KR20050110336A - Composite deck having shear connector using hybrid fiber reinforced plastics - Google Patents

Abstract

The present invention is combined with a lower frame made of Fiber Reinforced Plastics (hereinafter referred to as "FRP") and a concrete slab at the top thereof is used as a bottom plate structure of the bridge, shear with concrete The present invention relates to a composite bottom plate having a structure in which a hybrid FRP shear connector of a new structure suitable for use in an FRP lower frame for connection is installed.

In the present invention, it is composed of a lower frame made of fiber-reinforced plastic and a concrete slab formed thereon, wherein the lower frame is provided between the upper plate and the lower plate having an upper plate and a lower plate spaced at a predetermined height. In the composite bottom plate having a structure in which the cavity formed by the partition wall is formed continuously in parallel in the longitudinal direction and the cavity is formed long in the transverse direction to form a tube; On the upper surface of the lower frame, for coupling with the concrete slab poured on the upper part, as a shear connecting material, it has a predetermined length in the direction perpendicular to the throttle, and has a flat horizontal portion and a predetermined height at the center of the horizontal portion. Shear connector consisting of a vertical portion protruding integrally so as to be integrally installed by an adhesive, wherein the shear connector comprises an upper layer and a lower layer formed by impregnating the resin in a state in which fibers are arranged side by side in the longitudinal direction, and longitudinal and The hybrid fiber-reinforced plastics, characterized in that the fiber mat layer formed by impregnating the fiber mat mat of the cross-shaped fibers are formed in a lattice shape is integrally provided between the upper layer and the lower layer. There is provided a composite bottom plate having a shear connector.

Description

Composite Deck having Shear Connector using Hybrid Fiber Reinforced Plastics

The present invention relates to a fiber-reinforced plastic bottom plate having a shear connector made of a hybrid fiber-reinforced plastic, specifically, a lower frame made of fiber-reinforced plastics (hereinafter referred to as "FRP") and an upper portion thereof. Hybrid FRP shear connector with new structure that is easy to install in FRP lower frame for solid shear connection of FRP lower frame and concrete in composite bottom plate composed of concrete slab to be combined To a composite bottom plate.

In order to replace the conventional reinforced concrete baseplate as a baseplate of civil engineering structures, for example, bridges, a bottom plate using a lightweight FRP lower frame has been proposed.

Applicant has proposed a composite bottom plate structure of a new structure through Patent Application No. 10-2002-40869, Figure 5 of the applicant's composite bottom plate filed in Patent Application No. 10-2002-40869 A schematic perspective view is shown. The composite bottom plate 1 includes a lower frame 10 and a concrete slab 20 having a predetermined thickness integrally coupled to the upper portion of the lower frame 10. The lower frame 10 is a cavity formed by the upper plate 11 and the lower plate 12 spaced apart by a predetermined height, and the partition wall 13 formed between the upper plate 11 and the lower plate 12. The portion 14 is continuously formed side by side in the longitudinal direction (for example, the axial direction), the cavity 14 is formed long in the transverse direction (for example the axial direction perpendicular) to form a tube shape. Has The lower frame 10 is preferably made of all the configuration of the FRP, the lower frame 10 is a tubular member of a polygonal (for example rectangular) in addition to the above-described structure is arranged side by side next to each other, respectively It may have a structure in which a separate top plate and the bottom plate is coupled.

The composite bottom plate 1 having the above structure has a structure in which the lower frame 10 made of lightweight high strength material and the concrete slab 20 are synthesized. It is possible to significantly reduce the cross-sectional thickness, thereby reducing the self-weight of the bottom plate to prevent the cross-sectional enlargement of the lower structure supporting it. In addition, compared to a sole plate consisting of only a frame, the concrete slab is composited, so that the concrete reaches its ultimate state first, and the frame has additional strength so that it can be designed to reach the extreme state only at higher loads than the concrete. In this case, unlike the bottom plate made of conventional aggregates, brittle fracture of the bottom plate can be prevented in advance. Therefore, it becomes possible to predict the destruction of the structure, thereby exerting the effect of being able to properly prepare for the destruction of the structure.

