WO2013044340A1

WO2013044340A1 - Joist and precast slab for concrete slabs and method for building slabs comprising the same

Info

Publication number: WO2013044340A1
Application number: PCT/BR2012/000379
Authority: WO
Inventors: Fernanda Virginia GOZZO; Gerson GASPERETTI
Original assignee: Gozzo Fernanda Virginia; Gasperetti Gerson
Priority date: 2011-09-28
Filing date: 2012-09-28
Publication date: 2013-04-04
Also published as: BR112014007542A2

Abstract

A joist and a precast slab for concrete slabs and a method for building slabs comprising the same are disclosed. A joist (V) comprises a conduit (1), at least two joining elements (2) and at least one metallic structure (3), wherein the joining elements (2) can be coupled both to the conduit (1) and to the metallic structure (3), the joist (V) being characterised in that it comprises fastening means (61 and 62) located in the conduit (1) and in the joining elements (2), respectively, and in that the joining element (2) comprises at least two coupling means (52) for coupling the joining element (2) to the metallic structure (3). The structural principles and functions of the present invention have uses in the field of trussed joists and precast slabs, in particular trussed concrete joists and precast slabs for use in building concrete slabs in the civil engineering industry.

Description

VIGOTA AND PRE-SLAB FOR CONCRETE SLABS AND SLAB CONSTRUCTION PROCESS UNDERSTANDING THE SAME

Inventors: Fernanda Vigínia Gozzo, Gerson Gasperetti Technical Sector

The design principles and functionalities found in the present invention are applicable to the lattice-beam and pre-slab sector, particularly the lattice-beam and pre-slab concrete intended for use in the construction of concrete slabs in the construction industry. Description of the prior art

The construction industry employs in certain situations concrete elements comprising metal frames, also known as reinforced concrete elements. In this sense, there are some reinforced concrete elements that are previously built to be later commercialized and used in constructions, examples of these elements are the poles used in electrical distribution lines, the pillars and precast structural beams, among other elements.

Previously constructed reinforced concrete elements have a number of advantages over those constructed on site, among the most well-known advantages being easier to fill the molds with concrete, resulting in more homogeneous and uniform reinforced concrete elements, especially regarding the Proper concrete cladding around the metal structure. A reinforced concrete element must always coat its metal structure in order to protect it from moisture. However, the previously obtained reinforced concrete elements have disadvantages related to transportation compared to those elements built on site; elements may break during road transport and need to be lifted by specialized machines when installed on higher floors of buildings.

Lattice concrete slabs comprise pre-cast elements, such slabs may comprise pre-cast joists or pre-cast slabs, both comprising a metal structural member, generally metal lattices.

Said lattice pre-slabs have a transverse width ranging from 15 to 80 cm, lattice pre-slabs differ from said lattice joists in being larger, supporting greater overloads and comprising higher lattices. Typically, but not exclusively, lattice slabs are applied to concrete slabs that have large free spans (i.e., greater distance between the supporting elements such as pillars) and greater overhead.

Said lattice concrete slabs comprising the use of lattice pre-slabs are obtained by a process comprising the following steps: first the lattice pre-slabs are aligned side by side without spacing to form a plane without openings. ; later the volumes found between the lattices of each lattice pre-slab are filled by plates of ceramic or polymeric material, so that the lattice pre-slabs and the plates form a volume composed of a plane and a thickness composed by the thickness of the concrete. pre-slabs, metal trusses and slabs; finally the slab is completed by pouring concrete over said volume, the concrete is poured in order to fill both gaps between the pre-slabs, metal trusses and the plates, and to cover and coat the entire metal truss, resulting in said volume becomes thicker by the addition of poured concrete.

Said lattice concrete slabs comprising the use of lattice joists are obtained by a process similar to the concrete slabs comprising joists, the difference between them is the separation between the joists (or pre-slabs) and the geometry of said plates: slabs comprising studs have a separation between the studs greater than the separation between the slabs of a slab comprising pre-slabs.

Figure 1-A illustrates a reinforced concrete slab comprising lattice pre-slabs. Figure 1-B illustrates a reinforced concrete slab comprising latticed joists.

It is necessary to clarify that the plane formed by the pre-molded lattice slabs and the ceramic elements must resist not only the weight of the poured concrete on the plane formed by them, as well as all the dynamic and static loads associated with the concrete pouring and the workers passing over the plane at the time of distribution of poured concrete, usually done manually by means of "squeegees". The same applies to the plane formed by the latticed joists and the ceramic elements.

