Post-fire performance of closed profiled steel deck composite slabs with recycled aggregate concrete

In this work, the post-fire performance of closed profiled steel deck composite slab made of recycled aggregate concrete, referred to as the “RAC-CPSD slab”, was investigated. The slab was firstly subjected to ISO 834 fire curve for 90 min, and then residual loading tests were conducted after cooling down. The temperature developments within the slab during the heating and cooling stages were measured, while the failure pattern, load-deflection response, and the strains of concrete and steel deck after fire exposure were obtained. Test results showed that RAC slab experienced lower temperatures within both the concrete and the rib compared to normal concrete slab. All slabs, regardless of fire exposure, failed due to bending. Then, the finite element (FE) models, including both the heat transfer analysis and mechanical analysis, were established and were validated against the experimental results. A parametric investigation was performed to assess the effects of fire duration, replacement level of coarse recycled aggregate, rib height, steel deck thickness, heating curve and cooling method on the residual resistance of the composite slab. Finally, practical equations for predicting the residual resistance of RAC-CPSD slab exposed to fire were proposed.