JP2022175266A - Construction method and earthen floor structure - Google Patents

Abstract

To provide a construction method for an earthen floor with which cracks are unlikely to occur and work period can be reduced, and an earthen floor structure.SOLUTION: A floor structure 20 includes a hydraulic composition layer 23 containing a structure having a predetermined height as earthen floor part 30 and a ground layer that supports the hydraulic composition layer 23 from below. The ground layer is composed of a roadbed foundation 21 and a waterproof layer 22. The hydraulic composition layer 23 has a puffed part 29 integrally formed with the earthen floor part 30 between the lowest level 30L of the earthen floor part 30 and the upper surface 22a of the waterproof layer 22, which is the highest level of the ground layer.SELECTED DRAWING: Figure 1

Description

The present invention relates to a construction method for constructing an earth floor structure and an earth floor structure.

BACKGROUND ART Conventionally, in factories and the like, a structure formed by placing concrete as a hydraulic composition has functioned as an earthen floor. As a construction method for such an earthen floor, for example, Patent Document 1 discloses a technique of installing a formwork capable of integrally forming a foundation beam and an earthen floor, and then pouring concrete into the formwork. . This formwork is composed of a foundation beam formwork and a dirt floor formwork. The formwork for the foundation beam is installed on the discarded concrete and is composed of the outer formwork board and the inner formwork board whose top level is lower than the outer formwork board. The dirt floor formwork is made of strands made of reinforcing fibers, and is arranged in the area inside the formwork plate on the inner peripheral side. The earthen floor formwork is laminated to a polyethylene film that covers crushed stones laid on the ground from above. The upper surface of the formwork for the dirt floor is located at the same level as the crest level of the formwork on the inner peripheral side.

JP 2016-69895 A

In addition to the method described in Patent Literature 1, there are also known methods for constructing earthen floors that are placed on the ground, such as pouring concrete onto discarded concrete placed on the ground. However, since these construction methods reduce the thickness of the floor that can be included in the structural strength, cracks tend to occur. In addition, since the dump concrete and the floor are placed in separate processes, the construction period is lengthened.

A construction method for solving the above problems is a construction method for constructing an earth floor structure including a structure having a predetermined height as an earth floor by casting a hydraulic composition in a fluid state. a foundation layer installing step of installing a foundation layer for supporting the hydraulic composition in a state from below; placing the hydraulic composition in a fluid state to the highest level of the structure.

A floor structure for solving the above problems includes a hydraulic composition layer including a structure having a predetermined height as an earthen floor, and a foundation layer supporting the hydraulic composition layer from below, and the hydraulic composition The material layer has a puff integrally formed with the structure between the lowest level of the structure and the highest level of the underlayer.

As in the above configuration, by providing the puff portion integrally formed with the structure between the structure and the base layer, it is possible to improve the structural strength and increase the strength of the hydraulic composition layer. can. As a result, cracks are less likely to occur in the structure, that is, in the dirt floor. In addition, since there is no need to place dump concrete, the construction period can be shortened.

The construction method having the above configuration includes, between the base layer installing step and the placing step, a wire mesh installing step of installing a wire mesh in a portion forming the puff portion, and a portion forming the floor portion of the dirt floor 30. It is preferable to provide a reinforcing bar arrangement step of installing reinforcing bars in. As a result, the strength of the structure and the puffed portion is increased, so that the strength of the hydraulic composition layer can be further increased. As a result, cracks in the dirt floor are even less likely to occur.

In the construction method having the above configuration, in the wire mesh installation step, the wire mesh is supported by the base layer via mesh spacers, and in the reinforcing bar arrangement step, the reinforcing bars are attached to the base layer via reinforcing bar spacers. Support is preferred.

As a result, since the wire mesh and the reinforcing bar are supported by the underlying layer via separate spacers before the hydraulic composition is placed, even if the worker climbs on the reinforcing bar and works, Positional deviation can be suppressed.

