Experimental Study of an Innovative Double-Slab Composite Beam

Composite structures take advantage of the capabilities of the materials forming the structure in order to obtain an optimal solution. Although the concrete slab is usually placed in the compressed part of the structure, reasons linked to fire protection and stiffness enhancement suggest introducing a slab also in the flange under tension. Beams of such type already exist for the field of bridge engineering under the name of “Preflex Beams”; in this solution the lower slab is often prestressed with tendons or wires. In the paper a new type of slim floor beam composite with two slabs is presented. The key features of this solution are: ease of production, support of the precast floor panels, fire protection of the beam and reduced service deflection. In this first study, six experimental tests are presented and discussed allowing to evaluate the structural effectiveness of the proposed solution. By this way, the design criteria are established and some hints obtained, in order to bring the idea to the industrial development.