JP7300951B2 - How to build structures - Google Patents

Description

The present invention relates to a method of constructing a structure.

In general, when constructing a reinforced concrete structure such as a bridge pier, first, scaffolding is assembled, reinforcing bars are assembled in the foundation, a formwork is assembled so as to surround the reinforcing bars, concrete is poured into the formwork, and the concrete cures and hardens. Then dismantle the formwork. However, when constructing a structure using concrete such as a reinforced concrete structure, the assembly and dismantling of the formwork is a complicated task, which has been a factor in hindering the improvement of productivity in the construction of concrete structures.

Therefore, in recent years, a method has been proposed for constructing a structure by extruding or spraying a cementitious material onto a predetermined location using an additive manufacturing device and stacking the materials (see, for example, Patent Document 1).

JP 2018-069661 A

However, when the uncured cementitious material is piled up layer by layer and applied, the surface (side surface) has an uneven shape or striped pattern. In other words, in order to finish the surface smoothly, it was necessary to perform a post-treatment such as polishing the surface after the construction by stacking each layer. In addition, in Patent Document 1, the use of the side member prevents the formation of irregularities on the surface, but this method increases the steps of manufacturing and removing the side member, so it takes time and construction work. was complicated.

Therefore, the present invention has been made in view of the above circumstances, and provides a method of constructing a structure that can easily finish a smooth surface when laminating cementitious materials using an additive manufacturing apparatus. With the goal.

In order to achieve the above objects, the present invention provides the following means.

The method of constructing a structure of the present invention is a method of constructing a structure in which a hydraulic mixture is discharged from an additive manufacturing apparatus and the hydraulic mixture is layered to construct a structure. Alternatively, within 10 minutes after the discharge, the side surface of the discharged hydraulic mixture is sprayed with a finishing material using a sprayer to finish the side surface into a smooth surface.

According to the present invention, the side surface of the hydraulic mixture discharged from the additional manufacturing apparatus can be finished to a smooth surface by immediately attaching the finishing material to the side surface. That is, the surface of the structure can be easily finished smooth. The term "hydraulic mixture" refers to materials including various cementitious materials (eg, cement paste, mortar, concrete, etc.), geopolymer compositions, and the like.
In addition, the finishing material was sprayed within 10 minutes after the hydraulic mixture was discharged. By spraying the finishing material before the laminated hydraulic mixture starts to harden, it is possible to improve adhesion and integrity between the laminated hydraulic mixture and the finishing material.

Further, in the method for constructing a structure of the present invention, it is preferable that the finishing material discharged from the spraying device is a hydraulic mixture or a resin material.

According to the present invention, the dimensional stability of the laminated hydraulic mixture before curing can be enhanced by using a hydraulic mixture or a resin-based material as the finishing material.

Further, in the structure construction method of the present invention, a concrete modifier may be used as the finishing material discharged from the spraying device.

According to the present invention, by using a concrete modifier as a finishing material, it is possible to enhance the waterproof effect and improve the durability of the structure.

In the structure construction method of the present invention, the finishing material discharged from the spraying device may be a hydraulic mixture containing short fibers or a resin material.

According to the present invention, by using the fiber-reinforced mortar as the finishing material, it is possible to improve the load-bearing capacity and toughness of the structure after hardening.

Further, in the method of constructing a structure of the present invention, it is preferable that the finish material is sprayed to a thickness of 1 mm or more and 20 mm or less.

According to the present invention, unevenness formed on the side surface of the laminated hydraulic mixture can be covered and the smooth surface can be finished more reliably and easily with a finishing material.

According to the structure construction method of the present invention, the surface can be easily finished smooth when laminating and placing the cement-based material using the additive manufacturing apparatus.