In the construction of reinforced concrete slabs, the use of pre-molded pre-slabs or lattice joists has the advantage of allowing the construction of said plan able to receive the poured concrete, because they are rigid and withstand the dynamic loads associated with the process of reinforcement. pouring of concrete and the movement of workers on them. However, its use has disadvantages associated with transportation and, due to the difficulty of lifting the slabs to the higher floors. Another disadvantage is that these lattice concrete slabs do not have a homogeneous cure due to the fact that the lattice concrete slabs are cured before the poured concrete, so that the resulting slab does not have homogeneously cured and bonded concrete. , and lattice slabs may move relative to each other as loads are applied to the resulting lattice concrete slab.

Therefore, a pre-slab or lattice deck that can be constructed on the site of the concrete slab, and is capable of withstanding the forces static and dynamic conditions associated with the installation of bulky slabs and the concrete pouring process.

It is also necessary a process of construction of concrete slabs that do not require road transportation of pre-molded lattice slabs or trusses, as well as the stages of their lifting.

A concrete slab construction process that results in a lattice concrete slab where all the concrete undergoes the curing process simultaneously, resulting in a unique concrete volume, is also required.

The following describes some known solutions in the prior art for the purpose of obtaining a lattice concrete structure constructed at the site of forming the concrete slab, in order to avoid the manipulation of precast lattice slabs and the problems of curing homogeneity of the concrete. concrete:

Document PI0803964-0 discloses a beam obtained by a channel coupled to a steel lattice structure. According to his teachings, this canopy can be built at the construction site of the lattice concrete slab, because the metal structure remains affixed directly next to the channel. The deck described therein may, together with at least one other deck, be employed in forming a plan by including ceramic plates arranged between the studs, and this plan may receive a concrete spill so that the poured concrete fills the channels and cover said plan; to result in a concrete slab. The technique described therein represents an advance towards the construction of the joists at the desired concrete slab site, however, according to said technique the perfect coating of the metal structure by the concrete is impaired by the large part of the structure directly attached to the channel. Another undesirable aspect of such a solution is that the configuration represented does not have the necessary resistance to static and dynamic stresses associated with concrete pouring. It is important to note that lattice joists and lattice pre-slabs have virtually the same function, they differ by the type of lattice concrete slab they are intended for; Lattice joists are generally used to obtain lighter concrete slabs of lower mechanical strength than concrete slabs obtained through lattice pre-slabs. In this sense, we refer to the commercial catalog of ribbed trusses used to obtain pre-molded lattice joists and pre-slabs available through the website.

http://www.belqo.com.br/produtos/civil construction / ribbed truss / pdf / ribbed truss.pdf. all of the information described therein being an integral part of this patent application. Lattice joists generally comprise lattice trusses smaller than those of lattice pre-slabs, another difference being their geometries; the joists have a smaller cross-sectional dimension (i.e.; narrower) than the pre-slabs, so that the pre-slabs remain in contact, side by side, when arranged in parallel while obtaining the lattice concrete slab.

Therefore, it remains deficient in the state of the art a pre-slab or deck that can be constructed at the site of formation of the concrete slab, which allows the concrete structure to cover the concrete and that resists the static and dynamic stresses associated with the installation of the ceramic elements or polymers and the concrete pouring process. Also deficient in the state of the art is a method of constructing concrete slabs comprising pre-slabs or lattice joists constructed at the concrete slab forming site that allows the metal structure to coat the concrete and resist the static and dynamic stresses associated with the installation of the slabs. ceramic elements and the pouring process of concrete.

Objectives of the present invention

It is an object of the present invention to provide a preform (P) and a lattice (V) truss that can be constructed at the site of formation of the concrete slab, allowing the coating the metal structure by the concrete and resisting the static and dynamic efforts associated with the installation of the ceramic elements and the concrete pouring process. The lattice pre-slab (P) or beam (V) is obtained by means of a channel, a metal structure and a joining element having the purpose of joining the metal structure to said channel.

Also object of the present invention is a method of obtaining concrete slabs comprising the steps of joining the channel to the joining element, fixing the metal frame to the joining element, installing at least two assemblies comprising the channel, the joining element. and the metal lattice at the site of forming the concrete slab so as to obtain a plan capable of receiving a concrete spill.

Description of the figures

Figure 1-A: Illustrates a state-of-the-art reinforced concrete slab, where we can see the side-by-side lattice slabs, slabs for occupying the concrete volume, complementary metal structures and subsequently poured concrete.

Figure 1-B: Illustrates a state-of-the-art reinforced concrete slab, where we can see the lattice joints arranged side by side, ceramic slabs in order to join the joists occupy the volume and form a plan to receive concrete, complementary metal structures and the concrete subsequently poured.

