KR101264577B1 - Steel frame concrete beam and manufacturing method of the same - Google Patents

Abstract

PURPOSE: A steel frame concrete beam and a manufacturing method of the same are provided to increase the strength and stiffness of a beam within a negative moment section without increasing the cross section of the beam by an end reinforcement steel material and a PS steel material for a negative moment section. CONSTITUTION: A steel frame concrete beam(10) comprises a concrete beam(12), an end reinforcement steel material(14), a plurality of negative moment section installation PS steel materials(16), and a plurality of positive moment section installation PS steel materials(18). The concrete beam is poured with concrete to have a regular length and an identical cross section and is equipped with a positive moment section(L1) in the center and a negative moment section(L2) on both sides. The end reinforcement steel material is positioned on both sides of the concrete beam. One side of the end reinforcement steel material is inserted into the negative moment section for being synthesized with concrete. The other side of the end reinforcement steel material is exposed by a predetermined length from the end of the concrete beam by escaping the negative moment section. A negative moment section installation PS steel material is installed on the top of the end reinforcement steel material through a post tension method. A positive moment section installation PS steel material is installed on the bottom side of the end reinforcement steel material through a post tension method. The positive moment section installation PS steel material is attached to the concrete only in the positive moment section to introduce pre-stress.

Description

Steel frame concrete beam and manufacturing method of the same

The present invention relates to a steel concrete beam and a method for manufacturing the same, and in particular, the beam supporting the floor slab of the steel structure is configured by combining a steel material that is easy to join the concrete and steel columns, which is advantageous for securing the integrity of the slab concrete, A steel concrete beam and a fabrication method thereof are provided in which steel materials are arranged in a parent moment section and pre-stress is introduced in advance, thereby increasing the strength and rigidity of beams in a constant moment section and a parent section section economically and efficiently.

Steel and reinforced concrete are used as representative materials of the building, steel is easy to large span, and reinforced concrete has structural characteristics that are advantageous for compressive force and rigidity.

HI (Hybrid & Intergrated Beam) beam is a new composite beam that integrates the two members by utilizing the structural advantages of steel and reinforced concrete. Both ends of the beam are made of reinforced concrete to secure the integrity of the reinforced concrete. The central part of the beam consists of steel, which is advantageous in large span.

However, the steel forming the central portion of the beam has a problem of increasing the manufacturing cost compared to reinforced concrete. In addition, both ends of reinforced concrete has a problem that it is difficult to join the steel pillars.

As a background technology of the present invention, Korean Laid-Open Patent Publication No. 2003-0094195 discloses an improved prestressed steel reinforced concrete beam and a bridge construction method using the same. It forms a T-shaped steel part by forming a through hole having a constant size in the central part of the abdomen of the I-type steel, and forms a plurality of bolt holes in a certain area of the upper part of the abdomen of a certain area of both side ends, After forming a bolt hole in a constant area, a connecting portion having triangular supports on both sides of the connecting portion abdomen is formed at both ends of the lower flange of the steel at regular intervals, and the T-shaped steel portion of the I-type steel is formed. Reinforcing bars outside the central through-hole I-beam with a pair of fixing brackets on the upper surface of the steel upper flange, and extending the steel bars of constant length to the connecting portions at both ends, and fixing the PC steel wires to the connecting portions. Install a plurality of PC steel wire anchorages, and then install a plurality of PC steel wires, and After installing the device gyojwa support the unit, and then curing the poured concrete in the central bore of steel I-beams except a connecting portion of said opposite sides is characterized in that produced by introducing a prestress to the PC steel.

However, the background art can implement a long span by applying steel to all the beams, whereas the cross section cannot be used efficiently and the construction cost remains high.

Korean Laid-Open Patent Publication No. 2003-0091521 Korean Laid-Open Patent Publication No. 10-2006-0038701

The present invention comprises a combination of steel and steel that is easy to join the steel pillars, which is advantageous for securing the integrity of the slab concrete, the beam supporting the floor slab of the steel structure, the steel is arranged in the parent section and the steel in advance It is an object of the present invention to provide a steel concrete beam and a method of manufacturing the steel beams which have increased the strength and rigidity of beams in the constant moment section and the parent section section economically and efficiently by introducing prestress.

Steel concrete beams according to a preferred embodiment of the present invention,

A concrete beam having a constant length and the same cross section and having a central moment section and a parent section section at both ends;

End reinforcing steels, each of which is positioned at both parent sections of the concrete beam, is integrally formed with the concrete beam, and partially exposed to a certain length from the end of the concrete beam;

PS steel materials for installing a plurality of parental sections are respectively installed in the upper tension of the end reinforcing steel in the post-tension method; And

It is tensioned and fixed by the pretension method, and is located below the neutral axis of the concrete beam, and is not attached to the parent moment section, and only the positive moment section is attached to the concrete, and includes a plurality of PS steels for installing the constant moment section to introduce prestress. .

