JP2021042545A - Precast plate connection structure and method - Google Patents

Abstract

PURPOSE: To provide a precast plate connection structure and method that can improve workability during construction and improve responsiveness of shear force transmission while avoiding breakage of a shear key due to a bending moment by reliably allowing rotational deformation.CONSTITUTION: A precast plate connection structure 104 according to the present invention is configured by filling and arranging a cement-based hardened body 32 so that the adhesive stress with groove inner surfaces 23a, 23b becomes substantially zero in a columnar filling space 31 in which the groove inner spaces of respective filling grooves 22a, 22b are integrated with each other in a state where precast floor slabs 1, 1 are arranged so that the filling grooves face each other. Further, a rubber-based block 33, as a water-stopping elastic material, is arranged between connection end faces 21a, 21b of the precast floor slabs 1, 1.SELECTED DRAWING: Figure 3

Description

The present invention mainly relates to a connecting structure and method of a precast plate applied when connecting a floor slab, particularly a bridge floor slab.

Social and economic infrastructures such as roads, railroads, rivers, and harbors are being constructed intensively in Japan during the period of high economic growth, and in relation to this, aging is progressing all at once in recent years. There is an urgent need for maintenance or renewal, but in the superstructure of bridges where roads and railroads are laid, if the floor slab is significantly damaged, it will be necessary to replace it, and the superstructure will be made of steel girders. In the case of a girder with an RC floor slab overlaid, measures to replace the RC floor slab with a precast concrete floor slab with an RC structure or PC structure (hereinafter simply referred to as a precast floor slab) have been widely adopted. There is.

Here, if the connecting portion of the precast floor slab is to resist bending around the bridge axis orthogonal axis, after removing the existing floor slab, the precast floor slabs are arranged along the bridge axis direction, and then connected. A method of interconnecting the two precast floor slabs by placing and filling concrete in the space between the facing surfaces so that the reinforcing bars extending from the facing surfaces of the two target precast floor slabs function as lap joints. Has been adopted in large numbers.

On the other hand, when it is not necessary to bend the precast floor slabs at their connecting parts, a simpler connecting structure can be adopted. For example, one of the two precast floor slabs to be connected can be used. It is possible to adopt a configuration in which a convex portion is provided on the other precast floor slab and a concave portion into which the convex portion is fitted is provided on the other precast floor slab to form a shear key.

Japanese Unexamined Patent Publication No. 2016-104931 Japanese Unexamined Patent Publication No. 60-238549

However, in the above-mentioned connection structure, if the shear key is to exert its function immediately after the load is generated, it is necessary to minimize the play between the concave portion and the convex portion, so that the function of the shear key is enhanced. The more it is done, the more time it takes to fit the convex part into the concave part when arranging the precast floor slab, and the problem that excessive force acts on the convex part at the time of fitting and there is a risk of damage. Furthermore, as a result of reducing the play, rotational deformation is not allowed and a bending moment is generated at the connecting portion, and the bending moment also causes a problem that the convex portion may be damaged.

Incidentally, Patent Document 1 discloses a connecting structure in which two precast members are interconnected via a columnar shear key 1. In such a connecting structure, the shear key 1 is made of a steel pipe or plastic. Since it is necessary to fill the cylindrical body 1a composed of pipes with the fiber reinforced concrete 6, it takes time and effort to manufacture the cylindrical body 1a, and even if the precast members can be accurately connected to each other, the precast members are relative to each other. If there is a specific installation error, it is not possible to connect the two in a state where the installation error is absorbed (see Fig. 4 (b)), so it is inherently difficult to apply it to the floor slab of a bridge, etc. Is.

Further, the invention described in Patent Document 1 defines, in paragraph [0018] of the document, a gap 5 for filling the grout material 4 (see FIG. 4D) between the two joint surfaces Pa at the time of abutting. As can be seen from the description, "the control caused by the dimensions can be realized by the shear key 1 and the recess 2", rotational deformation is not allowed in the first place, and it is assumed that rotational deformation is allowed. It is not directly related to the invention of the present application. In that respect, the invention described in Patent Document 2 in which the concrete filling portion 36 is formed so that the cross section has an elliptical shape is also the same.

