KR20100069847A - Precast steel-concrete composite girder and manufacturing method thereof - Google Patents

Abstract

PURPOSE: A precast cast steel composite girder and a manufacturing method thereof are provided to increase pre-stress and section hardness by improving coupling structure of a concrete member, a shape steel member, and a tension member. CONSTITUTION: A precast cast steel composite girder(100) comprises a concrete member(10), a tension member(20), a shape steel member(30), and a shear connection member(40). The concrete member comprises a hollow in the longitudinal direction and multiple holes in the width direction. The tension member is positioned in the concrete member toward the setting direction. The shape steel member is integrated with the concrete member.

Description

Precast composite girder and manufacturing method {PRECAST STEEL-CONCRETE COMPOSITE GIRDER AND MANUFACTURING METHOD THEREOF}

The present invention relates to a composite girder, and more particularly to a precast composite girder and a manufacturing method.

The general structure of the bridge includes a plurality of bridges placed on the ground at regular intervals, a girder disposed at regular intervals on the upper surface of the bridge, and a slab disposed on top of the girder.

Among various bridges, short span bridges of 20m or less include slab bridges that transfer vehicle loads to bridges or piers with slabs alone. Slab bridges are bridges whose superstructures consist solely of slabs. The slab bridge is mainly used reinforced concrete (RC) slab (RC slab) bridge or prestressed concrete (PSC) slab (PSC slab) bridge.

By the way, such a slab bridge is manufactured by pouring concrete into the formwork supported by the club in the field. This site casting method has disadvantages in that it is cumbersome to work with copper or formwork and delay in air.

The present invention provides a precast rigid girder and a manufacturing method capable of increasing the cross-sectional stiffness and prestress by improving the coupling structure of the concrete member and the tension member coupled to the concrete member formed by centrifugal molding.

In addition, it is possible to easily integrate the precast composite girders adjacent to each other, and to provide a precast composite girders and a manufacturing method that can maintain the prestress in the connection portion.

In addition, the present invention provides a precast composite girder and a manufacturing method which can facilitate the synthesis of the precast composite girder and the gradient concrete bonded to the upper side by improving the top structure of the precast composite girder.

Precast rigid girder is a concrete member having a hollow in the first direction in the longitudinal direction, extending in a second direction in the width direction, a concrete member having a plurality of holes, a plurality of arrangements provided in the set direction in the concrete member to provide a tension force to the concrete member A tension member of the member, a plurality of section members having an exposed surface on the upper surface of the concrete member and integrally coupled with the concrete member, and a floor coupled to each of the section members exposed surface and extending upward, integrally coupled to the upper side of the concrete member in the field It includes a plurality of shear connection member embedded in the member.

At least one side of the tension member is embedded inside the concrete member, and at least one side thereof is exposed to the outside of the concrete member, and a plurality of precast parts are cast through a process in which the parts connected to the tension members of the other precast rigid girder adjacent to each other are cast into concrete. Rigid girders can be integrally formed.

The tension member may include a plurality of first tension members disposed in the first direction in the concrete member and supporting the longitudinal tension, and a plurality of second tension members disposed in the second direction in the concrete member and supporting the transverse tension. Can be.

The first tension member may be disposed along the circumferential surface from the lower side with respect to the circumferential surface center line of the hollow portion, and the second tension member may be disposed at positions displaced from the shape steel member and the first tension member, respectively.

The concrete member may be formed by centrifugal molding.

On the other hand, the precast rigid girder manufacturing method comprises the steps of forming a concrete member having a hollow portion in the longitudinal direction in the longitudinal direction by centrifugal molding, forming a plurality of holes in the second direction in the width direction of the concrete member, Arranging a plurality of tension members in a set direction in the concrete member, combining a plurality of member steel members having an exposed surface on the upper surface of the concrete member with the concrete member integrally, extending upward from each member steel member exposed surface And a plurality of shear connection members embedded in the bottom member integrally coupled to the upper side.

Arranging the plurality of tension members may be so that at least one side is exposed to the outside of the concrete member, respectively, in a state buried inside the concrete member.

Arranging a plurality of first tension members in a first direction in the concrete member to support longitudinal tension, and arranging a plurality of second tension members in a second direction in the concrete member to support transverse tension; can do.

The first tension member may be disposed along the circumferential surface from the lower side with respect to the circumferential center line of the hollow portion.

