Nonlinear numerical modeling of two-way reinforced concrete slabs subjected to fire

This paper proposes a transient strain model of concrete with a transient modulus under the biaxial stress state and a failure criterion for determining the fire resistance of two-way reinforced concrete slabs. A program was developed to calculate the three-stage response mode and fire resistance of such slabs. Unlike tests and past studies, this program verified the developed constitutive model of concrete and the necessity of including transient strain in the model. The parametric study included in this research further specified the influence of concrete’s thermal strain and steel’s creep strain on the behavior of the slab during fires.

► The transient strain model of concrete under the biaxial stress state is proposed.
► A concept of the transient modulus is put forward.
► A failure criterion for determining the fire resistance of the slab is suggested.
► Three-stage response mode of the slab subjected to fire is revealed and simulated.