KR20100078640A - Deck plate unit for constructing concrete slab and concrete slab having the same - Google Patents

Abstract

PURPOSE: A deck plate unit for constructing a slab and a concrete slab including the same are provided to improve resistance to sagging and to prevent a form from sagging when concrete is placed. CONSTITUTION: A deck plate unit(100) for constructing a slab comprises a deck plate(110) and an FRP member(120). The FRP member is integrally attached on the bottom surface of the deck plate and reinforces bending strength of the deck plate when concrete is placed. Multiple FRP sheets are arranged on the deck plate.

Description

Deck Plate Unit for Constructing Concrete Slab and Concrete Slab Having the Same}

The present invention relates to a deck plate unit for a slab construction and a concrete slab having the same, and more particularly, to a deck plate unit and a concrete slab constructed thereby, which is applied as a floor formwork for slab and has improved flexural rigidity, that is, resistance to deflection. will be.

In general, concrete or civil constructions constructed of concrete show a material property that is strong in compression but weak in tension. Concrete slabs that form the floor or ceiling of a building, or the ceiling of a top tunnel of a bridge, are made of cement and aggregate. The structure is also sag due to the self-weight of the structure itself and the load applied from the upper side, the upper side is compressed and the lower side is pulled out, and if the deflection is excessive, the slab may be cracked or exposed to collapse.

In general, concrete slab refers to a flat plate, and is also called floor slab or top plate. In the general reinforced concrete structure, the surroundings are surrounded by beams, and the load applied to the slab structure is shared by the surrounding beams, and the force flows to each column. And the flat slab is a reinforced concrete slab directly mounted on the column without support by beams, in which the reinforcing bar is arranged so that the bending strength of the floor is maintained to a safe level.

Referring to FIG. 1, a conventional concrete slab generally includes a concrete layer 10 and a plurality of reinforcing bars 20 arranged inside the concrete layer 10, the concrete layer 10 having an upper side. The concrete is formed by pouring concrete on the floor formwork 30 is arranged in the reinforcement 20, the formwork 30 is removed after curing the concrete to complete the concrete slab structure.

Here, the reinforcing bar 21 arranged long along the lower portion of the concrete slab layer 10 mainly serves to resist tension, and the concrete slab layer 10 and the reinforcing bar 22 arranged along the upper portion thereof are It is primarily resistant to compression, thereby resisting the slab deflection.

The formwork 30 supports the concrete placed on top of the slab construction as described above, the formwork is supported by the clubs. That is, the clubs support the formwork up to the ceiling height.

The clubs prevent the formwork from collapsing or sagging due to the weight of the concrete when the concrete is being poured, in consideration of the weight of the concrete placed on top of the formwork 30 and the sagging of the formwork accordingly. Clubs are installed.

At this time, the formwork 30 is easily sag due to the weight of the concrete. The greater the weight of the concrete placed on top of the formwork, for example, the thicker the thickness of the slab, the greater the number of circles required. If the slab dance (thickness) to increase the length of the slab to increase the number of clubs and the conventional formwork has a problem such as collapsed by sag because it can not support the weight of the concrete.

Accordingly, the present inventors have invented a slab formwork having improved resistance to deflection by improving flexural rigidity by using FRP having excellent tensile resistance.

Meanwhile, between a point and a point of a building / civil structure such as a building or a bridge, that is, between a column and a pillar or a pier and a pier, it is called a span or a span, and when the conventional conventional concrete slab is applied to a building, the concrete slab In consideration of the deflection of the span was set to about 4m to 7m.

In addition, when the span needs to be increased, that is, when the span needs to be extended longer, the dance is increased. In this case, the material cost and the weight of the slab structure are increased. This becomes long, and it becomes difficult to satisfy conditions for vibration and the like.

Therefore, according to the conventional concrete, the distance between the column and the pillar, that is, the span is limited, thereby increasing the number of pillars or the number of beams supported by the girder, thereby limiting the design freedom of the building or civil engineering structure. As a result, the internal space is reduced and internal design conditions are also limited.