It is a front view for explaining the construction method of the structure according to the first embodiment of the present invention, and is a diagram for explaining a reinforcing bar assembling process. FIG. 4 is a front view for explaining the construction method of the structure according to the first embodiment of the present invention, and is a diagram for explaining a mortar frame forming step. FIG. 4 is a vertical cross-sectional view for explaining the construction method of the structure according to the first embodiment of the present invention, and shows a state in which a mortar frame is formed. 4 is a cross-sectional view taken along line XX of FIG. 3; FIG. FIG. 4 is a diagram for explaining the construction method of the structure according to the first embodiment of the present invention, and is a partially enlarged perspective view in the mortar frame forming process. FIG. 4 is a diagram for explaining the construction method of the structure according to the first embodiment of the present invention, and is a partial cross-sectional view of the mortar frame. FIG. 4 is a vertical cross-sectional view for explaining the construction method of the structure according to the first embodiment of the present invention, and is a diagram for explaining a concrete core forming step. FIG. 8 is a cross-sectional view along line YY of FIG. 7; It is a figure for demonstrating the construction method of the structure which concerns on 2nd embodiment of this invention, and is a perspective view explaining the mortar containing fiber construction process. It is a schematic diagram for explaining the construction method of the structure according to the second embodiment of the present invention, and is a diagram for explaining an intermediate stage of the fiber-containing mortar construction process. FIG. 4 is a schematic perspective view showing yet another aspect of applying a finish material according to an embodiment of the present invention;

(First embodiment)
A first embodiment of a method for constructing a structure according to the present invention will be described below with reference to the drawings. In addition, in this embodiment, a case of constructing a reinforced concrete column using the method for constructing a structure according to the present invention will be described. Also, the case of using a fiber-containing mortar as a cementitious material (hydraulic mixture) will be described.

The method of constructing a structure according to the present embodiment is a method of constructing a newly constructed reinforced concrete column (structure), and includes a reinforcing bar assembling step, a fiber-filled mortar producing step, a mortar frame forming step, and a concrete core forming step. , provided. Each step will be described below.

[Reinforcing bar assembly process]
As shown in FIG. 1, in the reinforcement assembly process, reinforcements 10 are assembled at predetermined locations on a foundation (floor) S at a construction site of a concrete structure. The reinforcing bars 10 comprise a plurality of axial reinforcing bars (main bars) 12 and a plurality of shear reinforcing bars (ties) 14 . The plurality of axial reinforcing bars 12 are arranged at predetermined intervals in plan view so as to be aligned along the size and shape of the concrete structure in plan view, and the longitudinal direction of each axial reinforcing bar 12 is along the vertical direction. standing up in a state Each axial reinforcing bar 12 passes through the base portion S. In this step, depending on the size of the member (column), the upper end of the axial reinforcing bar 12a rising from the base portion S along the longitudinal direction and the lower end of another axial reinforcing bar 12b are joined to each other. An axial rebar 12 having a length is constructed. In addition, in FIG. 1, the reinforcing bar joint is omitted and the boundary portion between the axial reinforcing bars 12a and 12b is simply shown.

Subsequently, a plurality of shear reinforcing bars 14 are provided so as to bundle the plurality of axial reinforcing bars 12 . A plurality of shear reinforcing bars 14 are provided at predetermined intervals in the height direction.

[Fiber-containing mortar generation process]
In the fiber-containing mortar production process, a plurality of fibers 34 are mixed into the mortar material 32 to produce the fiber-containing mortar 30 (see FIG. 10). The mortar material 32 used in the present embodiment is a mortar having moderate fluidity in an uncured state, and a known material can be used. Furthermore, it is preferable that the material is a material that has a high strength in a short period of time by moderately hardening in the lamination process. Concrete may be used instead of mortar.

The fibers 34 to be mixed in the mortar material 32 are fibers made of chemically synthesized polymer or inorganic fibers. The former includes polypropylene fiber, polyvinyl alcohol fiber, polyethylene fiber, polyester fiber, aramid fiber and the like. The latter include glass fibers, steel fibers, carbon fibers, rock fibers (such as basalt), ceramic fibers, silica fibers, and the like. Although the diameter of the fibers 34 used in the present invention is not limited, the diameter of the short fibers is preferably 0.005 mm or more and 1.0 mm or less. It is preferable that the average length of the plurality of fibers 34 is, for example, 3 mm or more and 30 mm or less.

