Composite Beams with Hollow Core Slabs

Engineer appointed by Gerdau – Brazil

Composite Beams with Hollow Core Slabs

Building use

Office building

Country/Region

Brazil

Overview

To contribute to expanding the knowledge and consolidate the use of composite structures providing guidance on the design of composite beams where steel rolled shapes acts compositely with hollow core precast slabs.

Issue and/or innovation

Composite steel and concrete structures have been increasingly widely used in building constructions in Brazil. Taking advantage of the best characteristics of each material, an adequate interaction between them is provided, in order to obtain high-performance structures.
In these systems, composite beams have already established their use through the interaction of the profile steel with different types of slabs, like solid slabs and composite slab using steel deck, but not yet using precast concrete slabs. The precast concrete slabs are now beginning to be widely used in Brazil.

Technical details

Composite Beams using Precast Concrete Slabs Manual
This publication presents design guidance for the calculation and execution of the steel structure supporting prefabricated hollow core slabs in a composite system, considering two stages, as described below:
• construction stage, when the concrete placed in-situ has not yet cured.
In this situation, the beam works as an isolated steel beam, to support the weight of steel components, hollow core slabs, concrete placed in-situ (including reinforcement), and also a live load of 1.0 kN/m² expected during concreting.
• stage after the curing of concrete placed in-situ.
In this case, the steel beam, attached to a hollow core slab, starts to have a steel-concrete composite behavior, supporting all loads applied before and after curing, including expected live loads.

References / Technical Papers Content

UFRJ – Análise experimental de vigas mistas de aço e concreto compostas por lajes alveolares e perfis laminados, 2016
https://mais.gerdau.com.br/catalogos-e-manuais/viga-mista-com-laje-alveolar