Dangerous damage of RC structural members caused by thermal spalling of concrete during fire in an enclosed car park of residential building

Abstract

This paper presents a description of structural damage caused by a fire in an underground car park of a six-storey residential building. It also describes how the damaged members were repaired. It was found that the fire had reached the fully developed stage over a large area of the car park, which resulted in considerable extent of damage: (1) approximately 210 m² of the ceiling slab were completely destroyed - it was necessary to demolish the slab and replace it with a new one, (2) one of the walls constituting the main load-bearing structure of the building was in a state very close to actual destruction, (3) several columns required significant strengthening. The main cause of the resulting damage was the unusually intense thermal spalling of the concrete.