The present inventors have invented a concrete slab structure having a structure capable of long span of the slab by using alfalfa having excellent tensile resistance.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a deck plate unit having a high bending rigidity, that is, a deck plate unit which is applied as a formwork of a concrete slab, and a concrete slab having the same.

In order to solve the above object, the present invention comprises: a deck plate (Deck Plate) forming a formwork for slab so that concrete is poured on the top; And it is provided integrally to the deck plate provides a deck plate unit for the slab construction comprising a FRP member to reinforce the flexural rigidity of the deck plate when the concrete slab construction.

The FRP member is characterized in that it comprises a FRP plate attached to the bottom of the deck plate integrated.

And the FRP plate may be configured to include a FRP sheet arranged long in the span direction on the deck plate; In this case, the FRP sheet is preferably provided with a plurality on the deck plate.

The deck plate may be integrated with the concrete layer formed after the concrete is poured to form the bottom of the slab.

In another aspect, the present invention provides a display device comprising: the deck plate unit; Disclosed is a concrete slab formed by pouring the concrete on top of the deck plate unit and including a concrete layer integrated with the deck plate unit after the concrete is poured.

In addition to the above configuration, the concrete slab may be further comprises a hollow non-filled FRP pipe to be embedded in the interior of the concrete in the span direction to reinforce the flexural rigidity of the concrete layer.

According to the deck plate unit for a slab construction according to the present invention has the following effects.

First, according to the present invention, since the flexural rigidity of the formwork is improved by applying the FRP member having excellent tensile resistance to the formwork deck plate, in particular, when the slab construction (concrete placing) minimizes the deflection of the formwork Suitable for long span implementations.

Second, according to the present invention, the construction period is reduced, the labor cost is reduced, and the work space of the field worker can be secured, because the number of copper bars required for the slab construction is reduced compared to the conventional concrete slab construction formwork having the same dance.

Third, according to the present invention, since the deck plate unit for slab formwork with improved flexural rigidity is integrated with the concrete layer formed by the casting of concrete to form the bottom of the slab, the flexural rigidity of the slab can be improved.

Fourth, according to the present invention, when the concrete slab structure is embedded in the FRP pipe is not filled with concrete in the span direction in the non-filling type in the span direction in the concrete layer further improves the bending stiffness of the slab is further spanned It is possible to reduce the weight of the slab and to reduce the requirements of cement and aggregates, thereby reducing the construction cost and shortening the construction period. In addition, the internal space of the FRP pipe may be used as a passage for electric / electronic cables and / or other equipment such as various electric wire cables and communication cables.

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention that can specifically realize the above object will be described. In the description of the present embodiment, the same names and symbols are used for the same components, and additional descriptions and redundant descriptions thereof will be omitted below.

First, with reference to Figures 2a to 5, it will be described an embodiment of a concrete slab structure and a deck plate unit for the same according to the present invention.

Here, Figure 2a is a perspective view showing an embodiment of the deck plate unit according to the invention, Figure 2b is a perspective view showing one embodiment of a concrete slab having a deck plate unit according to the present invention, Figure 3 is a present invention 4 is a front view showing an embodiment of the deck plate unit according to the present invention, and FIG. 4 is a perspective view showing the FLP plate as an embodiment of the FRP member of the deck plate unit according to the present invention.

2A and 2B, the deck plate unit 100 according to the present invention forms the formwork of the slab for slab construction, the concrete slab according to the present invention is the deck plate unit 100 and the deck plate unit It is configured to include a concrete layer 200 formed on the top of the (100).

In more detail, one embodiment of the deck plate unit 100 according to the present invention, the deck plate 110 and the deck plate 110 is integrally provided with the FRP (FRP: fiber reinforced) Plastic 120, hereinafter abbreviated as FRP) member 120.

The deck plate 110 forms a formwork of the slab, the concrete is poured on the upper side, that is, the upper side of the deck plate 110, the concrete layer 200 is formed when the concrete is cured and hardened.

In other words, the deck plate 110 forms a floor formwork for concrete pouring during the slab construction. And the upper side of the deck plate 110 is arranged the main bars 131, 132 to reinforce the concrete slab according to the present invention.

