KR20220074551A - Composite Rahmen Structure And Method for Constructing the Same - Google Patents

Abstract

The present invention relates to a fire-resistant synthetic Ramen structure using a precast girder in which a fire-resistant material layer is integrated on the lower surface of a concrete layer and a construction method thereof. a plurality of vertical members to be installed; The upper part is made of a concrete layer, and the lower part is made of a fire retardant layer of a flame retardant or non-combustible material that is integrally laminated on the concrete layer. girder; coupling means for connecting the plurality of precast girders to each other without gaps; and a slab made of cured concrete after being poured on the plurality of precast girders.

Description

Composite Rahmen Structure And Method for Constructing the Same

The present invention relates to a fire-resistant synthetic Ramen structure, and more particularly, to a fire-resistant synthetic Ramen structure using a precast girder in which a fire-resistant material layer is integrated with a lower surface of a concrete layer, and a construction method thereof.

In general, the Ramen (Rahmen) structural form has a structure (Rigid-Frame) in which a horizontal member supporting a horizontal force and a vertical member supporting a vertical force are integrally rigidly bonded to each other at a right leg portion. That is, the ramen structure can be said to be a structure in which the rigidity of the entire structure is increased by resisting an external load by the flexural rigidity of the rigid horizontal and vertical members.

Therefore, a Rigid-Frame Bridge or Rahmen Bridge is a bridge in which a pier or abutment, which is a vertical member, and a girder, which is a horizontal member, are rigidly connected to each other. After installing the girder on the pier or abutment formed together, the slab is poured on the upper part of the girder, and then the right leg part is rigidly constructed.

Since a normal reinforced concrete ramen bridge consists of only a slab and a pier or abutment, the cross section is increased at the point where the slab and the pier or abutment are connected to each other to resist the external force acting on the bridge itself. However, if the cross-section increases, problems such as an increase in the fixed load and a reduction in the forming space of the bridge occur. A general form using a girder is being used.

On the other hand, the conventional Ramen bridge using precast girder has a disadvantage in that it is vulnerable to fire because the entire or lower surface of the precast girder is made of concrete.

Accordingly, conventionally, a method of constructing a separate fire-resistance panel made of a flame-retardant or non-combustible board on the lower side of the precast girder or finishing with a fire-resistant coating material is used.

However, in the dry construction method of fire-resistance panels, it is difficult to secure fire-resistance performance at the joint between the fire-resistance panel and the fire-resistance panel manufactured in advance at the factory. There is a problem in that it is difficult to install an anchor to fix it, so that the workability is deteriorated.

In addition, in the method of spraying fireproof material on the lower surface of the precast girder, it is very difficult to secure a uniform thickness of the fireproof material. There is a disadvantage in that the work to secure adhesion by additionally installing anchors and wire meshes is preceded.

In particular, refractory spraying installed on site is large-scale safety due to the separation and drop-off of refractory materials and structures during long-term operation of the precast girder and freezing and thawing due to residual water or seepage water remaining in the material to be sprayed, wind load and vibration impact of heavy vehicles, etc. The risk of accidents has existed. In addition, since the lower refractory material layer and the upper concrete layer of the precast girder are different materials, the separation phenomenon can easily occur. present as a major risk factor.

Republic of Korea Patent Publication No. 10-2009-0070496 (published on July 1, 2009) Republic of Korea Patent Registration No. 10-1169003 (Registered on July 20, 2012)

The present invention is to solve the above-mentioned conventional problems, and an object of the present invention is to produce a precast girder by integrating a refractory material layer on the lower surface of a concrete layer, thereby providing a fire-resistant synthetic ramen structure with excellent workability and fire resistance and a construction method thereof. will provide

Another object of the present invention is to provide a fire-resistant synthetic Ramen structure capable of constructing a slab by pouring concrete directly on a precast girder without using a separate copper bar or formwork for slab construction, and a construction method thereof.