Figure 2: Represents a profile view of a channel (1) obtained in accordance with the present invention for obtaining a pre-slab (P);

Figure 3: Represents a profile view of a joint element (2) obtained in accordance with the present invention for obtaining a pre-slab (P);

Figure 4: Represents a profile view of a lattice pre-slab (P) obtained in accordance with the present invention to describe the coupling a connecting element (2) with the channel (1) and the metal frame (3); Figure 5: Represents a top view of a joint element (2); Figure 6: Represents a top view of a segment of a channel.

(1 ); Figure 7: Represents a top view of a coupling element (2) transversely positioned in its installation position before rotating to the coupling next to the channel (1);

Figure 8: Represents a top view of a coupling element (2) coupled to the channel (1); Figure 9: Illustrates details of possible coupling means between the sides of the channels (1);

Figure 10: Illustrates a set of pre-slabs (P) fitted before the concrete pouring step in the process of obtaining a lattice concrete slab; Figure 11: Represents a profile view of a channel (1) obtained in accordance with the present invention for obtaining a stud (V);

Figure 12: Represents a profile view of a joint element (2) obtained in accordance with the present invention for obtaining a stud (V);

Figure 13: Represents a profile view of another coupling element (2) obtained in accordance with the present invention for obtaining a stud (V);

Figure 14: A profile view of a latticed beam (V) obtained in accordance with the present invention, depicting the coupling of a connecting element (2) with the channel (1) and the metal frame (3). ;

Figure 15: Represents the arrangements related to a single beam test (V) constructed in accordance with the present invention. Detailed Description of the Present Invention

A latticed pre-slab (P) or beam (V) designed in accordance with the teachings of the present invention comprises a channel (1), at least two joining elements (2) and at least one metal frame (3); (2) being able to couple both the channel (1) as well as the metal structure (3).

Also object of the present invention is a latticed pre-slab (P) or stud (V) where the coupling means (2) have coupling means (52) comprising extended elements (98). It is a latticed pre-slab (P) or beam (V) where the extended elements (98) have curved terminals (99).

Still in accordance with the principles of the present invention, the joining elements (2) have fixing means (62) and coupling means (52), for joining together with the channel (1) and the metal frame (3) respectively. A method of obtaining truss concrete slabs comprising a sequence of steps and truss pre-slabs (P) or studs (V) is also an object of the present invention.

According to figure 2, the channel (1) has a profile, an outer surface (11) and an inner surface (10); its profile includes segments defining its contour as the base segment (112), the two vertical segments (111), and the horizontal segments (110) parallel to the base segment (112). The horizontal segments (110) protrude from the vertical segment (111) towards the opposite segment (110), so that the channel in its three-dimensionality has tabs (113). The flaps (113) on their inner surface (10) have fastening means

(61) for cooperating with securing means (62) located on the coupling element (2) so as to join the channel (1) to the coupling elements (2). The channels (1) may be made of various materials, preferably they are made of polymeric materials due to their low density and the resulting low weight of the channel (1). Most preferably, channel (1) is comprised of polymers selected from polypropylene, polystyrene and polyethylene. Due to their constant profile, the channels (1) can be easily obtained by extrusion processes, however injection and rotational molding processes can also be employed.

As shown in figures 3 and 4, we observe that the joining elements (2) are three-dimensional objects having part of their outer surface (20) facing the inner surface (10) of the tabs (113) present in the channel (1). We further observe that the channel (1) and the joining elements (2) fit together by the fact that the channel (1) surrounds at least partially the joining elements (2) and the securing means (61, 62) located respectively in the channel (1) and the connecting elements (2). As shown in Figures 3 and 4, we observe that the securing means (62) are located to face the securing means (6) located on the inner surface of the tab (111).

The connecting elements (2) are preferably made of polymeric materials due to their density and low weight resulting from the element. Due to its complex geometry, its manufacture is preferably obtained by the injection process, however the stamping and extrusion processes could also be employed in its manufacture. Even more preferably, the connecting element (2) is made of molded injected polypropylene. Preferably the securing means (62) are recesses for cooperating with the channel securing means (61) where said cooperation is by means of male-female type engagement. Still preferably, but not necessarily, the securing means (62) are female recesses and the securing means (61) are protruding. Alternatively, the male-female type cooperating system 61, 62 comprises a degree of dimensional interference (for example, if the male volume dimensions are larger than the female volume dimensions). to provide greater resistance to the disintegration of the fixture. Alternatively, the male volume may exhibit some dimensional variation intended to cooperate with a corresponding dimensional variation found in the female volume to provide greater resistance to dismemberment of the fixation.

It is important to note with respect to the positioning of the fasteners (61, 62), close to the inner surface (10) of the channel flaps (113) and to the surface (20) of the coupling element (2), respectively, that these positions were observed. as ideal for the lattice pre-slab (P) of the present invention to withstand the static and dynamic loads by keeping the channel (1), the joining elements (2) and the metal frame (3) in their locking configuration during pouring and curing the concrete.