In manufacturing the composite bottom plate 1 having the above configuration, it is very important to firmly combine the lower frame 10 and the concrete slab 20. In order to firmly synthesize the lower frame 10 and the concrete slab 20, the upper connection plate 11 of the lower frame 10 should be provided with a solid shear connector such as studs.

There is a method of screwing the stud made of steel to the upper plate 11 of the lower frame 10, but this is not preferable because it is a combination of different materials (steel / FRP), further down the screw for screwing the stud The screw holes must be formed in the upper plate 11 of the frame 10, which requires additional work and costs.

Therefore, in order to expand the application of the composite bottom plate as described above, it is urgently required to develop a new shear connector that is suitable for use in the lower frame made of FRP but is easy to construct.

The present invention was developed in order to meet the need to install the shear connector in a simple and robust method in the composite bottom plate with the newly proposed FRP lower frame, specifically, the FRP lower frame It is an object of the present invention to provide a F composite bottom plate made of the same material as the frame and attached to the lower frame of the FRP in a simple manner, but with a shear connector of a new configuration that can achieve a strong composite action with the concrete slab.

In order to achieve this object, in the present invention, the cavity formed by the upper plate and the lower plate spaced apart by a predetermined height, and the partition wall formed between the upper plate and the lower plate are continuously formed side by side in the longitudinal direction, The cavity is formed in a transverse direction to form a tube form a lower frame made of fiber-reinforced plastic, and a composite bottom plate consisting of a concrete slab on the upper, the upper surface of the lower frame, placed on top For coupling with the concrete slab, the shear connector, which is a shear connector, has a predetermined length in the crosswise perpendicular direction, and has a flat horizontal part and a shear connector comprising a vertical part protruding integrally to have a predetermined height from the horizontal part. It is integrally installed by an adhesive, the shear connector, The upper and lower layers formed by impregnating the resin in a state in which fibers are arranged side by side in the direction, and the fiber mat layer formed by impregnating the fibrous mat formed in the shape of a mat by the longitudinal and transverse fibers arranged in a lattice shape, the fiber mat layer Provided is a composite bottom plate having a shear connecting material made of a hybrid fiber reinforced plastic, characterized in that the structure is integrally provided between the upper layer and the lower layer.

In the present invention, the shear connector may have an inverted T-shaped, b-shaped, or c-shaped cross section.

In the present invention described above, it is preferable that a plurality of holes are formed in the vertical portion of the shear connecting member to allow concrete to flow during concrete pouring for the concrete slab of the upper upper frame.

Hereinafter, with reference to the accompanying drawings will be described the configuration and effect of the present invention.

1 is a perspective view of a bottom plate with one embodiment of a hybrid FRP shear connector 100 according to the present invention. 2A is a schematic perspective view of the hybrid FRP shear connector 100 described above, and FIG. 2B is an exploded perspective view of the hybrid FRP shear connector 100 shown in FIG. 2A.

In the embodiment shown in the figure, the hybrid FRP shear connector 100 has a shape having a cross-section inverted T-shaped cross section and a predetermined length in the longitudinal direction. Specifically, the hybrid FRP shear connector 100 is composed of a flat horizontal portion 101 and a vertical portion 102 having a predetermined height in the center of the horizontal portion 101 and integrally protruding. The vertical portion 102 is more preferably formed with a plurality of holes 103, the concrete slab 20 is formed on the upper portion of the FRP lower frame 10, the hybrid FRP shear connector 100 is the concrete When embedded in the slab 20, concrete is cured while flowing into the hole 103. Therefore, the hybrid FRP shear connector 100 and the concrete slab 20, and further it is possible to achieve a more robust mechanical synthesis and shear connection between the FRP lower frame 10 and the concrete slab 20.

Through 2b it can be seen a specific internal configuration of the hybrid FRP shear connector (100). Unlike the conventional FRP, in which only longitudinal fibers are arranged side by side in the resin, the hybrid FRP further includes a fiber mat in which the longitudinal and transverse fibers are arranged in a lattice to form a mat. Has a structure.

