JP5875951B2 - Girder and floor slab joint structure and method - Google Patents

Description

  The present invention relates to a joining structure and method of a girder and a floor slab for joining a floor slab to an upper part of a precast girder.

  As a joining structure of a girder and a floor slab for joining a floor slab to the upper part of a precast girder, for example, a technology disclosed in Patent Document 1 is known.

  FIG. 5 shows a joint structure between a girder and a floor slab disclosed in Patent Document 1. The precast girder 2 has an upper flange 11 in which a lower lateral portion 3 of the double-headed locking member 1 is embedded and fixed. In the double-headed slip prevention member 1, the lower lateral portion 3 is disposed below the upper main reinforcement 12 embedded and arranged in the longitudinal direction of the upper flange 11 so as to intersect the upper main reinforcement 12. Further, the double-headed detent member 1 is disposed along and parallel to the upper horizontal reinforcing bar 13 as a flange reinforcing bar which is arranged in a direction perpendicular to the bridge axis so that the lower horizontal part 3 intersects the upper main reinforcing bar 12 at a right angle. The The precast girder 2 is configured by being fixed to the upper main reinforcing bar 12 or the upper horizontal reinforcing bar 13 with a wire or the like, and in a state where a predetermined position and a predetermined posture are maintained, concrete 14 is provided so as to be embedded therein. .

  Incidentally, the upper surface 11a of the upper flange 11 in the precast girder 2 may be washed out. This washing process is a so-called rough surface process, and the surface roughness is adjusted in advance to a predetermined level by bringing a chemical solution or the like into contact with the upper surface 11a of the upper flange 11, for example.

  More specifically, a pair of the double-headed displacement preventing members 1 are embedded and arranged in parallel in the upper flange 11 at intervals in the width direction. Each double-headed detent member 1 is also embedded and arranged in parallel in the longitudinal direction at intervals, forming a row of double-headed detent members.

  A cast-in-place concrete floor slab is installed so that the precast girder 2 having the above-described structure is placed on an abutment or a pier, and the upper part of the double-headed detent member 1 is embedded in the upper part of the precast girder 2. 15 is provided. Specifically, an embedded mold 17 made of a precast concrete embedded mold is placed over the support step 16 provided at the end of the precast girder 2 in the width direction, and appropriate reinforcement is made. After that, concrete 19 is cast so as to embed the upper part of the embedded mold 17 and the upper flange 11 of the precast girder 2 and the double-headed displacement prevention member 1, and the cast-in-place concrete floor slab 15 is cast integrally with the precast girder 2. Will be. At this time, the cast-in-place concrete floor slab 15 and the upper flange 11 are adhered by roughening the upper surface 11a of the upper flange 11 as described above.

2007-113338

  However, in the technique disclosed in Patent Document 1 described above, the main girder is a precast member, whereas the floor slab is made of cast-in-place concrete. For this reason, there has been a problem that construction time and construction labor for placing cast-in-place concrete on site are excessive. In addition, from the viewpoint of firmly attaching the floor slab to cast-in-place concrete, it is necessary to dispose a large number of double-headed displacement preventing members, which increases the construction cost.

  Therefore, the present invention has been devised in view of the above-mentioned problems, and the object of the present invention is to reduce the construction time and construction labor described above by not placing the floor slab. It is to provide a joint structure between a girder and a floor slab.

  In order to solve the above-mentioned problems, the present inventor filled each time-curing material on the rough upper end surface of the upper flange of the precast girder, and made each precast for making all the floor slabs precast. The invention has invented a joining method between a girder and a floor slab, and a joining structure between the girder and the floor slab, which are joined to the time-curable material through the lower end surface of the floor slab.

The joining structure of a girder and a floor slab according to claim 1 includes: an upper end surface that has been subjected to a washing process on the upper flange of the precast girder to form a rough surface; and each precast floor for making all of the floor slab precast. The time-hardening material is filled between the rough surface and the lower end surface of the plate, and the rough surface formed on the upper end surface has at least unevenness continuously formed in the bridge width direction. Features.

The joining structure between the girder and the floor slab according to claim 2 is that, in the invention according to claim 1 , the time-curable material enters the unevenness of the rough surface formed on the upper end surface and is firmly attached. Features .

The method for joining a girder and a floor slab according to claim 3 is characterized in that each precast for precast the entire floor slab on the upper end surface that has been subjected to a washing process on the upper flange of the precast girder and is made rough. The lower surface of the floor slab is provided with a gap so as to be opposed to each other, and at least on the upper surface of the rough surface in which irregularities are continuously formed in the bridge width direction. The end faces are opposed to each other, and the gap is filled with a time-curable material.