The fibers 34 are preferably mixed with the mortar material 32 at, for example, 0.1% by volume or more and 5.0% by volume or less. Specifically, the ratio of the fibers 34 in the mortar material 32 is adjusted to such an extent that the fiber-filled mortar 30 can maintain its shape in the air and to the extent that drying shrinkage and cracking of the fiber-filled mortar 30 can be suppressed. In order to exhibit the tensile toughness of the fiber-reinforced mortar body 31 against external force after the fiber-filled mortar 30 hardens, it is preferable that the fiber 34 is mixed with the mortar material 32 in an amount of 1.0% by volume or more. .

[Mortar frame forming process]
As shown in FIG. 2, in the mortar frame forming step, an uncured fiber-filled mortar (first concrete) 30 is extruded around the reinforcing bars 10 from the additive manufacturing device 40 to form the mortar frame 20 shown in FIGS. to form

In the mortar frame forming step, the fiber-containing mortar 30 is supplied to the additional manufacturing device 40 and extruded around the reinforcing bars 10 from the nozzle 42 of the additional manufacturing device 40 . The additional manufacturing device 40 includes a nozzle 42 , a lifter section 44 and a self-propelled section 46 . The lifter part 44 supports the nozzle 42 and a supply part (hose) 48 for supplying the uncured fiber-filled mortar 30 to the nozzle 42, and raises and lowers the nozzle 42 to a predetermined height. The self-propelled portion 46 is connected to the lifter portion 44 , self-propelled around the reinforcing bar 10 , and interlocked with the lifter portion 44 to move the nozzle 42 to the extruding position of the fiber-filled mortar 30 .

As shown in FIGS. 2 and 3, while extruding the fiber-filled mortar 30 from the nozzle 42, the nozzle 42 is circulated around the reinforcing bars 10 so as to trace the outline of the reinforced concrete column (concrete structure) to reinforce the bottom layer with fibers. A mortar body 31-1 is constructed. Since the fiber-filled mortar 30 has shape retention properties as described above, it starts to harden while retaining the shape extruded onto the base portion S. Subsequently, the nozzle 42 is raised to the same height as the height directly above the hardened fiber-reinforced mortar body 31-1, and is circulated so as to trace the upper surface of the fiber-reinforced mortar body 31-1 to form the second layer of the fiber-reinforced mortar body. 31-2 is constructed. The same operation is repeated until the uppermost fiber-reinforced mortar body 31-k reaches a predetermined height. k is any natural number. The fiber-filled mortar 30 forming the fiber-reinforced mortar bodies 31 (31-1 to 31-k) are made of the same material and are in contact with each other, so that they are well integrated when hardened. The fiber-reinforced mortar body 31 is completely cured to form the mortar frame 20 as shown in FIG.

Here, in this embodiment, the finishing material 36 is sprayed on the side surface 35 of the fiber-filled mortar 30 at the same time as or immediately after the fiber-filled mortar 30 is extruded from the nozzle 42 of the additive manufacturing device 40 .

As shown in FIGS. 2 and 5, the finishing material 36 is discharged from finishing material supply hoses 92 arranged on both sides of the nozzle 42 of the additional manufacturing device 40 and sprayed onto both side surfaces 35, 35 of the fiber-filled mortar 30. , has a finishing material 36 applied to the sides 35 , 35 .

The finishing material 36 is, for example, the same material as the mortar material 32 (hydraulic mixture) or a resin material. By using such a material, the shape stability of the laminated fiber-containing mortar 30 before curing can be enhanced. A finished surface 38 is formed as a smooth surface by spraying a finishing material 36 onto the side surface 35 .