The present invention has been made in consideration of the above-mentioned circumstances, and is capable of transmitting shear force while improving workability during construction and reliably allowing rotational deformation to avoid damage to the shear key due to a bending moment. It is an object of the present invention to provide a connecting structure and method of a precast plate capable of enhancing the responsiveness of the precast plate.

In order to achieve the above object, the connection structure of the precast plates according to the present invention is the connection structure of the precast plates in which the two precast plates are connected to each other as described in claim 1.
The two precast plates are formed so that the inner surface of the groove forms an arc in the cross section with the axis parallel to the connecting end face and extending in the in-plane direction as the reference axis, and the filling groove is formed along the direction of the reference axis. It is composed of precast plates provided on the connecting end faces, and in a state where the two precast plates are arranged so that the filling grooves face each other, the space inside the grooves of the filling grooves is integrated with each other. The cement-based hardened material is filled and arranged in the filling space so that the adhesion stress with the inner surface of the groove becomes substantially zero.

Further, as described in claim 2, the method of connecting the precast plates according to the present invention is the method of connecting the precast plates for constructing the connecting structure of the precast plates according to claim 1, wherein the two precast plates are connected to the above. The filling grooves are arranged so as to face each other, a cement-based hardened material is injected and filled into the filling space, and the cement-based hardened material is hardened to obtain the cement-based hardened material.

Further, the method for connecting the precast plates according to the present invention is provided so that the injection filling of the cement-based curing material is communicated to at least one of the two precast plates in the groove space. It is done through the injection hole.

Further, in the method of connecting the precast plates according to the present invention, the filling space is formed from the front surface or the back surface of each of the precast plates after the two precast plates are arranged facing each other and before the cement-based curing material is injected and filled. By inserting the reinforcing bars through the reinforcing bar insertion holes formed through the reinforcing bars, the intersecting reinforcing bars along the plane orthogonal to the reference axis are arranged in the filling space.

Further, in the method of connecting the precast plate according to the present invention, when arranging the reinforcing bars, a cylindrical holding member is inserted into the reinforcing bar insertion hole, and the reinforcing bar is passed through the hollow space of each holding member. The holding member temporarily holds the ends thereof.

Further, in the method of connecting the precast plates according to the present invention, after arranging the intersecting reinforcing bars, the reinforcing bars temporarily fixed near the bottom of the filling groove are translated and moved toward the center of the filling space. Reinforcing bars extending in the direction of the reference axis are arranged in the filling space.

Further, in the method for connecting precast plates according to the present invention, before injecting and filling the cement-based curing material, a water-stopping elastic material is arranged in a clearance extending between the connecting end faces so as to communicate with the filling space. It is a thing.

The precast plate used in the connecting structure according to the present invention is provided with a filling groove on the connecting end face along the direction of the reference axis when the axis parallel to the connecting end face and extending in the in-plane direction is used as the reference axis. The filling groove is formed so that the inner surface of the groove forms an arc in the cross section, and in a connecting structure in which two precast plates respectively composed of the precast plates are interconnected, the filling grooves are opposed to each other. After arranging one precast plate, cement-based hardening is performed in a columnar filling space in which the groove inner space of each filling groove is integrated with each other so that the adhesion stress with the groove inner surface becomes substantially zero. The body is filled and arranged.

In this way, the columnar cement-based hardened body is fitted into each filling groove of the two adjacent precast plates, so that the shear key capable of restraining the out-of-plane relative movement of the two precast plates is used. In addition to functioning, it is filled and arranged so that the boundary with the inner surface of the groove is an arc in the cross section and the adhesive stress with the inner surface of the groove is substantially zero. Therefore, it functions as a pin joint that allows relative rotational deformation around the reference axis of the two precast plates.

In addition, since the columnar cement-based hardened body is formed with the precast plates facing each other, there is no concern that the precast plates will be damaged during the work of arranging the precast plates as in the case of the conventional shear key, and the precast plates will not be damaged. Since there is substantially no play between the two precast plates, the relative movement of the two precast plates is restrained without delay in response to the start timing of the relative movement of the two precast plates.

As the connecting structure of the precast board according to the present invention, it is possible to use a precast board manufactured as an RC structure or a PC structure, and the application site is applied to a floor slab, particularly a precast floor slab used for a road bridge. The case is a typical example, but it is arbitrary to apply it to any part, and it can be used for a wall body, for example.

