KR101921024B1 - Perfobond Rib Supplemented with Steel Tube - Google Patents

Abstract

The present invention relates to a shear connecting material essential for a composite structure of a steel material and concrete, and more specifically relates to a shear connecting material which is able to easily provide additional shear restriction force by inserting and installing a reinforcing member in a conventional perfobond hole. The present invention provides the shear connecting material used in the composite structure of the steel material and concrete, comprising: a steel plate main body long in one direction; the perfobond hole formed in the main body; and the reinforcing member inserted and fixed to the perfobond hole and being a steel tube having an identical length exposed to the outside of the perfobond hole to both sides of the hole, wherein at least a part of the main body, the perfobond hole, and the reinforcing member are coupled while being accommodating in the concrete.

Description

{Perfobond Rib Supplemented with Steel Tube}

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a shear connector essential to a composite structure of steel and concrete, and more particularly, to a shear connector capable of easily providing an additional shear resistance by inserting a reinforcing member into a conventional perforated bond hole.

Composite girder combined with steel girder and concrete slab is a typical composite structure which is very efficient in terms of structure. Various types of shear connectors have been developed because shear connectors are required for the synthesis of steel and concrete. One of such shear connectors is the perforated rod sheathed connector shown in FIG. 1A. The perforated bond ribbed shear connection was designed by Leonhardt to solve the fatigue problem of the stud and was applied to the Third Caroni Bridge of Venezuela as a shear connection material. The steel plate with four holes was installed on the upper flange of the girder at a predetermined interval in the longitudinal direction of the girder. Respectively. 1B is a view illustrating a shear resistance operation mechanism of the perforated bond rib as shown in FIG. 1A, wherein the shear resistance is a horizontal shear resistance, a vertical shear resistance, and a perforation bond hole. Shear resistance by the passing reinforcing bar, and (4) shear resistance by the action of the pressing action of the rib end. 1B and 1B are the horizontal and vertical components of the shear resistance due to the dowel action of the concrete passing through the perforated bond hole, respectively. The perforated bond rib is a rigid shear connection material and lacks ductility. However, using a reinforcing bar passing through the perforated bond hole in Fig. 1B can achieve a considerable ductility. 1B, the shear resistance due to the pressing action of the end of the rib is considerably large and is generally about the same as the sum of (1) the horizontal shear resistance of the perforated bond holes (3 to 4) in the rib.

FIG. 2 is a view of a perforated bond rib, which is a continuous type of perforated bond ribs, which is difficult to apply automatic welding by a machine, and which can solve the problem of the perforated bond rib shown in FIG. .

Fig. 3 shows the magnitude of the design shear force generally considered in the simple beam composite girder design, which is large at the point portion and constant at the center portion. The shear force due to the distributed load is the largest at the point where the point is located and becomes 0 at the center, but the shear force due to the moving concentrated load is constant over the entire interval. Also, considering the temperature difference between steel and concrete, shrinkage of concrete, minimum design shear force, etc., the size of the design shear force is usually the same as that of the lower diagram in Fig. Although not shown, the design shear force is large at the point and small at the center of the span in the case of continuous beams.

The continuous perforated-rib rib as shown in Fig. 2 can not obtain the shear resistance due to the seam pressure at the end of the rib at the end of Fig. 1B, and thus the shear resistance performance is lower than that of the perforated rib. The shear resistance can be increased by increasing the diameter of the reinforcing bar passing through the perforated bond hole. However, since the reinforcing bar provided in the perforated bond hole is not made of a separate reinforcing bar but is made of a transverse reinforcing bar disposed at the lower end of the slab, It is practically difficult to change. Since the lateral reinforcing bars of the slab are always arranged at regular intervals, the perforated bond holes are arranged so as to fit thereon (generally, the reinforcing bars are installed one by one per perforated bond hole because the lateral reinforcing bar spacing is wide). Therefore, in the case of the continuous perforated-rib rib as shown in FIG. 2, the shear resistance can be changed only by changing the size of the perforated bond hole. However, in order to increase the size of the holes, it is practically impossible to increase the height of the ribs, since the height of the ribs must be increased but interference with the upper-side slab-side rebars passing over the perforated ribs should be avoided. As described above, since the continuous perforated-rib rib shear connector as shown in FIG. 2 provides shear resistance of almost the same size in all sections, it is difficult to efficiently cope with the design shear force varying according to the section as shown in FIG. In fact, intermittently installed perforated bond ribs can provide a somewhat greater shear resistance than continuous perforated bond ribs, but it is difficult to significantly increase shear resistance according to varying shear forces.

Generally, the shear force acting on the composite girder is proportional to the girder length. Therefore, there is no problem in applying the continuous perforated rib rib shear connection material as shown in FIG. 2 to synthetic girders having a short diameter, but in the case of synthetic girders having a long diameter, the design shear force in the vicinity of the rib is considerably large, It is difficult to provide enough shear resistance only with the penetrating reinforcing bars.

 SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the related art, and it is an object of the present invention to provide a perforated bond which is installed at regular intervals in order to use a transverse reinforcing bar of a concrete slab as a penetrating reinforcing bar, A shear connection member having additional shear resistance performance in addition to the shear resistance by the hole.

As a means for solving the above-mentioned problems,

In the shear connector used for the composite structure of steel and concrete,

A main body which is a long steel plate in one direction;

A perforated bond hole formed in the body; And

And a reinforcing member inserted and fixed in the perforated bond hole, and the length of the perforated bond hole exposed to the outside is the same steel pipe on both sides of the hole,

Wherein at least a part of the main body and the perforated bond hole and the reinforcing member are engaged with each other while being accommodated in the concrete.

The length of the portion of the reinforcing member exposed from the perforated bond hole is preferably determined according to the required shear resistance.

The reinforcing member is preferably joined to the perforated bond hole by tack welding.

According to the present invention, it is possible to provide an economical and structurally efficient shear connection member by inserting a steel pipe into a hole of a plate-shaped shear connection member having a perforated bond hole and adding a shear resistance due to a pressing action of a steel pipe projected to both sides of the hole.

Figure 1a is a perfobond rib shear connector.
1b shows a shear-resistant actuation mechanism of a perfobond rib shear connector.
FIG. 2 shows a conventional application example of continuous perforated ribs.
3 is a magnitude distribution diagram of the shear force used in designing a shear connection of a simple beam composite girder.
4 is a view for explaining a shear connector according to one embodiment of the present invention.
Figures 5A-5C illustrate another embodiment of a shear connector according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

4 is a view for explaining a shear connector according to an embodiment of the present invention.

The shear connector according to the present embodiment is used for a composite structure of steel and concrete, and is usually used in a form of being joined to a steel material by welding or the like.

The shear connector according to the present embodiment comprises a main body 10, a perforated bond hole 20, and a reinforcing member 30.

The main body 10 is a steel plate which is long in one direction as shown in the lower part of Fig.

The perforated bond hole 20 is a hole formed along the longitudinal direction of the main body 10.

The reinforcing member 30 is inserted into the perforated bond hole 20 and is fixed and exposed to the outside of the perforated bond hole 20, thereby increasing the shear resistance.

The length of the perforated bond hole 20 exposed to the outside is equally symmetrical with respect to both sides of the perforated bond hole 20.

The reinforcing member 30 is inserted into the concrete at the time of synthesis with the concrete and is fixed by the hardened concrete after the concrete is cured.

The shear force of the composite girder is determined by the contact action acting between the perforated bond hole 20 and the reinforcing member 30 and the acupressure action between the reinforcing member 30 and the concrete and the concrete dowel action at the end of the reinforcing member 30. [ the reinforcing member 30 can be fixed only to the extent that it does not move when the concrete is poured. That is, in the present invention, slip between the shear connector and the concrete is caused by the dowel action of the concrete placed in the reinforcing member 30 and the reinforcing member 30, which are tightened to the perforated hole 20, The reinforcement member 30 fixed to the perforated bond hole 20 may be formed in a structure that prevents the shear slip by inserting the reinforcement member 30 fixed to the perforated bond hole 20 into the perforated bond hole 20 ).

For this reason, in the present embodiment, the reinforcing member 30 is fixed to the perforated bond hole 20 by tack welding. Tack welding is a welding method in which a part of the joints is welded in a spot shape with a welding rod, and is a welding method used to temporarily fix two members to be welded before welding the front surface. In addition to tack welding, the reinforcing member 30 may be fixed to the perforated hole 20 by using an adhesive or using a wedge.

Since the reinforcement member 30 is hollow, the reinforcing member 30 can be installed through the reinforcing member 30 even if the reinforcing member 30 is provided in the perforated bond hole 20, and the reinforcing member 30 can be installed in the perforated hole 20 by the concrete dowel action. The shear resistance force is transferred to the exposed both ends of the reinforcing member 30 and is still operated. The perforated bond hole 20 reinforced by the reinforcing member 30 as in the present invention is exposed to the outside of the perforated hole 20 of the reinforcing member 30 in addition to the shear resistance of the conventional perforated bond hole 20 The shear resistance of the reinforcing member 30 is increased.

In the case of the shear connector according to the embodiment of the present invention shown in FIG. 4, since the shear connector is long and continuous in one direction unlike the shear connector shown in FIG. 1A, there is no shear resistance due to the pressing action at the end indicated by? It can be seen that the reinforcing member 30 reinforces the shear resistance.

As long as the length of the reinforcing member 30 is not very long, the strength of the reinforcing member 30 filled with concrete is so great that the final shear failure is caused by the breakage of the outside concrete of the reinforcing member 30 and the inner side of the reinforcing member 30 It is dominated by the dowel destruction of concrete.

The length of the portion of the reinforcing member 30 exposed from the perforated-hole 20 is determined according to the required shear resistance. The length of the exposed portion is increased in a portion where a relatively large shear resistance is required and the length of the exposed portion is shortened in a portion where a relatively small shear resistance is required.

