JP2873613B2 - Dome roof and construction method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention is used as a storage facility for a liquid such as water or petroleum, a low-temperature liquefied gas such as LPG or LNG, or a powder such as grain powder or coal powder. The present invention relates to a concrete dome (hereinafter referred to as a dome in the present invention refers to various shapes such as a spherical surface, a curved surface, and a polyhedron) in a structure such as a storage tank to be used, and a method of constructing the same.

2. Description of the Related Art Conventionally, in constructing a dome-shaped roof made of concrete in a structure such as a storage tank, a total scaffold is placed in a structure body consisting of a bottomed tubular body made of concrete or steel plate which has been constructed in advance. After assembling, forming a formwork on the upper open surface of the main body of the structure in the shape of a dome roof, performing temporary work to support this formwork with support, and then casting concrete It is.

As another method of constructing a dome-shaped roof made of concrete, Japanese Patent Application Laid-Open No. 1-295974, or Japanese Patent Application No. 1-190434 filed earlier by the applicant on July 25, 2001 is described. As described in the invention, the upper open surface of the structure body is air-tightly covered with a flexible film body, and the flexible film body is expanded into a dome roof shape by pressure increase by blowing air into the structure body. There has been proposed a structure having a configuration in which mortar or concrete is cast on the flexible film body after being kept in a tension state.

[Problems to be Solved by the Invention] However, the former construction method, that is, assembling a total scaffold in the structure body, and then forming a formwork on the upper open surface of the structure body in a dome roof shape, After constructing the temporary work to support the formwork with the shoring, and then casting concrete, the material costs and man-hours required for assembling the scaffolding and the temporary shoring work are enormous. In addition, work inside the structure and work at many high places are required, so that the work efficiency is poor and involves risks.

Further, using a flexible membrane, the flexible membrane is expanded in the shape of a dome roof by pressurization by blowing air into the structure main body and maintained in a tensioned state. In the latter construction method, which is cast on a film body, the temporary construction work of assembling scaffolds and supporting works is not necessary, but when casting mortar or concrete, it is cured with local deformation occurring. I was worried about it.

SUMMARY OF THE INVENTION An object of the present invention is to form a mortar layer having a reliable formwork function, which does not require assembling of a scaffold or temporary construction of a shoring, is safe and easily free of local deformation, and is capable of forming a mortar layer. By providing a concrete layer on the mortar layer using the formwork of the layer itself as a part of the dome type roof, to provide a dome type roof with excellent aesthetics and excellent strength and its construction method is there.

[Means for Solving the Problems] In order to solve the above-mentioned problems, a dome-shaped roof according to the present invention includes a flexible film body that hermetically covers an upper open surface of a main body of a structure such as a storage tank. It has a laminated structure consisting of a mortar layer mixed with a setting retarder, which is installed together with a reinforcing material on a flexible membrane, and a concrete layer cast on the mortar layer.

Further, as a method of constructing such a dome-shaped roof, the present invention provides a step of airtightly covering an upper open surface of a structure body such as a storage tank with a flexible film, A step of expanding the body by pressurization by blowing air into the body to maintain a tension state, and a step of disposing a reinforcing material on the upper surface of the flexible membrane body maintained in the tension state and mixing the setting retarder with the mortar. It comprises a step of constructing a mortar layer and a step of casting a concrete layer on the upper surface of the mortar layer.

In this case, whether to remove the flexible film after curing of the mortar layer or to leave it as it is is arbitrarily selected, and when the flexible film is left, the upper surface of the flexible film is Preferably, a number of anchor pins are implanted in advance.

[Action] In the present invention, when a mortar layer is applied on a flexible film having airtightness and water-blocking properties, a proper amount of a setting retarder in consideration of an appropriate curing time is mixed into the mortar, so that the mortar is applied during the mortar application. The mortar can be prevented from being hardened in a state where the mortar is locally deformed by various loads applied to the flexible film body, and the mortar layer having a uniform and highly reliable mold function can be constructed as a whole.

A dome-shaped roof formed by casting a concrete layer on a mortar layer mixed with a setting retarder formed in this way, that is, a three-layer laminate of a flexible membrane, a mortar layer mixed with a setting retarder, and a concrete layer A dome-shaped roof having a structure is excellent in aesthetic appearance without local deformation, and is a dome-shaped roof excellent in strength due to the uniform thickness of the mortar layer and the concrete layer.

Also, by implanting a large number of anchor pins in advance on the upper surface of the flexible membrane, these anchor pins serve as dowels. It is possible to further enhance the adhesion between the layer, the mortar layer and the concrete layer, and since the inner surface of the roof is protected by a durable flexible film, anticorrosive coating is not required.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

As shown in FIG. 1, reference numeral 1 denotes a structure main body as a storage tank having a dome-shaped roof according to the present invention. The structure body 1 is used as a storage facility for a liquid such as water or petroleum, a low-temperature liquefied gas such as LPG or LNG, or a powder such as grain powder or coal powder. A dome-shaped roof 4 made of concrete is formed on the upper open surface 1a of the cylindrical body having a single or multi-layered structure or a cylindrical body having a bottom.