The two precast plates are separated from each other so that relative rotational deformation around the reference axis is allowed.

Here, the cement-based cured product must be configured so that when the two precast plates try to start rotating from the initial state, they do not collide with the opening edge of the filling groove and the rotation is not hindered. A typical example is a structure in which a cement-based hardened body is formed so that its cross section has a circular shape.

In this case, the two precast plates are in a state of being rotatable around the material axis passing through the center of the cement-based hardened body, but since the two precast plates are spaced apart from each other, the cross-sectional shape of each filling groove is formed. Is not strictly a semicircle, but a shape surrounded by an arc having a central angle of less than 180 ° and a chord connecting their end points, that is, a bow shape.

On the other hand, in the above example, the two precast plates rotate with the material axis of the cement-based cured product as a common rotation center, but in the present invention, the two precast plates need to rotate on the same rotation axis. Therefore, it may be a cross section in which two circles are overlapped so as to be offset from each other.

In this configuration, when the cement-based hardened body has a rectangular cross-sectional shape in which a rectangle is sandwiched between semicircles that are symmetrical to each other, so to speak, the cement-based hardened body and the opening of the filling groove are formed. Mutual rotation of the precast plates may be hindered due to interference with the edges. In this case, the portion corresponding to the separation region of the two precast plates is cut out in a groove shape, for example. Just do it.

In order to construct the connection structure of the precast plates described above, first, the two precast plates are arranged so that the filling grooves face each other, and then a cement-based curing material is injected and filled in the filling space, and then the cement-based The cured material may be cured to obtain a cement-based cured product.

The cement-based curing material may be appropriately selected from known grout materials.

As long as the cement-based curing material is injected and filled into the filling space, how to inject and fill it is arbitrary, but it is necessary to form a clearance between the two precast plates as described later, and cement is used. At the time of injection and filling of the system curing material, it is necessary to take appropriate measures so that the cement system curing material does not flow out through such a clearance and does not flow into the clearance.

Therefore, the cement-based curing material may be injected and filled through the above clearance, but at least one of the two precast plates is provided so as to communicate with the groove space. If the work is performed through the holes, it is possible to avoid interference with the work for which the above measures are taken, and it is possible to improve the overall work efficiency.

The injection hole is typically formed through the front or back surface of the precast plate, or if the precast plate is a floor slab, from the upper surface to the space inside the groove in the installed state.

Whether or not the cement-based hardened body has a reinforcing material embedded in it is optional, and the structure in which fibers are mixed is not excluded, but since it is press-fitted through the injection hole, the reinforcing bar is reinforced. Is desirable.

Specifically, after the two precast plates are placed facing each other and before the cement-based curing material is injected and filled, the reinforcing bars are inserted through the reinforcing bar insertion holes formed through the front or back surface of each precast plate toward the filling space. By inserting the reinforcing bars respectively, it is possible to adopt a configuration in which the intersecting reinforcing bars along the plane orthogonal to the reference axis are arranged in the filling space.

Further, after arranging the intersecting reinforcing bars, the reinforcing bars temporarily fixed near the bottom of the filling groove are moved in translation toward the center of the filling space, so that the reinforcing bars extending in the direction of the reference axis are arranged in the filling space. By adopting the structure, a stronger cement-based hardened body can be constructed.

In the injection filling step of the cement-based hardened material, since the precast plates are arranged facing each other so that the relative rotational deformation around the reference axis of the two precast plates is allowed, between the connecting end faces of the two precast plates, A clearance is formed so as to communicate with the filling space, and it is necessary to prevent the cement-based curing material from flowing into the clearance.

Here, an appropriate padding is applied to the entire clearance, or at least the portion near the boundary with the filling space, and the cement-based hardening material is injected and filled in such a state, and then the filling is removed after waiting for the cement-based hardening material to harden. However, if a water-stopping elastic material is placed in the clearance before the cement-based curing material is injected and filled, the inflow of the cement-based curing material into the clearance is prevented and the cement-based cured material is prevented from flowing into the clearance. Since the deformation performance of the water-stopping elastic material is exhibited even after curing, there is no risk that the relative rotational deformation of the two precast plates will be hindered, and therefore it is not necessary to remove the cement-based cured material after it has hardened. Can be done.