The second tension member may be disposed at a position that is displaced from the beam member and the first tension member, respectively.

Providing a plurality of precast rigid girders, connecting the tension members exposed from each of the adjacent precast rigid girders to each other, and placing concrete on the parts where the tension members are connected to each other to form a plurality of precast rigid girders It may further comprise the step of integrally forming the girders.

The precast rigid girder can increase the stiffness of the cross section that can resist the compressive stress because the form steel member is synthesized on the upper surface of the centrifugal concrete member.

In addition, since the neutral shaft is moved to the compression part by arranging the shaped steel member on the upper side of the precast rigid girder, the amount of eccentricity of the tension member is increased so that a large compressive stress can be introduced at least in the tension portion.

In addition, when the precast composite girders are connected to each other and used for bridges, adjacent precast composite girders can be easily integrated, and the prestress is joined by welding the tension members exposed to each other by welding and casting concrete. Can be maintained.

In addition, by improving the structure of the upper surface of the precast rigid girder by coupling the shear connection member to the upper surface of the steel member disposed on the upper side of the concrete member to facilitate the synthesis of the precast rigid girder and the gradient concrete coupled to the upper side can do.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the specification and drawings, the same reference numerals denote the same elements.

1 is a perspective view showing the shape of a precast rigid girder according to an embodiment of the present invention. And Figure 2 is a perspective view showing a partially cut shape coupled to the bottom member in a state in which the precast composite girder according to the embodiment of the present invention is connected to each other, Figure 3 is a schematic view of the connection portion between the precast composite girder It is sectional drawing.

Referring to FIG. 1, the precast rigid girder 100 according to the embodiment of the present invention includes a concrete member 10, a tension member 20, a shape steel member 30, and a shear connection member 40.

The concrete member 10 extends with the hollow portion 12 in the first direction (z-axis) in the longitudinal direction, and has a plurality of holes 14 in the second direction (x-axis) in the width direction. For reference, the plurality of holes 14 are also arranged in the third direction (y-axis) in the height direction. That is, the plurality of holes 14 are provided at both sides in the second direction and at both sides in the third direction, respectively. Looking at the concrete member 10 in the first direction, a plurality of holes 14 are made of four, each arranged to be close to the corner portion.

Concrete member 10 is formed by centrifugal molding. Concrete member 10 may have a cross-sectional shape perpendicular to the longitudinal direction in a square. For example, as shown in Figure 1 may be formed in a rectangular shape, each corner may be formed to have a rounding (rounding) with a set radius of curvature.

The tension member 20 is disposed in the setting direction in the concrete member 10 to provide a tension force to the concrete member 10. The tension member 20 is provided in plurality. The tension member 20 is disposed in the first direction in the concrete member 10 to support the longitudinal tension in the plurality of first tension members 22, and in the second direction in the concrete member 10 in the transverse tension It may include a plurality of second tension member 24 for supporting.

At least one side of the tension member 20 is embedded inside the concrete member 10 and is exposed to the outside of the concrete member 10, and a portion connected to the tension member 20 of the other precast rigid composite girders adjacent to each other. A plurality of precast rigid composite girders 100 may be integrally formed through a process of pouring concrete.

Referring to FIG. 3, the length of the first tension member 22 is formed longer than the length of the first direction based on the concrete member 10, and the first tension members 22 adjacent to each other are overlapped with each other. Can be arranged. The first tension members 22 adjacent to each other are joined by welding, respectively. Therefore, the first tension members 22 adjacent to each other may be formed as an integral first tension member 22 through respective welding couplings.

The first tension member 22 may be disposed along the circumferential surface from the lower side with respect to the circumferential center line of the hollow part 12. If necessary, the first tension member 22 may be disposed in a straight shape without being disposed along the circumferential surface of the hollow part 12. That is, the first tension member 22 may be disposed in the form of a straight line in the first direction from the lower side of the hollow part 12. Here, the form in which the plurality of first tension members 22 are disposed along the corresponding direction may be made different through various design changes, and any structure may be used to reinforce the lower side of the precast rigid girder 100. Do.