In the construction method having the above configuration, the reinforcing bar includes a first reinforcing bar and a second reinforcing bar located above the first reinforcing bar, and the reinforcing bar arrangement step is performed on the base layer via the first reinforcing bar spacer. It is preferable to include a first reinforcing bar arrangement step of supporting the first reinforcing bar and a second reinforcing bar positioning step of supporting the second reinforcing bar on the underlying layer via a second reinforcing bar spacer.

This can further increase the strength of the hydraulic composition layer. In addition, since the first reinforcing bar and the second reinforcing bar are supported by the underlying layer via separate spacers before placing the hydraulic composition, the second reinforcing bar can be placed on top of the second reinforcing bar when the hydraulic composition is placed. Even if a worker works by

In the construction method having the above configuration, in the base layer installing step, the base layer is installed in a region sandwiched between a plurality of beams installed on the ground, and in the placing step, above the crest level of the plurality of beams. You may cast the said hydraulic composition to. As a result, all of the portions of the hydraulic composition layer formed in the spaces sandwiched between the plurality of beams can be used as puffs.

In the dirt floor structure having the above configuration, the structural body and the puffed portion integrally form a structural floor member. As a result, the hydraulic composition layer becomes thicker and structural integrity is obtained, thereby improving the strength.

In the dirt floor structure having the above configuration, it is preferable that the base layer has a waterproof layer positioned immediately below the hydraulic composition layer. As a result, the infiltration of water from the ground into the hydraulic composition layer is suppressed, so that the structural strength of the hydraulic composition with a predetermined composition and formulation can be ensured.

In the dirt floor structure having the above configuration, the hydraulic composition layer has a wire mesh in the portion forming the puff portion, and the first reinforcing bar in the portion forming the dirt floor portion and positioned above the first reinforcing bar. It is preferable to have a second reinforcing bar that

According to the above configuration, the hydraulic composition layer has a structure having the first reinforcing bar and the second reinforcing bar, and the puff portion reinforced with the wire mesh, which are integrated to form the structural floor member. is doing. This makes it possible to further improve the strength.

BRIEF DESCRIPTION OF THE DRAWINGS Sectional drawing which shows schematic structure of one Embodiment of earth floor structure. 4 is a flow chart showing an embodiment of a construction method; (a) Cross-sectional view showing a state in which the wire mesh installation process is completed, (b) Perspective view showing a schematic configuration of reinforcing bars with spacers, (c) Cross-sectional view showing a state in which the first bar arrangement process is completed, (d) Sectional drawing which shows the state which the 2nd bar arrangement process was completed.

An embodiment of an earthen floor structure and its construction method will be described with reference to FIGS. 1 to 3. FIG. In the following, one direction on the horizontal plane is called the vertical direction, and the direction orthogonal to the vertical direction is called the horizontal direction. Moreover, the direction perpendicular to the horizontal plane is referred to as the up-down direction.

As shown in FIG. 1, the earthen floor structure 20 is applied to the lowest floor of a building. The dirt floor structure 20 is supported by a plurality of foundation beams 12 installed on the ground 11 . The plurality of foundation beams 12 are installed at positions corresponding to the formation range of the dirt floor structure 20 . The dirt floor structure 20 includes a roadbed base 21 and a waterproof layer 22 that constitute a base layer, and a hydraulic composition layer 23 that is supported by the base layer from below. The dirt floor structure 20 includes a wire mesh 25 , first reinforcing bars 26 and second reinforcing bars 27 inside the hydraulic composition layer 23 .

