Construction method of permanent mold and precast permanent mold panel

Abstract

To provide a construction method of a permanent mold and a precast permanent mold panel used for the construction method of the permanent mold for preventing generation of cracks on a front surface of a precast permanent mold panel body after construction.SOLUTION: A construction method of a permanent mold includes a process of arranging a buffer partition member 4 at a position between a left side metal fitting 3A to be connected and a right side metal fitting 3B to be connected on a rear surface 2a of a precast permanent mold panel 1. Self-shrinkage deformation of ready mixed concrete 12 generated in a cure process is restrained with the buffer partition member 4 to disperse tearing force causing generation of cracking so as to suppress its transmission to a panel body 2 of the precast permanent mold panel 1, which prevents generation of cracking on a front surface side of the panel body 2 of the precast permanent mold panel 1 after constructing a permanent mold 10.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a method for constructing a remaining formwork for preventing cracks from occurring on the front surface of a precast remaining formwork panel body after the remaining formwork is constructed.

Background Art

[0002] As a method for decorative coating the wall surface of a retaining wall, for example, there is known a method for constructing a remaining formwork in which precast remaining formwork panels are erected at a predetermined interval from the wall surface, and fresh concrete is placed between the wall surface and the precast remaining formwork panels.

[0003] In a conventional method for constructing a remaining formwork, for example, as shown in FIG. 6(a), a precast remaining formwork panel 101 provided with a connected fitting 103 on the back surface where there are many craters U is used. This connected fitting 103 protrudes from the back surface of the precast remaining formwork panel 101 and is exposed. In this method for constructing a remaining formwork, as shown in FIGS. 6(a) and (b), for example, the precast remaining formwork panels 101 are stacked in the left-right direction X and the up-down direction Y on the front surface of the steel sheet pile 104, and the connected fitting 103 and the steel sheet pile 104 are connected via a separator 111 to construct a precast remaining formwork 110. Then, fresh concrete 112 is placed between the back surface of the precast remaining formwork panel 101 and the steel sheet pile 104 and hardened. When it hardens, the fresh concrete 112 shrinks, causing a cracking displacement, and a crack C2 occurs in the fresh concrete 112. When this crack C2 occurs, a force that tears the precast remaining formwork panel 101 in the left-right direction X is generated, so a crack C1 occurs in the precast remaining formwork panel 101. When a crack C1 occurs on the surface of the precast remaining formwork panel 101, in addition to being aesthetically unfavorable, the long-term durability performance of the precast remaining formwork panel 101 may decrease. Specifically, as shown in FIG. 7, a plurality of cracks occur on the surface of the precast remaining formwork panel in the up-down direction Y.

[0004] A method for constructing a residual formwork for preventing cracks on the surface of a precast residual formwork panel as described above is disclosed (for example, Patent Document 1). The method for constructing the residual formwork described in Patent Document 1 is to provide an isolation sheet having a moisture-permeable waterproof function or a water-blocking function on the back surface of the panel body of the precast residual formwork panel, and connect the ends of the isolation sheets of the adjacent precast residual formwork panels with a sealing material, so that the entire back surface of the precast residual formwork panel is covered with the connected isolation sheets, and a residual formwork construction step of constructing a residual formwork using the precast residual formwork panel, a step of placing fresh concrete on the back side of the precast residual formwork panel after constructing the residual formwork, and a curing step of curing the fresh concrete after placing the fresh concrete. In the above method for constructing the residual formwork, by providing the isolation sheet, a gap is formed between the concrete structure placed on the back surface of the precast residual formwork panel, and the crack displacement caused by the hardening shrinkage of the placed fresh concrete and the crack displacement caused in the concrete structure by external force are hardly transmitted to the panel body of the precast residual formwork panel, and after construction, the occurrence of cracks in the precast residual formwork panel is suppressed.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In the construction method of the residual formwork described in Patent Document 1, after joining the ends of the isolation sheets of adjacent precast residual formwork panels with a sealing material, fresh concrete is placed on the back side of the precast residual formwork panel. When vibrating the fresh concrete for compaction using a vibrator, there is a risk that the sealing material may peel off or the isolation sheet itself may be torn. Then, the placed fresh concrete adheres to the back of the precast residual formwork panel body and integrates with the connecting fitting provided on the back of the panel. As a result, in the days after the residual formwork panel is constructed, there is a possibility that the crack suppression effect cannot be expected on the front side surface of the residual formwork panel.