Since the length of the reinforcing member 30 is not so long, it is possible to easily change the shear resistance by changing the length of the reinforcing member 30 without interfering with the slab reinforcement.

4, a reinforcing member 30a having a relatively long length is provided at the end portion where the shearing force largely acts, and a middle portion at which the relatively small reinforcing member 30b is provided and the shearing force is smallest The right end of the composite girder is designed not to be provided with a reinforcing member but is designed to effectively cope with the design shear force of the composite girder which changes according to the section.

Hereinafter, a shear connector according to another embodiment of the present invention will be described.

5A to 5C are views showing another embodiment of the shear connector according to the present invention.

5A to 5C also include a main body 10, a perforated bond hole 20 and a reinforcing member 30. This configuration is substantially the same as the configuration of the embodiment described above, Will be omitted and only the differences will be briefly explained.

The embodiment shown in FIG. 5A is an embodiment using the abdomen of the T-shaped stiffener as the main body 10, as compared with the use of the rod-shaped rib shown in FIG. 4 as the main body 10, It is effective to use the ribs of the cross section as the main body 10 as a structural element of the mold. The shear connector using the abdomen of the T-shaped cross-section rib as the body 10 as shown in Fig. 5A can be used to lower the mold height of the synthetic girder. Reference numerals 1, 2, and 3 denote upper flange, abdomen, and lower flange, respectively.

The shear connector shown in FIG. 5B uses a part of the abdomen portion of the inverted T-shaped steel girder as the main body 10 and the perforated bond hole 20 and the reinforcing member 30 are installed in the main body 10 to serve as a shear connector This is an example of configuration. Since the upper flange of the steel girder and the concrete slab have the same structural role after the synthesis, they are used in the case of composing the girder prior to the main girder. 5B, the shear connection member shown in FIG. 5B has a structure in which the abdomen portion of the steel girder buried in concrete is used as the main body 10, the perforated bond hole 20 and the reinforcing member 30 are provided in the main body 10, It is possible to avoid the use of a separate shear connection member as in the prior art, thereby omitting the welding connection between the steel girder and the shear connection member. Reference numerals 2 and 3 in Fig. 5B denote the abdomen and the lower flange, respectively.

5b, all of the plate-like components of the steel girder buried in the concrete in the course of the synthesis are used as the main body 10 and the perforated bond hole 20 and the reinforcing member 30 ) Can be formed and used as shear connectors.

The embodiment shown in FIG. 5C is an embodiment in which the vertical reinforcing member of the lower box girder lower flange is used as the main body 10 and the perforated bond hole 20 and the reinforcing member 30 are formed in the main body 10. The lower flange 3 of the double composite steel box girder is combined with the concrete lower slab S and generally uses a stud as the shear connection material between the lower flange 3 and the lower slab S, A shear connector using a longitudinal stiffener provided on a flange 3 as a main body 10 is used as a substitute for a generally used stud.

Unlike ordinary steel box girders in which longitudinal stiffeners are installed on the lower flange to prevent buckling in the section of consecutive bridges, double composite steel box girders are required to have longitudinal stiffeners after synthesis because the lower flanges are combined with the lower slab of concrete It disappears. However, in general, a double composite steel box girder requires a minimum of longitudinal stiffener to prevent buckling due to the compressive stress of the lower flange during installation because the steel box girder is placed on the lower structure and then the lower slab concrete is laid . 5c, a longitudinal stiffener is used as the main body 10, and a perforated bond hole 20 and a reinforcing member (not shown) are formed on the main body 10, 30, it is possible to reduce the number of studs (not shown) installed on the lower flange because the shear connector can function as a shear connector in addition to the buckling prevention function. The shear connector used in combination with the longitudinal stiffener shown in FIG. 5C has a perforated bond hole in the stiffener abdomen (main body) to reduce the rigidity. However, since the rigidity of the longitudinal stiffener is evaluated by the second- Since the longitudinal stiffener of the lower flange 3 can prevent buckling only against the load up to the lower concrete installation, the rigidity required is small, and the vertical stiffener (body) Is not a problem.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, But can be embodied as various types of shear connectors within a range that does not deviate.

10: main body 20: perforated bond hole
30: reinforcing member

Claims (3)

In the shear connector used for the composite structure of steel and concrete,
A main body which is a long steel plate in one direction;
A perforated bond hole formed in the body; And
And a reinforcing member inserted and fixed in the perforated bond hole, and the length of the perforated bond hole exposed to the outside is the same steel pipe on both sides of the hole,
At least a part of the main body and the perforated bond hole and the reinforcing member are received in the concrete,
The length of the portion of the reinforcement member exposed from the perforated bond hole is determined according to the shear resistance required in consideration of the occurrence of shear failure caused by the breakage of the outer concrete of the reinforcing member and the destruction of the dowel of the reinforcing member inner concrete And the shear connection member is determined.
delete The method according to claim 1,
Wherein the reinforcing member is joined to the perforated bond hole by tack welding.

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