In accordance with the present invention for achieving the above object, there is provided a fire-resistant synthetic Ramen structure, comprising: a plurality of vertical members installed to face each other at a predetermined interval in the ground; The upper part is made of a concrete layer, and the lower part is made of a fire retardant layer of a flame retardant or non-combustible material that is integrally laminated on the concrete layer. girder; coupling means for connecting the plurality of precast girders to each other without gaps; and a slab made of cured concrete after being poured on the plurality of precast girders.

The concrete layer of the precast girder may be formed in an inverted 'T' or 'ㅛ' shape.

An auxiliary connecting member for integrally connecting the refractory material layer and the concrete layer may be installed between the refractory material layer and the concrete layer of the precast girder.

A plurality of bonding reinforcing fibers that increase bonding strength while integrally connecting the fire resistance layer and the concrete layer to the interface between the fire resistant layer and the concrete layer of the precast girder may be dispersed.

A reinforcing wire may be embedded in the concrete layer of the precast girder.

The reinforcing wire may be a pre-stressed steel wire or a post-stressed steel wire to which tension is introduced.

The reinforcing wire may be a plurality of reinforcing bars embedded in the longitudinal direction or the width direction of the precast girder.

The method of constructing the fire-resistant synthetic Ramen structure according to the present invention is,

(S1) forming a fire resistant layer by spraying or applying a wet fire resistant material up to a predetermined height required to secure fire resistance performance inside the formwork for manufacturing a girder;

(S2) forming a concrete layer by pouring concrete on the upper surface of the refractory material layer;

(S3) after curing the refractory material layer and the concrete layer, demolding the formwork for manufacturing the girder to manufacture a precast girder;

(S4) installing a plurality of vertical members on the ground;

(S5) seating both ends of the plurality of precast girders manufactured through the steps (S1) to (S3) on the upper end of the vertical member and arranging them continuously laterally;

(S6) connecting the plurality of precast girders by coupling means, and fixing both ends of the precast girders to the upper ends of the vertical members; and,

(S7) pouring concrete on the plurality of precast girders, curing the concrete, and constructing a slab;

may include

Before performing the step (S1), a plurality of auxiliary connecting materials are disposed on the bottom surface of the formwork for manufacturing the girder, and when the fire resistant layer is formed in the step (S1), the upper portion of the auxiliary connecting material protrudes above the upper surface of the fire resistant layer A refractory material layer may be formed.

The formwork for manufacturing the girder may be formed in an inverted 'T' or 'ㅛ' shape.

In addition, between the steps (S1) and (S2), a plurality of bonding reinforcing fibers are dispersed on the refractory material layer, and the bonding reinforcing fibers are embedded in the interface between the fire resistant material layer and the concrete layer to increase bonding strength.

According to the present invention, since the precast girder constituting the fire-resistant synthetic Ramen structure is manufactured as an integrated structure with the lower refractory material layer and the upper concrete layer, there is no need for separate refractory material construction after construction. There is an effect that can improve safety and fire resistance because the phenomenon of separation and drop-off does not occur.

In addition, since the precast girder is formed in a reverse 'T' shape or a double reverse 'T' shape ('ㅛ' shape) as a whole, a plurality of girders are continuously arranged in the lateral direction (width direction) without gaps, so separate formwork and copper bars are installed. There is also the effect of being able to construct a slab without doing so.

1 is a perspective view of a fire-resistant synthetic Ramen structure according to an embodiment of the present invention.
FIG. 2 is a side view of the fire-resistant synthetic Ramen structure shown in FIG. 1 .
3 is a perspective view of a main part of the fire-resistant synthetic ramen structure shown in FIG. 1 .
FIG. 4 is a front cross-sectional view of the fire-resistant synthetic Ramen structure shown in FIG. 1 .
5 is a cross-sectional view showing the connection structure of the precast girder constituting the fire-resistant synthetic Ramen structure shown in FIG.
6 is a side view showing a modified example of some components of the precast girder constituting the fire-resistant synthetic Ramen structure of the present invention.
7 is a front cross-sectional view showing another embodiment of the precast girder constituting the fire-resistant synthetic Ramen structure of the present invention.
8A to 8D are views showing an embodiment of a construction method of a fire-resistant synthetic Ramen structure according to the present invention.