In addition, the PS steel material for installing the parent section is characterized in that the number of installations decreases toward the center direction starting from the end of the concrete beam.

In addition, the PS steel for installing the constant moment section is characterized in that the number of installation decreases toward the end direction starting from the center of the concrete beam.

In addition, the concrete beam is characterized by having a rectangular cross section or an I-shaped cross-sectional structure.

In addition, the end reinforcing steel is characterized in that it has an H-shaped or I-shaped cross-sectional structure.

In addition, the concrete beam is configured only in the parent moment section and the PS steel for installing the constant moment section is removed, the both ends reinforcing steel is characterized in that it forms a continuous integral type extending to the constant moment section.

In addition, the concrete beam in the constant moment section is continuously configured only in the upper portion of the neutral shaft, and the PS steel for installing the constant moment section is removed, both ends reinforcing steel is characterized in that the continuous integral form extending to the constant moment section.

In addition, both end reinforcing steel is characterized in that it further extends in the same cross-section to form a continuous integral type.

Method for producing a steel concrete beam according to a preferred embodiment of the present invention,

Arranging the PS steel for installation of the constant moment section under the neutral axis (X) in the formwork for manufacturing the concrete beam, but inserting or taping the non-attachment pipe to the PS steel 18 in the parent moment section;

After the upper reinforcement is provided with the end reinforcement steel which is installed in the tension tension of the PS steel for the installation of the parent section section, the part of the end reinforcing steel is respectively located inside the mold end and the other part is exposed outside the end of the formwork. Installing to make;

Pulling the PS steel for the constant moment section in a pretension manner;

Manufacturing concrete beams by pouring concrete into the formwork; And

After the hardening of the concrete by the pre-tension method is characterized in that it is manufactured through the step of introducing the prestress only in the moment of the positive moment by releasing the tensile force of the PS steel for the moment installation section.

According to the steel-concrete beam of the present invention and a method of manufacturing the same, an increase in the strength and rigidity of the beam in the parent cement section without increasing the cross section of the beam by the end reinforcement steel and the PS steel for tension-fixed parent cement section installed at the upper end thereof Has the possible effect.

In addition, since the PS steel material for the installation of the parent section is embedded in the concrete slab, the fire resistance is not affected by the fire, and thus, a separate fireproof process is unnecessary.

In addition, the steel-concrete beam is made of concrete, except for the exposed portion of the end reinforcing steel can be reduced in manufacturing cost compared to the beam made of steel as a whole, it is possible to reduce the construction cost of the entire steel structure.

In addition, the strength and stiffness of the constant moment section by the PS steel for installation of the constant moment section and the strength and stiffness of the parent section by the PS steel for installation of the parent moment section can be increased, respectively, thereby making it possible to make the long span into an efficient cross section.

In addition, the height of the cross section of the concrete beam can be lowered to minimize the height of the floor, it is advantageous for large spaces.

The following drawings, which are attached in this specification, illustrate the preferred embodiments of the present invention, and together with the detailed description thereof, serve to further understand the technical spirit of the present invention. It should not be construed as limited.
1 is a perspective view of a steel concrete beam according to an embodiment of the present invention.
FIG. 2 is a partially enlarged recessed view of FIG. 1; FIG.
3 is a cross-sectional view taken along the line AA and BB of FIG.
4 to 6 is a cross-sectional view of the steel concrete beam according to another embodiment of the present invention.
Figure 7 is a moment diagram of the steel concrete beam shown in the state the PS steel is removed.
8 is a manufacturing process of the steel concrete beams according to an embodiment of the present invention.
9 is a view showing a state of joining the steel concrete beam and the pillar according to an embodiment of the present invention.
10 is a construction state diagram of the concrete slab in FIG.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the embodiments shown in the accompanying drawings, but the present invention is not limited thereto.

Steel concrete beam 10 according to an embodiment of the present invention is shown in Figures 1-3. 1 is a perspective view of a steel concrete beam according to an embodiment of the present invention, FIG. 2 is a partially cut-out enlarged view of FIG. 1, and FIG. 3 is a cross-sectional view taken along line A-A and line B-B of FIG. 1.

As shown in FIGS. 1 to 3, the steel concrete beam 10 has a constant length and the same cross section and is cast in concrete so that the concrete beam 12 having the constant moment section L1 at the center and the parent section sections L2 and L2 at both sides thereof. Has At this time, the overall length of the concrete beam 12 is configured to be shorter than the length between the columns (5, 5) consisting of adjacent steel frame or reinforced concrete as shown in FIG. Concrete beam 12 may have a rectangular cross section or an I-shaped cross-sectional structure.

