Manufacturing method for concrete panel, concrete panel, water cut-off structure of opening

Abstract

To economically and efficiently manufacture a concrete panel while reducing its weight.SOLUTION: A manufacturing method for a concrete panel containing a foam includes the steps of inserting a foam fixed to a fixing member suspended from an anti-floating member into a formwork, pouring a fiber-reinforced concrete so as to embed the foam, and removing the formwork and the anti-floating member after a fiber-reinforced concrete is hardened.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a concrete slab containing a foamed material, a concrete slab, and a water stop structure for an opening.

Background Art

[0002] Conventionally, as a countermeasure against flooding of living spaces due to floods, high tides, tsunamis, etc., a water stop wall constructed on the outer periphery of building facilities and the like is known. The water stop wall forms an opening and installs a water stop gate that closes the opening. Normally, people and vehicles can move in and out of the water stop wall through the opening.

[0003] On the other hand, in an emergency, the opening is closed with a water stop gate to prevent flooding into the living space. For such water stop gates, for example, those with various structures such as the undulating type, the sliding door type, and the floating body type disclosed in Patent Document 1 are adopted.

[0004] In general, water stop gates of any structure adopt steel members and often use mechanical and electrical equipment for opening and closing operations, which affects the total cost of disaster countermeasures. For this reason, breakwaters and water stop walls with openings, although effective means for flood control measures, are generally expensive countermeasures.

[0005] Under such circumstances, it is conceivable to adopt a concrete floating body for the water stop gate as disclosed in, for example, Patent Document 2. If a concrete floating body is adopted for the water stop gate, the opening and closing operation can be performed using buoyancy, so mechanical and electrical equipment can be omitted. Such a concrete floating body is manufactured by placing concrete around a block made of expanded polystyrene installed in a formwork.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0007] However, if a block made of expanded polystyrene is simply placed, when concrete is placed, floating will occur, and it is impossible to construct a concrete floating body into a desired shape. Therefore, in Patent Document 1, after manufacturing a concrete bottom wall in advance, a block is fixed to the concrete bottom wall using various metal fittings, and then concrete is placed on the bottom wall to manufacture a concrete floating body.

[0008] The concrete floating body manufactured in this way is not only in a state where blocks made of expanded polystyrene are embedded, but also a large number of metal fittings for fixing the concrete bottom wall and the blocks are embedded, so the weight tends to increase, and it cannot necessarily be said to be a reasonable structure as a floating body.

[0009] In addition, when it is adopted for a water stop gate on which an external force such as water pressure acts from the side, it is necessary to arrange a reinforcing material such as a reinforcing bar to ensure the tensile strength. This lacks economic efficiency and the working process tends to be complicated. Furthermore, when arranging the reinforcing bars, the member thickness of the concrete floating body has to be increased to ensure the cover thickness, and the weight is more likely to increase.

[0010] The present invention has been made in view of such problems, and its main object is to manufacture a concrete slab economically, efficiently, and while achieving weight reduction.

Means for Solving the Problems

[0011] In order to achieve the above object, the method for manufacturing a concrete panel of the present invention is a method for manufacturing a concrete panel containing a foam, and includes a step of inserting a foam fixed to a fixing member suspended from a floating suppression member into a formwork, a step of placing fiber-reinforced concrete so as to embed the foam, and a step of removing the formwork and the floating suppression member after the fiber-reinforced concrete has hardened.

[0012] The method for manufacturing a concrete panel of the present invention is characterized in that the fiber-reinforced concrete has a slump flow value of 230 mm or more and 290 mm or less.

[0013] The method for manufacturing a concrete panel of the present invention is characterized in that the floating suppression member includes a horizontal member detachably installed at the upper end of the formwork, a vertical member installed on the horizontal member, and a connecting member connecting the vertical member and the fixing member.

[0014] The method for manufacturing a concrete panel of the present invention is characterized in that a plurality of the vertical members are installed on the horizontal member with intervals therebetween, and the fixing member to which the foam is fixed is connected for each of the vertical members.

[0015] The method for manufacturing a concrete panel of the present invention is characterized in that a plurality of foams are fixed to the fixing member with intervals in the height direction.

[0016] The concrete panel of the present invention is characterized by being manufactured by the method for manufacturing a concrete panel of the present invention.

[0017] The water stop structure for an opening of the present invention is a water stop structure for an opening provided in a water stop wall constructed on the outer periphery of a building, and includes a water stop gate for closing the opening and a water stop gate storage portion provided at a position lower than the opening. The water stop gate is composed of the concrete panel of the present invention and is stored in the water stop gate storage portion so as to be able to float.