The configuration shown in the embodiments and drawings described in this specification is only a preferred example of the disclosed invention, and there may be various modifications that can replace the embodiments and drawings of the present specification at the time of filing of the present application.

Hereinafter, a fire-resistant synthetic Ramen structure and a construction method thereof will be described in detail according to the embodiments described below with reference to the accompanying drawings.

1 to 4, the fire-resistant synthetic Ramen structure according to an embodiment of the present invention includes a plurality of vertical members 100 that are installed to face each other at a predetermined interval on the ground, and both ends of the vertical member 100. A plurality of precast girders 200 arranged on the side of the vertical member 100 while being connected to the upper end, a coupling means for connecting the plurality of precast girders 200 to each other without a gap, the plurality of precast girders ( 200) and includes a slab 300 made of cured concrete after being poured on it.

The vertical member 100 has a function of transmitting the transmitted load to the bottom of the excavation, and may be constructed by casting on-site or may be constructed by connecting to each other in the longitudinal direction with a precast member. The vertical member 100 may be a wall or column (pier or abutment) extending in a direction perpendicular to the ground, and one end of the precast girder 200 is rigidly attached to the upper end.

To this end, the upper surface of the coupler 110 for connecting the reinforcing bar is exposed at the upper end of the vertical member 100, and the steel reinforcing bar is fastened to the coupler 110 so that when the slab concrete is poured later, it is buried in the slab 300 The vertical member and the slab 300 may be rigidly bonded to each other after the slab concrete is cured by being bound to the steel reinforcement. The coupler 110 may be disposed on the outside and the inside of the upper end of the vertical member 100, respectively.

A plurality of shear reinforcing bars 121 protruding in an inverted 'U' shape are embedded in the upper end of the vertical member 100 , and H-shaped steel bracing brackets 240 are embedded in the lower ends of both ends of the precast girder 200 . do. The H-shaped steel bracing bracket 240 is positioned between the shear reinforcing bars 121, and a plurality of connection holes 241 to which the embedded reinforcing bars 122 pass while passing through are formed at the lower end of the flange. The shear reinforcing bar 121 is embedded in the right leg portion to serve as a kind of reinforcing material. It has an important function of constraining the position of the precast girder 200 due to construction impact and impact during upper slab concrete pouring, etc.

The precast girder 200 is installed in the transverse direction on an underpass or the like, and may be made of fire-resistant PSC (Prestressed Concrete) to which prestress is introduced. The precast girder 200 has a structure in which the upper part is made of a concrete layer 210, and the lower part is a fire retardant layer 220 made of a flame retardant or non-combustible material that is integrally laminated on the concrete layer 210 to ensure fire resistance. have

The precast girder 200 as a whole is made in the form of a reverse 'T' or a double reverse 'T', that is, a 'ㅛ' shape, and a plurality of them are continuously arranged without gaps in the lateral direction (width direction), so that a separate formwork is not installed. It is possible to construct the slab 300 by pouring concrete directly on the precast girder 200 without it.

The reinforcing wire 230 may be embedded in the concrete layer 210 of the precast girder 200 . The reinforcing wire 230 may be a pre-stressed steel wire or a post-stressed steel wire to which tension is introduced, or may be composed of a plurality of reinforcing bars 260 (refer to FIG. 8c ) arranged at regular intervals in the concrete layer 210 . . Of course, the pre-stressed steel wire or the post-stressed steel wire may be installed together with the reinforcing bar 260 .