The deck plate 110 includes a metal plate made of a substantially rectangular metal plate, for example, a galvanized steel sheet. The deck plate unit, in particular the deck plate 110 may be composed of a synthetic slab flooring device that is integrated with the concrete layer 200 when the concrete is poured and cured on top, in this case, no separate formwork removal work do. Therefore, since no additional formwork is removed, the construction of the slab is simplified, the construction period can be shortened, and the rigidity of the slab structure can be maintained. Here, the deck plate 110 may be formed on the top surface wrinkles or protrusions to improve the integrity of the concrete layer 200.

The main roots 131 and 132 are provided at positions spaced apart from the upper side of the deck plate 110, and a main root located relatively upward among the main roots 131 and 132 is called an upper main root 131. The lower main locator is called the lower main 132. Examples of the upper main 131 and the lower main 132 are reinforcing bars made long.

The plurality of the main roots (131, 132) is integrally fixed to the upper side of the deck plate 110 at the time of manufacturing the deck plate unit 100, the deck plate unit 100 may be modularized, the deck The plate unit 100 is manufactured in a modular form and then transferred to a construction site and installed as a slab formwork. After slab construction, the plate unit 100 is permanently integrated with the concrete layer. Of course, the upper main 131 and the lower main 132 may be directly on-site at the slab construction site.

The upper side surface of the deck plate 110 is provided with a main root mounting member 140 for the installation of the main roots, the main root mounting member 140 in the present invention is called a lattice (Lattice), the upper main root 131 And the lower main root 132 is fixed to the main root mounting member, that is, the lattice 140 and installed on the deck plate 110. At least one of the upper freckle 131 and the at least one lower freckle 132 is fixed to the lattice 140 by welding, wire binding, or fitting.

In the present embodiment, the lattice 140 is installed on the upper side of the deck plate 110 by welding or the like, and has a lattice shape having a truss shape when viewed from the front of the deck plate unit 100. A plurality of 140 is disposed in the longitudinal direction of the main roots (131, 132), that is, a plurality of spaced apart or integrally arranged in the longitudinal direction (span direction) to form a row of lattice line (140a), that is, the main root mounting member The shape of the lattice is not limited thereto.

In more detail, a plurality of freckles are installed on the deck plate 110 in the left and right directions to form a plurality of rows of the lattice lines 140a.

In the present embodiment, the upper freckle 131 is fixed to the upper end of each of the lattice 140, that is, the upper vertex of the truss, and the lower freckle 132 is fixed to the lower sides of each of the lattice 140, one by one. The shape of the lattice 140 or the number of the upper main rod 131 and the lower main root 132 fixed to one of the lattice lines and the fixing method thereof are not limited thereto.

And, the upper side of the deck plate is the upper back muscles (not shown) that crosses the upper main rod 131 is long, the lower back muscles (not shown) that cross the lower main root 132 is elongated desirable.

The FRP member 120 reinforces the bending rigidity of the deck plate 110, that is, the resistance to deflection during the concrete slab construction. As an example, the FRP member 120 may include a flat plate-shaped FRP plate. 4, an FRP plate 121 is shown as an embodiment of the FRP member 120 for the deck plate unit 100 according to the present invention.

In the present embodiment, the FRP member 120 forms an FRP layer on the deck plate unit 100, wherein the FRP plate 121, more specifically, the FRP sheet is the deck plate. The surface of at least one of the upper and lower surfaces of (110) is entirely or partially coated to reinforce the flexural rigidity of the deck plate (110).

The FRP (fiber-reinforced plastic) has excellent resistance to tensile strength and can improve resistance to shock waves applied to the deck plate, and has good heat resistance and thermal insulation, crack-free properties and molding workability. Since this is good, it is easy to manufacture into various shapes.

In the present embodiment, the FRP plate 121 is attached to the bottom surface of the deck plate 110 to be integrated with the deck plate 110 to be integrated with the deck plate 110, accordingly the deck The bending rigidity of the plate 110 is reinforced.

