Panel of compound sheets for the construction of light-weight one-way joist slabs

Abstract

The invention relates to a prefabricated panel for light-weight one-way joist slabs of the compound section type, comprising an upper contributing layer, a lower contributing layer having a series of upper peaks and troughs and shear transfer bolts which secure the upper contributing sheet to the upper peaks of the lower contributing sheet, and shear bolts or pins which secure the lower contributing layers to the slab framework beam. The functioning of the upper and lower contributing layers as a compound section permits the production of a highly efficient system for supporting the requirements of bending and shear forces, having a low unitary weight in comparison to the existing systems, which involves lower loads in terms of its own weight and a reduction in the inertia effects during seismic events, while constituting a less bulky structural solution, having fewer ground requirements and being much more economical, thereby reducing the time and input, labour and equipment required for the production and assembly thereof.

Claims

1. A prefabricated sheet panel for the manufacture of concrete slabs, comprising: an upper contributing layer, comprised of at least one of a cement or polymer resin; a lower contributing layer, formed of a single piece of metal, including: a series of upper surfaces; and at least one lower surface with walls connecting the upper surfaces and lower surface, wherein the upper surfaces and at least one lower surface form peaks and valleys in the lower contributing layer, wherein the walls are perpendicular to the upper contributing layer and the upper surfaces and lower surfaces, the lower contributing layer having a first end and a second end, the first end and the second end each having a horizontal flange that folds inwards toward the center of the panel; a first series of shear transfer bolts or pins that secure the upper contributing layer to each one of the upper surfaces of the lower contributing layer; and a second series of shear transfer bolts or pins that are configured to connect the sheet panel to a second sheet panel or to a support beam via the walls at the first end and the second end of the lower contributing layer.

2. The panel in accordance with claim 1, wherein the upper contributing layer is made of a cement material combined with a thermostable polyester resin.

3. The panel in accordance with claim 1, wherein the upper contributing layer has a thickness of 15-20 mm, a compressive strength of 27-28 MPa, and a specific weight of 1550.0-1600.0 kg/m.sup.3.

4. The panel in accordance with claim 1, wherein the lower contributing layer is a layer of cold-rolled steel that has a thickness of 0.6-1.2 mm or cold-rolled stainless steel whose thickness is between 0.5 mm and 0.8 mm.

5. The panel in accordance with claim 1, wherein the peaks have a height (h) that varies between 100 and 150 mm, a width (a) of 185-250 mm, and a peak-to-peak distance (b) of 190-260 mm.

6. The panel in accordance with claim 1, wherein the horizontal flanges, which are located at the first end and the second end of the lower contributing layer, are 20 mm in length.

7. The panel in accordance with claim 1, wherein the weight of the panel weight varies between 40.0 and 48.0 kg/m.sup.2.

8. A slab construction system, that comprises sheet panels in accordance with claim 1 supported on slab beams.

9. The slab construction system in accordance with claim 8, wherein the lower contributing layers of the sheet panels are secured to an upper face of a support beam via the second series of shear transfer bolts or pins, wherein the second set of transfer bolts or pins comprise bolts or pins or fired nails.

10. The slab construction system in accordance with claim 8, wherein the slab beams are made of steel or concrete.

11. The slab construction system in accordance with claim 8, further comprising intermediate beams, which are parallel to the sheet panels, and support beams, which are perpendicular to the sheet panels.

12. The slab construction system in accordance with claim 11, wherein the support beams intersect, forming a grid.

13. The slab construction system in accordance with claim 8, wherein a plurality of columns rise above the sheet panel at the point where a central beam and the support beams come together.

14. The slab construction system in accordance with claim 8, wherein the sheet panels are joined to the support beams by shear bolts or pins or fired nails that run through a cut in the upper contributing layer, where said cut is located along an edge that abuts a central axis of the support beam and makes it possible for a central valley of the lower contributing layer to be secured to the support beams.

15. A slab construction system comprising: a plurality of sheet panels, each of the plurality of sheet panels including: a prefabricated sheet panel for the manufacture of slabs, characterized by the fact that it includes an upper contributing layer, a lower contributing layer, which has a series of upper peaks and valleys with walls that are perpendicular to the upper contributing layer, the upper contributing layer having a first end and second end, the first end and the second end each having a horizontal flap that folds toward the center of the panel; and shear transfer bolts that secure the upper contributing layer to the upper peaks of the lower contributing layer, and shear transfer bolts or pins that interconnect the sheet panel via the peaks of the first and second ends of its lower contributing layers or secure the lower contributing layers to a support; wherein at least one of the sheet panels is joined to support beams via a plurality of shear bolts or pins or fired nails that run through a cut in the upper contributing layer, where said cut is located along an edge that abuts a central axis of the support beam and makes it possible for a central valley of the lower contributing layer to be secured to the support beams; and wherein the cut in the slab construction system is covered by a fragment removed to create the cut and wherein that the fragment is attached with epoxy resin.