As shown in FIG. 2, a finishing material supply device 90 for supplying the finishing material 36 includes a nozzle 91 for discharging the finishing material 36, a finishing material supply hose 92 connected to the nozzle 91, a nozzle 91 and the finishing material supply hose. It has a lifter portion 93 for moving 92 to a predetermined position and a self-propelled portion 94 . The lifter part 93 supports the nozzle 91 and the finishing material supply hose 92, and raises and lowers the nozzle 91 to a predetermined height. The self-propelled section 94 is connected to the lifter section 93 , self-propelled along substantially the same route as the additional manufacturing apparatus 40 , and moves the nozzle 91 to the side surface 35 of the fiber-filled mortar 30 in conjunction with the lifter section 93 . Although FIG. 2 shows only the finishing material supply device 90 for discharging the finishing material 36 to the outer side surface 35 of the fiber-containing mortar 30, the finishing material 36 is discharged to the inner side surface 35 of the fiber-containing mortar 30. A finishing material feeder (not shown) is also located. The finishing material 36 may be discharged to both side surfaces 35, 35 of the fiber-filled mortar 30 using a single finishing material supply device.

As shown in FIG. 6, a finishing material 36 is applied to the side surface 35 of the fiber-filled mortar 30 to finish the side surface into a smooth surface (finished surface 38). At this time, the finishing material 36 can be applied by using a device that divides the material into many layers (about 1 mm per layer) and sprays them with high accuracy, like spray painting (to form a film on the surface). It can be finished to a precise smooth surface.

The spraying thickness of the finishing material 36 may be a thickness that fills the unevenness of the side surface 35 of the fiber-filled mortar 30, and is preferably 1 mm to 20 mm.

The spraying of the finish material 36 is preferably performed at the same time or immediately after applying the fiber-filled mortar 30 with the additive manufacturing equipment 40 . Preferably, finish material 36 is sprayed within 10 minutes after application by additive manufacturing equipment 40 at the latest.

The finishing material 36 is adhered only to the side surface 35 of the fiber-filled mortar 30 and is not adhered to the upper surface, so that the fiber-filled mortars 30, 30 which are stacked vertically can be reliably integrated with each other. can be done. Alternatively, the finishing material 36 may be attached only to one side surface 35 of the fiber-filled mortar 30 (for example, only the outer peripheral surface).

Finishing material 36 is supplied using, for example, a pump (not shown). A pump capable of metering the finishing material 36 is preferably used.

In addition, in order to improve the spray thickness and dimensional accuracy of the finishing material 36, it is desirable to constantly measure the outer dimensions of the structure under construction using a 3D scanner. By transmitting the measurement data to the finishing material supply device 90 in real time, the spraying position and the spraying amount of the finishing material 36 can be controlled with higher precision.

[Concrete core forming process]
As shown in FIGS. 7 and 8, in the concrete core forming step, uncured fresh concrete (second concrete) 62 is cast into the space 50 inside the mortar frame 20 to form the concrete core 60 that fills the space 50. do. Specifically, the supply pipe 68 of the fresh concrete 62 is inserted into the space 50 inside the mortar frame 20 using the lifting device 66, and the fresh concrete 62 is supplied from the tip of the supply pipe 68 into the space 50 while supplying. The tube 68 is raised accordingly. A space 50 is filled with fresh concrete 62 to the same height as the upper end of the mortar frame 20, cured and hardened to form a concrete core 60. - 特許庁In this manner, a reinforced concrete column (structure) 70 including the reinforcing bars 10, the mortar frame 20 and the concrete core 60 can be constructed.

The method of constructing a structure according to the present embodiment described above includes the reinforcing bar assembly process, the fiber-containing mortar generation process, the mortar frame formation process, and the concrete core formation process. In the construction method of the structure of the present embodiment, the mortar frame 20 is formed using the additional manufacturing device 40 without using a formwork, and the fresh concrete 62 is poured into the mortar frame 20 using the mortar form 20 as a formwork. be able to. According to the construction method of the structure of the present embodiment, the assembling and dismantling of the formwork as in the conventional method becomes unnecessary, and the construction efficiency of the reinforced concrete column (structure) 70 can be improved.

In the structure construction method of the present embodiment, at the same time (or immediately after ejection) when the fiber-filled mortar 30 is ejected, the finishing material 36 is sprayed onto both side surfaces 35, 35 of the ejected fiber-filled mortar 30. Even if the fiber-containing mortar 30 is laminated vertically, the surface can be easily finished smooth.

