KR20120111506A - Girder making methos for precast end seggement using end mold and girder therewith - Google Patents

Abstract

PURPOSE: A girder manufacturing method using a precast end segment as an end form and a girder manufactured thereby are provided to reduce manufacturing costs by efficiently using a form. CONSTITUTION: A girder manufacturing method using a precast end segment as an end form is as follows. Both ends of a girder(100) in which prestress is concentrated are manufactured as precast end segments(110). The precast end segments are separated from each other in a longitudinal direction to be located at both ends of the girder. A center segment(120) is manufactured by setting a center form between the precast end segments. The outer edge surface of the center form and the inner surface of a form for the center segment are matched each other. Concrete is placed in the center form and is cured. The center form is de-molded. [Reference numerals] (AA) Longitudinal direction

Description

Girder manufacturing method using precast end segment as end formwork and girder made by the method {GIRDER MAKING METHOS FOR PRECAST END SEGGEMENT USING END MOLD AND GIRDER THEREWITH}

The present invention relates to a girder fabrication method using a precast end segment as an end form and to a girder made by the method. More specifically, in the fabrication of the beam for beams (girder), both ends are prefabricated first, because the load by the tension member is concentrated and the shape is complicated by the fixing device, and the center between the two ends is precast. The end segment manufactured first by cast method is used as end formwork, but it is possible to use more efficient formwork especially in the middle segment manufacturing, and the girder for the bridge which is easy to quality control due to the difference in the strength of the end and the central concrete. And to a method of manufacturing the same.

In general, bridges are expensive structures made to cross rivers, straits, bays, canals, lowlands, or other traffic routes or structures. Depending on the type of structure, there are girder bridges, trust bridges, arch bridges, suspension bridges, and ramen bridges.

On the other hand, the girder bridge 1 is a bridge mainly composed of the girder 10, and as shown in FIG. 1A, an upper portion thereof is provided by the girder 10 having an I-shaped cross section mounted on the upper surface of the pier 20. As a structure for supporting the bottom plate 30 of the girder, the slab concrete is poured on the upper surface of the girder 10 after the plurality of girders 10 are mounted between the bridge piers 20 and the piers 20 during the bridge manufacturing The bottom plate 30 is integrally formed on the upper surface of the 10.

And the girder bridge 1 is a plurality of cross beams 40 are installed in a direction orthogonal to the plurality of girders 10 mounted on the pier 20 to structurally connect the plurality of girders structurally.

Figure 1b is a partial perspective view of the completed girder 10 by the formwork 50 and formwork demoulding for producing the girder 10.

The formwork 50 is usually made of steel (steel plate and a plurality of angles), and first, the bottom member 51 is installed on both side members 52, and a plurality of tie bars 53 on the upper side of the side member 52. Are fixed by bolts 54,

The girder 10 is manufactured by pouring concrete (C) into the formwork space.

FIG. 1C illustrates an example of manufacturing the girder 10 having a predetermined length by using segments in which a plurality of girders are divided in the longitudinal direction, but combining the segments together.

That is, when the girder 10 having a predetermined length is used in a long bridge, workability and workability are very poor in transportation and construction, and thus the girder 10 is manufactured by combining a plurality of segments and then combining them.

That is, according to FIG. 1c, the girder 10 is made of three segments and then bonded to each other. In particular, the center segment 12 and the both end segments 11 and 13 are first connected to each other by using the joining block 14. After 15) to be bonded, it can be seen that the girder is manufactured in such a way as to be press-connected to each other using the tension member 16.

At this time, the junction block 14 can be seen that it can be used in both ends form the die in particular in the center segment 12, it is made of concrete having a compressive strength greater than the compressive strength of the center segment 12 It can be seen that.

That is, the junction block 14 is manufactured separately, and is used as an end form, and is integrally manufactured with the central segment 12, and the remaining both end segments 11 and 13 also have the junction block 14 as an end form at one end. It is manufactured by using the central segment to integrate the final segments (10, 12, 13) to complete the girder.

However, when fabricated in the PSC girder in this way, the prestress can only be concentrated at both ends of the girder by the tension material disposed therein, and the segments 11, 12, and 13 are applied by applying the joining block 14 to which high strength concrete is applied. Although the construction quality and performance of the joints are improved, the high-strength concrete is not applied to the fixing part where prestress is concentrated, and thus there is a limit in reducing the size and weight of the cross section by improving the construction quality and improving the sectional efficiency.

Therefore, when high strength concrete such as that applied to the joint block 14 is applied to each end of both end segments 11 and 13 in order to improve the cross-section efficiency of the fixing unit, the efficiency of the fixing unit is improved, but the amount of high strength concrete is too high. There is a disadvantage in that the material cost is greatly increased by the application of.