16. The slab construction system in accordance with claim 8, wherein central joints, which are distributed along the support beams, comprise a joint filler with a high modulus of elasticity.

17. The slab construction system in accordance with claim 8, wherein a lower face of the lower contributing layer has a fire-resistant coating.

18. The slab construction system in accordance with claim 17, wherein the fire-resistant coating comprises a ceramic-particle paint.

19. A prefabricated building construction panel, comprising: an upper contributing layer, the upper contributing layer having a first extending planar upper surface on a first side and a second extending planar lower surface on a second side opposite the first side; and a lower contributing layer formed of a single piece of metal, the lower contributing layer including: a plurality of peak portions, each of the plurality of peak portions having an upper extending planar surface with a first end and a second end, each of the upper extending planar surfaces of the peak portions extending in directions parallel to one another; a plurality of connecting portions, each of the plurality of connecting portions having at least one extending planar surface with a first end and a second end, each of the plurality of connecting portions extending from the first end to one of the first end or the second end of one of the plurality of peak portions, each of the at least one planar surfaces of each of the plurality of connecting portion extending in directions perpendicular to the directions of extension of each of the extending planar surfaces of the plurality of peak portions; at least one valley portion, each of at least one valley portion having a lower extending planar surface with a first end and a second end, each of the lower extending planar surfaces of the at least one valley portion extending in directions parallel to each of the upper extending planar surfaces of the peak portions; wherein each of the at least one valley portion is connected to the second end of at least one of the plurality of connecting portions via the second end of the connected portion; and a first flange having a first flange extending planar surface with a first flange first end and a first flange second end, the first flange extending planar surface of the first flange extending in directions parallel to each of the extending planar surfaces of the peak portions; wherein the first flange is connected via the first flange first end to an end of the first of the plurality of connecting portions; a second flange, having a second flange extending planar surface with a second flange first end and a second flange second end, wherein the second flange extending planar surface of the second flange extends in directions parallel to each of the extending planar surfaces of the peak portions; wherein the second flange is connected via the second flange first end to a second of the plurality of connecting portions; a plurality of first shear transfer bolts connecting the upper contributing layer to the lower contributing layer via each one of the upper extending planar surfaces of the plurality of peak portions; and a plurality of second shear transfer bolts provided for connecting the at least one of the first or second of the plurality of connection portions to a support beam.

Description

DESCRIPTION OF THE FIGURES

(1) FIG. 1 shows a schematic section of a one-way slab lightened with blocks or caissons.

(2) FIG. 2A shows a longitudinal section of a system with a compound section.

(3) FIG. 2B shows a cross-section of a compound-section system.

(4) FIG. 3 depicts the elements that make up the easy-sheet system.

(5) FIG. 4 shows a system of prestressed alveolar prefabricated sheets.

(6) FIG. 5 shows the longitudinal section of the compound-sheet panel (5) in accordance with this patent application.

(7) FIG. 6 shows the cross-section of the compound-sheet plate (5) in accordance with this patent application.

(8) FIG. 7 shows in detail the characteristics of the lower contributing layer (52) of the sheet panel of this application.

(9) FIG. 8 depicts the internal distribution of last-minute stresses in the longitudinal section of the compound-sheet panel in accordance with this application.

(10) FIG. 9 depicts a schematic of the arrangement of the sheet panels (5) over the lattice of beams (7) that comprise the system that constitutes the slab.

(11) FIG. 10 shows the section A-A of FIG. 9, in which the positioning of the bolts in the sheet and in the beams is depicted.

(12) FIG. 11 shows the section B-B of FIG. 9, in which the leveling treatment for the central beam is depicted.

(13) FIG. 12 shows a detail of the attachment of the sheet panel (5) in the support beam (71, 72) by means of bolts working in shear.

(14) FIG. 13 shows the section C-C, in which a different point of view of the attachment of the sheet panel (5) in the support beam (71, 72) is depicted.

(15) FIG. 14 shows the section C-C, in which the filler (9) with a high modulus of elasticity along the central joint of the support beam (71, 72) is depicted.

