Precast concrete products for slabs and floor systems

Hollow core slabs (UNE-EN 1168): A monolithic element, generally prestressed, with a constant overall depth, divided into an upper and lower flange (called wings), linked by vertical webs, so constituting cores as longitudinal voids in the cross-section, which is constant and presents one vertical symmetrical axis. The elements are produced in the factory by extrusion, sliding formwork or moulding. During the production phase or later, accessory plates (narrow plate elements) and hollows can be made to the hollow core plates.

Solid slabs: Surface elements of reinforced and/or prestressed concrete without any lightening, which are used in slabs, balcony formation, etc. Manufacturers adapt the elements to the mechanical and geometric requirements of the slab or roof. With tongue and groove profile on both sides, to allow the fitting of some pieces into others. They can be completed on site with a layer of concrete in situ and/or with the final surface finish (wood laminate, paint, etc.).

Reinforced concrete beams for beam-and-block floor systems (UNE-EN 15037-1): A structural linear element with a small cross-section, made of reinforced concrete, which is placed next to pieces of interbeam (blocks) to form, together with the concrete and the reinforcements placed in situ, a composite slab. In this type of beams, only the lower shoe, on which the basic electrowelded lattice reinforcement will be anchored, is precast in concrete.

Prestressed concrete beams for beam-and-block floor systems (UNE-EN 15037-1): A linear structural element with a small cross-section, made of prestressed concrete, which is placed next to interbeam pieces (blocks) to form, together with the concrete and the reinforcements placed in situ, a composite slab. Two types of prestressed beams can be differentiated: self-resistant and half-resistant. Self-resistant (or self-supporting): the one that, without propping up, is capable of supporting its own weight, that of the block and that of the compression layer. They are beams with a higher degree of industrialization, which are also reinforced at the top. Half-resistant: This type of beam behaves in a more monolithic way in the slab as a whole, since the concrete of the compression layer bonds well and forms a body with the beam, through the connectors that favor this adhesion.

Reinforced concrete floor plates for floor systems (UNE-EN 13747): Surface precast element composed of a lower sheet of concrete of constant thickness and ribs in the longitudinal direction of the same, intended to serve as formwork for the slab that will later be concreted in situ. The ribs are usually basic electrowelded trusses in latticework, generally in the longitudinal direction to provide strength and rigidity in transitory situations. Once the concrete has hardened, it will form the composite slab with the floor plate. 

Prestressed concrete floor plates for floor systems (UNE-EN 13747): Surface precast element composed of a lower sheet of concrete of constant thickness and ribs in the longitudinal direction of the same, intended to serve as formwork for the slab that will later be concreted in situ. The slab usually has two or more continuous stiffening ribs, usually in the longitudinal direction to provide strength and rigidity in transient situations.

Ribbed floor elements (UNE-EN 13224): They are composed of an upper plate and a nerve (in "T") or usually two nerves that contain the main longitudinal reinforcement. They may also consist of a lower plate and transverse nerves. Applicable in those spaces where it is necessary to reach relatively important spans. It can be laid with and without concrete slab in situ.

Other elements for slabs : Any other precast concrete element used for the design and construction of building slabs, which does not fall within the above definitions.