In addition, when the concrete having different strengths is poured at the same time to synthesize them, the hardening speed of each other is different. Therefore, when the concrete having different strengths is poured at the same time, the connection of concrete with different strengths may cause material separation on the concrete interface having different strengths. There was a problem that could be.

In addition, since the shape of the center segment 12 and the both end segments 12 and 13 manufactured using the junction block 14 is different, there is a disadvantage in that formwork having different shapes must be manufactured separately.

That is, since the length of the girder for each bridge can be varied, there is a problem that the initial production cost of the girder must be too much to manufacture the girder according to the actual various lengths as shown in FIG. 1C.

Therefore, while reducing the requirement of the formwork for manufacturing the girders (beams) most effectively, the necessity of efficient technology development in terms of the use of the form of girders, in particular in terms of the use of formwork, can effectively be required.

Accordingly, the present invention to improve the efficiency of the girder formwork in manufacturing the girder having a variety of conventional lengths to increase the production efficiency of the girder according to the extension length of the girder, through the reinforcement on both ends of the girder in which prestress is concentrated The present invention aims to solve a girder fabrication method using a precast end segment having efficient quality control as an end form and to provide a girder manufactured by the above method.

In the present invention, basically, both ends of the girder are first manufactured by a precast end segment having a predetermined length, and a bogie and a rail are used to set them as both end forms of the girder.

Through this, the setting work of the precast end segment according to the extension length of the girder is precise, and thus the die for the central segment can be used to have a unit length such as 1M and 2M.

In addition, by making the outer surface of the cross section of the girder center side of the precast end segment coincide with the inner surface of the formwork for the center segment having the same cross-sectional shape as that of the girder center side cross section of the end segment, the form utilization along the entire girder can be efficiently proceeded. Will be.

To this end,

Both end segments of the girder where the prestress by the fixing device is concentrated are first made of precast end segments using high-strength concrete,

The precast end segments are spaced apart from each other in the longitudinal direction of the girder so as to be located at both ends of the girder to be manufactured corresponding to the girder fabrication length,

A central section is manufactured by setting a central formwork between the precast end segments, wherein the central formwork has a central section having an outer surface of the cross section of the girder center side of both precast end segments having the same cross-sectional shape as the cross section of the girder center side of the end segment. According to the inner surface of the formwork for the segment, after the concrete is poured into the central formwork to cure, and providing a girder fabrication method using the precast end segment comprising the step of demolding the formwork.

Also preferably, the precast end segment and the central segment may be formed by connecting the connecting reinforcing bar and the inner reinforcing bar for the middle segment to be protruded in a longitudinal direction from both end faces of the precast end segment in an overlapping manner. Then, it provides a girder fabrication method using the precast end segment as an end form to cast and cure concrete to be integrated with each other.

Also preferably, the girder integrated by the precast end segment and the central segment ends the precast end segment such that the step of introducing the prestress by a tension member installed through a sheath preinstalled therein as the prestressed reinforced concrete girder Provides a method of making girders used as formwork.

Also preferably, the precast end segment is set to be located at both ends of the girder to be manufactured corresponding to the girder length in a state where both end brackets are movable in the longitudinal direction by a rail in a state where the precast end segment is prefabricated and stacked, and Provided is a girder fabrication method using a precast end segment as an end form to allow a central formwork to be set on an upper rail.

In addition, the present invention provides a girder by the girder manufacturing method,

Both end segments of the girder where the prestress by the fixing device is concentrated are first manufactured by the precast end segment using high-strength concrete, and the precast end segments are positioned at both ends of the girder to be manufactured according to the length of the girder. Spaced apart from each other in the longitudinal direction, and the center form between the precast end segment is set to produce a center segment, the center form is the outer surface of the cross section of the girder center side of both precast end segment is the center side of the girder of the end segment Endcast form precast end segment comprising the step of conforming to the inner surface of the formwork for the central segment having the same cross-sectional shape as the cross-section, casting and curing concrete inside the central formwork, and demoulding the central formwork. Ugh By using the girder, the strength of the concrete precast end segment provides girders using a precast segment to the end of the end mold to be formed higher than the concrete strength of the center segment.

Also preferably, the girders are provided inside the girders using precast end segments integrated with each other through pre-installed sheath pipes and precast end segments for introducing prestress into the central segment.

In accordance with the present invention, since the entire girder is manufactured in a state in which both ends are prepared in advance, not only can the efficiency of the formwork for the girder be used to reduce the cost of the girder,

Both ends of the girder are manufactured by precasting, but using high-strength concrete, it is possible to effectively resist the concentration of local load due to the introduction of prestress by the fixing device.