In addition, by leaving the water-stopping elastic material, foreign matter is prevented from entering the clearance. Therefore, when used as a road slab, for example, foreign matter such as sand and stone causes relative rotational deformation of the two precast plates. There is no risk of being hindered.

The water-stopping elastic material, which is composed of rubber blocks, is attached in advance to the connecting end face of one of the two precast plates, and is attached when the two precast plates are arranged facing each other. The side opposite to the side may be arranged so as to be in contact with the connecting end face of the other precast plate, or the two precast plates are arranged so as to face each other and then the clearance is filled with an elastic sealant. May be good.

If the water-stopping elastic material is configured as in the former case, when the two precast plates are arranged facing each other, the function as a cushioning material is exhibited, and it is possible to prevent the precast plates from being damaged due to a collision. ..

It is a figure which showed the appearance that the floor slab 101 of a bridge was constructed by connecting the precast floor slabs 1 and 1 to each other by using the connection structure 104 of the precast plate which concerns on this embodiment, and (a) is an overall layout drawing, (b) is a cross-sectional view taken along the line -AA. It is the figure which showed the precast floor slab 1, (a) is the detailed sectional view, (b) is the arrow view seen from the BB line direction. It is a figure which showed the connection structure 104 of the precast plate, (a) is a sectional view, (b) is a detailed sectional view, (c) is an exploded perspective view. The explanatory view which showed the operation of the connection structure 104 of the precast plate which concerns on this embodiment. The figure which showed the construction procedure of the connection structure 104 of the precast board which concerns on this embodiment. The cross-sectional view which showed the connection structure of the precast plate which concerns on a modification. The figure which showed the connection structure of the precast board which concerns on another modification, and the construction procedure thereof. The cross-sectional view which showed the connection structure of the precast plate which concerns on still another modification. The perspective view which showed the construction procedure in the connection method of the precast board which concerns on still another modification.

Hereinafter, embodiments of the connection structure and method of the precast plate according to the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a view showing a state in which a precast floor slab 101 as a precast plate is connected to each other by using a connection structure 104 of the precast plate to construct a bridge floor slab 101, and FIG. 1A is a view showing an overall arrangement. The figure, (b) is a cross-sectional view along the −AA line direction.

As shown in the figure, in the floor slab 101, a plurality of precast floor slabs 1 are juxtaposed along the bridge axis direction so as to bridge the main girder 102 of the bridge, and the precast floor slabs are adjacent to each other. The precast floor slabs 1 and 1 are connected to each other by using the precast plate connecting structure 104.

As shown in FIG. 2, the precast floor slab 1 extends in the in-plane direction parallel to the connecting end faces 21a and 21b, in the direction orthogonal to the paper surface in the figure (a), and in the vertical direction in the figure (b). When the axis is the reference axis, the filling grooves 22a and 22b are provided on the connecting end faces 21a and 21b along the direction of the reference axis, respectively.

The filling grooves 22a and 22b each have groove inner surfaces 23a and 23b formed so as to form an arc in the cross section, and the groove inner spaces 24a and 24b are formed so as to be surrounded by the respective groove inner surfaces. ..

Here, the precast floor slab 1 is formed through an injection hole 25 for injecting grout so that the upper surface side and the groove inner space 24a communicate with each other in the installed state.

FIG. 3 shows a connecting structure 104 of a precast plate formed by connecting the precast floor slabs 1 and 1.

As can be seen in FIG. 3A, the precast plate connecting structure 104 according to the present embodiment is filled with the precast plate slabs 1 and 1 in a state where the filling grooves 22a and 22b are arranged so as to face each other. A cement-based hardened body 32 is packed and arranged so that the adhesion stress between the groove inner surfaces 23a and 23b becomes substantially zero in the columnar filling space 31 in which the groove inner space of the groove is integrated with each other. There is.

Further, a rubber block 33 as a water-stopping elastic material is arranged between the connecting end faces 21a and 21b of the precast floor slabs 1 and 1.

Here, in the precast floor slabs 1 and 1, as shown in FIG. 6B, the arcs of the groove inner surfaces 23a and 23b formed in the filling grooves 22a and 22b have radii R, respectively, and their centers are common. Since the cement-based hardened body 32 is also arranged in such a manner, the cement-based hardened body 32 is also constructed as a columnar shape having their common axis as the material shaft 34.