The subgrade 21 is layered on the ground 11 in a region sandwiched between the plurality of foundation beams 12 . The subgrade 21 is made of a material harder than the ground 11, such as crushed stone.
The waterproof layer 22 is laminated on the subgrade 21 . The upper surface 22a of the waterproof layer 22 is the highest level of the underlying layer. The waterproof layer 22 prevents water from entering the hydraulic composition layer 23 from the ground 11 . The waterproof layer 22 is composed of one waterproof sheet or a plurality of waterproof sheets. An example of a waterproof sheet is made of polyethylene. The waterproof layer 22 preferably has moisture permeability. As a result, excess water in the hydraulic composition layer 23 can be absorbed into the ground 11 while preventing water from entering the hydraulic composition layer 23 from the ground 11 .

The hydraulic composition layer 23 is laminated on the waterproof layer 22 . The hydraulic composition layer 23 is formed by hardening the hydraulic composition placed in a state where the wire mesh 25, the first reinforcing bars 26, and the second reinforcing bars 27 are arranged. The hydraulic composition is a fluid obtained by kneading at least hydraulic powder and water. For example, a cement mixture obtained by mixing cement, which is hydraulic powder, with gravel or sand, which is an aggregate, and water. It is mixed concrete.

The hydraulic composition layer 23 has a puffed portion 29 and a dirt floor portion 30 which are integrally formed. The puffed portion 29 and the dirt floor portion 30 integrally form a structural floor member. The raised portion 29 is a portion where the wire mesh 25 is arranged and serves as a raised portion for the dirt floor portion 30 . The dirt floor portion 30 is a portion where the first reinforcing bars 26 and the second reinforcing bars 27 are arranged. The dirt floor 30 is a structure whose thickness, amount of reinforcing bars, etc., are designed based on strength calculations performed in advance. The lowest level 30L of the dirt floor 30 is provided between the wire mesh 25 and the first reinforcing bars 26 in the vertical direction. In this embodiment, the lowest level 30L is the same level as the crest level of the foundation beam 12 .

The wire mesh 25 is a lattice-shaped member in which vertical wires 31, which are metal rods extending in the vertical direction, and horizontal wires 32, which are metal rods extending in the horizontal direction, are connected. Before placing the hydraulic composition, the wire mesh 25 is supported by the waterproof layer 22 via the mesh spacer 33 . The wire mesh 25 is strong enough to allow a worker to move over the wire mesh 25 while being supported by the waterproof layer 22 via the mesh spacers 33 .

The first reinforcing bars 26 are positioned above the wire mesh 25 . The first reinforcing bar 26 is a grid-shaped member in which a first vertical bar 36 extending in the vertical direction and a first horizontal bar 37 extending in the horizontal direction are connected. The first horizontal bar 37 is arranged below the first vertical bar 36 . The first horizontal bar 37 is the bottom bar of the reinforcing bar installed in the portion where the hydraulic composition layer 23 is formed. The first vertical reinforcement 36 and the first horizontal reinforcement 37 are, for example, deformed reinforcing bars.

Before placing the hydraulic composition, the first reinforcing bars 26 are supported by the waterproof layer 22 via first reinforcing bar spacers 38 . The first reinforcing bars 26 are strong enough to allow a worker to move over the first reinforcing bars 26 while being supported by the waterproof layer 22 via the first reinforcing bar spacers 38 .

The second reinforcing bars 27 are positioned above the first reinforcing bars 26 . The second reinforcing bar 27 is a grid-shaped member in which a second vertical bar 41 extending in the vertical direction and a second horizontal bar 42 extending in the horizontal direction are connected. The second horizontal bar 42 is arranged above the second vertical bar 41 . The second horizontal bar 42 is the upper end bar of the reinforcing bar installed in the portion where the hydraulic composition layer 23 is formed. The second vertical reinforcement 41 and the second horizontal reinforcement 42 are, for example, deformed reinforcing bars.

Before placing the hydraulic composition, the second reinforcing bar 27 is supported by the waterproof layer 22 via the second reinforcing bar spacer 43 . The second reinforcing bar 27 has a strength that allows a worker to move over the second reinforcing bar 27 while being supported by the waterproof layer 22 via the second reinforcing bar spacer 43 .

