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

Abstract

ABSTRACT:- The effect of steel fiber on the deflection of self- compacted slabs underfire (6000c) was investigated in this study. Three specimens were tested experimentally andnumerically ( by using sophisticated finite element programme ANSYS 7.0) to determine thedeflection of these specimens under two point load after burned under (6000c) in a testedfurnace for four hours. Numerical study by using ANSYS programme is performed tocalculate the critical temperature and the temperature through the slabs with steel fibercontent 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 ofparameters 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 reinforcedconcrete 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 failureload. While the deflection of burned slab with steel fiber of (0.5%) decreased to 50% than thedeflection 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 finiteelement programme (ANSYS 7.0) and it was found that the results were acceptable and thedifference was not more than 9%. The results from thermal analysis showed that thetemperature decrease with the increase in the concrete depth of the self compacted steel fiberreinforced 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 onthe fire resistance of the self compacted steel fiber reinforced concrete slabs, while concretecover thickness has a significant effect on the fire resistance of the self compacted steel fiberreinforced concrete slabs. Fire resistance increases with an increase in the moisture content ofthe concrete in the slabs.Keywords: Steel fiber, ANSYS 7.0, Concrete, Fire resistance.