 Specifically, the hybrid FRP shear connector 100 has an upper layer 114 and a lower layer 115 formed by being impregnated in the resin 113 in a state in which fibers 112 are arranged side by side in the longitudinal direction, and in the longitudinal and transverse directions. A fibrous mat layer 117 formed by impregnating the resin 113 with the fibrous mat 116 formed in a lattice form and having a lattice shape is integrally provided between the upper layer 114 and the lower layer 115. Has a structure. In FIG. 2B, the resin 113 is illustrated in dashed lines so that the longitudinal fibers 112 and the fiber mat 116 are easily seen.

The upper layer 114, the lower layer 115 and the fibrous mat layer 117 are merely for the purpose of explanation and are not attached after their respective layers are formed separately. In the manufacturing process of the hybrid FRP shear connector 100, the longitudinal fibers 112 and the fiber mat 116 are impregnated in the liquid resin 113 at the same time is formed so that each layer is integral.

The longitudinal fibers 112 disposed in the longitudinal direction in the upper layer 114 and the lower layer 115 are arranged side by side in the longitudinal direction, that is, the longitudinal direction of the hybrid FRP shear connector 100, the fiber mat 116 is Since the fibers are already formed in a mat shape arranged to form a lattice shape in the longitudinal and transverse directions, the reinforcing fibers are also arranged in the lateral direction in the hybrid FRP shear connector 100. Various fibers may be used as the fibers constituting the fiber mat 116, and glass fibers, carbon fibers, and the like may be used as representative ones. In addition, various fibers may also be used as the longitudinal fibers 112 disposed on the upper layer 114 and the lower layer 115, and representative examples thereof include carbon fibers and aramid fibers.

Since the hybrid FRP shear connector 100 having the above configuration has the transverse fibers of the fiber mat 116 in the transverse direction, the fiber is reinforced in the transverse direction and thus stress is uniformly applied to the entire fiber. Because of the distribution, even if a direct tensile force in the transverse direction of the shear connector or a tensile force due to bending is applied, the reinforcing member has rigidity against it, so that a crack does not occur rapidly due to long cracks in the longitudinal direction as in conventional FRP. Will be effective. Therefore, the shear between the concrete slab 20 and the lower frame 10 will be able to resist.

Conventional FRP can not make the inverted T-shaped shear connector as shown in Figure 2a. In the conventional FRP, the fibers contained therein are arranged side by side only in the longitudinal direction, and have only a binding force by the resin in the transverse direction and thus have a very weak tensile strength in the transverse direction. This is because the restraining force in the transverse direction is expressed only by the resin, because the resin is a material that causes brittle fracture and is very vulnerable to tensile force. Therefore, the FRP is cracked easily in the longitudinal direction even if only a weak tensile or bending stress in the transverse direction, it is easily broken.

Therefore, when the inverted T-shape is made of the conventional FRP as described above, longitudinal cracking occurs in the vertical part due to shear force generated between the concrete slab and the lower frame, so that the vertical part can be easily split and separated from the horizontal part. FRP cannot produce such shear connectors.

On the contrary, the hybrid FRP as described above is reinforced in the lateral direction, so that the above problems do not occur and the reverse T-shaped shear connector 1 can be achieved.

Inverted T-shaped hybrid FRP shear connector 100 of the present invention having the configuration as described above can be installed by attaching the horizontal portion 101 to the FRP lower frame 10 by a very simple method by an adhesive such as epoxy.

On the other hand, the hybrid FRP shear connector 100 can be manufactured so that its cross-sectional shape is N-shaped, C-shaped, Figure 3a and 3b is a schematic perspective view and decomposition of the hybrid FRP shear connector 100 having a N-shaped cross section A perspective view is shown, respectively, and FIGS. 4A and 4B show schematic and exploded perspective views of the hybrid FRP shear connector 100 having a U-shaped cross section, respectively.

Similar to the inverted T-shaped hybrid FRP shear connector 100, the embodiment shown in FIGS. 3A, 3B, 4A, and 4B also includes an upper layer 114, a lower layer 115, and integrally therebetween. It is composed of a fiber mat layer 117 formed. The detailed configuration of the upper layer 114, the lower layer 115, the fibrous mat layer 117, and the configuration of these layers are the same as in the embodiment of FIG. 2A, and thus a repeated description thereof will be omitted.