A method of constructing an earthen floor structure will be described with reference to FIGS. The construction method of the dirt floor structure 20 includes a ground compaction step (step S101), a subgrade base formation step (step S102), a waterproof layer formation step (step S103), a wire mesh installation step (step S104), and a first bar arrangement. It includes a step (step S105), a second bar arrangement step (step S106), and a placement step (step S107). In addition, foundation beams 12 are installed on the ground 11 according to the formation range of the dirt floor structure 20 . Each foundation beam 12 is installed so that the top level is positioned on the same horizontal plane.

In the ground compaction step (step S101), the ground 11 is compacted in the area sandwiched between the foundation beams 12 using a compaction machine. Thereby, voids are eliminated from the surface layer of the ground 11 in the formation portion of the dirt floor structure 20 and unevenness of the ground 11 is adjusted.

In the subgrade formation step (step S102), the subgrade 21 is formed by laying crushed stones in the area sandwiched between the foundation beams 12 and then rolling the crushed stones.
In the waterproof layer forming step (step S103), the waterproof layer 22 is formed by laying a waterproof sheet on the subgrade 21 . Specifically, when the waterproof layer 22 is composed of one waterproof sheet, the waterproof sheet is laid on the subgrade 21 . When the waterproof layer 22 is composed of a plurality of waterproof sheets, the plurality of waterproof sheets are laid on the subgrade 21 without any gaps. The subgrade formation step (step S102) and the waterproof layer formation step (step S103) constitute a sublayer installation step of installing a sublayer.

As shown in FIG. 3( a ), in the wire mesh installation step (step S<b>104 ), the wire mesh 25 is installed above the waterproof layer 22 . In this embodiment, after the wire mesh 25 is arranged on the waterproof layer 22, the wire mesh 25 is placed above the waterproof layer 22 by sandwiching the mesh spacer 33 between the waterproof layer 22 and the wire mesh 25. Install. In addition, when the mesh spacer 33 is made of metal, the mesh spacer 33 may be joined to the wire mesh 25 .

In the first bar arrangement step (step S105) and the second bar arrangement step (step S106), spacer-equipped reinforcing bars 50 having the structure shown in FIG. 3(b) are used. The spacer-attached reinforcing bar 50 is composed of a reinforcing bar spacer 51 and a reinforcing bar 52 . The spacer-attached reinforcing bar 50 is a member in which U-shaped reinforcing bar spacers 51 are joined to a reinforcing bar 52 at predetermined intervals. The reinforcing bar 52 is joined to the vertex portion of the reinforcing bar spacer 51 . The reinforcing bars 50 with spacers are members capable of adjusting the height position of the reinforcing bars 52 .

As shown in FIG. 3C, in the first bar arrangement step (step S105), the first reinforcing bar 26 is installed above the wire mesh 25. As shown in FIG. Specifically, first reinforcing bar spacers 38 having reinforcing bars 52 interposed between foundation beams 12 are arranged side by side, and then first horizontal reinforcing bars 37 are arranged so as to be supported by the reinforcing bars 52 . Immediately above the foundation beam 12 , the first horizontal reinforcement 37 is arranged on a mortar spacer or the like (not shown) placed on the foundation beam 12 . After that, the first vertical reinforcement 36 is arranged so as to be supported by the first horizontal reinforcement 37 . Then, the reinforcing bars 52, the first vertical bars 36, and the first horizontal bars 37 are connected using connecting tools such as wires. As a result, the first reinforcing bar 26 supported by the waterproof layer 22 via the first reinforcing bar spacer 38 is installed above the wire mesh 25 . Since the first horizontal bar 37 located on the lower side is connected to the reinforcing bar 52 of the first reinforcing bar spacer 38, the installation work of the first reinforcing bar 26 is facilitated and the height of the first reinforcing bar spacer 38 is suppressed. be able to.