In addition, in the present embodiment, since the spraying thickness of the finishing material 36 is set to 1 mm or more and 20 mm or less, the finishing material 36 covers the uneven shape formed on the side surface 35 of the laminated fiber-filled mortar 30 to ensure In addition, a smooth surface (finished surface 38) can be easily finished.

Furthermore, in this embodiment, the finishing material 36 is sprayed on the side surface 35 within 10 minutes after the fiber-filled mortar 30 is discharged from the additional manufacturing device 40, so that the laminated fiber-filled mortar 30 begins to harden. A finish material 36 can be sprayed before. As a result, it is possible to improve adhesion and integrity between the laminated fiber-filled mortar 30 and the finishing material 36 .

Although the first embodiment of the present invention has been described in detail above, the present invention is not limited to the above first embodiment, and various can be changed.

For example, in the present embodiment, the fiber-filled mortar 30 is used as the first concrete, but the fiber-filled mortar 30 is not limited to the first concrete as long as it has fluidity and shape retention and can resist the tensile force generated by the lateral pressure of the concrete core 60. .

In addition, although fresh concrete 62 is used as the second concrete in the present embodiment, the type of concrete is not particularly limited, and can be cast inside a conventional formwork such as a wooden one in a normal construction method for concrete structures. Includes all concrete materials.

Also, in this embodiment, the case of constructing the reinforced concrete column 70 has been described, but it is needless to say that the construction of the structure can be adopted for other than the reinforced concrete column.

Moreover, in the present embodiment, the mortar frame forming process is performed after the reinforcing bar assembling process, but the order of performing the reinforcing bar assembling process and the mortar frame forming process is not particularly limited. That is, the reinforcing bar assembling process may be performed after the mortar frame forming process. In that case, for example, after forming the mortar frame 20 as described above, the reinforcing bar cage can be lifted by a crane and inserted inside the mortar frame 20 . In addition, a reinforcing bar cage is formed by assembling a plurality of reinforcing bars, fixing them with wires or the like, and integrating them.

Further, in the present embodiment, only the reinforcing bars 10 are assembled on the base portion S in the reinforcing bar assembling process, but the steel frame may be erected on the base portion S first, and the reinforcing bars 10 may be assembled around the steel frame. That is, the construction method of the structure of the present invention can be used not only for the above-mentioned reinforced concrete (RC) concrete structure, but also for construction of a reinforced steel concrete (SRC) concrete structure.

Further, in the present embodiment, the finishing material 36 is the same hydraulic mixture or resin material as the concrete material 32, but it is not limited to this. For example, a concrete modifier may be used as the finishing material 36 . By using the concrete modifier, the waterproof effect can be enhanced, and the durability of the structure can be improved. A fiber reinforced mortar may also be used as the finishing material 36 . By using the fiber-reinforced mortar, it is possible to improve the load-bearing capacity and toughness of the structure after hardening.

(Second embodiment)
Next, a second embodiment of the method for constructing a structure according to the present invention will be described with reference to the drawings. In addition, in this embodiment, a description will be given of a case where reinforcing fiber-containing concrete (hydraulic mixture) is constructed on an existing reinforced concrete column using the method for constructing a structure according to the present invention. In addition, the same reference numerals are assigned to portions having substantially the same configuration as in the first embodiment, and detailed description thereof will be omitted.

The construction method of the structure of the present embodiment is a method of reinforcing an existing reinforced concrete column 80, and includes a fiber-containing mortar generation step and a fiber-containing mortar construction step. Each step will be described below.

[Fiber-containing mortar generation process]
In the fiber-containing mortar production step, the fiber-containing mortar 30 is produced by substantially the same method as in the first embodiment.

