Computer modeling of restrained reinforced concrete slabs in fire conditions

This paper describes the computer modeling of axially restrained, one-way reinforced concrete slabs in fire conditions. The study was carried out for slabs with pin supports and slabs with rotationally restrained supports. A single span, 5 m slab, carrying a uniformly distributed load was analyzed using a special purpose, nonlinear finite element program, SAFIR. The study for pin-supported slabs considered the effects of the position of the thrust force at the supports and different axial restraint stiffnesses. The effects of axial restraint on slabs with rotationally restrained supports were also investigated. The analyses found that the behavior of pin-supported slabs is very sensitive to the position of the thrust force at the end supports and the axial restraint stiffnesses. Slabs with rotationally restrained supports are predicted to have much better fire resistance than equivalent pin-supported slabs due to moment redistribution. The behavior of rotationally restrained slabs in fire conditions is less sensitive to the different axial restraint stiffnesses than pin supported slabs.