Alternatively, the channel (1) and the coupling elements (2) may be coupled by lower central coupling means comprising at least one coupling means (71) and at least one coupling means (72). Coupling means (71) having a profile in the shape of the letter "L", and coupling means (72) having a profile in the shape of the letter "L", but upside down. The coupling means (71) is located on the surface (10) of the channel (1) and the coupling means (72) located on the coupling element (2) in its opposite position to the coupling element (71).

It was observed that the essentially "L""profile" shape would be the most suitable for obtaining said lower central coupling, since during the process of assembling the latticed pre-slab (P) the joining elements (2 ) the installation position is transverse into the channel so that the user must turn the coupling element clockwise (or counterclockwise, depending on the orientation of the coupling means (71, 72) such that the element (61) can be fitted to the respective element (62) and the coupling means (71) to their respective coupling means (72).

Alternatively, the coupling elements (2) may also have guiding means (92) to indicate to the user which direction of rotation should be employed to the coupling element (2) for proper coupling between the coupling means. coupling (71, 72). In this sense, Fig. 7 shows said guiding means (92) in the form of arrows, which could be by painting, embossing or any other known inscription means.

As shown in Figure 3, while in the assembled configuration, the latticed pre-slab (P) having the lower central coupling comprises each coupling means (71, 72) cooperating so that the respective base of the letter "L" remains attached to another, to prevent the segment (112) of the channel (1) from deforming with the weight of the concrete to be poured. In this sense, preferably, the joining element (71) should be located as close as possible to the center of segment (112), where the greatest stresses occur due to the weight of the poured concrete.

Preferably said lower central coupling is comprised of a single pair of coupling means (71, 72), however one skilled in the art could employ more than one pair of coupling means (71, 72). The coupling element (2) has coupling means (52) for engaging part of the metal frame (3) to provide the coupling of the metal frame (3) to the coupling element (2). In this regard, as shown in figures 3, 4, 10 and 11, the coupling means (52) are essentially circular interior cavities so as to surround the generally circular cross sections of the metal structures. However, other geometric shapes could be employed to obtain the coupling means 52, other than necessarily the shapes shown in the figure. Coupling means (52) further comprise elongate members (98), elongate members (98) have a cooperating geometry for securing the metal structure (3) to the joining member (2) when the truss (P) or lattice (V) of the present invention is subjected to static loads. and dynamics associated with concrete pouring and worker movement.

Preferably, the elongate elements (98) comprise curved terminals (99), said curved terminals (99) have the purpose of keeping the metal structure (3) engaged in the coupling means (52) even though said static and dynamic loads result in some deformation of the elongate element (98).

More preferably, the elongate members (98) have "hook" shaped curved terminals (99), where the curvature of the curved terminal (99) has a radius of curvature close to half the diameter of the metal frame (3) which will be joined to the coupling means (52). Variations between the radius of curvature and half of the diameter of the metal structure to be coupled to the joint (2) may vary by a maximum of 100%.

Figure 13 illustrates the profile of a coupling member (2) sized for a stud (V) where coupling means (52) have elongate members (98) and curved terminals (99) with a radius of curvature similar to half the diameter. of the metal frame (3) which will be attached to the coupling means (52).

The use of curved terminals (99) has the advantage of reducing the required length of the respective extended element (98); It has been observed that the extended elements must be longer if they do not have curved terminals (99) to keep the metal frame (3) engaged in the coupling means (52) even if the static and dynamic loads result in some deflection of the elongated element (98). ). It is important to note that the shorter the elongate elements (98) of the joining elements (2) the less deformation will be required to fit the metal frame (3) into the coupling means (52) of the joining elements (2).

The metal frame (3) may be constructed on site or a commercially available ribbed truss may be employed, such as models TB8L, TB8M, TB12, TB12R, TB16L, TB16L, TB20R, TB25M, TB25R, TB30M, TR30R TR-8644 or TR-12645 sold by Belgo-Arcelor itttal Long Steel (www.arcelormittal.com/br).

The latticed pre-slab (P) or beam (V) of the present invention is assembled from a sequence of fittings, where first the joining elements (2) are fitted next to the channel (1) by means of cooperation between the elements. (61, 62), respectively located in the groove (1) and the joining elements (2), the smaller the separation between the joining elements (2) fitted along the longitudinal length of the groove, the greater the resistance static and dynamic concrete pouring efforts. Once fitted, the groove (1) and the joining elements (2) will be joined to the metal frame (3) by fitting the metal frame (3) to the fasteners (52) present on the joining elements (2), For this purpose, a small manually applied force is required to bring the lower members of the metal frame (3) closer together so that they have a relative distance smaller than the distance between the terminals (99) once the manually applied force is released. lower parts of the metal frame (3) fit into the coupling means (52). In this configuration, the lattice pre-slab (P) will have the structural stiffness required to be employed in the construction of lattice concrete slabs. Alternatively, the mounting of the lattice pre-slab (P) or stud (V) of the present invention may include the coupling step between the coupling means (71, 72), respectively located on the channel (1) and the coupling element ( 2), this coupling aims to increase the structural stiffness of the latticed pre-slab (P) or stud (V), particularly the coupling between the connecting element (2) and the channel (1).