DETAILED DESCRIPTION OF THE PRESENT INVENTION

(16) The compound-sheet panel (5) of this invention was designed as a prefabricated panel for the field of sheets made of one-way light-weight slabs. As FIG. 5 shows, said panel is composed of an upper layer (51) of the cement type and/or polymer resins, cured, with thicknesses of between 15 and 20 mm, a compressive strength of between 27 Mp and 28 Mp, and a specific weight of between 1550.0 and 1600.0 kg/m.sup.3; hereinafter this layer will be referred to as the upper contributing layer (51), and a lower contributing layer (52) made of cool-roll (CR) steel, which is among the references described in section A.3.1 of standard AISI 1996 and which has a thickness of 0.6-1.2 mm, or which is made of cold-rolled stainless steel having a thickness of between 0.5 and 0.8 mm.

(17) The cross-section of said panel is depicted in FIG. 6, which shows that the lower contributing layer (52) features a series of upper peaks (521) and valleys (522). The upper contributing layer (51) is secured by shear bolts or pins (53) working in shear and compression on the upper peaks (521) of the lower contributing layer (52), while the valleys (522) are connected by means of shear bolts or pins (53) to the slab (7) lattice beam, which can be made of steel or concrete. In this system, the shear bolts or pins (53) take up the shear stresses that are generated by the integrated operation of the system under shearing conditions.

(18) The selection of the lower contributing layer (52) is subject to the AISI standard, and its dimensions will vary depending on the requirements as regards loads and separation between supports. FIG. 7 depicts the lower contributing layer (52) in detail and independently. As can be seen, said layer includes the peaks (521), which have a width (h) that varies between 100 and 150 mm, a width (a) of 185-250 mm, a peak-to-peak distance (b) of between 190 and 260 mm, and which have at each of the ends of the lower contributing layer (52) a horizontal flange (54) whose length is 20 mm.

(19) By contrast, the selection of the upper contributing layer (51) will be determined by resistance to compression and shearing stresses according to the LRFD [Load and Resistance Factor Design] design method, standard ACI. Both contributing components (51, 52) must comply with verification of [Translator's note: this should perhaps be “guarantee resistance to”] the compression stresses generated by the shear bolts or pins (53).

(20) Under the action of loads distributed over the upper contributing layer (51), the internal stresses of the sheet panel (5) exhibit the behavior of a sheet with a length/width ratio of >3, where said stresses resemble the behavior of a wide beam; this makes it possible to assume that there exists a distribution of similar internal stresses: as shown in FIG. 8, the forces of strain (T) are taken up by the lower contributing layer (52), and the majority of the compression (C) stresses are taken up by the upper contributing layer (51). This figure also shows the neutral axis (6), which is located between the compression (C) stresses and the strain (T) forces.

(21) The sheet panel of this invention is conceived of as prefabricated and operating under conditions of simple support, on the system of beams of the slab (7), where the panel is secured to the beams by means of attachments or shear connectors consisting of fired bolts and/or nails, joining the lower contributing layer (52) to the upper face of the support beam (7), which is made of concrete or steel. The inherent weight of the panel varies between 40.0 and 48.0 kg/m.sup.2. For a concrete slab, assuming support-beam cross-sections of 150×400 mm, the weight per square meter of this slab system is between 108.0 and 116.0 kg/m.sup.2.

EXAMPLES: STRUCTURAL DETAILS

Example 1. Arrangement of the Sheet Panels (5) on the Lattice of Beams (7) of the Slab

(22) The arrangement of the panels (5) of this invention on the lattice of beams (7) is depicted in FIG. 9 for the purpose of forming a system that makes up the slab. Once the sheet panel (5) has been selected based on the requirements of gaps and loads, it is put in place simply resting on the beams (7) of the slab lattice, midline to midline of the beams, working on a single gap. Said beams (71, 72, 7A, 7B) are crossed, forming a grid.

(23) The integrated working of the set of panels (5) as a system of flat beams is achieved by virtue of the fact that the shear bolts or pins (53) depicted in FIG. 10 work on shear: “Section A-A FIG. 9”. The shear bolts or pins (531) guarantee the transfer of shear forces in order to ensure integral operation between the upper contributing layer (51) and the lower contributing layer (52), while the shear bolts or pins (532) are responsible for transferring shear forces in order to guarantee integral operation between sheet panels (5), thereby avoiding cracks between joints. These shear bolts or pins (532) keep different levels of deflection from arising along the longitudinal lines that delimit the panels (5), thereby preventing the floor finishes from cracking along said lines.

Example 2. Treatment of Intermediate Beams (7A, 7B) that are Parallel to the Sheet Panels (5)

(24) As regards the treatment of the intermediate beams (7A, 7B), which are parallel to the plate panels, said beams are shown in FIG. 11, which depicts a section B-B of FIG. 9. The leveling treatment of the central beam (7A) is carried out with a concrete f′c=10 Mp to accommodate the floor finish. The sheet panels (5) that confine the filler would act as skirts. Later and once the filler (R) has hardened, the skids of the lower contributing layer (52) that push against it are secured with appropriately selected shear bolts or pins (53) (bolts of Type A490 for metal beams or epoxy fasteners or fired nails for concrete beams). FIG. 11 also shows the column (8) that rises above the sheet panel (5) at the point where the central beam (7A) and the support beam (71) come together.

