Contribution to the Numerical Modelling of the Spalling Phenomenon: Case of a Reinforced Concrete Beams

The paper presents a numerical study of reinforced concrete (RC) beams in fire, in which spalling is taken into account in a simplified manner and its effects on the structural response are investigated. Finite element simulations are conducted using the software SAFIR. The criteria to determine the onset of spalling are the temperature reached in the finite element: concrete layers are removed when their temperature reaches 400 ∘ C . The effect of spalling on the temperature distribution inside the beam section and on the time of failure is discussed. Different configurations are studied, in terms of extent of spalling along the beam and type of supports. Further, it is also shown that the extent of spalling has significant influence on the fire resistance of RC beams and that this is by reducing the failure time and/or by reducing the yield strength and tangent modulus.