The FRP plate 121 may be formed into a sheet or mat formed of a fiber reinforced plastic material and then attached to the deck plate 110 using an adhesive such as epoxy, and may be subjected to a primer treatment as necessary. It may be.

In addition, the deck plate 110 and the FRP plate 121 may be integrated with each other by hardening the fiber material as it is by using a curing agent after attaching the fiber plate 110. For example, a fiber material, for example, glass fiber, carbon fiber or aramid fiber is attached to the surface of the deck plate 110, there is a method of curing and fixing using a resin (resin), such as a polycoat and a curing agent. Accordingly, the FRP plate 121 may be integrated on the surface of the deck plate 110.

Accordingly, the characteristics of the FRP is applied to the deck plate 110 forming the slab formwork to reinforce the bending rigidity of the deck plate 110, when the concrete is poured on the deck plate 110 when the deck plate The deflection of the unit 100 can be minimized, and the construction cost and construction period can be shortened by increasing the number of dances or reducing the number of clubs compared to the conventional art.

 Specific examples of the FRP are CFRP (CFRP; carbon fiber reinforced plastic), GFRP (GFRP; glass fiber reinforced plastic) and AFRP (AFRP; aramid fiber reinforced plastic). The FRP layer may be composed of a composite material further including other materials that can improve the strength of the pillar including such a material.

The arrangement direction of the fiber filament in the FRP plate 121 may be variously changed according to the design conditions in consideration of the anisotropy of the FRP, but the grid filament, for example, +45 ° direction and -45 ° woven fiber filament cross May be arranged. Of course, the fiber filaments may be arranged long in the span direction.

Meanwhile, referring to FIG. 5, the FRP plate 121 may include the FRP sheet 122 as described above, and may be arranged to span the deck plate 110 in the span direction. More specifically, the FRP plate 121 may be entirely coated on the surface of the deck plate 110 as described above, or may be partially coated as shown in FIG. 5.

In other words, the FRP sheet 122 is arranged at least on one side of the upper and lower surfaces of the deck plate 110, more specifically, in the span direction, ie, the front and rear direction, as shown in FIG. 5. By being integrated with the deck plate 110 to prevent sagging of the deck plate 110.

Here, the FRP sheet 122 is preferably provided with a plurality in the deck plate 110, it is configured in a long strip shape that is spaced apart from each other in the left and right directions, that is, the direction perpendicular to the span direction.

Of course, a string or string type FRP member may be integrated in the deck plate instead of the strip-shaped FRP sheet.

In one embodiment of the deck plate unit 100 according to the present invention configured as described above when the concrete is poured on top of the deck plate 110, the upper main 131 and the lower main 132 is embedded in the interior The concrete layer 200 is formed. That is, the concrete layer 200 is formed by pouring concrete into a form, that is, the thickness of the deck plate unit 100 to meet the design conditions and curing it.

Concrete slab according to the present invention can be variously applied, such as the floor or ceiling of the building or the top of the bridge or the ceiling of the tunnel.

Meanwhile, referring to FIGS. 6 to 8, a concrete slab according to the present invention is embedded in the concrete layer 200 in a span direction to be long and is a non-filled FRP pipe for reinforcing the bending rigidity of the concrete layer 200. It may be configured to further include (300).

The concrete slab needs excellent resistance to bending behavior, that is, deflection according to the load distribution and the design conditions according to its own weight. The present invention sags by further improving the bending rigidity of the slab by using excellent tensile strength among the characteristics of FRP. Can minimize the cost and reduce the material cost.

Specific examples of the FRP include CFRP (carbon fiber reinforced plastic), GFRP (glass fiber reinforced plastic) and AFRP (aramid fiber reinforced plastic) and the like, the FRP pipe 300 is the flexural rigidity / It can also be composed of composites, including other materials that can improve strength.

The FRP pipe 300 is to support the deflection of the concrete layer 200, more specifically, after the concrete is poured into the concrete layer 200 is formed as the concrete is cured and firmly firmly Minimize the deflection of the self-weight of the concrete slab according to the invention and the external load applied on the top of the slab.