3A, 3B, 4A, and 4B, similar to the embodiment of FIG. 2A, a plurality of holes 103 through which concrete may pass through a portion perpendicular to the upper surface of the lower frame of the FRP may be used. ) Is formed, the horizontal portion is integrally attached to the upper surface of the FRP lower frame by an adhesive such as epoxy to function as a shear connector.

As described above, in the present invention, since the longitudinal and transverse fibers are arranged in a lattice shape, the shear connector is composed of a hybrid FRP having a fibrous mat layer formed by impregnating a fibrous mat having a mat shape. While fully functioning as a connecting material, the effect of utilizing the material properties of hybrid FRP is exhibited.

That is, since the shear connector brings light weight, it does not increase the weight of the lower frame, and the shear connector is made of the same material as the lower frame and can be attached by an adhesive, so that the installation of the shear connector is easy and simple. Therefore, there is a significant advantage in construction cost and construction period.

Therefore, it is possible to further increase the utilization of the FRP lower frame.

Although the embodiments of the present invention have been described above, the present invention is not limited to the described embodiments, and free modifications and improvements can be made within the spirit and claims of the present invention.

1 is a perspective view of a bottom plate with one embodiment of a hybrid FRP shear connector in accordance with the present invention.

Figure 2a is a schematic perspective view of the hybrid FRP shear connector.

Figure 2b is an exploded perspective view of the hybrid FRP shear connector shown in Figure 2a.

3A is a schematic perspective view of a shear connector having an N-shaped cross section as an embodiment of the above-described hybrid FRP shear connector according to the present invention.

Figure 3b is an exploded perspective view of the hybrid FRP shear connector shown in Figure 3a.

Figure 4a is a schematic perspective view of a shear connector having a c-shaped cross section as an embodiment of the hybrid FRP shear connector according to the present invention.

Figure 4b is an exploded perspective view of the hybrid FRP shear connector shown in Figure 4a.

5 is a schematic perspective view of the applicant's composite bottom plate filed in patent application 10-2002-40869.

* Explanation of symbols for the main parts of the drawings *

1 Composite deck 10 Lower frame

20 Concrete Slab 100 Hybrid FRP Shear Connector

101 Horizontal 102 Vertical

114 Top Layer 115 Bottom Layer

116 Fiber Mat 117 Fiber Mat Layer

Claims (5)

It consists of a lower frame 10 made of fiber-reinforced plastic and a concrete slab 20 formed thereon, wherein the lower frame 10 has a top plate 11 and a lower plate 12 spaced apart by a predetermined height. The cavity part 14 provided by the partition 13 which is provided between the upper plate 11 and the lower plate 12 is continuously formed side by side in the longitudinal direction, and the said cavity part 14 is transverse In the composite bottom plate having a structure that is formed long in the direction to form a tube, In order to couple the lower frame 10 and the concrete slab 20, the upper surface of the lower frame 10, has a predetermined length in the direction perpendicular to the throttle, the flat horizontal portion 101 and the horizontal portion Shear connecting member 100 consisting of a vertical portion 102 protruding integrally to have a predetermined height in the center of the 101 is integrally installed by the adhesive, The shear connector 100, the upper layer 114 and the lower layer 115 and impregnated in the resin (3) in the state in which the fibers 2 are arranged side by side in the longitudinal direction, the longitudinal and transverse fibers grating The fiber mat layer 117 formed by impregnating the resin 113 with the fiber mat 116 arranged in the shape of a mat is formed in a structure that is integrally provided between the upper layer 114 and the lower layer 115. A composite bottom plate having a shear connector made of a hybrid fiber reinforced plastic, characterized in that. The method of claim 1, The shear connector 100 is a composite bottom plate, characterized in that having an inverted T-shaped cross section. The method of claim 1, The shear connector 100 is a composite bottom plate, characterized in that it has a b-shaped cross section. The method of claim 1, The shear connector 100 is a composite bottom plate, characterized in that it has a c-shaped cross section. The method according to any one of claims 1 to 4, In the vertical portion 102 of the shear connecting material 100, a plurality of holes 103 is formed so that the concrete flows when placing concrete for the concrete slab 20 of the upper upper frame 10 is formed Composite bottom plate.