EVALUATION OF FIRE ENDURANCE OF SELF COMPACTED CONCRETE SLAB REINFORCED WITH STEEL FIBER REINFORCEMENT AND STEEL BARS

Abstract

The effect of steel fiber on the deflection of self- compacted slabs under fire (600⁰c) was investigated in this study. Three specimens were tested experimentally and numerically ( by using sophisticated finite element programme ANSYS 7.0) to determine the deflection of these specimens under two point load after burned under  (600⁰c) in a tested furnace for four hours. Numerical study by using ANSYS programme is performed to calculate the critical temperature and the  temperature through the  slabs with steel fiber content of (0%,0.2%, and 0.5%). Another six model slabs with steel fiber content of (0.5%) were studied numerically by using ANSYS 7.0 to investigate the effect of arrange of parameters on the fire performance of self- compacted steel fiber reinforced concrete slabs. The main factors that influence the fire resistance of self- compacted steel fiber reinforced concrete slabs are: slab thickness, concrete cover thickness , moisture content. The  experimental results showed that the deflection of burned slab with steel fiber of (0.2%) decreased to 30% than the deflection of burned slab without steel fiber under the same failure load. While the deflection of burned slab with steel fiber of (0.5%) decreased to 50% than the deflection of burned slab without steel fiber under the same failure load. On the other hand , the deflection results were checked with finite elements method by using sophisticated finite element programme (ANSYS 7.0) and it was found that the results were acceptable and the difference was not more than 9%. The results from thermal analysis showed that the temperature decrease with the increase in the concrete depth of the self compacted steel fiber reinforced concrete slabs, while the critical  temperature  for the slabs with steel fiber of (0%,0.2%,0.5%) were (250⁰c, 350⁰c, 580⁰c) respectively. Parametric study results showed that  the slab thickness dose not have significant effect on the fire resistance of the self compacted steel fiber reinforced concrete slabs, while concrete cover thickness has a significant effect on the fire resistance of the self compacted steel fiber reinforced concrete slabs. Fire resistance increases with an increase in the moisture content of the concrete in the slabs.