[0007] Therefore, an object of the present invention is to provide a construction method of a residual formwork for preventing cracks from occurring on the front side surface of a precast residual formwork panel body after construction, and a precast residual formwork panel used in this construction method of the residual formwork.

Means for Solving the Problems

[0008] The construction method of the residual formwork according to the present invention is a method of constructing a residual formwork using a precast residual formwork panel provided with connecting fittings on the left and right of the back surface. The method includes a step of providing a buffer partition member at a position between the left connecting fitting and the right connecting fitting on the back surface of the precast residual formwork panel, and a step of placing fresh concrete on the back surface of the precast residual formwork panel after providing the buffer partition member. By the buffer partition member, the self-shrinkage deformation occurring in the step of hardening the fresh concrete is restrained, and the tearing force, which is a factor causing cracks, is dispersed, thereby suppressing the transmission to the main body of the precast residual formwork panel. After the residual formwork panel is constructed, cracks are prevented from occurring on the front side surface of the main body of the precast residual formwork panel.

[0009] The construction method of the residual formwork according to the present invention is a method of constructing a residual formwork using a precast residual formwork panel provided with connecting fittings on the left and right of the back surface, and a buffer partition member is provided at a position between the connecting fitting on the left side and the connecting fitting on the right side. The method includes a step of stacking the precast residual formwork panels, and a step of placing fresh concrete on the back surface of the precast residual formwork panels after stacking them. By the buffer partition member, the self-shrinkage deformation generated in the step of hardening the fresh concrete is restrained, and the tearing force, which is a factor causing cracking, is dispersed, thereby preventing the tearing force from being transmitted to the main body of the precast residual formwork panel. After the residual formwork panel is constructed, cracking is prevented from occurring on the front side surface of the main body of the precast residual formwork panel.

[0010] The precast residual formwork panel according to the present invention is a precast residual formwork panel provided with connecting fittings on the left and right of the back surface and used for constructing a residual formwork panel. A buffer partition member is provided at a position between the connecting fitting on the left side and the connecting fitting on the right side on the back surface of the precast residual formwork panel.

Effect of the Invention

[0011] The construction method of the residual formwork according to the present invention is constructed using a precast residual formwork panel provided with connecting fittings on the left and right of the back surface. On the back surface of the precast residual formwork panel, a step of providing a buffer partition member at a position between the connecting fitting on the left side and the connecting fitting on the right side, and a step of placing fresh concrete on the back surface of the precast residual formwork panel are included. By providing the buffer partition member, the self-shrinkage deformation generated in the step of hardening the fresh concrete is restrained, and the tearing force, which is a factor causing cracking, is dispersed. By doing so, the transmission of the tearing force to the main body of the precast residual formwork panel is suppressed, and after the residual formwork panel is constructed, cracking can be prevented from occurring on the front side surface of the main body of the precast residual formwork panel.

[0012] The precast residual formwork panel according to the present invention is provided with connecting fittings on the left and right of the back surface, and is used for constructing the residual formwork panel. On the back surface of the precast residual formwork panel, a buffer partition member is provided at a position between the left connecting fitting and the right connecting fitting. By using this precast residual formwork panel, after the residual formwork panel is constructed, it is possible to prevent cracks from occurring on the front surface of the main body of the precast residual formwork panel.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Modes for Carrying Out the Invention

[0014] [First Embodiment] The construction method of the residual formwork according to this embodiment (hereinafter referred to as the construction method) is a method for suppressing cracks generated on the front side of the precast residual formwork panel after constructing the precast residual formwork using the precast residual formwork panel. Hereinafter, the construction method according to this embodiment and the precast residual formwork panel used in this construction method will be described with reference to FIGS. 1 to 5.