[0018] According to the method for manufacturing a concrete slab, the concrete slab, and the water stop structure of the opening of the present invention, by adopting fiber-reinforced concrete for the concrete slab, it is possible to manufacture a concrete slab that exhibits a desired tensile strength while reducing or omitting reinforcing materials such as steel bars. Further, along with reducing or omitting the reinforcing material, the member thickness can be made thinner, so that the weight of the concrete slab can be reduced.

[0019] Furthermore, when adopting fiber-reinforced concrete having a high fluidity and self-filling property with a slump flow value of about 260 mm, even if the foam is divided into a plurality of parts and arranged at intervals, the fiber-reinforced concrete can be uniformly filled up to the details. In this way, since the fiber-reinforced concrete is placed in a strip or lattice shape, it is possible to manufacture a concrete slab with a further improved tensile strength while reducing the thickness.

[0020] Also, a concrete slab is manufactured by inserting a foam fixed to a fixing member suspended from a floating suppression member into a formwork and then filling it with fiber-reinforced concrete. Thereby, when filling the fiber-reinforced concrete, the floating suppression member resists the floating of the foam generated in the formwork, and after the fiber-reinforced concrete hardens, the floating suppression member can be removed.

[0021] Therefore, the manufactured concrete slab has a simple structure composed of fiber-reinforced concrete, a foam, and a fixing member fixed to the foam, and the number of metal fittings left buried can be significantly reduced. Therefore, an increase in the weight of the concrete slab can be suppressed, and a reasonable structure can be achieved for weight reduction. Also, since there is no need to prepare special equipment or materials, it is economically advantageous and can greatly improve the working efficiency during manufacturing.

[0022] If such a concrete panel is adopted for the water stop gate of a water stop structure for stopping the water flow through an opening provided in a water stop wall constructed on the outer periphery of a building, the opening and closing operation can be performed by utilizing buoyancy, so that mechanical and electrical equipment can be omitted and reliable operation can be ensured even during a power outage. In addition, not only is the structure simple, but the concrete panel can be manufactured at a lower cost compared to a steel gate. Coupled with the fact that mechanical and electrical equipment can be omitted, this is economically advantageous. This can contribute to the popularization of the water stop structure for openings, which is an effective measure against flood damage.

Effect of the Invention

[0023] According to the present invention, by inserting a foam body fixed to a fixing member suspended from a floating suppression member into a formwork and then filling it with fiber-reinforced concrete, it is possible to manufacture a concrete panel with a desired tensile strength while achieving weight reduction economically and efficiently.

Brief Description of the Drawings

[0024]

Figure 1

Figure 2

Figure 3

Figure 4

Embodiment for Carrying Out the Invention

[0025] The present invention aims to achieve weight reduction and manufacturing efficiency improvement while ensuring a tensile strength capable of withstanding a planned external force for a concrete panel containing a foaming material. Hereinafter, the case where the concrete panel is adopted for the water stop structure of an opening provided in a water stop wall will be taken as an example and described in detail.

[0026] The water stop wall 10 shown in Fig. 1(a) is provided so as to surround the outer periphery of a facility in order to prevent flooding into the facility when floods, high tides, or tsunamis occur in the ocean, rivers, etc. Such a water stop wall 10 is provided with an opening 11 at an arbitrary position so that people and ordinary vehicles can freely move in and out of the facility during normal times. And a water stop structure 20 is provided at this opening 11 so as to surely block it in an emergency.

[0027] ≪≪Water stop structure of the opening≫≫ As shown in Fig. 1(b), the water stop structure 20 includes a water stop gate 21 that closes the opening 11, a water stop gate storage part 22 that stores the water stop gate 21, and a water supply facility 23 that supplies water to the water stop gate storage part 22.

[0028] The water stop gate 21 is a concrete slab 60 as shown in Fig. 2(a) having a height and length capable of covering the opening 11 of the water stop wall 10. The concrete slab 60 is a plate-like member that functions as a so-called concrete floating body in which a foam 61 is covered with fiber-reinforced concrete 62.

[0029] As the foam 61, a resin foam such as polystyrene foam or Styrofoam (registered trademark) can be adopted. Also, for the fiber-reinforced concrete 62, any cement-based material mixed with fibers may be adopted, but a material having high fluidity and self-filling property is preferable. The fiber-reinforced concrete 62 will be described later.

