JP6960082B2 - How to build a skeleton by spraying concrete - Google Patents

Description

The present invention relates to a method for constructing a skeleton by spraying concrete.

Conventionally, in a structure having a top plate such as a box culvert, when constructing the top plate, a scaffolding is installed, a formwork support is installed, reinforcing bars are assembled, and cast-in-place concrete is used. The construction method of placing slab formwork concrete was generally adopted.

In addition, from the viewpoint of shortening the construction period and workability, a construction method was also adopted in which the box culvert was constructed of precast concrete, the top plate block was lifted by a lifting machine, and the box culvert was placed on the side wall block. (See Patent Document 1)

Japanese Patent No. 4917576

However, in the above-mentioned conventional construction method, when constructing the top plate, the time and labor required for temporary construction such as scaffolding and formwork support work have a great influence on the construction period and cost. ..

Further, in the method of mounting the top plate block made of precast concrete as described in Patent Document 1, the weight per top plate block is limited by the lifting capacity of the lifting machine. Therefore, it is inevitable to reduce the length of the top plate block in the longitudinal direction, and in the case of a box culvert with a long construction extension, it may not be possible to shorten the construction period.

Furthermore, when constructing a top plate with a large span of more than 10 m, it is practically difficult to install a top plate block with a lifting machine because precast concrete would result in a very large weight. Is.

Therefore, an object of the present invention is to provide a skeleton construction method by concrete spraying, which enables a significant shortening of the construction period as compared with the conventional skeleton construction method without installing scaffolding or formwork support. do.

(1) A method of constructing a skeleton by spraying sprayed concrete (sprayed concrete 3) to construct a skeleton (top plate 10, floor slab, beam 10A) by spraying concrete, and a plurality of skeletons are constructed in a predetermined direction of the skeleton. Reinforcing materials (reinforcing material 1) are arranged at predetermined intervals, and a grid-like connecting material (connecting material 2) is bound over the plurality of reinforcing materials, and the connecting material is described from below and above. A method for constructing a skeleton by spraying concrete, which comprises spraying sprayed concrete to construct the skeleton.

According to the configuration of (1) above, the skeleton such as the top plate 10, the floor slab, and the beam 10A can be formed by spraying the sprayed concrete 3 without installing the scaffolding or the formwork support as in the past. Since it can be constructed, it is possible to significantly shorten the construction period and construct the formwork economically. That is, when the sprayed concrete 3 is sprayed, the lattice-shaped connecting material 2 serves as a formwork, and the spraying concrete 3 is attached to the connecting material 2 from below and above to form a skeleton having a predetermined structural cross section for a short period of time. It is possible to build between.

(2) A method of constructing a skeleton by spraying sprayed concrete (sprayed concrete 3) to construct a skeleton (top plate 10, floor slab, beam 10A) by spraying concrete, and a plurality of skeletons are constructed in a predetermined direction of the skeleton. Reinforcing materials (reinforcing material 1) are arranged at predetermined intervals, and a grid-like connecting material (connecting material 2) is bound over the plurality of reinforcing materials, and the connecting material is sprayed from below. A method for constructing a skeleton by spraying concrete, which comprises spraying concrete and casting cast-in-place concrete from above to construct the skeleton.

According to the configuration of (2) above, the skeleton such as the top plate 10, the floor slab, and the beam 10A can be formed by spraying the sprayed concrete 3 without installing the scaffolding or the formwork support as in the past. Since it can be constructed, it is possible to significantly shorten the construction period and construct the formwork economically. That is, when the sprayed concrete 3 is sprayed, the sprayed concrete 3 is attached to the lattice-shaped connecting material 2 from below to construct the lower part of the skeleton, and further, the cast-in-place concrete is cast on the upper part of the skeleton. It is possible to construct a skeleton having a predetermined structural cross section in a short period of time.

(3) The method for constructing a skeleton by spraying concrete according to (1) or (2), wherein the skeleton is a top slab (top slab 10) or a floor slab.

According to the configuration of (3) above, when constructing a top plate (top plate 10) or a floor slab that requires a lot of labor and materials and equipment for scaffolding installation and formwork support installation work, the above (1) ) Or the effect obtained by the configuration described in (2) can be obtained more remarkably.

(4) Of the reinforcing material (reinforcing material 1) and the connecting material (connecting material 2), at least the reinforcing material is formed of carbon fiber reinforced plastic or aramid fiber reinforced plastic (1) to (3). ), The method of constructing the skeleton by spraying concrete.

According to the configuration of (4) above, at least the reinforcing material of the reinforcing material (reinforcing material 1) and the connecting material (connecting material 2) is formed of carbon fiber reinforced plastic or aramid fiber reinforced plastic. That is, since it is much stronger and lighter than the normally used reinforcing bars, it is possible to more efficiently assemble the reinforcing material (reinforcing material 1) and the connecting material (connecting material 2).