The second tension member 24 may be replaced with a steel bar and inserted into the plurality of holes 14 disposed in the second direction in the concrete member 10. When the plurality of precast rigid composite girders 100 are connected in the lateral direction through the second tension member 24, separate coupling members may be provided at both ends of the second tension member 24. For example, as shown in FIG. 2, the coupling structure at both ends of the second tension member 24 may process the threaded portions at both ends of the second tension member 24 and may be fastened by a nut to the threaded portion. The second tension member 24 and the coupling structure can be made different through various design changes, the connection relationship and the transverse direction of the precast rigid girder 100 adjacent to each other in the transverse direction of the precast rigid girder 100 Any structure that can relieve tension is possible.

On the other hand, the second tension member 24 is disposed at positions displaced from the shape steel member 30 and the first tension member 22, respectively. That is, the second tension member 24 may be disposed between the upper portion of the shaped steel member 30 and the hollow portion 12 with respect to the second direction. The second tension member 24 may be disposed between the lower side of the first tension member 22 and the bottom surface of the concrete member 10. If necessary, the second tension member 24 may be disposed between the lower side of the hollow portion 12 and the first tension member 22.

The shaped steel member 30 has an exposed surface on the upper surface of the concrete member 10 and is integrally coupled with the concrete member 10. The shaped steel member 30 has a first member 32 forming an upper surface and a second member 34 extending downward from the first member 32. The second member 34 is formed in a direction perpendicular to the center of the width direction of the first member 32. Shaped steel member 30 is formed in the shape of Hangul vowel (TT).

As shown in FIG. 1, the shaped steel member 30 is disposed to extend in the first direction, and is provided in plurality in a second direction.

Shear connection member 40 is coupled to a plurality of exposed members of each of the section steel member 30 is extended upward. Shear connection member 40 is embedded in the bottom member 50 that is integrally coupled to the concrete member 10 on the site. Therefore, the connection state of the concrete member 10 and the bottom member 50 can be more firmly maintained through the plurality of shear connection members 40.

1 to 3 will be described a method of manufacturing a precast composite girder 100 according to an embodiment of the present invention.

First, a plurality of precast rigid composite girders 100 pre-tensioned in a factory are manufactured. Subsequently, the plurality of precast rigid composite girders 100 are transported to the site and hypothesized according to the site situation. Precast rigid composite girders 100 manufactured according to an embodiment of the present invention can be used for short span bridges. Therefore, in the case of using the precast rigid girder 100 for short span bridges, in the field, the precast rigid girder 100 is installed by placing no gaps in the axial direction so that the floor member 50 is poured by gradient concrete. Form.

In the precast rigid composite girders 100 produced at the factory, there is a restriction on the compression and tensile strength of the concrete, so that the shape member 30 and the tension member 20 are appropriately disposed in consideration of the cross-sectional shape. That is, the precast rigid composite girders 100 according to the embodiment of the present invention are manufactured by arranging the shaped steel member 30 on the upper side of the concrete member 10 and centrifugally molding the concrete member 10 and then introducing pretension. do.

Centrifugal molding takes the form of curing at high temperatures while placing concrete in the closed formwork and rotating it in the axial direction when manufacturing pile members. In this case, concrete can express 1.5 times higher strength than general curing and can pretension the steel rod inserted into the rebar, so it is efficient to use as a tension member. However, if the prestress is largely applied, the compressive stress is also increased, which is not suitable for use as a girder in which the compressive stress is large.

For this reason, the precast rigid girder 100 according to the embodiment of the present invention is centrifugally molded into a concrete member 10 having a circular hollow portion 12 in the center and a tension member 20, or steel rod for pretension. ) Is disposed below the concrete member 10. And the upper side of the concrete member 10 is disposed a member steel member 30 to resist the compressive force. In addition, the upper surface of the shaped steel member 30 is provided with a shear connecting member 40 for synthesis with the gradient concrete used as the bottom member 50.

As described above, the precast rigid composite girders 100 according to the embodiment of the present invention may be disposed on the upper side of the concrete member 10 to resist the compressive stress, and to resist the tensile stress Prestress can also be increased. In addition, since the section steel member 30 is synthesized with the concrete member 10, the cross-sectional rigidity is increased, and the neutral shaft is moved to the compression section, so that the eccentric amount of the tension member 20 is increased, so that even if the number of the tension members 20 is small, a large compressive stress is applied to the tension section. Can be introduced. In addition, by attaching the shear connection member 40 to the upper surface of the shaped steel member 30 disposed on the upper side of the concrete member 10 can be easily synthesized with the gradient concrete used as the floor member 50.