In addition, it is easy to manufacture girders according to the extension length of the girders to ensure full quality control in the factory.

The scope of the present invention is shown by the following claims rather than the above description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included in the scope of the present invention. do.

Figure 1a is a construction attempt of the conventional girder bridge,
Figure 1b is a partial perspective view of the girder after the formwork and demolding for the conventional girder,
Figure 1c is a manufacturing perspective view of a conventional segmented girder,
Figure 2a and 2b is a perspective view of the combination of the precast end segment and the center segment in accordance with the present invention,
3a, 3b, 3c and 3d is a construction sequence diagram of the girder according to the present invention,
4 is a perspective view of the girder bridge by the girder of the present invention.

DETAILED DESCRIPTION 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. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

<Girder 100 using precast end segment as end formwork>

Figures 2a and 2b show a perspective view of the combination of the precast end segment and the center segment according to the present invention.

First, as shown in FIG. 2A, the girder 100 of the present invention is largely divided into a precast end segment 110 and a center segment 120.

First, the precast end segment 110 is determined according to the cross-sectional shape of the girder, but since the girder is usually manufactured with an I-shaped cross section or a T-shaped cross section, the present invention looks at the basis of the girder manufactured with the T-shaped cross section in particular.

Accordingly, the precast end segment 110 is largely composed of an upper flange 111 having a horizontal plate shape and an abdomen 112 having a rectangular parallelepiped extending downward from the center bottom surface of the upper flange.

The precast end segment 110 is made of prestressed reinforced concrete, and the fixing unit 113 for introducing the prestress to the girder is installed on the end face.

The fixing device 113 is a sheath for accommodating a tension member (not shown), an anchor body in which a plurality of wedge holes are connected to which end portions of the sheath are connected and a tension member such as a PC strand is penetrated, and a wedge for fixing the tension member 125. And a fixing plate, and means a fixing device for a normal PC strand.

This fixing device 113 is exposed from the outside of the precast end segment 110, only the fixing plate and / or sheath is exposed, the anchor body is embedded in the precast end segment 110 and the tension and wedge tension the actual tension material And when settling.

2a shows that a plurality of fixing devices 113 are formed on both end faces of the abdomen 112 of the precast end segment 110. However, four fixing devices are installed. More or less than this.

However, when the long span girders are manufactured, many fixing devices 113 are inevitably formed on both end faces of the precast end segment 110 even though the tension material in the form of a lot is required.

In addition, since the local tension is concentrated in the fixing device 113 after the actual tension material is settled after tension, it is necessary to secure a cross-sectional area and a coating thickness that can resist such local stress, but the girder cross section is recently slimmed. In line with the trend, there is a problem that it is difficult to manufacture the precast end segment 110 having an end face capable of accommodating all of these fixing devices.

In addition, in order to sufficiently resist the local stress, high-strength concrete should be used, but only the end of the precast end segment 110 is formed of high-strength concrete, and the middle portion between the ends has a high strength when mixed with concrete of less strength than the high-strength concrete. Sliding due to load concentration may occur on other concrete interfaces later.

Therefore, it is not desirable to pour two concretes with different strengths at once, but first, a concrete member made of one strength should be manufactured, but the connecting reinforcing bar which can secure the integrity can be extended from the prefabricated member, and the concrete member having different strengths. This problem can be prevented by integrating a concrete member having a different strength with a concrete having different strength by pouring concrete of different formwork and different strength into the formwork while connecting the internal reinforcing bars to each other.

Therefore, the present invention is to produce the first using a high-strength concrete in manufacturing the precast end segment (110).

The precast end segment 110 manufactured as described above is manufactured to have a predetermined length. The length of the precast end segment 110 may be as small as possible in consideration of transport and the like after the production. It can be seen that the protrusion is formed so as to extend in a plurality of longitudinal directions.

The connecting bars 114 are connected to the internal reinforcing bars 124 of the central segment 120 to be integrated so as to extend over the upper flange 111 and the abdomen 112 of the precast end segment 110 to integrate with each other. The castle can be secured enough.

The precast end segment 110 is prefabricated formwork for the precast end segment 110 is manufactured in the factory and can be manufactured by applying strict quality control.

The precast end segment 110 is then formed such that the central segment 120 is integrated between the two precast end segments 110 in a state spaced apart from each other along the length extending in the entire longitudinal direction of the girder.