As shown in FIG. 3D, in the second reinforcing bar arrangement step (step S106), the second reinforcing bar 27 is installed above the wire mesh 25. As shown in FIG. Specifically, reinforcing bars with spacers, in which a plurality of second reinforcing bar spacers 43 are joined to the second vertical bars 41, are arranged side by side. Then, after the second horizontal reinforcements 42 are arranged on the aligned second vertical reinforcements 41, the second vertical reinforcements 41 and the second horizontal reinforcements 42 are connected using a connector such as a wire. As a result, the second reinforcing bars 27 supported by the waterproof layer 22 via the second reinforcing bar spacers 43 are installed above the first reinforcing bars 26 . Since the second reinforcing bar spacer 43 is joined to the second vertical bar 41 located on the lower side, the work of installing the second reinforcing bar 27 is facilitated and the height of the second reinforcing bar spacer 43 can be suppressed. can.

In the placing step (step S107), the hydraulic composition layer 23 is formed by placing and hardening the fluidized hydraulic composition. Specifically, the hydraulic composition is cast to a predetermined height (the highest level of the dirt floor 30) so that the wire mesh 25 and the reinforcing bars 26 and 27 are embedded, and the cast hydraulic composition Vibrate the composition. After leveling the surface of the placed hydraulic composition, it is cured and hardened. Thereby, as shown in FIG. 1, the hydraulic composition layer 23 in which the wire mesh 25, the first reinforcing bars 26 and the second reinforcing bars 27 are embedded is formed.

(action)
In the dirt floor structure 20 , the hydraulic composition layer 23 has a puff portion 29 between the dirt floor portion 30 and the waterproof layer 22 in addition to the dirt floor portion 30 . The dirt floor portion 30 and the puffed portion 29 are formed by hardening a hydraulic composition cast at the same time, and are integrated. The puffed portion 29 is formed in a space surrounded by the foundation beams 12 . The thickness of the entire hydraulic composition layer 23 is increased by the puffed portion 29 .

Effects of the present embodiment will be described.
(1) In the dirt floor structure 20 , the thickness of the entire hydraulic composition layer 23 increases due to the padded portion 29 integrated with the dirt floor portion 30 . As a result, the strength of the hydraulic composition layer 23 is increased, and cracks are less likely to occur in the dirt floor portion 30 .

(2) In the dirt floor structure 20, the hydraulic composition layer 23 having the dirt floor portion 30 and the puffed portion 29 is formed in one casting step. As a result, the construction period can be shortened compared to, for example, the case of forming a waste concrete in the portion where the hydraulic composition layer 23 is placed.

(3) Since the lowest level 30L of the dirt floor section 30 is the same level as the top level of the foundation beams 12, all portions of the hydraulic composition layer 23 in the space sandwiched by the foundation beams 12 are puffed. 29. Thereby, the strength of the hydraulic composition layer 23 can be further increased.

(4) Since the wire mesh 25 is embedded, the strength of the puffed portion 29 can be increased. Thereby, the strength of the hydraulic composition layer 23 can be further increased.
(5) By embedding the first reinforcing bars 26 and the second reinforcing bars 27 in the dirt floor section 30, the strength of the dirt floor section 30 can be increased. Thereby, the strength of the hydraulic composition layer 23 can be further increased.

(6) In the dirt floor structure 20, the wire mesh 25, the first reinforcing bars 26, and the second reinforcing bars 27 are supported by the waterproof layer 22 by separate spacers. As a result, even if a worker climbs on the first reinforcing bar 26 and the second reinforcing bar 27 to work, the displacement of the reinforcing bars 26 and 27 can be suppressed.

This embodiment can be implemented with the following modifications. This embodiment and the following modified examples can be implemented in combination with each other within a technically consistent range.
- The 1st reinforcing-bar 26 may be supported by the wire mesh 25 via the spacer.