The FRP pipe 300 may have any structure as long as it has a structure that integrates with the concrete layer 200, may be directly integrated with the concrete layer 200 by the concrete pouring, or may be a separate member. In the present embodiment, the FRP pipe 300 may be embedded in the concrete layer 200 by the concrete pouring so that the FRP pipe 300 is disposed to be long in the span direction across the interior of the concrete layer 200. To be integrated with the concrete layer 200.

The FRP pipe 300 may be embedded so that a portion of the circumferential surface is exposed to the outside of the concrete layer 200, in this embodiment is completely embedded in the interior of the concrete layer 200, the outer peripheral surface is the concrete layer It is configured not to be exposed to the outside of the (200).

And the FRP pipe 300 may be of a filling type filled with concrete inside, the concrete is poured only to the outside of the FRP pipe 300 so that the concrete is not poured into the interior during the construction of the slab, the inside It may also be configured as a non-rechargeable (hollow form) that is not filled by concrete. Accordingly, the internal space of the FRP pipe 300 can be used as a passageway for electric / electronic cables such as various electric wire cables and communication cables, and / or other facilities, and the consumption of aggregates as much as the internal space of the FRP pipe 300 can be achieved. It can be saved and the weight of the slab can be reduced.

An example of a method of forming the FRP pipe 300 is a filament winding method, the filament winding method is a fiber filament to a mandrel of a long cylindrical or other shape to form the FRP pipe It refers to a method of forming a hollow tube-shaped pipe by winding, and the FRP pipe 300 may be formed into various cross-sectional shapes such as an annular cross section, an elliptical cross section, and a polygonal cross section according to the cross-sectional shape of the mandrel.

And since the FRP pipe 300 is easy to form and light in weight, the thickness, diameter, shape, etc. of the pipe can be appropriately selected according to the design conditions required for the FRP pipe, and in consideration of the anisotropy of the FRP to the mandrel The direction in which the fiber filament is wound, that is, the arrangement direction, may be variously changed. For example, the fiber filament may be wound alternately by repeating the + 45 ° spiral direction and the -45 ° spiral direction.

Accordingly, the FRP pipe 300 may be made of a hollow tube of various cross-sectional shapes, such as a polygonal cross-section tube or an annular cross-sectional tube, the FRP pipe 300 in the present embodiment shows an example of a hollow pipe of an annular cross-section as an example. do.

The concrete slab is sag due to external load and self weight applied from the top. In other words, deflection occurs in the concrete slab. When the concrete slab vulnerable to bending or deflection is reinforced with the FRP pipe 300, the advantages of FRP having excellent tensile resistance are applied to the concrete slab vulnerable to tension. Overall bending stiffness can be improved.

The FRP pipe 300 is disposed long along the direction of the force applied to the concrete slab, that is, the direction of action of the load according to the design conditions, in this embodiment the FRP pipe 300 of the concrete slab as described above A plurality of FRP pipes are formed in the span direction and arranged in the upper side of the deck plate unit 100 so as to be integrated in the interior of the concrete layer 200 by the concrete pouring. Here, the plurality of FRP pipes 300 are arranged at the same interval next to each other, but is not limited thereto.

As described above, if the FRP pipe 300 is integrated with the concrete layer 200, the deflection of the slab structure is minimized assuming that the same span and dance are applied.

The FRP pipe 300 may be installed to be in contact with the upper surface of the deck plate 110 or may be installed to be directly supported by the lattice 140, in the concrete slab according to the invention the FRP pipe 300 is It was to be supported by a separate support member 150. The support member 150 is provided above the deck plate 110, and is directly provided on the upper side of the deck plate 110, or through another member, for example, the lattice 140. 110 may be provided on the upper side.

The supporting member 150 is arranged in a plurality of lines in the front-rear direction, that is, span (span) direction between adjacent parallel lattice lines 140a, the FRP pipe 300 is the main roots (131, 132) The support members 150 form a support line parallel to the lattice line 140a to be disposed in parallel with the support member 150.