In the present embodiment, since the cross section of the rubber block 33 is rectangular, the portion of the cement-based hardened body 32 that forms a boundary with the rubber block 33, in other words, between the connecting end faces 21a and 21b The cross section is not an arc but a straight line, and the overall shape of the cement-based cured product 32 is not strictly a cylindrical shape as shown in the exploded perspective view of FIG. In addition, each cross section of the groove inner surfaces 23a and 23b is not strictly a semicircle, but has a shape surrounded by an arc whose central angle is slightly smaller than 180 ° and a string connecting their end points, that is, a bow shape. ..

The precast floor slab 1 used for the connecting structure of the precast plates according to the present embodiment is provided with filling grooves 22a and 22b on the connecting end faces 21a and 21b along the direction of the reference axis described above, and the filling grooves are grooved. In the connecting structure 104 in which the inner surfaces 23a and 23b are formed so as to form an arc in the cross section and the precast floor slabs 1 and 1 are connected to each other, two filling grooves 22a and 22b are opposed to each other. In addition to arranging the precast floor slabs 1 and 1, the groove inner spaces 24a and 24b of the respective filling grooves are integrated with each other so that the adhesion stress is substantially zero between the precast floor slabs 1 and 1 and the groove inner surfaces 23a and 23b. The cement-based hardened body 32 is filled and arranged in the columnar filling space 31.

In this way, the columnar cement-based hardened body 32 is fitted into the filling grooves 22a and 22b of the two adjacent precast floor slabs 1 and 1, respectively. Therefore, as shown in FIG. It functions as a shear key that can restrain the out-of-plane relative movement of the two precast floor slabs 1 and 1 (movement along the direction of the straight arrow in the figure), and the boundary between the two precast floor slabs 1 and 1 is an arc in the cross section. Since the filling is arranged so that the adhesive stress with the inner surface of the groove becomes substantially zero, in combination with the above-mentioned function of the shear key, the two precast floor slabs 1 and 1 are arranged around the reference axis (same as above). It functions as a pin joint that allows relative rotational deformation (around the curve arrow in the figure).

In order to construct the connection structure 104 of the precast board according to the present embodiment, after removing the existing floor slab as a nighttime closure from the night of the first day, for example, around 8:00 pm, first, it is shown in FIG. 5 (a). As described above, they are arranged so that the filling grooves 22a and 22b of the precast floor slabs 1 and 1 face each other.

When arranging the precast floor slabs 1 and 1 facing each other, the rubber block 33 is attached in advance to one of the connecting end faces 21a and 21b, and when the precast block 33 is hung down, the side opposite to the attachment side is attached. It may be brought into contact with the other connecting end face.

Next, as shown in FIG. 5 (b), asphalt 51 is laid on the precast floor slabs 1 and 1 so as to straddle them, and in this state, the asphalt 51 is temporarily used as a road from the morning of the second day.

If the height of the installation top of the precast floor slab 1 and the existing floor slab is the same, the work up to this point may be divided into two days.

That is, of the adjacent existing floor slabs, one of the existing floor slabs and the precast floor slab 1 are first replaced, and then asphalt is laid so as to straddle them to complete the work of the first day, and the work is temporarily used in this state. After that, on the night of the second day, the asphalt may be peeled off once to replace the remaining existing floor slab with the other precast floor slab 1, and then the asphalt may be laid again to achieve the state shown in FIG. 5 (b). Absent.

After being temporarily put into service in the state shown in FIG. 5 (b), the road is closed again at night that night, and the asphalt 51 is temporarily removed.

Next, between the precast floor slabs 1 and 1, a columnar filling space 31 in which the in-groove spaces 24a and 24b of the filling grooves 22a and 22b are integrated with each other is formed. As shown in FIG. 5 (c), the grout material 52 as a cement-based hardening material is injected and filled through the injection holes 25.

When injecting and filling the grout material 52, air is appropriately evacuated from an air bleeding hole (not shown) so that the injecting operation is not hindered by the air pressure in the filling space 31. The air bleeding hole can be configured by arranging tubes on the connecting end faces 21a and 21b by burying or sandwiching the rubber block 33.