[0030] The water stop gate storage part 22 is arranged at a position lower than the opening 11 and along this opening 11, and has a structure that smoothly floats the water stop gate 21 when water flows in. The water supply facility 23 is a facility that conducts seawater, river water, etc. that have risen in water level during an emergency to the water stop gate storage part 22, and its structure is not limited in any way.

[0031] Thus, when the concrete slab 60 that functions as a concrete floating body is adopted for the water stop gate 21, as shown in Fig. 1(b), the opening and closing operation for the opening 11 can be achieved by the water supply and drainage to the water stop gate storage part 22 using the water supply facility 23. Therefore, complicated mechanical and electrical equipment can be omitted, and it can operate reliably even during a power outage. In addition, not only is the structure simplified, but the concrete slab 60 can be manufactured at a lower cost compared to a steel gate. Combined with the fact that mechanical and electrical equipment can be omitted, it is also economically advantageous.

[0032] Furthermore, by adopting the fiber-reinforced concrete 62 for the concrete slab 60, it is possible to ensure the same level of tensile strength as when a steel gate is adopted for the water stop gate 21 while reducing or omitting reinforcing materials such as steel bars. In addition, as the reinforcing materials are reduced or omitted, the member thickness can be thinned, so that the weight of the water stop gate 21 can be reduced.

[0033] ≪≪Manufacture of Concrete Slab≫≫ The concrete slab 60 adopted as the above-mentioned water stop gate 21 can be manufactured using the equipment shown below.

[0034] ≪Manufacturing Equipment for Concrete Slab≫ For the manufacture of the concrete slab 60, as shown in Figs. 3(a) and (b), a floating suppression member 30, a fixing member 40, and a formwork 50 are used.

[0035] The floating suppression member 30 is a member used to suppress the possible floating of the foam 61 when the fiber-reinforced concrete 62 is placed around the foam 61 inserted into the formwork 50 shown in Fig. 3(b). The fixing member 40 is a member used to fix the foam 61 to the floating suppression member 30.

[0036] As shown in Figs. 3(a) and 3(b), the floating prevention member 30 includes a horizontal member 31 installed at the upper end of the formwork 50 and a vertical member 32 installed on the horizontal member 31. Two vertical members 32 are arranged on the horizontal member 31 with a space therebetween, and a fixing member 40 is connected to the lower end thereof via a connecting member 321.

[0037] In this embodiment, a case is exemplified where a long steel material such as a square steel pipe is used for the horizontal member 31, a Form Ty (registered trademark) is used for the vertical member 32, and a plastic cone is used for the connecting member 321. Note that the number of vertical members 32 installed on the horizontal member 31 is not limited to two.

[0038] The fixing member 40 includes a support bar 41 that penetrates the foam 61 in the vertical direction, and a nut 42 and a washer 43 that are fastened to the support bar 41 above and below the foam 61. In this embodiment, a case is exemplified where all-thread bolts are used for the support bar 41.

[0039] The upper end of the support bar 41 constituting the fixing member 40 is attached to the connecting member 321 provided on the vertical member 32 of the floating prevention member 30. Thereby, the foam 61 fixed to the fixing member 40 is in a state of hanging down from the floating prevention member 30.

[0040] ≪≪Method for manufacturing concrete slab≫≫ As shown in Fig. 3(b), the foam 61 hanging down from the floating prevention member 30 via the fixing member 40 is inserted into the formwork 50, and the horizontal member 31 of the floating prevention member 30 is supported at the upper end of the formwork 50. The foam 61 is arranged at a height that does not reach the bottom of the formwork 50, and is positioned at a position where the front and back surfaces and both side surfaces do not contact the formwork 50.

[0041] Thereafter, fiber-reinforced concrete 62 is placed in the formwork 50 to embed the foam 61. Then, although the foam 61 floats, it is resisted by the weight of the floating prevention member 30. Therefore, when manufacturing a concrete floating body, the concrete bottom wall, which is generally used for the purpose of preventing floating, can be omitted.

[0042] After curing for a certain period, when the fiber-reinforced concrete 62 has hardened and a predetermined compressive strength has been developed, demolding is performed. At the same time, the support bar 41 that constitutes the fixing member 40 is removed from the connecting member 321 of the floating suppression member 30. Thereby, the concrete plate 60 forming the water stop gate 21 as shown in Fig. 3(c) can be manufactured.

[0043] The concrete plate 60 thus manufactured has a simple structure in which only the foam 61 and the fixing member 40 are embedded in the fiber-reinforced concrete 62. Compared with the conventional manufacturing method of concrete floating bodies, the number of metal fittings that act as fillers can be significantly reduced. As a result, an increase in the weight of the concrete plate 60 can be suppressed, and a reasonable structure can be achieved for weight reduction. In addition, since there is no need to prepare special equipment or members, it is economically advantageous and the working efficiency during manufacturing can be significantly improved.