Alternatively still, the latticed pre-slab (P) or beam (V) of the present invention is assembled from a sequence of fittings, wherein first the joining elements (2) are fitted together with the channel (1) by means of cooperation between the fastening elements (61) and (62), located respectively in the groove (1) and the connecting elements (2), and the lower central coupling comprised by the coupling of the elements (71) and (72), the smaller the The separation between the joining elements (2) fitted along the longitudinal length of the channel, the greater the resistance to static and dynamic stresses related to concrete pouring. Once fitted, the channel (1) and the joining elements (2) will be joined to the metal frame (3) by fitting part of the metal frame (3) to the fasteners (52) present on the joining elements (2). ). In this configuration, the lattice pre-slab (P) will have the structural stiffness required to be employed in the construction of lattice concrete slabs.

Also alternatively, the latticed pre-slab (P) or beam (V) of the present invention may further comprise additional structural members (4), in addition to the metal frame (3), additional structural members (4) may be provided in In the form of thin and long structures, gravity deposited on the flat upper part of the coupling elements (2), preferably the flat upper part of the coupling element (2) has one or more recesses (82) for receiving and disposing in parallel. to the longitudinal axis of the pre-slab (P) or lattice (V) the additional structural members (4). In this sense, Figure 4 presents three recesses (82). In the case of a pre-slab (P), the channel (1), as shown in Figure 9, the channel (1) has at least one coupling element (101) or (102) in its vertical segments (111). ), such that the element (101) or (102) will couple to the respective coupling element (102) or (101) so as to enable the lateral union of the slabs (P) of the present invention. Said The lateral joint, by coupling the elements (101) and (102), contributes to the rigidity and mechanical strength of the structural plane formed by a set of laterally arranged pre-slabs (P).

Preferably the coupling means (102) are recesses intended to cooperate with the channel coupling means (101) where said cooperation is by means of male-female type engagement. Still preferably, but not necessarily, the coupling means (102) are female recesses and the coupling means (101) are male protrusions. Alternatively, the coupling system between male-female type fasteners 101 and 102 comprises a certain degree of dimensional interference (for example, if the dimensions of the male volume are greater than the dimensions of the female volume). ) in order to provide a greater resistance to the disintegration of the fixture. Alternatively, the male volume may exhibit some dimensional variation, intended to cooperate with a corresponding dimensional variation found in the female volume, in order to provide greater resistance to attachment dismemberment. Figure 9 of the present patent application by examples a, b, c and d illustrate some possible embodiments for the coupling elements (101, 102). However, one skilled in the art may draw upon the teachings described herein and perform other forms of coupling in accordance with the same teachings.

The method of constructing reinforced concrete slabs, including the latticed pre-slabs (P) of the present invention comprises the steps of: assembling lattice pre-slabs (P) by engaging at least two joining elements (2) in their respective positions next to the channel (1) by means of cooperation between fittings (61, 62) and the subsequent fit of the metal frame (3) next to the joining elements (2), by means of coupling elements (52) comprising extended element (98) and curved terminals (98); arranging at least two parallel and laterally latticed pre-slabs (P) by coupling at least one pair of joining elements (101, 102) so as to form a structural plane rigid enough to receive a certain amount of poured concrete; It is the pouring of concrete to fill the voids between the metal frame (3), the joining elements (2) and the channel (1), to result in a reinforced concrete slab. The method of constructing reinforced concrete slabs, including the latticed joists (V) of the present invention comprises the steps of: assembling latticed joists (V) by engaging at least two joining elements (2) in their respective positions. next to the channel (1) by means of the cooperation between fittings (61, 62) and the subsequent fit of the metal frame (3) next to the joining elements (2), by means of the coupling elements (52) comprising an extended element ( 98) and curved terminals (98); the arrangement of at least two parallel lattice (V) lattices and partially overlapping slabs (V), where latticed lattice (V) and slabs form a structural plane rigid enough to receive a certain amount of poured concrete; and pouring concrete to fill the voids between the metal frame (3), the joining elements (2) and the channel (1) to result in a reinforced concrete slab.