The grout material 52 needs to have substantially zero adhesive stress with the groove inner surfaces 23a and 23b, but if the groove inner surfaces 23a and 23b are configured to be smooth so as not to have irregularities, vehicle vibration and the like may occur. The adhesive stress on the groove inner surfaces 23a and 23b can be made substantially zero by the external force acting after the service.

If necessary, a water repellent or a release agent may be appropriately applied to the groove inner surfaces 23a and 23b prior to the grout injection, for example, before the precast floor slabs 1 and 1 are arranged to face each other.

Next, after waiting for the completion of the filling work of the grout material 52, as shown in FIG. 5 (d), the asphalt 51 is re-laid so as to straddle the precast floor slabs 1 and 1, and on the 3rd or 4th day. In the morning, the road closure will be lifted and the road will be put into service.

On the other hand, after the filling work of the grout material 52 is completed, the grout material 52 is cured as the cement-based cured body 32, so that the construction of the connection structure 104 of the precast plate is completed. The material and composition of the grout material 52 are selected and prepared so that the strength is developed after the grout material 52 is placed and before the start of service.

As described above, according to the connection structure 104 of the precast plates according to the present embodiment, the columnar cement-based cured body 32 is placed in the filling grooves 22a and 22b of the two adjacent precast floor slabs 1 and 1, respectively. Since it is fitted, as described in FIG. 4, it functions as a shear key capable of restraining their out-of-plane relative movement, and the boundary between the groove inner surfaces 23a and 23b becomes an arc in the cross section. Moreover, since the filling is arranged so that the adhesion stress with the inner surface of the groove becomes substantially zero, the relative rotation of the two precast floor slabs 1 and 1 around the reference axis is combined with the above-mentioned function of the shear key. It functions as a pin joint that allows deformation.

Further, according to the connection structure 104 of the precast plate according to the present embodiment, the rubber block 33 is arranged between the connection end faces 21a and 21b of the precast floor slabs 1 and 1, so that the precast floor depends on its deformation performance. While the relative rotational deformation of the plates 1 and 1 is allowed, foreign matter such as sand and stone is mixed in the clearance between the connecting end faces 21a and 21b to prevent the relative rotational deformation of the precast floor slabs 1 and 1 from being hindered. It becomes possible to prevent.

Further, according to the method of connecting the precast plates according to the present embodiment, the cement-based cured body 32 is formed by post-casting with the precast floor slabs 1 and 1 facing each other, and thus is formed like a conventional shear key. , There is no concern that the precast board will be damaged during the work of arranging the precast board, and there will be virtually no play with the precast board. It reacts promptly to the timing and restrains the above-mentioned relative movement outside the plane without delay.

Further, according to the method of connecting the precast plates according to the present embodiment, the rubber block 33 is arranged between the connecting end faces 21a and 21b of the precast floor slabs 1 and 1 before the grout material 52 is injected and filled. Therefore, it is possible to prevent the grout material 52 from flowing into the clearance extending between the connecting end faces 21a and 21b, and the deformation performance is exhibited even after the cement-based cured body 32 is cured, so that it is precast. There is no possibility that the relative rotational deformation of the floor slabs 1 and 1 is hindered, and therefore, it is possible to save the trouble of removing the rubber block 33 after the grout material 52 is cured.

In the present embodiment, the asphalt is once peeled off and then the grout material 52 is injected and filled. However, the injection pipe communicating with the injection hole 25 and the air bleeding pipe communicating with the filling space 31 penetrate the asphalt. If the asphalt is laid after the installation, it is not necessary to temporarily peel off the asphalt when the grout material 52 is injected and filled.

Further, in the present embodiment, the connection structure of the precast plates according to the present invention has been described as being applied when connecting the precast floor slabs 1 and 1 used for the road bridge. It is optional to apply it, and it can be used for a wall body, for example.

Further, in the present embodiment, the rubber block 33 is attached to the connecting end surface 21a or the connecting end surface 21b of the precast floor slab 1 in advance, but the rubber block 33 and the precast floor slab 1 interfere with each other. If the hanging operation is hindered, the precast floor slabs 1 and 1 are placed facing each other, and then the clearance extending between the connecting end faces 21a and 21b is filled with an elastic sealing agent to form the water-stopping elasticity of the present invention. The material may be arranged.