[0044] ≪Fiber-Reinforced Concrete≫ In manufacturing the above concrete plate 60, if a material having high fluidity and self-filling property (for example, flow value of 230 mm or more and 290 mm or less: mortar flow test (without dropping) defined in JIS R 5201) and further a material that exhibits high tensile strength after curing is adopted for the fiber-reinforced concrete 62, higher tensile strength can be ensured by the concrete plate 60.

[0045] For example, ultra-high strength fiber-reinforced concrete (Ultra high strength Fiber reinforced Concrete) can be adopted for the fiber-reinforced concrete 62. Among them, "Slimcrete (registered trademark)", which has high fluidity and can exhibit sufficient strength characteristics at room temperature without performing special curing such as heat supply curing, is preferable.

[0046] "Slim Crete (registered trademark)" is a high-fluidity and high-strength mortar composition containing cement, silica fume, water, water reducer, fine aggregate, and high-tensile fibers such as metal fibers and carbon fibers. Its flow value is about 260 mm (controlled between 230 mm and 290 mm), and the tensile strength after hardening reaches 8.8 N / mm 2 or more. By adjusting the above formulation, the strength development at room temperature is realized. For details, refer to Patent No. 5336300.

[0047] When such a material with high fluidity and self-filling property is adopted for the fiber-reinforced concrete 62, for example, as shown in Fig. 2(b), even if the foam 61 is divided into a plurality of parts and arranged with intervals in the height direction and the length direction, the fiber-reinforced concrete 62 is filled homogeneously. As a result, since the fiber-reinforced concrete 62 is placed in a grid-like state, it is possible to omit reinforcing materials such as steel bars and reduce the member thickness, and further improve the tensile strength compared with the concrete slab 60 as shown in Fig. 2(a).

[0048] Therefore, the concrete slab 60 can function not only as a concrete floating body but also as a lightweight floor material or wall material having high tensile strength, and can be adopted in an environment where various external forces such as hydrostatic pressure and wind pressure act, as shown in Fig. 2(c).

[0049] Specifically, as an example of being provided in an environment where hydrostatic pressure acts, a cut-off wall, etc. can be cited. Also, as an example of being provided in an environment where wind pressure acts, as shown in Fig. 4(a), the parapet panel 71 provided on the wall parapet 70 of a road bridge or a railway bridge can be cited as an example. Furthermore, as floor materials, artificial ground and the use as a concrete floating pier bridge 80 as shown in Fig. 4(b) can be cited as examples.

[0050] When using the concrete slab 60 in an environment exposed to seawater or rainwater, for example, a highly durable mortar containing non-ferrous fibers such as vinylon fibers instead of high-tensile fibers may be adopted. As an example of the highly durable mortar, "Slim Flow Grout (registered trademark)", which has high durability against salt damage, can be cited.

[0051] "Slim Flow Grout (registered trademark)" is a material obtained by improving "Slim Concrete (registered trademark)" and further enhancing the fillability into narrow parts. It includes a cement-based composition containing cement, silica fume, water, water reducer, defoaming agent, fine aggregate, and inorganic fine powder, a shrinkage reducing material and / or an expansive material, and non-ferrous fibers. For details, reference is made to Japanese Patent Application Laid-Open No. 2021-95724.

[0052] Although "Slim Flow Grout (registered trademark)" is inferior to "Slim Concrete (registered trademark)" in terms of tensile strength, it has high fluidity and self-fillability, and the flow value is controlled to about 290 mm (260 mm or more and 320 mm or less: mortar flow test (0 blows) specified in JIS R 5201). Also, by mixing organic fibers, high crack resistance is ensured. Therefore, even when the arrangement interval of the foam 61 is narrow, it can be filled to every corner, and a high-quality concrete slab 60 that exhibits the desired tensile strength can be manufactured. Further, even when the organic fibers are exposed on the surface of the concrete slab 60, rust does not occur as in the case of adopting steel fibers, so the aesthetic appearance can be maintained.

[0053] When a material capable of curing at normal temperature as described above is adopted for the fiber-reinforced concrete 62, a concrete slab 60 with a desired shape can also be manufactured at the yard of the construction site without being restricted. Thereby, compared with factory products, the costs and labor involved in transportation can be omitted, contributing to cost reduction of labor and shortening of the construction period.