Alternatively, the slab construction process according to the present invention further comprises slabs (5) positioned between the lattice structures so as to partially occupy the space occupied by the poured concrete in order to decrease the total weight of the constructed slab. Since slabs (5) are essentially bulky elements that are less dense than concrete, the mechanical strength of the slab is mainly attributed to the metal structure. Thus, the materials employed in obtaining the plates (5) are typically polymeric, ceramic and preferably closed-cell expanded polymers such as expanded polystyrene, i.e.; Styrofoam.

Alternatively, the slab construction process comprises the fact that the coupling element (2) is coupled to the channel (1) by rotation to provide coupling between the coupling means (71, 72). As described above, the slabs (5) are essentially bulky elements less dense than concrete that aim to reduce the total weight of the lattice concrete slab, the mechanical strength of the slab being mainly attributed to the metal structure. Thus, the materials employed in obtaining the slabs (5) are typically polymeric, ceramic and preferably closed cell expanded polymers such as expanded polystyrene, ie; Styrofoam.

Three specimens of lattice stud (V) obtained according to the teachings of the present invention were constructed and tested as follows: The channel (1) is made of PSA (high impact polystyrene) and obtained by the extrusion process, the joining elements (2) consisting of PP (polypropylene) and obtained by the injection process and the metal structure (3) being a ribbed lattice with a height of 8 cm, a superior wire with a diameter of 6 mm, a diagonal wire with a diameter of 4.2 mm and a wire lower diameter 4.2mm sold under reference TB 8L, designation TR-8644 sold by Belgo-Arcelormittal; the channel (1) having a longitudinal length of 2.2 m, a horizontal segment (112), vertical segments (111) and flaps (110), male-type fixing means (61) and a coupling element (71); the coupling element (2) having female-type securing means (62) cooperating with the elements (61), a coupling element (72) oriented opposite the coupling element (71) so that coupling occurs, three recesses (82) for receiving and disposing parallel to the longitudinal axis of the lattice pre-slab (P) the additional structural elements (4), and coupling means (52) having an extended element (98) and a curved terminal ( 99); the channel (1), showing the coupling elements (2) coupled to the channel, the additional structural elements (4) deposited in the recesses (82) and the metal frame (3) coupled to the coupling elements (2) by means of couplings (52).

The joists (V) were tested according to the arrangement described by illustrations in figure 15 by the following configuration:

> Two specimens with a total length of 220 cm were positioned on two movable supports 40 cm from the ends to have a theoretical span of 140 cm.

> Three ceramic filling blocks were placed between specimens, one in the middle of the gap and another two near the supports.

) Loading was applied by means of a hydraulic cylinder to the ceramic block in the middle of the gap, at a distance of 2.5 cm from the edge of the ceramic block.

) Vertical displacements were measured by displacement transducers in the mid-span of the two specimens.

> Loading speed was 50 Kgf per minute, and simultaneous recording of force and displacements was performed by the data acquisition system at the rate of one per second.

> Three specimens were tested.

The equipment used in the test were:

- Reaction structure composed of reinforced concrete slab, metal gantries, support devices and other accessories;

- Single acting hydraulic cylinder, capacity 250 KN, stroke 150 mm, Enerpac brand, model RC256, for force application;

- Manual hydraulic pump, pressure capacity 70 Mpa, Enerpac brand, model P-462, to drive the hydraulic cylinder;

- Load cell, capacity 500 Kgf, Shinkoh brand, model LC-500KA, for applied force measurement;

- Kyowa brand 50 mm and 100 mm travel resistive transducers, DT-50A and DT-100A, for measuring linear displacements;

- Data acquisition system, brand Vishay icro-Measurements, System 5000, for recording the measurements indicated by the load cell and the displacement resistive transducers.

The results of the three tests showed that the joists (V) withstood a force greater than 80 Kgf before suffering any damage. It is important to note that the example described above allows for the homogeneous coating of the metal structure by concrete, in order to meet the normative requirements set by the Brazilian Association of Technical Standards - ABNT.

An example of a concrete slab construction process comprising lattice pre-slabs (P) according to the present invention comprises the following steps:

Assembly of lattice pre-slabs (P) comprising the channel (1) consisting of PSA (high impact polystyrene) and obtained by the extrusion process, the joining elements (2) consisting of PP (polypropylene) and obtained by the process injection and the metal structure (3) being a 200 mm high ribbed lattice, model TB 20L sold by Arcelormittal; the channel (1) having a longitudinal length of 10 m, a horizontal segment (112) of 200 mm in length and 2 mm in thickness, the vertical segments (111) being 35 mm in length and 4 mm in thickness and the tabs ( 110) having 80 mm in length and 2 mm in thickness, the male-type fixing means (61) and a coupling element (71); the coupling element (2) having female-type securing means (62) cooperating with the elements (61), a coupling element (72) oriented opposite the coupling element (71) so that coupling occurs, three recesses (82) for receiving and disposing parallel to the longitudinal axis of the lattice pre-slab (P) the additional structural members (4), three structural members (4) made of steel and having a diameter of 4 mm and coupling (52) having an internal diameter of 5.5 mm, an extended member (98) and a curved terminal (99) having a radius curvature of 2.2 mm; the channel (1) having the coupling elements (2) coupled to the channel and distributed every 200 mm along the length of the channel (1), the additional structural elements (4) deposited in the recesses (82) and the metal structure (3) coupled to the coupling elements (2) by means of couplings (52); arrange in parallel the laterally latticed pre-slabs (P); arrange slabs (5) made of expanded polystyrene along the volumes located between the metal structures (3) and the subsequent concrete pouring to fill the voids between the metal structure (3), the joining elements (2) and the channel (1) so as to result in a concrete slab.