Further, in the present embodiment, the precast floor is formed so that the cross sections of the groove inner surfaces 23a and 23b formed in the filling grooves 22a and 22b of the precast floor slabs 1 and 1 form an arc centered on the common material shaft 34. The plates were arranged, but instead, as shown in FIG. 6, the precast floor slabs were formed so that the cross sections of the groove inner surfaces 23a and 23b were arcs centered on two material shafts 61a and 61b, which were different from each other. You may arrange 1 and 1.

In this case, the cross-sectional shape of the filling space 64 in which the in-groove spaces 24a and 24b of the filling grooves 22a and 22b are integrated with each other, or the cement-based cured product obtained by curing the grout material 52 injected and filled in the filling space. As shown in the figure, the cross-sectional shape of 62 is a so-called planar shape of a track competition in which a rectangle is sandwiched between semicircles symmetrical to each other. Since the mutual rotation of the precast floor slabs 1 and 1 may be hindered by interfering with the opening edge of 22b, the portion corresponding to the separated region of the two precast floor slabs 1 and 1 is as shown in the figure. It is desirable to cut out in a groove shape.

In such a groove-shaped notch, the rubber-based block 63 as a water-stopping elastic material is made wider than the rubber-based block 33 in accordance with the separation distance of the connecting end faces 21a and 21b, and the depth thereof is set to the connecting end faces 21a and 21b. It can be formed by adjusting the depth deeper than the depth and injecting and filling the grout material 52 in that state.

Further, although not particularly mentioned in the present embodiment, the cement-based hardened body 32 can be reinforced with reinforcing bars if necessary.

FIG. 7 shows a procedure for reinforcing the reinforcing bar of the cement-based hardened body 32. First, in the same manner as in the above embodiment, the existing floor slab is removed and as shown in FIG. 7A. The precast floor slabs 1 and 1 are arranged so that the filling grooves 22a and 22b face each other.

Next, as shown in FIG. 7 (b), asphalt 51 is laid on the precast floor slabs 1 and 1 so as to straddle them, and in this state, the asphalt 51 is temporarily used as a road from the morning of the day.

After temporary service, the road was closed at night again, the asphalt 51 was temporarily removed, and then the reinforcing bars 73a and 73b intersected the filling space 31 along the plane orthogonal to the reference axis as shown in FIG. 7 (c). Arrange in a shape.

In arranging the reinforcing bars 73a and 73b, cylindrical holding members 72a and 72b are separately prepared, and then the reinforcing bars 73a and 73b are inserted into the hollow portions of the holding members to align the base end sides of both, and then the reinforcing bars 73a and 73b are aligned. The reinforcing bars 73a and 73b inserted into the holding members 72a and 72b are inserted into the reinforcing bar insertion holes 71a and 71b formed through the upper surfaces of the precast floor slabs 1 and 1 toward the filling space 31.

In this way, the outer diameters of the holding members 72a and 72b are substantially matched with the inner diameters of the reinforcing bar insertion holes 71a and 71b, and the reinforcing bars 73a and 73b inserted into the hollow spaces of the holding members 72a and 72b do not fall out of the hollow space. By being configured as such, the reinforcing bars 73a and 73b are fixed to the reinforcing bar insertion holes 71a and 71b via the holding members 72a and 72b, respectively, and are temporarily held in the filling space 31 in a crossed posture.

Next, as shown in FIG. 7 (d), the asphalt 51 was laid again on the precast floor slabs 1 and 1 in a form straddling them, and in this state, it was temporarily used as a road from the morning of the 3rd or 4th day. In service.

Next, after closing the road again at night, the asphalt 51 was temporarily removed, and then, as shown in FIG. 7 (e), the grout material 52 was injected and filled through the injection hole 25 in the same manner as in the above embodiment. To do.

Next, after waiting for the completion of the filling work of the grout material 52, as shown in FIG. 7 (f), the asphalt 51 is re-laid so as to straddle the precast floor slabs 1 and 1, and on the 4th or 5th day. In the morning, the road closure will be lifted and the road will be put into service.

On the other hand, after the filling work of the grout material 52 is completed, the grout material 52 is cured as a cement-based cured body 32, so that the construction of the connection structure of the precast plate is completed.