According to the extension length of the central segment 120 can also be formed by using a separate formwork for the central segment, an important point of the connecting rod 114 and the central segment 120 of the precast end segment 110 The internal reinforcing bars 124 must be connected.

This is because it is very important for the structural integration of the precast end segment 110 and the central segment.

For this purpose, the center segment 120 corresponds to the position of the connecting bar 114 in consideration of the connection of the connecting bar 114 of the precast end segment 110 when reinforcing the internal reinforcing bar 124 required for load resistance. Internal reinforcement 124 is to be arranged to the center segment.

When the connecting reinforcement 114 and the internal reinforcing bar 124 is connected to each other in the concrete in the center portion of the formwork to pour the concrete when the central segment and the precast end segment 110,

As shown in FIG. 2B, the girder 100 using the precast end segment 110 of the present invention as the end form is completed.

The final girder is thus pre-stressed to introduce the sheath constituting the fixing device described above to communicate with each other in the precast end segment and the center segment not shown, inserting a tension member 115, such as PC strands into the sheath. Then, when both ends of the tension member are fixed after tensioning the fixing device 113 of the precast end segment, prestress is introduced into the girder 100 of the present invention.

Such prestressing introduces a necessary compressive stress to the entire girder, and even if the compressive stress is largely formed, the precast end segment 110 is made of high strength so that the resistance performance of the precast end segment due to local stress is increased. It is possible to secure enough.

Method of manufacturing girders 100 using precast end segments as end formwork>

3A to 3D show the girder manufacturing method according to the present invention in a schematic order.

First, Figure 3a shows a rail portion 210 and the cart 220 for producing a girder according to the present invention in a front view.

The rail unit 210 is set on the ground to have a length that extends longer than the length for manufacturing the girder 100 having at least a predetermined length, and the rail unit is installed laterally spaced apart from the rail in the ground to be described later The cart 220 is to act as a guide to move the position while sliding.

In addition, the trolley 220 is a precast end segment 110 of the present invention described above to be mounted on the at least two, respectively, as a pedestal to move along the rail portion 210, precast end segment 110, One manufactured to have an area that can be loaded is used.

Accordingly, the bogie may be configured to include wheels that move along the rails on the top and bottom of the top plate.

The trolley 220 on which the precast end segment 110 is mounted is longitudinally spaced apart from each other along the rail portion 210 to extend the lengths of both precast end segments 110 at the total extension length L of the girder. Only apart from L1) (L-2 × L1 = L2).

Accordingly, by setting the formwork for the central portion corresponding to the distance (L2) spaced apart it is possible to standardize the production and installation of formwork for girder fabrication will be described later.

Thus, between the precast end segments 110 longitudinally spaced by both trucks 220, the formwork 230 for the central segment is to be installed by the usual formwork pedestal 240.

The central segment formwork 230 can be used by assembling a plurality of steel formwork as shown in Figure 1b, the important thing is that the outer surface of the cross section of the girder center side of the precast end segment 110 made in advance is the end segment 110 It is to match the inner surface of the formwork 230 for the center segment having the same cross-sectional shape as the cross section of the girder center side.

That is, the precast end segment 110 of the present invention is not manufactured to have a length varying according to the entire length of the girder, but is manufactured in advance to have a uniform length and has a length as small as 2 m or less for transport and installation. Will be produced in advance.

On the other hand, since the central segment 120 integrated with the precast end segment 110 has various lengths according to the entire extension length of the girder, the formwork 230 for the central segment for this purpose also has various extension lengths.

However, such a central segment formwork 230 is also manufactured by installing the formwork having a unit length in advance, such as 1m, 2m connected to each other, so that the central segment formwork 230 having a desired length is precast end segment 110 It is common to be unable to accurately match the separation distance of.

For example, when the length of the central segment 120 is 25.5M, when using 1 mold form 26 pieces, 0.5M is left.

Accordingly, the present invention is the outer surface of the cross section of the girder center side of the precast end segment 110 as shown in Figure 3b and the inner surface of the formwork for the central segment 230 having the same cross-sectional shape as the cross section of the girder center side of the end segment 110 and If it is to be matched, even if the setting length of the center segment formwork 230 does not correspond to the separation length of the precast end segment 110, the precast end segment 110 is placed inside the center segment formwork 230. By inserting and installing the length, it is possible to meet the required separation distance.

Next, the connecting reinforcing bar 114 of the precast end segment 110 and the inner reinforcing bar 124 of the central segment 120 are placed inside the formwork, and the sheath of the precast end segment 110 is not shown. To correspond to the

Next, the connecting reinforcing bars and the internal reinforcing bars are connected to each other by using thin wires, etc., in a state of overlapping each other in a lap joint manner.