The dome-shaped roof 4 has a flexible film 6 that is air-tightly supported and covered on the periphery of an upper open surface 1 a of the structure body 1 via a fixing ring 5, and an upper surface of the flexible film 6. Has a laminated structure consisting of a mortar layer 7 constructed by mixing a setting retarder into the mortar layer, and a concrete layer 8 cast on the upper surface of the mortar layer 7. , Fibers, etc., and a reinforcing bar 81 is arranged in the concrete layer 8.

By the way, the flexible film body 6 is tough and airtight,
Water and corrosion resistant sheets, such as glass fiber, polyamide fiber, polyaramid fiber, polyester fiber, polyvinyl alcohol fiber, etc. coated with tetrafluoroethylene resin, chloroprene rubber, chlorosulfonated polyethylene rubber, fluororesin, etc. Used
It is formed in a structure that can withstand the internal pressure in the process of constructing a dome-shaped roof described later.

Next, a method of constructing the dome-shaped roof 4 according to the present invention will be described with reference to FIGS.

First, as shown in FIG. 2, an upper open surface 1a of a pre-constructed structure body 1 having a bottomed cylindrical body is attached to a flexible membrane by using a fixing ring 5 as shown in FIG. At 6, the airtight and hanging support is applied and covered.

Next, as shown in FIG. 4, the blower 10 blows the air A into the structure main body 1 to raise the pressure inside the structure main body 1 to generate an internal pressure, so that the flexible membrane body in a suspended state is generated. 6 is inflated into a spherical shape (dome shape) to maintain a floating state in tension. In this case, the pressure for tensioning the flexible film body 6 is set on the upper surface of the flexible film body 6 in the work of arranging a reinforcing member 71 made of a lath, a wire mesh, a fiber, and the like, which will be described later, and in the work capable of withstanding the mortar 11. Safety-friendly pressure is sufficient.

In this state, as shown in FIG. 5, a reinforcing material 71 made of lath, wire mesh, fiber, etc. is arranged on the upper surface of the flexible film body 6 and the wrap portion is bound, and then an appropriate amount of a setting retarder is mixed. The mortar 11 is applied uniformly.

The mortar is used in such a proportion that the design standard strength can be obtained. In the construction of the mortar, for example, the surface of the flexible membrane 6 is divided into eight blocks, and a mortar in which the compounding amount of the setting retarder is changed in each block is prepared.
Mortar is sequentially applied to each block, and the mortar for each block simultaneously starts curing simultaneously after completing the application of the mortar to the entire surface of the flexible film body 6.

Further, the thickness of the mortar 11 is such that the strength of the mortar layer 7 after hardening is the strength required for concrete casting, that is, the strength for supporting the reinforcing steel weight, concrete weight, impact load at the time of concrete casting and working load. The thickness is obtained.

After hardening the mortar 11 in this way, as shown in FIG. 6, the hardened mortar layer 7 is used as a formwork and a support, a reinforcing material 81 of reinforcing steel is arranged on the upper surface thereof, and the mortar layer 7 is removed. It is made by casting concrete 12 as a formwork.

In the above-described embodiment, the flexible film body 6 is left as it is after the mortar layer 7 is hardened. However, the flexible film body 6 can be removed after the mortar layer 7 is hardened, and the selection is arbitrary.

The dome-shaped roof formed by the above-described construction method has a laminated structure in which a concrete layer is cast on a mortar layer, so that a high-quality concrete layer can be obtained.

In addition, because of the composite version structure of the mortar layer and the concrete layer, the lower mortar layer corresponds to the cover thickness of the concrete layer and the strength members. In this case, it is possible to reduce the cover thickness of the lower reinforcing bar,
The thickness of the entire roof can be reduced.

On the other hand, when constructing the dome-shaped roof, the flexible membrane body, which airtightly covers the upper open surface of the structure main body, is expanded by pressure increase by blowing air into the structure main body, and maintained in a tensioned state. Since the mortar layer is arranged and hardened by arranging a reinforcing material on the upper surface of the flexible film body maintained in a tensioned state, the mortar layer after this curing can be used as a mold,
As a result, the flexible membrane is reinforced and protected, and the concrete layer can be easily and safely cast.

Further, according to the above configuration, it is not necessary to support the entire load at the time of placing the concrete layer by the flexible membrane, and the pressure for expanding the flexible membrane is low, so that the tension acting on the flexible membrane is high. In addition, it is safe, the airtightness of the flexible body to the structure body is easily maintained, and the risk of crack propagation is reduced, so that the capacity of the blower and the size of the blower can be reduced.