[0015] In the construction method according to this embodiment, the precast residual formwork panel 1 shown in FIG. 1 is used. As shown in FIG. 1(a), this precast residual formwork panel 1 includes a precast residual formwork panel main body 2 (hereinafter also referred to as the panel main body 2) and a plurality of connected metal fittings 3 provided at predetermined positions on the back surface of the precast residual formwork panel main body 2.

[0016] [Panel Main Body] As shown in FIGS. 1(a) and (b), the panel main body 2 is rectangular, and a panel main body 2 with a size of height (H) 300 mm, width (W) 900 mm, and thickness (T) 35 mm is used. On the back surface 2a of the panel main body 2, two connected metal fittings 3 are provided in the left-right direction X and two in the up-down direction Y, and a total of four connected metal fittings 3 are fixed to one panel main body 2. The one fixed on the left side when viewed from the back side of the panel main body 2 is referred to as the connected metal fitting 3A, and the one fixed on the right side when viewed from the back side of the panel main body 2 is referred to as the connected metal fitting 3B. These connected metal fittings 3 are provided so as to protrude from the back surface 2a of the panel main body 2. In addition, a plurality of reinforcing bars 5 are provided in the left-right direction X and up-down direction Y inside the panel main body 2 to ensure the strength of the panel main body 2. Note that the sizes of the height H in the up-down direction Y, width W in the left-right direction X, and thickness T in the front-rear direction Z of the panel main body 2 can be appropriately changed. Note that the left-right direction X is expressed as the direction when viewed from the back surface of the panel main body 2.

[0017] [Connected Metal Fitting] The connected fitting 3 includes a hook portion 6 and embedded portions 7 connected to both ends of the hook portion 6 (Fig. 1(a)). The connected fitting 3 is provided on the panel body 2 in a state where the embedded portions 7 are embedded inside the panel body 2 and the hook portion 6 protrudes from the back surface 2a of the panel body 2. For this connected fitting 3, a metal one can be used, and it is preferable to use a material with excellent corrosion resistance. For example, a stainless steel material (SUS304) can be used.

[0018] [Buffer partition member] A buffer partition member 4 is provided in the middle between the connected fitting 3A and the connected fitting 3B on the panel body 2. This buffer partition member 4 is provided before constructing the precast residual formwork (residual formwork) 10 or after constructing the precast residual formwork 10 in the construction method of the residual formwork described later. In this embodiment, before constructing the precast residual formwork 10, the precast residual formwork panel 1 with the buffer partition member 4 provided on the back surface 2a of the panel body 2 is used. For the buffer partition member 4, for example, expanded polystyrene, a rubber-based material, or a silicone-based material, which are elastic members, can be used. The height of the buffer partition member 4 is the same as the height of the panel body 2, and the thickness t of the buffer partition member 4 is preferably not less than 1 / 2 of the thickness CT of the concrete layer 12A described later.

[0019] Next, the construction method of the residual formwork will be described. In the construction method of the residual formwork according to this embodiment, the case of stacking the precast residual formwork panels 1 with the buffer partition members 4 provided on the back surface 2a of the panel body 2 will be described as an example.

[0020] As shown in FIG. 2, the construction method of the remaining formwork according to this embodiment includes a remaining formwork construction step of stacking precast remaining formwork panels 1 provided with a buffer partition member 4 at an intermediate position between the connected fitting 3A on the left side and the connected fitting 3B on the right side of the panel body 2, and constructing a precast remaining formwork 10 on the front surface of a steel sheet pile retaining wall 13 composed of steel sheet piles having unevenness; a fresh concrete placing step of placing fresh concrete 12 on the back surface 2a of the precast remaining formwork panel 1; and a fresh concrete hardening step of hardening the fresh concrete 12 after placing the fresh concrete 12.

