Fire resistance of SFRC thin plates

Fire resistance is the most important limitation to the thickness reduction of cross section profiles used in the production of precast roof elements made of Steel Fibre Reinforced Concrete. An experimental investigation was carried out on HPSFRC to assess the mechanical behaviour, when subjected to high temperature. The damage was first investigated providing uniaxial tensile tests after thermal cycles at increasing maximum temperatures. The mechanical behaviour was also identified by means of bending tests, after a thermal cycle, and also for hot specimens after a fast extraction from the oven. A damage evolution law depending on the maximum temperature and a strain invariant was identified. It was adopted to reproduce the fire behaviour of 3 SFRC bent plates subjected to three load levels and a standard fire exposition curve. The comparison shows a good fitting of the experimental results and a significant efficiency of steel fibre in fire resistance.