In this embodiment, the support member 150 is formed by integrally extending from the lattice 140, but may be provided in a separate type. The support member 150 and the lattice 140 may be manufactured using a metal, for example, copper wire or iron wire, and may be fixed to the upper side of the deck plate 110 by welding or the like, but the material thereof. However, the fixing method is not limited thereto.

The support member 150 supports the FRP pipe 300 spaced apart from the upper side of the deck plate 110, and thus, when the concrete is placed on the deck plate 110, the FRP pipe 300 Is surrounded by the concrete layer 200.

One or a plurality of the FRP pipes 300 may be arranged between a pair of lattice lines neighboring each other, and in this embodiment, a state in which one FRP pipe is installed between a pair of lattice lines adjacent to each other is started. do.

Referring to the construction method of the concrete slab using the deck plate unit 100 configured as described above are as follows. First, the FRP member 120, for example, the FRP plate 121 or the FRP sheet 122, or the string or string type FRP member 120 is integrated to the upper of the deck plate reinforced with flexural rigidity The main rods 131, 132 and the FRP pipe 300 are installed. The deck plate 110 is installed in a slab construction position, for example, a column or a girder, and when the concrete is formed on the upper surface of the deck plate 110 to form a thickness to meet the design conditions, the main root The concrete slab in which the fields 131 and 132, the FRP pipe 300, the deck plate 110, and the concrete layer 200 are integrated is completed.

When the deck plate unit 100 is permanently integrated with the concrete layer 200, a separate formwork is not necessary, and the FRP pipe 300 and the FRP member 120 resist the deflection of the slab. The span can be implemented and the amount of cement aggregates saved by the internal volume of the FRP pipe can be saved, thereby reducing the number of clubs due to the reduced weight.

Deck plate unit 100 of the above-described structure is applicable to all steel frame, reinforced concrete group, SRC group, PC group, TSC structure, wall structure.

Hereinafter, the cross-sectional secondary moment and deflection amount of the deck plate unit according to one embodiment and the comparative example of the deck plate unit according to the present invention were compared. However, the following examples are merely illustrative of one specific example to which the features of the present invention are applied, and the present invention is not limited to the following examples.

[Comparative Example]

Span (span: ℓ) is 8m, slab width (k) is 1m, upper covering (d ₁ ) is 20mm, lower coating (d ₂ ) is 25mm, lattice width per pitch (b) 200mm, reinforcing bars (reinforcement) A comparative example of the deck plate unit is constructed as shown in Figs. 9A and 9B when the elastic modulus of E _s is 200000 MPa. The deck plate is 0.5mm, the upper main diameter (D ₁ ) is 14mm, the lower main diameter (D ₂ ) is 10mm, each of the lattice line has one upper main root, the lower main side parallel to each other at the same height Based on the installed state of two places, the concrete was placed on the top of the deck plate unit according to the comparative example so that the slab thickness was 200 mm, and the cross section second moment was obtained to determine the deflection amount.

EXAMPLE

Span (span: ℓ) is 8m, slab width (k) is 1m, top cover (d ₁ ) is 20mm, bottom cover (d ₂ ) is 25mm, width per pitch (b) is 200mm, reinforcing bar When the modulus of elasticity (E _s ) is 200000 MPa, the diameter of the uppermost base (D ₁ ) is 14mm, the diameter of the lower base (D ₂ ) is 10mm, and the thickness of the FRP plate made of AFRP (Aramid Fiber Reinforced Plastic) is 5mm. Thus, in the deck plate unit having the same structure as the comparative example described above, the FRP plate is attached to the lower side of the deck plate as a whole to constitute a specific embodiment of the deck plate unit according to the present invention, After placing the concrete so that the slab thickness is 200mm on the upper part, the secondary moment of the cross section is obtained, and the deflection amount is obtained.

Here, the modulus of elasticity (E _FRP ) of the AFRP plate is set to 100000 MPa, and the effect of the deck plate itself is neglected in calculating the second moment and the deflection amount of the examples and the comparative examples, but concrete is placed on the deck plate. The strength of concrete was neglected because it was calculated based on the fluidity of concrete as it was before hardening (before curing).

