WO2009071708A1

WO2009071708A1 - Prefabricated structural system for constructing two-way or waffle slabs

Info

Publication number: WO2009071708A1
Application number: PCT/ES2007/000707
Authority: WO
Inventors: Luis Alfredo Rodriguez Tirado
Original assignee: Puentes Y Calzadas Grupo De Empresas, S.A.
Priority date: 2007-12-03
Filing date: 2007-12-03
Publication date: 2009-06-11

Abstract

The invention relates to systems based on using prefabricated concrete slabs (1) containing a built-in reinforcement framework (3) which dispenses with the need for the traditional wood panels used in traditional formwork for waffle slabs, since the prefabricated concrete slabs (1) act as resistant elements and formwork substitutes, defining a fully continuous formwork on the lower surface. As such, the wood panels used as horizontal planar elements in traditional formwork are no longer required. In this way, the prefabricated slabs (1), once on site together with the built-in framework and the corresponding lightening elements or top slabs (6), receive the poured concrete in order to form the corresponding compression layer (7) and structural ribs.

Description

PREFABRICATED STRUCTURAL SYSTEM TO BUILD RETICULAR OR BIDIRECTIONAL FORGINGS

D E S C R I P C I Ó N

OBJECT OF THE INVENTION

The present invention relates to a prefabricated structural system for constructing reticular slabs, based on the use of prefabricated concrete slabs or pre-slabs with lost lightening blocks of high density polymers or other materials, as well as with unidirectional assemblies, serving as self formwork. -portant and with a resistant function in the direction of the floor, simultaneously.

The object of the invention is to achieve a reduction of costs in the construction of reticular slabs, without beams, using prefabricated concrete as a collaborative formwork, as well as improving its mechanical characteristics, operational safety, fire resistance and acoustic insulation.

BACKGROUND OF THE INVENTION

As it is known, the reticular slabs are made based on flat formwork with longitudinal and transverse reinforcements arranged in the ribs that are generated between the corresponding cases or vaults, so that the corresponding concrete that will constitute the concrete will be poured on site. wrought. Logically, the plates that constitute the continuous and uniform base of the entire slab and on which the cases are placed or vaults, are metal or wooden formwork boards that are supported by struts during the period of setting of the concrete, using parallel sops on which the alignments of panels or formwork plates are supported, and whose sops support in turn on strut alignments.

DESCRIPTION OF THE INVENTION

The prefabricated structural system to build reticular slabs that is recommended, has the particularity of not needing to form the entire surface to be built, since it will be enough to place sopandas lines or struts in the area of pillars or other secondary to serve as provisional support to Prefabricated plates as base elements of the system, whose plates incorporate unidirectional reinforcements that have a double function, since they act both as resistant elements and as substitute elements of conventional formwork, when the corresponding face is defined with the total forged with total continuity.

Based on the use of the aforementioned prefabricated concrete slabs, with the unidirectional reinforcement and with the complement of lost lining cases or vaults of high density polymers or other material, the classic panels used in conventional formwork will not be necessary, but that only the sops or similar elements and struts arranged in correspondence with the imaginary joining lines between the slab plates or secondary lines for deformation control will be required, since they have sufficient strength to support the cassettes, that is the elements or blocks lost of high density polymers and the concrete that will fill the nerves or spaces defined between said lost blocks, as well as the one that will constitute the corresponding upper compression layer in which nerves that make up the longitudinal reinforcements are embedded, which are formed by rod trusses that, starting from the classic longitudinal rods, converge superiorly upwards according to an angular arrangement, a longitudinal rod concurring at that vertex or upper reinforcement nerve, which remains, as it was said, embedded in the concrete of the compression layer.

Accordingly, the structural system of the invention starts from a prefabricated element that is the plate, and which is previously designed for the formation of unidirectional slabs, combining in such a way that a high performance reticular slab can be obtained.

The plates that are to constitute the prefabricated structural system of the slab can be of two types, one self-supporting and manufactured on static metal molds, and the other manufactured on tracks with dynamic laying machines or advance molding machines.

In relation to the first type of plate used in the prefabricated structural system of the invention, it will be constituted by a prefabricated concrete pre-slab in which metal reinforcing lattices are located that will serve as a connection between the prefabricated concrete of the pre-slab and the pouring on site as a complement to the system, so that these metal lattices define a lower reinforcement with longitudinal reinforcement of the slab, and an upper reinforcement or stiffening rib of the prefabricated element during its handling and placement, with the particularity that the sections that run diagonally This metal lattice will cover the shear stresses that the concrete is only unable to withstand.