As shown in FIG. 2, the precast rigid girder 100 manufactured as described above is closely adhered to each other so that there is no gap in the second direction, and the slab bridge is then formed by pouring gradient concrete without forming a separate form. Can be completed.

Referring to FIG. 3, when using a precast rigid composite girder 100 having a relatively long length, such as a bridge, it is possible to know the details of the first directional joint when the span is extended.

The precast rigid girder 100 is manufactured to a set length in consideration of transportation when manufactured in a factory. And a plurality of precast rigid composite girders 100 are used in the field. For example, when forming the precast concrete girder to connect the neighboring precast rigid girder 100 in the first direction, the first tension member 22 inserted into the concrete member 10 in the first direction. To extend. Then, the exposed first tension members 22 are connected to each other by a lap joint or a coupler, and then the concrete is poured and integrated.

1 is a perspective view showing the shape of a precast rigid girder according to an embodiment of the present invention.

Figure 2 is a perspective view showing a partially cut shape coupled to the bottom member in a state in which the precast composite girder according to the embodiment of the present invention is connected to each other.

3 is a cross-sectional view schematically showing the connection between the precast composite girder.

<Description of the symbols for the main parts of the drawings>

10; Concrete member 20; Tension

22; First tension member 24; Second tension member

30; Section steel member 40; Shear connector

50; Floor member 100; Precast rigid girder

Claims (12)

A concrete member having a hollow portion in a first direction extending in a longitudinal direction and having a plurality of holes in a second direction in a width direction; A plurality of tension members disposed in the setting direction in the concrete member to provide tension to the concrete member; A plurality of member steel members having an exposed surface on the upper surface of the concrete member and integrally coupled with the concrete member; and A plurality of shear connection members coupled to each of the member steel member exposed surfaces and extending upward, and embedded in a floor member integrally coupled to an upper side of the concrete member at a site; Precast composite girder comprising a. The method of claim 1, At least one side of each of the tension members is exposed to the outside of the concrete member in a state embedded in the concrete member, a plurality of parts through the process of being connected to the tension member of the other precast rigid composite girder adjacent to each other Precast composite girder, in which the precast composite girders are integrally formed. The method of claim 2, The tension member A plurality of first tension members disposed in the first direction in the concrete member to support longitudinal tension; and A plurality of second tension member disposed in the second direction in the concrete member to support the transverse tension Precast composite girder comprising a. The method of claim 3, The first tension member is a precast rigid girders are disposed along the circumferential surface from the lower side relative to the circumferential center line of the hollow portion. The method of claim 4, wherein The second tension member is a precast rigid girder disposed in a position that is displaced from the first steel member and the first tension member, respectively. The method according to any one of claims 1 to 5, The concrete member is a precast rigid girder formed by centrifugal molding. Centrifugally forming a concrete member having a hollow portion in a first direction that is longitudinal; Forming a plurality of holes in a second direction that is a width direction of the concrete member; Disposing a plurality of tension members in a setting direction from the concrete member; Coupling the plurality of shaped steel members having an exposed surface integrally with the concrete member on an upper surface of the concrete member, and And a plurality of shear connection members embedded in a bottom member that is extended upward from the exposed surface of each of the shape members and is integrally coupled to the upper side of the concrete member. Precast steel composite girder manufacturing method comprising a. The method of claim 7, wherein Disposing the plurality of tension members Precast rigid composite girder manufacturing method for exposing at least one side to the outside of each concrete member in the state embedded in the concrete member. The method of claim 8, Arranging a plurality of first tension members in a first direction in the concrete member to support longitudinal tension; and Arranging a plurality of second tension members in a second direction in the concrete member to support lateral tension; Precast steel composite girder manufacturing method comprising a. 10. The method of claim 9, The first tension member is a precast rigid girder manufacturing method disposed on the circumferential surface from the lower side based on the circumferential center line of the hollow portion. The method of claim 10, The second tension member is a precast rigid composite girder manufacturing method disposed in a position that is displaced from the member and the first tension member, respectively. The method of claim 8, Providing a plurality of precast rigid girder; Connecting the tension members exposed from each of the precast rigid girder adjacent to each other; Placing concrete on the part where the tension members are connected to each other to form a plurality of precast rigid composite girders integrally Precast steel composite girder manufacturing method comprising a more.

Images