The partial encasement of the steel beam in the concrete slab, as occurs on the slim floor constructional system, provides thermal protection which improves the behavior of the beam when exposed to fire. In order to evaluate the thermal and structural performance of the slim floor system, numerical models considering partially encased beams were developed using the FEM-based computational code DIANA. With respect to the constitutive models of the materials, it wasn't possible to represent the formulation presented in EUROCODE 4 or ABNT NBR 14323:2013, being replaced by alternative models. Numeric models were created at room and elevated temperature, which used some of the available options for the constitutive models of concrete and steel. Also, some parameters were analyzed such as: (a) the interaction rate between the steel and concrete and (b) the optimal combination of the thermal parameters, in order to obtain a more realistic response of the slim floor beams in fire.
termostructural analysis; slim floor; partially encased beams; fire