Here, as shown in FIG. 7, the positive moment section L1 is a (+) section in which the tensile force acts downward based on the neutral axis, and the parent moment sections (L2, L2) are (-) in which the tensile force acts upward on the neutral axis. It means a section.

At both ends of the concrete beam 12, end reinforcing steels 14 and 14 are located, respectively. The end reinforcing steels 14 and 14 are partially inserted into the parent cement section L2 and are composited with concrete, and the other part is installed by being exposed to a predetermined length from the end of the concrete beam 12 beyond the parent cement section L2. do. The end reinforcing steels 14 and 14 have an H-shaped or I-shaped cross-sectional structure. The exposed portion of the end reinforcing steels 14 and 14 has a plurality of joining holes 141 for bolting. On the upper surfaces of the end reinforcing steels (14, 14), a plurality of PS steel fixing plates (142) disposed in the parent section (L2) is provided.

On the upper surfaces of the end reinforcing steels (14, 14), a plurality of parent steel sections for installing the PS steel material 16 is provided by introducing a tension force by a post-tension method. Therefore, the PS steel 16 is disposed in the parent section (L2) of the concrete beam 12. Preferably, the PS steel material 16 for installing the parent section is installed so that the number of installations decreases toward the center direction starting from the end of the concrete beam 12. In the present embodiment, the PS steel material 16 for installing the parent section is configured to decrease in the order of four and two, but the present invention is not limited to the number of such reductions.

A PS steel material 18 for installing a constant moment section by a pretension method is installed below the neutral axis X of the concrete beam 12. At this time, the PS steel material 18 for installing the constant moment section is unattached in the parent moment section L2, and only the constant moment section L1 is attached to the concrete so that prestress is introduced.

The moment in the middle of the center of the concrete beam 12 is the largest and smaller toward both ends. At this time, the non-attachment section of the PS steel material 18 installed in the parent section (L2) is preferably installed in step length by extending the section to the constant moment section (L1) in consideration of the size of the moment.

This is a pretensioning installation method derived from the same concept as the concept of reducing the number of installation of the PS steel 16 installed in the parent section (L2) from the end toward the center.

The manufacturing method of the steel-concrete concrete beam 10 comprised in this way is demonstrated.

First, as shown in (a) of FIG. 8, a plurality of PS steels 18 for installing a constant moment section are disposed in the formwork 100 for manufacturing the concrete beam 12 below the neutral axis X. At this time, the PS steel material for installing the constant moment section 18 is inserted into the non-attachment pipe 102 as shown in Figure 2 in the parent section (L2) or put to tape. At this time, the length of the non-attachment pipe may extend part of the constant moment section.

Then, a part of the end reinforcing steel (14, 14) is placed in the interior of the end of the formwork 100, respectively, and installed so as to expose the other portion to the outside of the end of the formwork 100 for a predetermined length. At this time, the end reinforcing steel (14, 14) is used that is equipped with the PS steel material 16 for the installation of the parent section section is fixed to the PS steel fixing plate 142 through a known fixing device, respectively.

Next, the PS steel 18 for constant moment section installation is tensioned. At this time, the fixing point of the PS steel material 18 for the constant moment section is placed in a position outside the formwork 100. The tensioning of the PS steel 18 is made by a pretensioning tensioning tool including a hydraulic jack.

Then, concrete is poured into the formwork 100 to produce a concrete beam 12.

Then, after curing of the concrete as shown in Fig. 8 (b), the formwork is removed and the tension of the PS steel 18 for static moment section installation in which tension is introduced by the pretension method is released and cut at the end of the concrete beam 12. After the pre-stress is introduced only in the constant moment section. At this time, in the parent section, the PS steel material 18 for installing the constant moment section penetrates the non-attachment pipe 102 so that adhesion with concrete does not occur.

The steel-concrete beam 10 manufactured as described above is steel-bonded to the steel column 5 through the end reinforcing steels 14 and 14 to perform the function of the beam. In addition, after the installation of the steel concrete beam 10, the concrete slab 100 is completed by pouring concrete after installation of the deck plate 30 and the reinforcement as shown in FIG.

As such, when the concrete slab is constructed, the PS steel 16 for installing the parent section, which is installed in tension on the top of the end reinforcing steels 14 and 14, is embedded in the concrete slab to have fire resistance without being affected by fire. There is no need for a separate fireproof process.

In addition, the PS steel material 18 installed in the constant moment section (L1) is embedded in the interior of the concrete beam 12 has a fire resistance that is not affected by the fire, and thus there is no need for a separate fire process.