Both ends of the precast girder 200 are connected to the upper end of the vertical member 100 , and a plurality of the precast girder 200 are continuously arranged laterally of the vertical member 100 . A plurality of precast girders 200 are connected to each other without a gap by a coupling means. Referring to FIG. 5 , the coupling means may include a first connection bracket 251 and a second connection bracket 252 that are fastened to both ends of the lower flange of the precast girder 200 with bolts 255 . The first connection bracket 251 is embedded in one end of the lower flange of the precast girder 200 and has a structure in which a first bolt fastening hole 251a into which the bolt 255 is inserted is formed. And the second connection bracket 252 has a rectangular box shape with an open upper surface, and has a structure in which a second bolt fastening hole 252a corresponding to the first bolt fastening hole 251a is formed on the outer surface. have. Accordingly, in a state in which the first connection bracket 251 and the second connection bracket 252 are connected to each other, the operator uses the first bolt fastening hole 251a and the second connection bracket 252 through the open upper surface of the second connection bracket 252. A plurality of precast girders 200 are connected to each other by fastening the bolts 255 to the bolt fastening holes 252a, and then concrete is poured in the field through the open upper surface of the second connection bracket 252 to make the second It is possible to secure continuity by filling in the empty space of the connection bracket (252).

On the other hand, the concrete layer 210 and the refractory material layer 220 of the precast girder 200 is poured into the formwork 400 for girder production in a factory and manufactured integrally. The refractory layer 220 may be formed of a known flame retardant or non-flammable refractory mortar, but preferably a hydration reactant including gypsum and cement, blast furnace slag, fly ash, fumed silica, and metakaolin. A pozzolan material containing at least one of, an explosion inhibitor containing styrofoam powder, cellulose ether, and cellulose, an admixture containing a binder, a moisture reducing agent, and a surfactant, and a fire-resistant mortar containing aggregate can The binder may include at least one of a vinyl acetate-ethylene copolymer, a styrene-(meth)acrylate copolymer, and a vinyl acetate-vinyl versatate copolymer. The refractory material layer 220 made of this composition has excellent fire resistance and chemical resistance, and the effect of absorbing moisture (water vapor) generated from the concrete layer 210 and absorbing thermal stress is excellent, thereby preventing the explosion and damage of the precast girder. It is excellent, and has the advantage of excellent workability and adhesion.

The refractory material layer 220 and the concrete layer 210 of the precast girder 200 are sequentially poured on the formwork 400 for girder production, then cured and integrated, and the fireproof material layer 220 and the concrete layer 210 are Since they are made of different materials, in order to increase the bonding force between the fireproof material layer 220 and the concrete layer 210 and secure mechanical strength, a fireproof material is disposed between the fireproof material layer 220 and the concrete layer 210 of the precast girder 200 . An auxiliary connecting material for integrally connecting the layer 220 and the concrete layer 210 may be installed. The auxiliary connecting material may include stud members 260 arranged at regular intervals in the width direction and the length direction in the fire resistant material layer 220 and the concrete layer 210 as shown in FIG. 8A . The stud member 260 is formed to extend upwardly in the center of the mesh plate 261 embedded in the fire resistant layer 220 and the mesh plate 261 to the fire resistant layer 220 and the concrete layer 210 at the same time. The embedded stud pin 262 may be included.

In addition, the structure of the H-shaped steel grain bracket 240 installed at the lower ends of both ends of the precast girder 200 for connection with the vertical member 100 may be modified and used as an auxiliary connecting material. For example, as shown in FIG. 6, after extending the web 240b of the steel bracket 240 in one direction, the bonding ribs 243 are formed in the upper and lower sides at the ends of the web 240b in the form of a square box. , as the bonding rib 243 is embedded in the fire resistant layer 220 and the concrete layer 210 , the bonding strength between the fire resistant layer 220 and the concrete layer 210 may be increased.

Connection holes 242 to which a plurality of U-shaped reinforcing bars 245 are connected are formed to penetrate through the upper ends of both side flanges of the rigid bracket 240 .

