident. The results from the tests showed that combustion began when the insulation material was exposed to the fire source. Then, molten XPS fell onto the SMC, establishing a new fire source that destroyed the ceiling material, leading to increased combustion due to the inflow of oxygen.