- The 2nd reinforcing bar 27 may be supported by the 1st reinforcing bar 26 or the wire mesh 25 via a spacer.
・Reinforcing bars may not be buried in the earthen floor. When reinforcing bars are embedded in the dirt floor 30, only the first reinforcing bars 26 may be embedded, or three or more reinforcing bars with different arrangement levels may be embedded.

- The wire mesh 25 may not be embedded in the puffed portion 29 . Moreover, a plurality of wire meshes having different arrangement levels may be embedded in the puffed portion 29 .
- The lowest level 30L of the dirt floor 30 may be a level lower than or higher than the crest level of the foundation beam 12 .

- The hydraulic composition is not limited to concrete as long as it is a fluid obtained by kneading hydraulic powder and water. For example, the hydraulic composition may be mortar such as Slimcrete (registered trademark), or may be a mixture of fibers (fiber-reinforced concrete material).

REFERENCE SIGNS LIST 11: Ground 12: Foundation beam 20: Dirt floor structure 21: Subgrade base that constitutes base layer 22: Waterproof layer that constitutes base layer 22a: Top surface as highest level 23: Hydraulic composition Layer, 25... Wire mesh, 26... First reinforcing bar, 27... Second reinforcing bar, 29... Reinforced part, 30... Earth floor part as structure, 30L... Bottom level, 31... Vertical wire, 32... Horizontal wire, 33 Mesh spacer 36 First vertical bar 37 First horizontal bar 38 First reinforcing bar spacer 41 Second vertical bar 42 Second horizontal bar 43 Second reinforcing bar spacer 50 Reinforcing bars with spacers, 51... Spacers for reinforcing bars, 52... Reinforcing bars.

Claims (9)

A construction method for constructing an earthen floor structure including a structure with a predetermined height as an earthen floor by pouring a hydraulic composition in a fluid state, comprising:
a foundation layer installing step of installing a foundation layer that supports the cast hydraulic composition in a fluid state from below;
a casting step of casting a hydraulic composition in a fluid state up to the highest level of the structure such that a puff is formed between the lowest level of the structure and the highest level of the underlayer; construction method. Between the base layer installation step and the placing step,
a wire mesh installation step of installing a wire mesh in the portion forming the puff portion;
The construction method according to claim 1, further comprising a reinforcing bar arrangement step of installing reinforcing bars in the formation portion of the dirt floor. In the wire mesh installation step, the wire mesh is supported by the underlying layer via a mesh spacer,
3. The construction method according to claim 2, wherein in the reinforcing bar arrangement step, the reinforcing bar is supported by the underlying layer via a reinforcing bar spacer. The reinforcing bar includes a first reinforcing bar and a second reinforcing bar located above the first reinforcing bar,
The bar arrangement step includes
a first reinforcing bar arrangement step of supporting the first reinforcing bar on the underlying layer via a first reinforcing bar spacer;
4. The construction method according to claim 2 or 3, further comprising: a second reinforcing bar arrangement step of supporting the second reinforcing bar on the underlying layer via second reinforcing bar spacers. In the base layer installation step, the base layer is installed in a region sandwiched between a plurality of beams installed on the ground,
The construction method according to any one of claims 1 to 4, wherein in the placing step, the hydraulic composition is placed up to above the top end level of the plurality of beams. a hydraulic composition layer including a structure having a predetermined height as an earthen floor;
and a base layer that supports the hydraulic composition layer from below,
The earth floor structure, wherein the hydraulic composition layer has a padded portion integrally formed with the structure between the lowest level of the structure and the highest level of the foundation layer. The dirt floor structure according to claim 6, wherein the structure and the puffed portion integrally form a structural floor member. The dirt floor structure according to claim 6 or 7, wherein the foundation layer has a waterproof layer positioned directly below the hydraulic composition layer. The hydraulic composition layer is
Having a wire mesh in the part forming the puff part,
The dirt floor structure according to any one of claims 6 to 8, wherein a first reinforcing bar and a second reinforcing bar located above the first reinforcing bar are provided in a portion forming the dirt floor portion.

Images