The prefabricated plate referred to will be complemented on site with the corresponding layer of compression and filling of nerves with concrete, once all the necessary reinforcements have been placed according to the calculation for the slab, such as transverse reinforcement of ribs, longitudinal reinforcements if any, connectors, abacus reinforcements, punching reinforcements, reinforcements to shear, upper reinforcements, mesh in compression layer, etc. In addition, the plate is complemented with a reinforcement, being able to define a passive reinforcement or active reinforcement, being necessary to withstand the efforts coming from its own weight, handling, commissioning and design requests of the slab itself, collaborating in it lower than existing lattices.

Finally, the assembly will be complemented with the transverse ribs armed "in situ" and with the spaced placement of the lightening blocks, constitutive of the shells or vaults themselves, as lost elements of the slab itself, which may be of a material such as expanded polystyrene, or any other that serves to lighten the weight of the structure and in turn form the nerves of the reticle.

As for the second type of plate, it will have the same characteristics as the one described above, except for the metal reinforcement lattice, which will instead include one or more central ribs according to the design, with active or passive reinforcement, to stiffening the plate itself during the manipulation process, allowing the transverse reinforcement of the reticular floor to pass through openings or steps arranged and made in the plate manufacturing process itself, also allowing the placement of the longitudinal assembly on site in the nerves formed by the placement of cassettes. DESCRIPTION OF THE DRAWINGS

To complement the description that is being made and in order to help a better understanding of the characteristics of the invention, according to a preferred example of practical implementation thereof, a set of drawings is attached as an integral part of said description. For illustrative purposes and not limitation, the following has been represented:

Figure 1 shows a longitudinal plan view of a first type of prefabricated plate used in the structural system to build reticular slabs according to the object of the invention.

Figure 2.- Shows a cross-sectional view of the plate of the previous figure corresponding to the cutting line A-B of said figure.

Figure 3.- Shows a plan view of a second type of prefabricated plate used in the structural system to build reticular slabs according to the object of the invention.

Figure 4.- Shows a cross-sectional view of the plate of the previous figure, corresponding to the C-D cut line represented in said figure.

Figure 5.- Shows a perspective view corresponding to the part of the second type of plate in which partial holes are made transverse to the nerve or central ribs to allow the transverse reinforcements of the reticular slab to pass through. Figure 6.- Finally, it shows a perspective view corresponding to the part of the second type of plate where total transverse holes are made to the nerve or central ribs to allow the transverse reinforcement of the reticular slab to pass through. In this case the rigidity of the piece for its transport and placement on site is given by the continuity of the upper assembly (active or passive) of the central nerve or nerves.

PREFERRED EMBODIMENT OF THE INVENTION

The prefabricated structural system for constructing reticular slabs object of the invention is based on the use of two types of prefabricated plates, such as those shown in figures 1 and 3, in cross-section in figures 2 and 4, and in perspective in the Figures 5 and 6 respectively, plates that are those referenced with (l) and (l ') and both being constituted from a concrete pre-slab, which corresponds to the reference itself (1) and (T) equipped with a reinforced longitudinal (2) and (2 '), respectively, necessary to withstand the stresses coming from its own weight, handling, commissioning and design requirements of the floor.

The plate (1) includes a reinforcing metal lattice (3) that is placed before concreting the plate itself (I) ₅ serving as a connection between the precast concrete, that is, the one belonging to the plate itself (1) and the pouring into It works as a complement to the structural system, so that the lower reinforcement (4) of this lattice (3) will constitute a longitudinal reinforcement of the slab while the upper assembly (5) of said lattice (3), will define a compression assembly of the prefabricated plate itself, during its manipulation and placement, serving the diagonal sections, that is to say those that converge in that upper cord (5 ), to cover the shear stresses that the concrete is only unable to withstand.

On the prefabricated plate in the manner described, and complemented with the corresponding cases or vaults or lightening elements (6), based on high density polymers or other lost or lightened formwork, you will receive the concrete pouring to constitute the compression layer (7) and filling the nerves themselves, once all the necessary reinforcements are placed.

