08.61: A new approach for the serviceability limit state design of composite steel‐concrete slabs

ABSTRACT Composite floors are a well‐established cost‐efficient and effective form of construction. They combine the advantages of two flooring systems that consist of post‐tensioned slabs in concrete structures and of composite slabs in steel structures. These flooring systems include thin‐walled profiled steel sheeting, non‐prestressed reinforcement, concrete and prestressing strands in post‐tensioned slabs. The particularity of composite slabs rely on the ability of the profiled steel sheeting to act as permanent formwork and, once the concrete has hardened, as external reinforcement. This paper provides a brief overview of a new service model for the design of composite and post‐tensioned steel‐concrete floor systems. The serviceability limit state requirements are important for composite floor applications because they usually represent their governing criteria. The proposed approach focuses on the serviceability limit state requirements associated with deflections and places particular attention on the influence of shrinkage on the overall structural response. Recent research has highlighted the occurrence of a non‐uniform shrinkage profile through the composite slab thickness that originates form the inability of the concrete to dry from its underside due to the presence of the profiled steel sheeting. The proposed procedure is validated against selected experimental results available in the literature for composite and post‐tensioned composite slab samples.