According to a fourth aspect of the present invention, in the invention according to the third aspect, the girder and the floor slab are characterized in that the curable material is inserted into the rough surface irregularities formed on the upper end surface and firmly adhered. And

  In the joining structure of the girder and the floor slab having the above-described configuration, the floor slab can be configured not to be cast in place. That is, in addition to configuring the main beam with a precast member, the floor slab can also be configured with a precast member. For this reason, it is possible to pre-fabricate a precast floor slab having the above-mentioned configuration at the factory, and join this pre-cast pre-slab slab to a time-curable material in the field work. Only to do. For this reason, since there is no need to place cast-in-place concrete as in the prior art, it is possible to greatly reduce the work time and work labor at the site.

  Furthermore, in the present invention, it is possible to attach the precast floor slab more firmly to the time curable material by setting a large joining area between the lower end surface of the precast slab and the time curable material. Thus, it becomes possible to increase the mutual adhesion. For this reason, since it becomes possible to give intensity | strength with the adhesive force of a precast floor slab and a time-hardenable material, it is not necessary to give the intensity | strength to a slip prevention member. As a result, the number of slip prevention members can be greatly reduced. In addition, as a result of reducing the number of displacement preventing members and reducing the number of insertion holes, the construction cost itself can be reduced.

It is a perspective view in the junction structure of a girder and a floor slab to which the present invention is applied. It is a front view in the junction structure of the girder and floor slab to which the present invention is applied. It is a plane sectional view in the joined structure of a girder and a floor slab to which the present invention is applied. It is a figure for demonstrating the joining method of the girder and floor slab to which this invention is applied. It is a figure which shows the joining structure of the girder and the floor slab disclosed in Patent Document 1.

  Hereinafter, embodiments of the present invention will be described in detail. FIG. 1 is a perspective view of a joining structure 20 of a girder and a floor slab to which the present invention is applied, FIG. 2 is a front view thereof, and FIG. 3 is a plan sectional view thereof.

  The joining structure 20 is configured such that a time-curable material 50 is provided between the precast girder 30 and the precast floor slab 40.

  The precast girder 30 is formed by forming a web 33 between an upper flange 31 and a lower flange 32. The upper flange 31 is fixedly embedded with an offset member 34 made of, for example, a reinforcing bar at intervals in the longitudinal direction of the main girder, and at least a lower lateral portion 35 of the offset member 34 is fixedly embedded. Further, the upper end of the slip prevention member 34 protrudes upward from the upper end surface 31 a of the upper flange 31.

  Inside the precast girder 30, a main reinforcing bar 36 is arranged in the longitudinal direction (depth direction in the drawing), and a flange reinforcing bar 37 is arranged in a direction perpendicular to the bridge axis so as to intersect the main reinforcing bar 36. Although other reinforcing bars may be disposed inside the precast girder 30, illustration is omitted.

  Incidentally, the upper end surface 31a of the upper flange 31 in the precast girder 30 is washed out. This washing process is a so-called rough surface process. For example, the surface roughness is adjusted in advance to a predetermined level by bringing a chemical solution or the like into contact with the upper end surface 31a of the upper flange 31. Actually, in this washing-out process, for example, a curing retarder is sprayed, and this is washed out with high-pressure washing water, whereby the rough surface treatment can be performed on the upper end surface 31a.

The precast floor slab 40 is installed on the precast girder 30 by installing the precast girder 30 having the above-described configuration so as to be placed on an abutment or a pier. In the precast floor slab 40, main bars 41 are arranged in the longitudinal direction (the depth direction in the drawing). The lower end surface 40a of the precast floor slab 40 is washed out so as to be a rough surface. The precast floor slab 40 is arranged to make all of the floor slabs made of precast, not so-called cast-in-place where concrete is cast on site. A cast-in-place joint 63 is provided between the precast slabs 40 adjacent in the bridge axis direction. This cast-in-place joint portion 63 is cast-in-place concrete that is filled to fill a gap between the precast slabs 40 adjacent in the bridge axis direction.

  The precast floor slab 40 is provided with an insertion hole 43. As described above, the displacement preventing member 34 protruding upward is inserted into the insertion hole 43 from below. The insertion holes 43 are provided in a row in the direction of the bridge axis, as shown in the plan sectional view of FIG. Further, the insertion hole 43 into which the shift preventing member 34 is inserted is filled with a time-hardening material 44 such as mortar, grout, cement, or the like.