At this time, the end face of the precast end segment 110 also serves as an end formwork of the central segment 120, so that the concrete A is poured into the formwork 230 for the precast end segment.

When the final cast concrete is cured, it can be seen that the precast end segment 110 and the central segment 120 are integrated with each other.

Next, as shown in FIG. 3D, the mold 230 for the center segment is demolded, and the girders 100 of the present invention are lifted and stacked by the precast end segment 110 and the center segment 120 integrated with each other. Release to complete the final production.

Next, since the sheaths are arranged in communication with each other inside the girder 100, a compressive stress due to prestress may be introduced into the girder by using the fixing device 110 including the tension member and the anchor body in advance in the factory. In the state mounted on the site, the compressive stress may be introduced or the compressive stress may be introduced one or more times depending on the construction and construction.

The girder manufactured as described above is mounted between both piers 410 and the piers 410 as shown in FIG. 4, and a plurality of girders are installed to be constrained by the cross beams 420 in the lateral direction. As such, the slab 300 is formed on the upper part of the girder 100 mounted on the lower bridge structure including the shifts and the piers to complete the final girder bridge.

100: girder
110: precast end segment
111: upper flange 112: abdomen
113: fixing device 114: connecting rebar
115: tension
120: center segment 124: internal reinforcement
210: rail portion 220: cart
230: formwork for the center part segment 240: formwork support
300: slab
410: Pier A: concrete

Claims (8)

Both end segments of the girder where the prestress by the fixing device is concentrated are first made of precast end segments using high-strength concrete,
The precast end segments are spaced apart from each other in the longitudinal direction of the girder so as to be located at both ends of the girder to be manufactured corresponding to the girder fabrication length,
A central section is manufactured by setting a central formwork between the precast end segments, wherein the central formwork has a central section having an outer surface of the cross section of the girder center side of both precast end segments having the same cross-sectional shape as the cross section of the girder center side of the end segment. To match the inner surface of the formwork for the segment,
And casting the concrete inside the central formwork to cure, and then demolding the central formwork, using the precast end segment as an end form. The method of claim 1,
The precast end segment is set so as to be located at both ends of the girder to be manufactured in correspondence with the girder manufacturing length in a state in which both end brackets are movable in the longitudinal direction by the rail in a state in which the precast end segment is prefabricated and stacked. A method for fabricating a girder using precast end segments as end forms, characterized in that the formwork is set. The method of claim 1,
The precast end segment and the central segment are connected to each other by overlapping the connecting reinforcing bar and the inner reinforcing bar for the middle segment in a protruding manner so as to extend in advance in the longitudinal direction from both end faces of the precast end segment. A method for fabricating a girder using precast end segments as end formwork, characterized in that it is poured and cured to be integrated with each other. The method of claim 3, wherein
The girder integrated by the precast end segment and the center segment further includes the step of introducing the prestress by a tension member installed through a sheath preinstalled therein as the prestressed reinforced concrete girder. How to make girders used as formwork. Both end segments of the girder where the prestress by the fixing device is concentrated are first made of precast end segments using high-strength concrete,
The precast end segments are spaced apart from each other in the longitudinal direction of the girder so as to be located at both ends of the girder to be manufactured corresponding to the girder fabrication length,
A central section is manufactured by setting a central formwork between the precast end segments, wherein the central formwork has a central section having an outer surface of the cross section of the girder center side of both precast end segments having the same cross-sectional shape as the cross section of the girder center side of the end segment. To match the inner surface of the formwork for the segment,
By placing concrete in the center formwork to cure, and then using the precast end segment produced by including the demoulding the center formwork as end formwork,
The girder using the precast end segment as end form, characterized in that the concrete strength of the precast end segment is formed to be higher than the concrete strength of the central segment. 6. The method of claim 5,
The girder using the precast end segment as an end form, characterized in that the pre-stress is introduced into the precast end segment and the central segment integrated with each other through a sheath pipe pre-installed in the girder. 6. The method of claim 5,
The precast end segment is set so as to be located at both ends of the girder to be manufactured in correspondence with the girder manufacturing length in a state in which both end brackets are movable in the longitudinal direction by the rail in a state in which the precast end segment is prefabricated and stacked. A girder using precast end segments as end form, characterized in that the formwork is to be set. 6. The method of claim 5,
The precast end segment and the central segment are connected to each other by overlapping the connecting reinforcing bar and the inner reinforcing bar for the middle segment in a protruding manner so as to extend in advance in the longitudinal direction from both end faces of the precast end segment. A girder using precast end segments as end forms, characterized in that they are cast and cured to be integrated with each other.

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