Finally we note that the pre-slab (P) or beam (V) objects of the present invention, the method of obtaining a concrete slab comprising it, and its alternative embodiments do not exhaust the possible executions made in accordance with the teachings, so that other embodiments and variations may be performed in accordance with the teachings of the present invention.

Claims

Inventors: Fernanda Vigínia Gozzo, Gerson Gasperetti

1: Truss (V) comprising a channel (1), at least two coupling elements (2) and at least one metal frame (3), the coupling elements (2) being able to couple both channel (1) ) as well as the metal structure (3) comprising the securing means (61) and (62) located respectively in the channel (1) and the coupling elements (2), and the coupling element (2) comprising at least two coupling means (52) for providing coupling between the coupling element (2) and the metal frame (3).

Truss (V) as described in claim 1, characterized in that the coupling means (61) are located on the inner surface (10) of the tabs (113) and the coupling means (62) are located opposite the respective elements. (61) so as to offer greater mechanical resistance to the beam (V).

Truss (V) as described in the preceding claims, characterized in that the coupling means (61) are essentially protruding and the coupling means (62) are essentially recessed to provide a "male-female" coupling.

A beam (V) as described in the preceding claims characterized in that the coupling means (61) and (62) provide a "male-female" type coupling comprising a certain degree of dimensional interference so as to provide greater resistance to disassembly of the coupling.

Overhead (V) as described in the preceding claims, characterized in that the coupling means (61) and (62) provide a coupling of the type "male-female" and the coupling medium volume (61) have some dimensional variation intended to cooperate with a corresponding dimensional variation found in the coupling medium volume (62) so as to provide greater resistance to coupling dismemberment. Rail (V) as described in the preceding claims, characterized in that the joining elements (2) comprise at least one recess (82) for receiving and disposing parallel to the longitudinal axis of the rail (V) the additional structural elements (4). ).

A beam (V) as described in the preceding claims, characterized in that the elongate elements (98) and the coupling elements (2) comprise curved terminals (99) for the purpose of cooperating in the maintenance of the metal structure (3) fixed to the position engaged in the coupling means (52) even though said static and dynamic loads result in some deformation of the elongate element (98). A beam (V) as described in the preceding claims, characterized in that the channel (1) and the coupling elements (2) are also coupled by means of said lower central couplings, comprising at least one coupling means ( 71) and at least one coupling means (72), located in the channel (1) and the coupling element (2), respectively. A beam (V) as described in claim 8 characterized in that the coupling means (71) has an essentially "L" shaped profile and the coupling means (72) has an essentially "L" shaped profile. L ", but upside down. Rail (V) as described in claims 8 and 9, characterized in that the joining elements (2) comprise at least one orienting means (92) for guiding the user as to which direction of rotation should be employed to the joining element. (2) for proper coupling to the elements (71) and (72) of the channel (1) and the connecting element (2), respectively.

11: Concrete slab construction process characterized by understanding the steps of; mounting studs (V) by engaging at least two coupling members (2) in their respective positions with the channel (1) by cooperating the fittings (61) and (62) and subsequently engaging the frame metal (3) next to the joining elements (2); the arrangement of at least two joists (V) in parallel and filling of the spaces between the joists (V) by tiles (5) supported on the flaps (113) of the joists (V), so that the joists (V) together with the tiles (5) form a structural plane rigid enough to receive a certain amount of poured concrete; and pouring concrete to fill the voids between the metal structure (3), the joining elements (2) and the channel (1), as well as any gaps between the tiles (5) and the joists (V ) to result in a concrete slab.

A concrete slab construction process as described in claim 11, characterized in that the beam (V) comprises the step of arranging at least one additional structural element (4) over the recesses (82) so that the structural element (4) remain parallel to the longitudinal axis of the beam (V) and cooperate with the structural element (3) in the mechanical strength of the concrete slab.