In addition, the steel-concrete beam 10 is made of concrete, except for the exposed portion of the end reinforcing steel (14, 14) is made of concrete can reduce the manufacturing cost compared to the beam made of steel as a whole, construction cost of the entire steel structure You can make it cheaper.

In addition, the amount of deflection of the static moment by the PS steel material 18 for constant moment section installation and the amount of deflection of the parent moment by the PS steel material 16 for parent section installation can be reduced, respectively, and the long span can be increased.

In addition, the height of the cross-section of the concrete beam 12 can be lowered to minimize the height of the floor, it is advantageous in large space.

<Other Embodiments>

On the other hand, the cross-sectional structure in the constant moment section (L2) of the steel concrete beam 10 applied to the present invention may appear in various forms.

For example, as shown in FIG. 4, the concrete beam 12 is discontinuous in the constant moment section L1, that is, is configured only in the parent moment section L2, and the PS steel 18 for installing the constant moment section may appear in a removed form. have. At this time, both ends of the reinforcing steel (14, 14) is extended in the same section in the constant moment section to form a continuous integral type.

As another example, as shown in FIG. 5, the concrete beam 12 may be continuously formed only on the upper portion of the neutral axis X, and at the same time, the PS steel 18 for installing the constant moment section may be removed. At this time, both ends of the reinforcing steel (14, 14) extends in the same section in the constant moment section appears to form a continuous integral type.

As another example, as shown in FIG. 6, both end reinforcing steels 14 and 14 in the constant moment section L1 may further extend in the same cross section to form a continuous integrated type.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art in light of the above teachings. will be. The invention is not limited by these variations and modifications, but is limited only by the claims appended hereto.

10: reinforced concrete beam
12: concrete beam
14: end reinforcing steel
16: PS steel for installation of parent section
18: PS steel for regular moment section installation

Claims (9)

A concrete beam 12 having a cross section equal to a predetermined length and having a center constant moment section L1 and a parent section section L2 and L2 at both ends thereof;
The end reinforcing steels, which are positioned in the parent section sections L2 at both ends of the concrete beams 12, are integrally formed with the concrete beams 12, and are partially exposed at a length from the ends of the concrete beams 12 ( 14,14);
PS steels 16 for installing a plurality of parental sections, which are respectively installed on the upper surfaces of the end reinforcing steels 14 and 14 in a post tension manner; And
Tension and fixation by the pretension method, located below the neutral axis (X) of the concrete beam (12), unattached in the parent moment section (L2), and only a constant moment section (L1) of concrete, a plurality of static moment introduced prestress Steel concrete beam, characterized in that it comprises a section steel PS for installation section 18. The method of claim 1,
PS steel material for the non-mention section installation is a steel concrete beam, characterized in that the number of installation decreases toward the center starting from the end of the concrete beam 12. The method of claim 1,
PS steel material for constant moment section 18 is a steel concrete beam, characterized in that the number of installations decreases toward the end direction starting from the center of the concrete beam 12. The method of claim 1,
Concrete beam 12 is a steel concrete beam, characterized in that having a cross-section or I-shaped cross-section structure. The method of claim 1,
Steel frame for the end reinforcement (14, 14) is characterized in that the H- or I-shaped cross-section structure. The method of claim 1,
Concrete beam 12 is configured only in the constant moment section (L1) and the PS steel 18 for installing the constant moment section is removed, both ends reinforcing steel (14, 14) is extended to the constant moment section (L1) Steel concrete beams, characterized in that the integral. The method of claim 1,
Concrete beam 12 is constructed in the upper moment section (L1) continuously on the upper side only on the basis of the neutral axis (X), the PS steel for mounting the constant moment section (18) is removed, both ends reinforcing steel (14, 14) Steel concrete beam, characterized in that extending to the constant moment section (L1) to form a continuous integral. The method of claim 1,
Steel beams for both ends reinforcement (14, 14) is further extended in the same section with each other to form a continuous integral structure. In the formwork for manufacturing the concrete beam 12, the PS steel material 18 for installing the constant moment section is disposed below the neutral axis X, and the non-adhesive pipe is inserted or taped to the PS steel 18 in the parent moment section. Laying step;
After the end reinforcing steel (14, 14) is provided on the upper surface in the post-tension method to install the PS steel material (16) for tension section installation tension, a part of the end reinforcing steel (14, 14) of the form end Placing each inside and exposing the other to outside the end of the formwork;
Tensioning the constant moment section for mounting the PS steel 18 in a pretension manner;
Manufacturing concrete beams 12 by pouring concrete into the formwork; And
After the hardening of the concrete by releasing the tensile force of the PS steel material for installing the constant moment section 18 to introduce the prestress only in the constant moment section; manufacturing method of steel concrete beam, characterized in that produced through.

Images