And, as shown in FIG. 7 , the refractory material layer 220 and the concrete layer 210 are integrally connected to the interface between the refractory material layer 220 and the concrete layer 210 of the precast girder 200 and joined while being integrated. A plurality of bonding reinforcing fibers 270 that increase strength may be dispersed. The joint reinforcing fiber 270 may be a steel fiber having a length of about 2 to 6 cm, and the fire resistant layer 220 immediately after pouring the fire resistant layer 220 in the process of manufacturing the precast girder 200 . ), by pouring the concrete layer 210, it is attached to the interface between the refractory material layer 220 and the concrete layer 210 at the same time to connect the interface between the refractory material layer 220 and the concrete layer 210 to increase the bonding strength. acts to make

Next, a method of constructing the above-described fire-resistant synthetic Ramen structure will be described in detail.

First, the factory manufactures a precast girder 200 in which the refractory material layer 220 and the concrete layer 210 are integrated. That is, as shown in FIGS. 8a to 8d, a release agent such as lubricating oil is applied inside the formwork 400 for girder production having a cavity of a shape corresponding to the shape of the precast girder 200, and auxiliary A connecting material and/or a rigid bracket 240 is installed at a predetermined position on the bottom surface of the formwork 400 for girder production. Then, the fire resistant layer 220 is formed by spraying or applying the wet fire resistant material to the inside of the girder manufacturing form 400 to a predetermined height required to secure fire resistance performance. At this time, after the fire resistant layer 220 is formed, the bonding reinforcing fibers 270 (refer to FIG. 8c ) may be scattered and dispersed on the fire resistant layer 220 .

When the refractory material layer 220 is cured, the reinforcing rebar 245 is connected through the connection hole 242 at the upper end of the steel grain bracket 240, and a plurality of reinforcing bars or beams for reinforcement on the fire resistant layer 220 are used. installed reinforcement. Then, a prestressed steel wire is installed as a reinforcing wire and tension is introduced.

Next, concrete is poured on the upper surface of the fireproof material layer 220 to form the concrete layer 210, and then the fireproof material layer 220 and the concrete layer 210 are cured by steam curing method, etc. When demolding, the precast girder 200 in which the refractory material layer 220 and the concrete layer 210 are integrated can be manufactured. The precast girder 200 manufactured in this way is transferred to the construction site.

At the construction site, a plurality of vertical members 100 made of pillars or walls are installed on the excavated ground.

And both ends of the precast girder 200 are seated on the upper end of the vertical member 100 and are continuously arranged laterally. At this time, after arranging the lower end of the flange of the steel grain bracket 240 formed at both ends of the precast girder 200 between the shear reinforcing bars 121 at the upper end of the vertical member 100, the steel grain brackets ( 240) The precast girder 200 is rigidly attached to the upper end of the vertical member 100 by penetrating and connecting the embedded reinforcing bar 122 through the connecting hole 241 at the bottom. And a plurality of precast girders 200 arranged in the transverse direction are connected by the above-described coupling means.

After arranging a plurality of precast girder 200 continuously on the vertical member 100 and strengthening it, the space between the lower flange of the precast girder 200 is closed with a sealing material such as silicone so that there is no gap, and the precast After the reinforcing bar is connected to the coupler 110 above the girder 200 and constructed, concrete is poured on the plurality of precast girder 200 and cured to construct the slab 300 .

As described above, the precast girder 200 constituting the fire-resistant synthetic Ramen structure of the present invention has an integrated structure in which the lower fire-resistant material layer 220 and the upper concrete layer 210 are integrated, so there is no need for a separate fire-resistant material construction after construction, A phenomenon in which the refractory material layer 220 is separated and dropped from the concrete layer 210 does not occur.

In addition, since the precast girder 200 is formed in a reverse 'T' shape or a double reverse 'T' shape ('ㅛ' shape) as a whole, and a plurality of them are continuously arranged without gaps in the transverse direction (width direction), separate formwork and There is also the advantage of being able to construct the slab 300 without installing the copper bar.

In the above, the present invention has been described in detail with reference to the embodiments, but those of ordinary skill in the art to which the present invention pertains may make various substitutions, additions and modifications within the scope not departing from the technical spirit described above. Of course, it should be understood that such modified embodiments also fall within the protection scope of the present invention as defined by the appended claims below.