(5) The method for constructing a skeleton by spraying concrete according to any one of (1) to (4), wherein the reinforcing material (reinforcing material 1) and the connecting material (connecting material 2) are grounded.

According to the configuration of (5) above, the reinforcing material (reinforcing material 1) and the connecting material (connecting material 2) are grounded and installed at the construction site of the skeleton by a lifting machine. Installation can be minimized. Further, when the reinforcing material and the connecting material are molded of carbon fiber reinforced plastic or aramid fiber reinforced plastic, the reinforcing material and the connecting material that have been grounded are very light, so that they can be grounded largely. It becomes possible, and the construction period can be further shortened.

It is a schematic cross-sectional view which shows an example of the box culvert in the Example of this invention. An example of the construction flow of the top slab by spraying concrete in the embodiment of the present invention is shown. It is a figure which shows an example of the installation mode and the cross-sectional view of the groundwork guide in this invention. It is a figure which shows an example of the assembling mode of a reinforcing material and a connecting material in this invention. It is a figure which shows an example of the installation mode on the side wall of the ground-assembled reinforcing material and the connecting material in this invention. It is a figure which shows an example of the spraying procedure of the sprayed concrete in this invention. It is a schematic cross-sectional view which shows an example of a beam in another Example of this invention.

Hereinafter, the method of constructing the top plate will be described as an example in the method of constructing the skeleton by spraying concrete of the present invention with reference to the drawings.

As an example of the skeleton structure by concrete spraying of the present invention, FIG. 1A shows an overall schematic cross-sectional view of the box culvert 100. In the illustrated embodiment, the arch-shaped top plate 10 is erected on the left and right side walls 20 in a manner similar to a pin joint. The method for constructing a skeleton by spraying concrete of the present invention is not limited to the embodiment shown in FIG. 1 (a), and includes a linear top slab, various shapes of top slabs, and a floor. It can also be applied to slabs and beams. Further, the method of joining the top plate can be similarly applied not only to pin joining but also to rigid joining.

Further, FIGS. 1 (a) and 1 (b) show schematic cross-sectional views of the top plate 10, and a reinforcing member 1 arranged in the transverse direction (short side direction) is predetermined in the top plate 10. They are arranged at intervals, and a grid-like connecting member 2 is bound and arranged on the upper part of the reinforcing member 1. That is, the reinforcing member 1 plays the role of the main bar, and the connecting member 2 plays the role of the force distribution bar.

Then, the lower sprayed concrete 3a is sprayed from the lower side and the upper sprayed concrete 3b is sprayed from the upper side onto the lattice-shaped connecting member 2, and the top plate 10 is constructed.

(Material used)
The reinforcing material 1 used in this embodiment is made by molding carbon fiber reinforced plastic (so-called CFRP) into a hollow cylindrical shape, and is a lightweight and high-strength material. From the viewpoint of light weight and high strength, it is also possible to mold the reinforcing material 1 using aramid fiber reinforced plastic. Further, the carbon rod / pipe can be used as the reinforcing material 1.

Further, the shape of the reinforcing material 1 is not limited to the hollow cylindrical shape described above, and other shapes such as a solid rod shape, an H type, an I type, and a polygonal shape can be used, and the shape and dimensions of the top plate 10 can be used. It is possible to change the shape according to such factors. For example, when the cross-sectional shape of the top plate 10 is arch-shaped, it is preferable to use a hollow cylindrical shape because the reinforcing member 1 needs to be deformed into an arch shape when the reinforcing member 1 is installed. Further, if the shape of the top plate 10 is a linear shape, it is possible to make it difficult to bend at the time of erection by making it H-shaped or I-shaped.

The lattice-shaped connecting material 2 used in this embodiment is a net material formed of carbon fiber reinforced plastic (so-called CFRP), has a grid of about 2 cm square, is lightweight, has high strength, and is resistant to corrosion. It is a material. Since the connecting material 2 also functions as a formwork for the sprayed concrete 3, the shape and dimensions of the grid are not limited to those described above, as long as the sprayed concrete 3 is appropriately attached. good.

Further, from the viewpoint of light weight and high strength, it is possible to use a mesh sheet made of aramid fiber as a connecting material 2, and it is possible to reduce the cost as compared with the one made of carbon fiber. Further, the present invention is not limited to this, and a steel welded wire mesh or a lath wire mesh can be used as the connecting material 2.

The sprayed concrete 3 used in this embodiment has an aggregate having a maximum particle size of 15 mm and a quick-setting agent as an admixture, and is a material having an extremely fast onset rate of initial strength. The maximum particle size of the aggregate and the admixture to be blended are not limited to those described above, and the required initial strength and long-term strength, adhesion to the binder 2 and workability are taken into consideration. It is necessary to design the composition of the attached concrete 3.