Example 3. Treatment of Support Beams (71, 72) that are Perpendicular to the Sheet Plates (5)

(25) The way in which the plate panel of this patent application (5) and the support beams (71, 72) interact is presented in FIG. 12. In this figure a cut (S) is shown that is made in the upper contributing layer (51) along the edge that strikes against the central axis of the support beam (7) for the purpose of securing the central valley (522) of the lower contributing layer (52) to the support beam (71, 72) by means of shear bolts or pins (534) that are appropriately selected (bolts of Type A490 for metal structures, or epoxy fastening s for concrete structures) as shown in FIGS. 12 and 13. Once the attachment is made, the opening that has been made (S) is again closed with the epoxy resin, thereby securing the cut segment.

Example 4. Treatment of Joints Along the Centerlines of the Support Beams (71, 72)

(26) The split center joints along the support beams (71, 72) are sealed with a joint filler (9) with a high modulus of elasticity, such as Sikabond T2 or the like (see FIG. 14).

Example 5. Fire Protection

(27) To produce fire-resistant panels (5), a fire-resistant coating is applied to the lower face of the lower contributing layer; this coating guarantees that the coating will remain stable for at least 120 minutes after a fire starts.

Analytic Basis of the Behavior

(28) The plate panel (5) of this invention is made up of three components:

(29) Upper contributing layer (51): cement-type and/or polymer resin sheet with thicknesses of between 15 and 20 mm, autoclave-cured, with a compressive strength of greater than 27 Mp and a specific weight of between 1200.0 and 1600.0 kg/m.sup.3. It is selected in accordance with standard ACI318 11 by the LRFD [load and resistance factor design] method.
Lower contributing layer (52): made of CR steel with a trapezoidal cross-section within the references described in section A.3.1 of standard AISI 1996 and having thicknesses of between 0.6 and 1.2 mm, or cold-rolled stainless steel with thicknesses of 0.5-0.8 mm. The selection thereof is made in accordance with standard AISI 3. It is recommended that the Finite Elements Method be used for the analysis of the flat components of the system, the upper contributing layer (51), and the lower contributing layer (52). Shear transfer bolts (53). Among these components there exist the following categories, which are illustrated in FIGS. 10 and 11; they are:

(30) Shear bolts or pins (531) work on transferring shear forces between the upper contributing layers (51) and the lower contributing layer (52).

(31) Shear bolts or pins (532) work on transferring shear forces between lower contributing layers (52).

(32) These bolts are of the following type: matchtip Phillips milled-head screw with a diameter of at least 5.5 mm; selection thereof is made in accordance with standard ASIC-LRFD.

(33) Considering the panel (5) defined above, the applicant has analyzed its behavior and has determined that said panel and the system that includes it offer the following advantages:

(34) Lower weight per square meter of the system:

(35) Inherent weight 40.0-48.0 kg/m.sup.2. For a concrete slab and assuming support beam (71, 72) cross-sections of 150×400 mm, the weight per square meter of this slab system is within the range: 108.0-116.0 kg/m.sup.2.

(36) Compared to the existing lighter composite cross-section system, contributing layer+concrete, which has a slab weight range of 187.0-286.0 kg/m.sup.2 [sic, incomplete sentence].

(37) These data make it clear that the system based on the panel (5) of this application provides a reduction in weight of between 42.2% and 59.4% dead load per slab. This significant reduction in the inherent weight of the slabs means: lower demands on the structure due to gravitational loads and consequently lower cost for the structure, lower requirements due to the effects of inertial loads during seismic events, and consequently less rugged structural solutions and, finally, lower costs as well as less load on the ground and therefore lower-cost cementing solutions.

Ease of Execution of the Slab Item

(38) Since this is a prefabricated system, the activity of concrete casting is eliminated, thereby transforming the operation into the installation of a low-weight system, which translates into fewer resources required for the execution of the item or lower costs and shorter execution times.

(39) Likewise, the sheet panel enhances the moment of inertia of the section by putting the center of gravity closer to that of the upper contributing layer.

(40) Immediate load-bearing capacity. As a result, the requirement for shoring equipment is eliminated, meaning lower costs for this design.

Speed of Putting the Slab into Service

(41) Since this is a prefabricated system, it is available immediately, making it possible to initiate finishing activities sooner.