* Upper cover (d ₁ ): The distance from the upper surface of the concrete slab to the surface of the upper bar, in which the reinforcing bar is not placed in the upper layer of the slab. A layer that protects the rebar from exposure due to surface cracks in the slab, preventing corrosion of the rebar.

* Lower cover (d ₂ ): The distance from the lower surface (bottom, bottom) of the concrete slab to the surface of the lower main bar, in which the reinforcing bar is not placed in the lower part of the slab. A layer that protects the rebar from exposure due to surface cracks in the slab, preventing corrosion of the rebar.

* Lattice Width Per Pitch: The distance between neighboring parallel lattice lines, from the center of the lattice line to the center of the next lattice line. It is configured to be equal to the distance from the center of the upper major to the center of the next upper major neighbor.

* Self-weight and external working load: The self-weight of the comparative example and the example is assumed to be 5.05 kN / m (including the weight of the flowable concrete placed on top of the deck plate unit, and the weight of the AFRP plate is negligible compared to other members) Since it is light enough, the weight of the AFRP plate is ignored when calculating the deflection), and the work load (live load) is assumed to be 1 kN / m.

division
Example
Comparative example
Remarks
Section Second Moment
18.19 X 10 ⁶ mm ⁴

7.96 X 10 ⁶ mm ⁴
Deflection

88.67 mm
202.59 mm
56.2% sag decrease

As a result of comparing the specific example and the comparative example according to the present invention as described above, it can be seen that the deflection amount of the deck plate unit according to the specific embodiment is reduced by about 56.2% compared to the deflection amount of the deck plate unit according to the comparative example, Accordingly, it can be seen that according to the deck plate unit according to the present invention, the slab construction process, that is, the deflection may be remarkably improved when concrete is poured.

Deck plate unit according to the comparative example is configured as described above should adjust the amount of deflection by adjusting the height of the lattice or the number of upper and lower roots, the construction cost increases, but according to the present invention the FRP plate is the bending rigidity of the deck plate unit As it is reinforced, long span can be realized and material consumption and construction cost can be reduced.

Next, the cross section secondary moment and deflection amount of the concrete slab according to one embodiment and the comparative example of the concrete slab according to the present invention were compared. However, the following examples are merely illustrative of one specific example to which the features of the present invention are applied, and the present invention is not limited to the following examples.

[Comparative Example]

Span (span: ℓ) is 8m, slab thickness (t) is 300mm, slab width (k) is 1m, upper cover (d ₁ ) is 20mm, lower cover (d ₂ ) is 25mm, lattice width per pitch (b ) Is 200mm, the concrete modulus of elasticity (E _c ) is 21538.11MPa and the elastic modulus (E _s ) of the reinforcing bar (reinforcement) is 200000Mpa, a comparative example of the concrete slab constructed using the comparative example of the deck plate unit described above It is configured as shown in FIG. Here, the upper main diameter (D ₁ ) is 14mm, the lower main diameter (D ₂ ) is 10mm, based on the state in which one upper main root is installed at each lattice line and two lower main roots are installed next to each other at the same height. The secondary moment of the cross section was found for the concrete slab according to the comparative example.

EXAMPLE

Span (span: ℓ) is 8m, slab thickness (t) is 300mm, slab width (k) is 1m, upper covering (d ₁ ) is 20mm, lower coating (d ₂ ) is 25mm, width per pitch (b) 200mm, elastic modulus of concrete (E _c ) is 21538.11MPa, elastic modulus of reinforcing bar (E _s ) is 200000Mpa, diameter of upper rim (D ₁ ) is 14mm, diameter of lower rim (D ₂ ) is 10mm, The outer diameter Df ₁ of the AFRP pipe is 180 mm and the inner diameter Df ₂ of the AFRP pipe is 160 mm, and the concrete slab in which the non-filling hollow FRP pipe is further embedded in the same structure as the comparative example described above, that is, the deck plate described above. Specific examples of the concrete slab were configured using specific examples of the unit, the cross section secondary moment was obtained for the concrete slab according to the specific example, and the deflection amount was calculated and compared with the above comparative example in [Table 2]. Indicated.