(Construction procedure)
Next, the construction procedure of the top slab by spraying concrete in this embodiment will be described below with reference to each figure according to the flow of FIG.

[Installation of ground guide (S100)]
FIG. 3 shows an installation mode of the groundwork guide 4 for grounding the reinforcing material 1 and the connecting material 2 and a cross-sectional view thereof. As shown in FIG. 3A, L-shaped ground guides 4 are installed on the ground at both ends in the transverse direction (direction B in the drawing) according to the shape and dimensions of the top plate 10. Further, in order to maintain and fix the distance between the ground guides 4 corresponding to the dimensions of the top plate 10, the ground guide fixing members are at least at both ends in the longitudinal direction (direction of FIG. A) of the ground guide 4. Install 5.

In this embodiment, as shown in FIG. 3A, flat steel is used as the ground guide fixing member 5, but the present invention is not limited to this, and the distance between the ground guides 4 is fixed. If possible, steel bars, angles, wires, etc. may be used. With such a configuration, even when the linear reinforcing material 1 is bent upward and arranged on the ground guide 4, the reinforcing material 1 is prevented from returning to the original linear shape, and the shape of the top plate 10 is formed. The reinforcing member 1 and the connecting member 2 can be assembled on the ground corresponding to the above.

Further, FIG. 3B shows how to install the reinforcing material 1 on the groundwork guide 4, but in this embodiment, the hollow cylindrical reinforcing material 1 is placed at a predetermined position on the groundwork guide 4. Fixing protrusions 6 for arranging are provided at predetermined intervals. Although it is possible to arrange the reinforcing material 1 on the ground guide 4 without providing the fixing protrusions 6 on the ground guide 4, the reinforcing materials 1 such as the fixing protrusions 6 are arranged at predetermined intervals. By providing the groundwork guide 4 with some kind of positioning member for this purpose, it is possible to improve the workability of the work of arranging the reinforcing member 1.

[Assembly of Reinforcing Material (S110)]
As shown in FIG. 3B, in this embodiment, the reinforcing material 1 is inserted into the fixing protrusion 6 while being bent according to the shape of the top plate 10 on the groundwork guide 4, and the reinforcing material 1 is inserted. Place in place. After that, in the axial direction (direction A in FIG. 3A), an axial connecting member 7 for maintaining and fixing the interval between the reinforcing members 1 is installed, and the reinforcing members 1 and the binding member 8 bind the reinforcing members 1. The axial connecting material 7 may be any material such as a reinforcing bar or carbon fiber reinforced plastic that can maintain and fix the distance between the reinforcing materials 1.

Subsequently, as shown in FIGS. 3 (b) and 4 (b), the tie wires 9 are provided between the axial connecting members 7 installed at both ends in the transverse direction (direction B in FIG. 3 (a)). Put up. With such a configuration, even after the reinforcing material 1 and the connecting material 2 for which the groundwork has been completed are lifted and separated from the groundwork guide 4, the assembled shape of the reinforcing material 1 and the connecting material 2 (the present embodiment). Then the arch shape) will be retained.

[Installation of connecting material, binding (S120)]
As shown in FIGS. 4A and 4B, a grid-like connecting member 2 is arranged on the upper part of the reinforcing member 1 arranged in the groundwork guide 4, and the connecting member 2 is connected by using a binding line or the like. Bind to the reinforcing material 1.

[Floating installation of ground reinforcement and connecting material (S130)]
FIG. 5 shows a mode in which the reinforcing member 1 and the connecting member 2 assembled on the groundwork guide 4 are lifted and installed at the construction location of the top plate 10. After the assembly of the reinforcing material 1 and the connecting material 2 is completed on the groundwork guide 4, the slinging wire 40 is attached to the axial connecting material 7 as shown in FIGS. The reinforcing member 1 and the connecting member 2 assembled by the lifting machine 50 are lifted, moved to the construction location of the top plate 10, and installed at the installation location on the upper side wall 20.

When the installation at the installation location on the upper part of the side wall 20 is completed, the sling wire 40 is removed, and the tie wire 9 stretched to maintain the assembled shape of the reinforcing member 1 is removed. When the top plate 10 and the side wall 20 are rigidly joined, the fixing reinforcing bar (not shown) is exposed from the upper part of the side wall 20 and the fixing reinforcing bar (not shown) is bound to the reinforcing material 1. Will be done.

[Spraying concrete spraying (S140)]
FIG. 6 shows stepwise the spraying mode of the sprayed concrete 3 on the reinforcing member 1 and the connecting member 2 erected on the upper part of the side wall 20. First, as shown in FIG. 6 (a), the sprayed concrete 3 is sprayed onto the connecting material 2 from below the top plate 10, and then sprayed until the predetermined design thickness is reached as shown in FIG. 6 (b). To construct the lower sprayed concrete 3a.