The plate itself (1) is complemented on site with a transverse reinforcement (8), which may constitute passive or active reinforcement, being necessary to support the efforts coming from its own weight, handling and commissioning, collaborating in that assembly. lower trusses (4) of lattices (3) already commented.

Finally, the prefabricated plate (1) will be complemented with transverse ribs (9) located in the spaces between the lightening cases or vaults (6), so that by those transverse nerves (9) the necessary transverse reinforcement of all the reticular slab, thus generating the bidirectional reinforcement of reticular slabs "in situ".

For its part, the plate (V), in addition to the lower reinforcement (2 '), has one or more central ribs (3') with active or passive reinforcement, in correspondence with which windows or passageways are provided ( 4 ') for transverse reinforcements (8') ₅ complemented with blocks of lightening or vaults (6 '), so that on that prefabricated concrete layer (V) the concrete will be deposited to form the corresponding compression layer (7') and transverse and longitudinal ribs, as concrete filling, which is made on site once all the necessary reinforcements to generate the reticular or bidirectional slab are placed, such as transverse and longitudinal reinforcement, longitudinal reinforcements if any, abacus reinforcements, shear reinforcements, upper reinforcements, compression layer mesh, etc.

According to the characteristics of the plates (1) and (1 '), the construction process of a reticular floor according to the invention does not need to form the entire surface to be constructed, unlike conventional reticular floor slabs where it is necessary to form its entire surface, since according to the invention in the construction system it will be enough to place sopandas or struts lines in the area of pillars and secondary to serve as provisional support to the prefabricated plates (1) or (1 '), which will be self-supporting according to their assembly and length, or they will carry a line of sops half or a third of their length, depending on the case of the calculation, in such a way that this characteristic of the slab itself causes the execution times and costs to decrease to traditional reticular slabs, since overlapping activities on site and in the factory in the execution program of the works.

Once all the prefabricated plates (1) or (V) are placed, as in a traditional floor, the different lower transverse reinforcement will be placed with the remaining ribs when separating the lightening blocks (6 or 6 '), adding also the sharp cuts of the nerves in their encounter with the abacos, reinforcements of abacos, punctures, negatives of the forged, etc. For the formation of the abbots in pillars, the plates (1) or (1 ') will be cut to the size of the pillar, and the dimension of the abacus is achieved by eliminating the lightening blocks (6) or (6') to be able to solidify the area, so that once the slab is fully assembled, concrete will proceed, so that in the case of the plates (V) the lower transverse reinforcement must be sheathed or passed through the openings or gaps (4 ' ) arranged in the central rib or ribs (3 ') that serve as stiffeners for the corresponding prefabricated plate (1').

Once the plates (1) and (1 ') are placed according to project plans, it will be necessary, like all the reinforcements indicated above, to place the connectors (10) whose function is to connect the plates to each other longitudinally at their junction point and to the ends of closing on walls or beams of formation of holes.

The final finish of the reticular or bidirectional slab is in its lower part completely flat, that is to say that it forms a slab of exposed concrete, facilitating the ability to place all types of installations, being significantly improved the capacity of the slab as an insulating element for noise transmission and Fire resistance, comfortably meeting the requirements of the Technical Building Code.

Claims

R E I V I N D I C A C I O N E S

I ^a .- Prefabricated structural system to build reticular or bidirectional slabs, characterized in that it is based on the use of prefabricated concrete slabs (1) or (1 ') that incorporate the corresponding longitudinal lower reinforcements (2) or integrated into them.

(2 '), acting as resistant elements and in turn as substitute elements of the conventional formwork, also incorporating the corresponding lightening elements (6) or (6') on which the corresponding concrete is poured to form the compression layer ( 7) or

(7 ') and the structural nerves of the corresponding reticulated floor.

2 .- prefabricated structural system to build reticular or two - directional forgings according ^to claim I, characterized in that the plates (1) incorporate reinforcing steel trusses (3) with longitudinal lower rods (4) and a top bar and longitudinal (5 ) in each of said lattices (3), complementing on site with transverse ribs armed "in situ" (9) located between the lightening blocks (6) and the corresponding connectors (10).

3 .- prefabricated structural system to build reticular or two - directional forgings according ^to claim I, characterized in that the prefabricated plates (1 ') include one or more central ribs (3') with active or passive armor as well as openings (4 ' ) for the passage of the transverse reinforcement corresponding to the reticular slab itself, completing the rest of the longitudinal ribs with their respective assemblies and the corresponding connectors (10).