Here, the modulus of elasticity (E _FRP ) of the AFRP pipe is 100000 MPa, and the distance from the surface of the AFRP pipe to the upper surface of the concrete slab structure is equal to the distance (upper coating thickness) from the upper side to the upper surface of the concrete slab structure. To do so, the FRP pipes parallel to the upper / lower roots were disposed one by one as shown in FIGS. 6 to 8 between neighboring lattice lines.

* Self-weight and external working load: The self-weight of the comparative example is assumed to be 7.54 kN / m, the self-weight of the example is assumed to be 5 kN / m due to the introduction of the hollow FRP pipe, and the working load (live load) is assumed to be 1 kN / m, and the deck Calculate cross-sectional secondary moment and deflection, ignoring the effects of plate and FRP plate.

division
Example
Comparative example
Remarks
Section Second Moment
681.58 X 10 ⁶ mm ⁴

213.28 X 10 ⁶ mm ⁴
Deflection

18.17 mm
98.1 mm
About 81.5% sag decrease

As a result of comparing the specific example and the comparative example according to the present invention as described above, it can be seen that the amount of deflection of the concrete slab according to the specific embodiment is reduced by about 81.5% compared to the amount of deflection of the concrete slab according to the comparative example. According to the concrete slab according to the invention it can be seen that the long span can be implemented.

In addition, the present invention has been described with reference to the preferred embodiments as described above, and the fact that the present invention can be embodied in other specific forms without departing from the spirit or scope in addition to the embodiments described above is known to those skilled in the art. It is obvious to those who have it.

Therefore, the above-described embodiments are to be considered as illustrative and not restrictive, and thus, the invention is not limited to the above description, but may vary within the scope of the appended claims and their equivalents.

       1 is a perspective view showing a typical concrete slab structure.

Figure 2a is a perspective view showing an embodiment of a deck plate unit according to the present invention, Figure 2b is a perspective view showing an embodiment of a concrete slab having a deck plate unit according to the present invention.

Figure 3 is a front view showing an embodiment of the deck plate unit according to the present invention.

Figure 4 is a perspective view showing the FRP plate as an embodiment of the FRP member of the deck plate unit according to the present invention.

Figure 5 is a bottom view showing another embodiment of the deck plate unit according to the present invention.

6 is a perspective view showing another embodiment of a concrete slab according to the present invention.

FIG. 7 is a front view of the concrete slab shown in FIG. 6.

FIG. 8 is a side view of the large concrete slab shown in FIG. 6.

9A and 9B are perspective and cross-sectional views of the deck plate unit according to the comparative example.

10 is a perspective view illustrating a comparative example of the concrete slab constructed by the deck plate unit according to the comparative example.

 Explanation of symbols on the main parts of the drawings

100: deck plate unit 110: deck plate

120: FRP member 121: FRP plate

122: FRP sheets 131, 132: freckles

200: concrete layer 300: FRP pipe

Claims (6)

Deck plate forming a formwork for slab so that concrete is poured on the top; And The deck plate unit for slab construction comprising an FRP member integrally provided on the deck plate to reinforce the bending rigidity of the deck plate when the concrete slab construction. The method of claim 1, The FRP member is attached to the bottom of the deck plate deck plate unit for a slab construction, characterized in that it comprises a FRP plate integrated. The method of claim 2, The FRP plate is configured to include an FRP sheet arranged to span the deck plate in a span direction; The FRP sheet is a deck plate unit, characterized in that a plurality is provided on the deck plate. The method according to any one of claims 1 to 3, The deck plate unit is characterized in that the deck plate unit is integrated with the concrete layer formed after the concrete to form the bottom of the slab. The deck plate unit of any one of Claims 1-3; And Concrete slab is formed by pouring the concrete on top of the deck plate unit, comprising a concrete layer integrated with the deck plate unit after the casting of the concrete. The concrete slab according to claim 5, further comprising a hollow non-filling FRP pipe embedded in the concrete layer in the span direction to reinforce the bending rigidity of the concrete layer.

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