[Fiber-filled mortar construction process]
As shown in FIG. 9, in the fiber-containing mortar construction step, the fiber-containing mortar 30 produced in the fiber-containing mortar producing step is supplied to the additional manufacturing device 40, and the fiber-containing mortar 30 is supplied from the nozzle 42 of the additional manufacturing device 40 to a predetermined amount. The fiber reinforced mortar body 31 is constructed by extruding to the position of . Specifically, the fiber-containing mortar 30 is arranged along the outer peripheral surface of the existing reinforced concrete column 80, and the fiber-reinforced mortar body 31 is constructed.

In the fiber-containing mortar construction process, the fiber-containing mortar 30 is extruded from the extrusion port 51 of the nozzle 42 at a predetermined position, and is so-called three-dimensionally printed and laminated at the predetermined position. Then, the fiber-containing mortar 30 is extruded in layers in the vertical direction. At this time, the fiber-containing mortar 30 may be extruded a plurality of times according to the shape of the existing reinforced concrete column 80, or may be extruded once so as to trace the shape.

The fiber-containing mortar 30 hardens with the lapse of a predetermined time, the surfaces of adjacent fiber-containing mortar 30 are joined together, and the fiber-reinforced mortar body 31 is constructed. The fiber-containing mortar construction process is completed by constructing all of the fiber-containing mortar 30 extruded in accordance with the shape of the existing reinforced concrete column 80 as the fiber-reinforced mortar body 31 .

The fiber-containing mortar production step and the fiber-containing mortar application step may be performed in parallel.

In this embodiment, the finishing material 36 is applied to the outer side surface 35 of the fiber-filled mortar 30 at the same time or immediately after the fiber-filled mortar 30 is extruded from the nozzle 42 of the additive manufacturing device 40 . The finishing material 36 is discharged from a finishing material supply hose 92 disposed outside the nozzle 42 of the additional manufacturing device 40 and sprayed onto the outer side surface 35 of the fiber-filled mortar 30 to adhere to the side surface 35 .

By spraying and adhering the finishing material 36 to the outer side surface 35 of the fiber-filled mortar 30, the surface can be easily finished into a smooth surface (finished surface 38).

Also in this embodiment, substantially the same effects as those of the first embodiment can be obtained.

Although the embodiments of the method for constructing a structure according to the present invention have been described above, the present invention is not limited to the above embodiments, and can be modified as appropriate without departing from the scope of the invention.

For example, in the present embodiment, the case of casting the fiber-filled mortar 30 using the additional manufacturing device 40 has been described, but fibers may not be mixed, and concrete may be used instead of mortar. .

In addition, in the present embodiment, a case where the nozzle 42 of the additional manufacturing device 40 and the finishing material supply hose 92 are driven as separate equipment has been described, but as shown in FIG. and the finishing material supply hose 92 may be moved integrally.

In addition, the finishing material 36 may be sprayed after each layer of the fiber-filled mortar 30 is applied, or may be sprayed all at once after 2 to 3 layers are laminated. In short, it is sufficient that the laminated fiber-containing mortar 30 and the finishing material 36 are integrally applied and the finishing surface 38 is finished to be a smooth surface.

10 reinforcing bar 20 mortar frame 30 fiber-containing mortar (hydraulic mixture)
32 mortar material 34 fiber 35 side 36 finishing material 40 additional manufacturing device 90 finishing material supply device (spraying device)

Claims (5)

In a structure construction method for constructing a structure by discharging a hydraulic mixture from an additive manufacturing device and stacking the hydraulic mixture,
Simultaneously with discharging the hydraulic mixture or within 10 minutes after discharging, the side surface of the discharged hydraulic mixture is sprayed with a finishing material using a spray device to finish the side surface to a smooth surface. construction method of the structure. 2. The method of constructing a structure according to claim 1, wherein the finishing material discharged from the spraying device is a hydraulic mixture or a resin-based material. 2. The method of constructing a structure according to claim 1, wherein the finishing material discharged from the spraying device is a concrete modifier. 2. The method of constructing a structure according to claim 1, wherein the finishing material discharged from the spraying device is a hydraulic mixture containing short fibers or a resin-based material. 5. The method of constructing a structure according to any one of claims 1 to 4, wherein the finishing material is sprayed to a thickness of 1 mm or more and 20 mm or less.

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