  The time-curable material 50 filled between the precast girder 30 and the precast floor slab 40 is, for example, a non-shrink mortar, a non-shrink grout, etc., but is not limited thereto, and hardens with time. It may be composed of any material. The uppermost layer of the time-curable material 50 is in contact with the lower end surface 40a of the precast floor slab 40, and the lowermost layer of the time-curable material 50 is in contact with the upper end surface 31a of the upper flange 31. . The lower end surface 40a of the precast floor slab 40 and the upper end surface 31a of the upper flange 31 are both roughened by washing out and have a high coefficient of friction. Therefore, adhesion between the lower end surface 40a of the precast floor slab 40 having a rough surface and the time-curable material 50 can be increased. Moreover, it becomes possible to improve adhesiveness between the upper end surface 31a of the upper flange 31 made rough and the time-curable material 50.

  In order to actually construct the joint structure 20 having such a configuration, first, a precast girder 30 is constructed as shown in FIG. Incidentally, the upper end surface 31a of the upper flange 31 is subjected to a washing process in advance to be a rough surface.

  Next, as shown in FIG. 4B, a precast floor slab 40 manufactured in advance is provided on the precast girder 30. On the upper end surface 31a which is a rough surface in the upper flange 31 of the precast girder 30, the lower end surface 40a which is the rough surface in each precast floor slab 40 for making all the floor slabs is made to face each other. And provide a gap. Further, the above-described displacement preventing member 34 is inserted into the insertion hole 43.

  Next, as shown in FIG. 4 (c), the time-curable material 50 is placed in the gap formed between the upper end surface 31 a of the upper flange 31 in the precast girder 30 and the lower end surface 40 a in the precast floor slab 40. Fill. In particular, in the process of filling the time-curable material 50, the time-curable material 50 enters the rough surface unevenness of the lower end surface 40a of the precast floor slab 40, and the two are firmly adhered to each other. The insertion hole 43 is also filled with the time-curable material 44. The sealing material 61 is provided between the upper end surface 31a of the upper flange 31 and the lower end surface 40a of the precast floor slab 40 from the viewpoint of preventing the filled time-curable material 50 from leaking out before being cured. It may be. The sealing material 61 may be provided at the edge of the upper flange 31 as shown in FIG.

  These time-curable materials 50 and 44 are solidified with time. In the process in which the time-curable material 50 is solidified, since the time-curable material 50 has already entered the rough surface of the upper end surface 31a of the upper flange 31, the two are firmly attached to each other in the process of solidifying. It becomes.

  Before and after these steps, a cast-in-place joint 63 is provided between the precast slabs 40 adjacent in the bridge axis direction.

  In such a joining structure 20 between a girder and a floor slab, in addition to constituting the main girder with a precast member, the floor slab can also be constituted with a precast member. For this reason, for the floor slab, the precast floor slab 40 having the above-described configuration can be manufactured in advance at the factory, and the precast floor slab 40 that has already been manufactured is used as a time-curable material in the field work. 50 only. For this reason, since there is no need to place cast-in-place concrete as in the prior art, it is possible to greatly reduce the work time and work labor at the site.

  Furthermore, in the present invention, the precast floor slab 40 is made stronger with respect to the time-curable material 50 by setting the joining area between the lower end surface 40a of the precast floor slab 40 and the time-curable material 50 to be large. It becomes possible to attach to each other, and it becomes possible to raise the adhesive force of each other. For this reason, since it becomes possible to give intensity | strength with the adhesive force of the precast floor slab 40 and the time-hardening material 50, it is not necessary to give the intensity | strength to the slip prevention member 34. FIG. As a result, the number of the detent members 34 can be greatly reduced. For example, as shown in FIG. 3, the number of the stopper members 34 can be reduced. As a result, the area and number of the insertion holes 43 can be further reduced. Accordingly, it is possible to reduce the number of disposition preventing members 34 and reduce the number of insertion holes 43. As a result, the construction cost itself can be reduced.

20 Joint structure 30 Precast girder 31 Upper flange 32 Lower flange 33 Web 34 Displacement member 35 Lower lateral portion 36 Main bar 40 Precast floor slab 41 Main bar 43 Insertion holes 44, 50

Claims (4)

Curing with time between the upper end surface, which has been washed out on the upper flange of the precast girder and made rough, and the lower end surface, which has been made rough in each precast floor slab, to make all the floor slabs Filled with sex material,
The rough structure formed on the upper end surface has unevenness continuously formed at least in the bridge width direction . The joining structure of a girder and a floor slab according to claim 1, wherein a time-hardening material enters and firmly adheres to the unevenness of the rough surface formed on the upper end surface. The lower end surface of each precast floor slab is made to face each other on the upper end surface which has been subjected to a washing process on the upper flange of the precast girder to be a rough surface. The lower end surface is opposed to each other on the rough upper end surface in which irregularities are continuously formed at least in the bridge width direction, and a time-curable material is further provided in the gap. A method of joining a girder and a floor slab characterized by filling. The joining method of a girder and a floor slab according to claim 3, wherein a time-curable material is inserted into the unevenness of the rough surface formed on the upper end surface and firmly adhered.

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