[0054] As shown in Fig. 2(b), when a plurality of foams 61 are arranged at intervals in the height direction and the length direction, it is preferable to attach the foam 61 to the floating suppression member 30 and the fixing member 40 as follows.

[0055] On the support bar 41 of the fixing member 40, a number of foams 61 provided in the height direction of the concrete slab 60 are arranged at intervals and fixed with nuts 42 and washers 43. Thus, prepare as many support bars 41 with the foams 61 for one row fixed as the number of foams 61 provided in the length direction of the concrete slab 60.

[0056] Also, on the cross bar 31 of the floating suppression member 30, the same number of vertical bars 32 as the number of foams 61 provided in the length direction of the concrete slab 60 are installed at intervals. To each of these vertical bars 32, the support bar 41 with the foam 61 fixed via the connecting member 321 may be connected.

[0057] The manufacturing method of the concrete slab 60, the concrete slab, and the water stop structure of the present invention are not limited to the above-described embodiment, and various modifications are possible without departing from the spirit of the present invention.

[0058] For example, in the present embodiment, as shown in FIG. 1(b), the case where the opening and closing operation of the water stop gate 21 made of the concrete slab 60 is performed in a floating type is cited as an example. However, it is not limited to this, and it may be adopted when performing in a sliding door type, a rising and falling type, or the like.

[0059] Also, in the present embodiment, regarding the floating suppression member 30 described with reference to FIGS. 3(a) and (b), the case where the cross bar 31 is placed on the upper end of the formwork 50 and the floating of the foam 61 generated during the placement of the fiber-reinforced concrete 62 is suppressed by the weight of the cross bar 31 is cited as an example. However, it is not limited to this. For example, the cross bar 31 may be detachably fixed to the formwork 50, or the cross bar 31 may be detachably fixed to another structure or member instead of the formwork 50. Or, it may be a structure in which a pressing force is applied from above.

[0060] Furthermore, although the fixing member 40 has a structure in which the support bar 41 penetrates the foam 61 and is fixed with the nut 42 and the washer 43 in FIGS. 3(a) and 3(b), the present invention is not limited thereto. Any member may be adopted as long as it can fix the foam 61 and secure a posture of connecting to and hanging down from the vertical member 32 of the floating suppression member 30.

Explanation of Signs

[0061] 10 Watertight wall 11 Opening 20 Watertight structure 21 Watertight gate (concrete slab) 22 Watertight gate storage part 23 Water supply facility 30 Floating suppression member 31 Horizontal member 32 Vertical member 321 Connecting member 40 Fixing member 41 Support bar 42 Nut 43 Washer 50 Formwork 60 Concrete slab 61 Foam 62 Fiber-reinforced concrete 70 Wall railing 71 Railing panel 80 Floating walkway

Claims

1. A method for manufacturing a concrete slab containing a foam, comprising: inserting a foam fixed to a fixing member suspended from a floating prevention member into a mold; placing fiber-reinforced concrete so as to embed the foam; after the fiber-reinforced concrete has hardened, removing the mold and the floating prevention member; A method for manufacturing a concrete slab, characterized by including the above steps.

2. In the method for manufacturing a concrete slab according to Claim 1, the fiber-reinforced concrete has a flow value of 230 mm or more and 290 mm or less. A method for manufacturing a concrete slab, characterized by this.

3. In the method for manufacturing a concrete slab according to Claim 1, the floating prevention member includes: a horizontal member detachably installed at the upper end of the mold; a vertical member installed on the horizontal member; a connecting member connecting the vertical member and the fixing member. A method for manufacturing a concrete slab, characterized by this.

4. In the method for manufacturing a concrete slab according to Claim 3, a plurality of the vertical members are installed on the horizontal member with intervals therebetween; the fixing member to which the foam is fixed is connected for each of the vertical members. A method for manufacturing a concrete slab, characterized by this.

5. In the method for manufacturing a concrete slab according to Claim 3, a plurality of foams are fixed to the fixing member with intervals in the height direction. A method for manufacturing a concrete slab, characterized by this.

6. A concrete slab characterized by being manufactured by the method for manufacturing a concrete slab according to any one of Claims 1 to 5.

7. A water stop structure for an opening provided in a water stop wall constructed on the outer periphery of a building, comprising: a water stop gate for closing the opening; a water stop gate storage portion provided at a position lower than the opening; the water stop gate is constituted by the concrete slab according to Claim 6 and is stored in the water stop gate storage portion so as to be floating. A water stop structure for an opening, characterized by this.

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