Next, as shown in FIG. 6C, the sprayed concrete 3 is sprayed onto the upper surface side of the connecting member 2 until it reaches a predetermined design thickness, and the upper sprayed concrete 3b is constructed. The portion of the upper sprayed concrete 3b on the upper surface side is not limited to the method by spraying, and the concrete is pumped to the site by pumping or the like so as to add concrete to the already constructed lower sprayed concrete 3a. It is also possible to hit and build the top plate 10. At that time, since it is necessary for the worker to enter the already constructed lower spray concrete 3a, it is necessary that the lower spray concrete 3a has a strength that can withstand it.

[Cure (S150)]
When the spraying of the sprayed concrete is completed, it is cured for a predetermined period.

Although the construction procedure in this embodiment has been described above, the groundwork guide 4, the groundwork guide fixing member 5, and the tie wire 9 used when assembling the reinforcing material 1 and the connecting material 2 can be reused. The groundwork guide 4, the groundwork guide fixing member 5, and the tie wire 9 can be repeatedly used for assembling the reinforcing material 1 and the connecting material 2.

Further, the above description of the construction procedure is based on an example in which the shape of the top slab is an arch shape, but when constructing a flat top slab or in advance, the reinforcing material 1 is formed into an arch shape. In this case, the tie wire 9 is not always required.

(Other Examples)
In the above-described embodiment, the method of constructing the top slab by spraying concrete mainly in the arch-shaped top slab has been described, but it is also possible to construct a skeleton such as a beam or a floor slab by spraying concrete. For example, as shown in the schematic cross-sectional view of the beam 10A of FIG. 7, first, the reinforcing member 1 is arranged in the transverse direction, and the lattice-shaped connecting member 2 is bound as shown in the reinforcing member 1. ..

Then, the sprayed concrete 3 is sprayed onto the connecting member 2 from below to construct the lower sprayed concrete 3a. After that, the inside of the beam 10A is sprayed from above to construct the upper sprayed concrete 3b. The portion of the upper sprayed concrete 3b is not limited to the method by spraying, and the concrete is cast on-site by pumping or the like so as to add concrete to the already constructed lower sprayed concrete 3a. It is also possible to construct the beam 10A.

Although the embodiments of the present invention have been described above with reference to the drawings, the specific configuration is not limited to these embodiments. The scope of the present invention is shown by the scope of claims rather than the description of the above-described embodiment, and further includes all modifications within the meaning and scope equivalent to the scope of claims. In addition, the specific materials, dimensions, shapes, etc. described in the above examples can be changed as long as the problems of the present invention are solved.

1 Reinforcing material 2 Connecting material 3 Sprayed concrete 10 Top plate 10A Beam

Claims (5)

It is a method of constructing a skeleton by spraying concrete, which constructs a skeleton that is erected by spraying sprayed concrete.
Reinforcing materials having a straight or curved shape are arranged in parallel at predetermined intervals in the direction in which the skeletons are joined and supported, and the reinforcing materials are bridged in the erection direction of the skeletons.
The shotcrete plane lattice tether possible adhesion, as well as arranged in a planar across a plurality of the reinforcing material disposed in parallel, and bundling the該繋skill material to said reinforcing member,
Against one surface of the connecting member, spraying the shotcrete from the lower side of the skeleton to be laid, then from said upper side of said skeleton member to the other surface of the connecting member is bridged A method for constructing a skeleton by spraying concrete, which comprises spraying sprayed concrete to construct the skeleton to be erected. It is a method of constructing a skeleton by spraying concrete, which constructs a skeleton that is erected by spraying sprayed concrete.
Reinforcing materials having a straight or curved shape are arranged in parallel at predetermined intervals in the direction in which the skeletons are joined and supported, and the reinforcing materials are bridged in the erection direction of the skeletons.
The shotcrete plane lattice tether possible adhesion, as well as arranged in a planar across a plurality of the reinforcing material disposed in parallel, and bundling the該繋skill material to said reinforcing member,
Against one surface of the connecting member, spraying the shotcrete from the lower side of the skeleton to be laid, then to the other surface of the connecting member, the upper side or al of the skeleton to be bridged and Da設the onsite concrete, the skeleton construction method according to the concrete spraying, characterized in that to construct a building frame to be bridged. The method for constructing a skeleton by spraying concrete according to claim 1 or 2, wherein the skeleton to be erected is a top plate or a floor slab. The method for constructing a skeleton by spraying concrete according to any one of claims 1 to 3, wherein at least the reinforcing material among the reinforcing material and the connecting material is formed of carbon fiber reinforced plastic or aramid fiber reinforced plastic. The method for constructing a skeleton by spraying concrete according to any one of claims 1 to 4, wherein the reinforcing material and the connecting material are grounded.

Images