In this modified example, in the case of arranging the reinforcing bars 81 extending in the reference axis direction in the filling space 31 in addition to the intersecting reinforcing bars 73a and 73b along the plane orthogonal to the reference axis, the precast floor slabs 1, 1 Reinforcing bars 81 are retracted in advance near the bottom of one of the filling grooves, for example, the filling groove 22b, and the precast floor slabs 1 and 1 are arranged facing each other in this state, and the intersecting reinforcing bars 73a are arranged. After arranging, 73b, as shown in FIG. 8, the reinforcing bar 81 may be translated and moved toward the center of the filling space 31 by using the suspension rod 82.

Further, in the present embodiment, an injection hole 25 for injecting grout is formed through the precast floor slab 1, and the grout material 52 is injected and filled into the filling space 31 through the injection hole. Instead of this, as shown in FIG. 9, a configuration in which the grout material 52 is injected and filled into the filling space 31 can be adopted through a clearance extending between the connecting end faces 21a and 21b.

Specifically, after appropriately cutting the rubber block 33 as necessary, two pipes are inserted into the clearance, and the grout material 52 is inserted from the other pipe while bleeding air through one of the pipes. Should be injected. The pipe for injecting the grout material 52 may be arranged not on the upper surface side but on the lower surface side of the connecting end faces 21a and 21b. In this case, the grout material 52 is press-fitted from below. Will be done.

1 Precast floor slab (precast board)
21a, 21b Connecting end faces 22a, 22b Filling grooves 23a, 23b Groove inner surface 24a, 24b Groove inner space 25 Injection holes 31,64 Filling space 32,62 Cement-based hardened body 33,63 Rubber-based block (water-stopping elastic material)
52 Grout material (cement-based hardened material)
71a, 71b Reinforcing bar insertion holes 72a, 72b Holding members 73a, 73b Reinforcing bar 81 Reinforcing bar 104 Reinforcing bar 104 Precast plate connecting structure

Claims (7)

In the connection structure of the precast plates formed by connecting the two precast plates to each other,
The two precast plates are formed so that the inner surface of the groove forms an arc in the cross section with the axis parallel to the connecting end face and extending in the in-plane direction as the reference axis, and the filling groove is formed along the direction of the reference axis. It is composed of precast plates provided on the connecting end faces, and in a state where the two precast plates are arranged so that the filling grooves face each other, the space inside the grooves of the filling grooves is integrated with each other. A connection structure of a precast plate, characterized in that a cement-based hardened material is filled and arranged in a filling space so that the adhesion stress with the inner surface of the groove becomes substantially zero. The method for connecting precast plates according to claim 1, wherein the two precast plates are arranged so that the filling grooves face each other, and a cement-based curing material is injected into the filling space. A method for connecting precast plates, which comprises filling and curing the cement-based cured material to obtain the cement-based cured product. The precast plate according to claim 2, wherein the injection filling of the cement-based curing material is performed through an injection hole provided in at least one of the two precast plates so as to communicate with the space in the groove. How to connect. After the two precast plates are arranged to face each other and before the cement-based curing material is injected and filled, the reinforcing bars are inserted through the reinforcing bar insertion holes formed through the front or back surface of each of the precast plates toward the filling space. The method for connecting precast plates according to claim 2 or 3, wherein by inserting each of the reinforcing bars, intersecting reinforcing bars along a plane orthogonal to the reference axis are arranged in the filling space. When arranging each of the reinforcing bars, a cylindrical holding member is inserted into the reinforcing bar insertion hole, the reinforcing bar is passed through the hollow space of each holding member, and their ends are temporarily held by the holding member. The method for connecting precast plates according to claim 4. After arranging the intersecting reinforcing bars, the reinforcing bars temporarily fixed near the bottom of the filling groove are translated and moved toward the center of the filling space, so that the reinforcing bars extending in the direction of the reference axis are moved into the filling space. The method for connecting precast plates according to claim 4 or 5, wherein the precast plates are arranged. The invention according to any one of claims 2 to 6, wherein a water-stopping elastic material is arranged in a clearance extending between the connecting end faces so as to communicate with the filling space before the cement-based curing material is injected and filled. How to connect precast plates.

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