A concrete slab construction process as described in claim 11 or 12, characterized in that the mounting of the studs (V) comprises the step of coupling the connecting element (2) to the channel (1) by means of the rotational movement. to provide coupling between the elements (71) and (72). 14: Pre-slab (P) comprising a groove (1), at least two joining elements (2) and at least one metal frame (3), the joining elements (2) being able to couple both the groove (1) as well as the metal frame (3); the channel (1) having a profile, an outer surface (11) and an inner surface (10); its profile includes segments defining its contour as the base segment (110), the two vertical segments (111), and the horizontal segments (112), parallel to the base segment (110), the horizontal segments (112) protrude. from the vertical segment (111) towards the opposite segment (112), so that the channel in its three-dimensionality has tabs (113), the tabs (113) on its inner surface (10) have fastening means (61). ) intended to cooperate with securing means (62) located on the coupling element (2) so as to join the channel (1) to the coupling elements (2) characterized in that each vertical segment (111) comprises at least one coupling element. coupling (101) so as to engage with the respective coupling element (102) comprised in the vertical segment (11) of another pre-slab (P).

Lattice pre-slab (P) as described in claim 14, characterized in that the coupling means (61) are located on the inner surface (10) of the tabs (113) and the coupling means (62) are located in opposite position. to the respective elements (61) in order to offer greater mechanical resistance to the beam (V).

Lattice pre-slab (P) as described in claim 14 or 15, characterized in that the coupling means (101) are essentially protruding and the coupling means (102) are essentially recessed to provide a male-type coupling. -female".

Lattice pre-slab (P) as described in claims 14, 15 or 16, characterized in that the coupling means (101) and (102) provide a "male-female" coupling comprising some degree of dimensional interference of provide greater resistance to the disintegration of the coupling.

Lattice pre-slab (P) as described in claims 14, 15, 16 or 17 characterized in that the coupling means (101) and (102) provide a "male-female" coupling and the volume of the coupling medium. The coupling (101) exhibits some dimensional variation intended to cooperate with a corresponding dimensional variation found in the volume of the coupling medium (102) so as to provide greater resistance to coupling dismemberment.

Lattice pre-slab (P) as described by claims 14, 5, 16, 7 or 18 characterized in that the joining elements (2) comprise at least one recess (82) for receiving and disposing parallel to the longitudinal axis. (V) the additional structural elements (4).

Pre-slab (P) as described by claims 14, 15, 16, 17, 18 or 19 characterized in that the elongate elements (98), the joining elements (2) comprise curved terminals (99) for the purpose. to cooperate in maintaining the metal frame (3) in the position engaged with the coupling means (52) even if said static and dynamic loads result in some deformation of the elongate element (98).

Lattice pre-slab (P) as described by claims 14, 15, 16, 17, 18, 19 or 20 characterized in that the groove (1) and the coupling elements (2) are also coupled by means said lower central couplings, comprising at least one coupling means (71) and at least one coupling means (72), located in the channel (1) and the coupling element (2), respectively. Lattice pre-slab (P) as described in claim 21, characterized in that the coupling means (71) has an essentially shaped profile of the letter "L", and the coupling means (72) has an essentially shaped profile. of the letter "L", but upside down. Lattice pre-slab (P) as described in claim 21 or 22, characterized in that the joining elements (2) comprise at least one orienting means (92) intended to guide the user as to which direction of rotation to use when coupling element (2) so that proper coupling occurs to the elements (71) and (72) of the channel (1) and the coupling element (2), respectively.

24: Process of construction of concrete slabs characterized by comprising the steps of; truss pre-slab assembly (P) by engaging at least two joining elements (2) in their respective positions next to the channel (1) by cooperating between recesses (61) and (62) and the subsequent recess the metal structure (3) next to the joining elements (2); the arrangement of at least two lattice pre-lages (P) in parallel and later lateral coupling by at least one pair of coupling elements (101) and (102), wherein the lattice pre-slabs (P) form a rigid structural plane enough to receive a certain amount of poured concrete; and pouring concrete to fill the voids between the metal frame (3), the joining elements (2) and the channel (1) to result in a concrete slab. A concrete slab construction process as described in claim 24, characterized in that the lattice pre-slabs (P), when assembled, comprise the step of arranging at least one additional structural element (4) over the recesses ( 82) so that the additional structural member (4) remains parallel to the longitudinal axis of the beam (V) and cooperates with the structural member (3) in the mechanical strength of the concrete slab.

A concrete slab construction process as described in claim 24 or 25 wherein the pre-slab assembly is The lattices (P) comprise the step of coupling the coupling element (2) to the channel (1) by rotational movement to provide coupling between the elements (71) and (72).

A concrete slab construction process as described in claims 24, 25 or 26 which includes the step of installing the slabs (5) between the metal structures (3) to partially occupy the volume of the poured concrete. .