Furthermore, because the flexible film body is airtight and water-tight, when setting the mortar layer, by mixing an appropriate amount of a setting retarder in consideration of an appropriate curing time into the mortar,
The mortar can be prevented from being hardened in a state where the mortar is locally deformed due to various loads applied to the flexible membrane during the mortar application, and the mortar layer as a uniform and highly reliable mold can be applied as a whole.

When the flexible film 6 is left, a large number of anchor pins are provided on the upper surface of the flexible film 6 as shown in FIG.
By implanting 61 in advance, these anchor pins 61... Serve as dowel streaks, whereby the flexible membrane 6 and the mortar layer 7 due to the adhesive force of the mortar layer 7 and the concrete layer 8. The adhesion between the mortar layer 7 and the concrete layer 8 can be further enhanced. In this case, the anchor pins 61 are attached to the plate 62 by the anchor pins 61.
Are attached, arranged at required intervals, and planted with an adhesive.

In addition, flexible membranes, mortar layers and concrete layers
In the case of a layered structure, if a large number of anchor pins are planted on the upper surface of the flexible membrane, the adhesion between the flexible membrane and the mortar layer, and between the mortar layer and the concrete layer is further improved, and the inner surface of the roof is durable. Since it is protected by a flexible film body having no corrosion, anticorrosion coating is not required.

Further, as shown in FIG. 8, when placing a concrete layer 8 on the mortar layer 7, a reinforcing rod 81 as a reinforcing material is disposed on the mortar layer 7, and the concrete driving is performed by maintaining an interval with respect to the mortar layer 7. A spacer 82 may be provided to enhance the reliability of the installation.

[Effects of the Invention] As is clear from the above description, according to the present invention, when a mortar layer is applied on a flexible film having airtightness and water-blocking properties, a setting retarder considering an appropriate curing time is used. By mixing an appropriate amount into the mortar, the mortar can be prevented from hardening in the state of local deformation due to various loads applied to the flexible membrane during the mortar construction, and it functions as a uniform and highly reliable formwork as a whole Mortar layer can be constructed.

A dome-shaped roof formed by casting a concrete layer on a mortar layer mixed with a setting retarder formed in this way, that is, a three-layer laminate of a flexible membrane, a mortar layer mixed with a setting retarder, and a concrete layer A dome-shaped roof having a structure is excellent in aesthetic appearance without local deformation, and is a dome-shaped roof excellent in strength due to the uniform thickness of the mortar layer and the concrete layer.

Also, by implanting a large number of anchor pins in advance on the upper surface of the flexible membrane, these anchor pins serve as dowels. Layer, mortar layer and concrete layer can be more closely adhered to each other, and since the inner surface of the roof is protected by a durable flexible membrane, an excellent effect of eliminating the need for anticorrosive coating Is played.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing one embodiment of a large-sized structure such as a storage tank having a dome-shaped roof according to the present invention, and FIGS. 2 to 6 similarly show steps of constructing a dome-shaped roof according to the present invention. FIGS. 7 and 8 are enlarged explanatory views of a main part of a dome-shaped roof according to another embodiment of the present invention. DESCRIPTION OF SYMBOLS 1 ... Structure main body, 1a ... Top open surface, 4 ... Domed roof, 6 ... Flexible membrane, 61 ... Anchor pin, 7 ... Mortar layer, 71 ... Reinforcement, 8 ... Concrete layer, 81…
... rebar.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) E04H 7/18-302 E04G 11/04 E04B 7/08

Claims (3)

(57) [Claims] 1. A flexible film body having an upper open surface of a main body of a structure such as a storage tank air-tightly covered, a mortar layer containing a setting retarder mixed with a reinforcing material, and a mortar layer formed on the flexible film body together with a reinforcing material. A dome-shaped roof having a laminated structure including a concrete layer cast on a layer. 2. A flexible membrane body which covers an upper open surface of a structure main body such as a storage tank and has a plurality of anchor pins implanted on an upper surface thereof, and a flexible membrane having a large number of anchor pins implanted thereon. A dome-shaped roof having a laminated structure composed of a mortar layer containing a setting retarder mixed with a reinforcing material on a body and a concrete layer cast on the mortar layer. 3. A step of hermetically covering an upper open surface of a structure main body such as a storage tank with a flexible film body, and tensioning the flexible film body by pressure increase by blowing air into the structure main body. A step of arranging a reinforcing material on the upper surface of the flexible film body maintained in this tensioned state, and applying a mortar layer made of mortar mixed with an appropriate amount of a setting retarder; and Casting a concrete layer on the upper surface of the mortar layer.