100: vertical member 110: coupler
121: shear reinforcing bar 122: embedded reinforcing bar
200: precast girder 210: concrete layer
220: refractory material layer 230: reinforcing wire
240: steel bracket 241, 242: connection hole
243: joint rib 251: first connection bracket
252: second connection bracket 260: stud member
261: mesh plate 262: stud pins
270: joint reinforcement fiber 300: slab
400: Formwork for girder production

Claims (11)

a plurality of vertical members installed to face each other at predetermined intervals on the ground;
The upper part is made of a concrete layer, and the lower part is made of a fire retardant layer of a flame retardant or non-combustible material that is integrally laminated on the concrete layer. girder;
coupling means for connecting the plurality of precast girders to each other without gaps; and,
a slab made of cured concrete after being poured on the plurality of precast girders;
A fire-resistant synthetic Ramen structure comprising a. According to claim 1, wherein the concrete layer of the precast girder is a fire-resistant synthetic ramen structure in the form of an inverted 'T' or 'ㅛ'. [Claim 2] The fire-resisting synthetic ramen structure according to claim 1, wherein an auxiliary connecting material for integrally connecting the fire-resistant material layer and the concrete layer is installed between the fire-resistant material layer and the concrete layer of the precast girder. The fire-resisting synthetic ramen structure according to claim 1, wherein a plurality of bonding reinforcing fibers for increasing bonding strength while integrally connecting the fire-resisting material layer and the concrete layer to the interface between the fire-resistant material layer and the concrete layer of the precast girder are dispersed. The fire-resisting synthetic Ramen structure according to claim 1, wherein a reinforcing wire is embedded in the concrete layer of the precast girder. [6] The fire-resisting synthetic Ramen structure according to claim 5, wherein the reinforcing wire is a pre-stressed steel wire or a post-stressed steel wire to which tension is introduced. [Claim 6] The fire-resisting synthetic Ramen structure according to claim 5, wherein the reinforcing wire is made of a plurality of reinforcing bars embedded in the longitudinal direction or the width direction of the precast girder. A method for constructing a fire-resistant synthetic Ramen structure according to any one of claims 1 to 7, comprising:
(S1) forming a fire resistant layer by spraying or applying a wet fire resistant material up to a predetermined height required to secure fire resistance performance inside a formwork for manufacturing a girder;
(S2) forming a concrete layer by pouring concrete on the upper surface of the refractory material layer;
(S3) after curing the refractory material layer and the concrete layer, demolding the formwork for manufacturing the girder to manufacture a precast girder;
(S4) installing a plurality of vertical members on the ground;
(S5) seating both ends of the plurality of precast girders manufactured through the steps (S1) to (S3) on the upper end of the vertical member and arranging them continuously laterally;
(S6) connecting the plurality of precast girders by coupling means, and fixing both ends of the precast girders to the upper ends of the vertical members; and,
(S7) pouring concrete on the plurality of precast girders, curing the concrete, and constructing a slab;
A construction method of a fire-resistant synthetic Ramen structure comprising a. According to claim 8, wherein a plurality of auxiliary connecting materials are disposed on the bottom surface of the formwork for girder production before performing the step (S1), and when the fire resistant material layer is formed in the step (S1), the upper portion of the auxiliary connecting material is a fire resistant layer A construction method of a fire-resistant synthetic Ramen structure in which a fire-resistant material layer is formed so as to protrude above the upper surface of the [Claim 9] The method of claim 8, wherein the formwork for manufacturing the girder has an inverted 'T' or 'ㅛ' shape. The method according to claim 8, wherein a plurality of bonding reinforcing fibers are dispersed on the refractory material layer between the steps (S1) and (S2), and the bonding reinforcing fibers are embedded in the interface between the refractory material layer and the concrete layer to increase bonding strength. Construction method of fire-resistant synthetic Ramen structure.

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