[0021] [Remaining formwork construction step] As shown in FIG. 2, the construction method according to this embodiment stacks precast remaining formwork panels 1 and constructs a precast remaining formwork 10 on the front surface of the steel sheet pile retaining wall 13. As shown in FIG. 3, in the vertical direction Y, adjacent precast remaining formwork panels 1 are stacked in a staggered state shifted by half. Therefore, the buffer partition members 4 are approximately at the same position in the left-right direction X of the odd-numbered precast remaining formwork panels 1, and the buffer partition members 4 are approximately at the same position in the left-right direction X of the even-numbered precast remaining formwork panels 1. These precast remaining formwork panels 1 are fixed to the front surface of the retaining wall 13 by connecting the connected fitting 3 and the retaining wall 13 with a separator 11.

[0022] The retaining wall 13 is composed of steel sheet piles having recesses 13A and protrusions 13B. The precast remaining formwork 10 is constructed such that the center of the uppermost precast remaining formwork panel 1 and the protrusion 13B face the joint between the uppermost precast remaining formwork panels 1 and the recess 13A, respectively (FIG. 2). The precast remaining formwork 10 is constructed in a state where the distance between the protrusion 13B and the precast remaining formwork panel 1 is shorter than the distance between the recess 13A and the precast remaining formwork panel 1. At this time, the buffer partition member 4 is brought into contact with the protrusion 13B of the retaining wall 13.

[0023] [Fresh concrete placing step] After the precast residual formwork is constructed, fresh concrete 12 is placed between the precast residual formwork panel 1 and the retaining wall 13.

[0024] [Fresh concrete hardening process] After fresh concrete 12 is placed between the precast residual formwork panel 1 and the retaining wall 13, the fresh concrete 12 is hardened over a predetermined period of time. After hardening, a concrete layer 12A is formed. In this embodiment, the thickness CT of the concrete layer 12A means the distance between the panel body 2 and the retaining wall 13 facing the panel body 2. In this embodiment, since the retaining wall 13 is composed of corrugated steel sheets having unevenness, the thickness CT of the concrete layer 12A is different in the left-right direction X.

[0025] Next, the effects of the construction method of the residual formwork according to this embodiment will be described.

[0026] The construction method of the residual formwork according to this embodiment uses the precast residual formwork panel 1 provided with the buffer partition member 4 on the back surface 2a of the panel body 2. When the residual formwork is constructed, the buffer partition member 4 comes into contact with the retaining wall 13, and then fresh concrete 12 is placed. By arranging the buffer partition member 4 between the retaining wall 13 and the precast residual formwork panel 1, the self-shrinkage deformation that occurs in the process of hardening the fresh concrete 12 is restricted, and the tearing force, which is a factor causing cracking, is dispersed. By dispersing this tearing force, it is suppressed that the tearing force is transmitted to the main body of the precast residual formwork panel. Therefore, it is possible to prevent cracks from occurring on the front side surface of the panel body 2 after the residual formwork 10 is constructed.

[0027] Generally, from the design (appearance) of the precast residual formwork 10 after construction, the precast residual formwork panels 1 adjacent in the vertical direction Y are stacked with a shift of 1 / 2 of the length in the horizontal direction X. In the precast residual formwork 10, in the vertical direction Y, the intermediate position between the left connecting fitting 3A and the right connecting fitting 3B is the same as the joint position between the upper and lower precast residual formwork panels 1. Therefore, by arranging the buffer partition member 4 at the intermediate position between the left connecting fitting 3A and the right connecting fitting 3B, the tearing force acting in the horizontal direction can also be dispersed, and it is possible to further prevent cracks from occurring on the front side surface of the panel body 2 at a later date after construction.

[0028] [Other examples] In another example of the present embodiment, as shown in Fig. 4(a), the comp panel 13 is used. In this case, the buffer partition member 4 is not in contact with the comp panel 13, and a predetermined interval is provided between the buffer partition member 4 and the comp panel 13. When the constructed precast residual formwork 10 is viewed from the back, as shown in Fig. 4(b), the buffer partition members 4 are provided at different positions for odd-numbered rows and even-numbered rows, and in the precast residual formwork panels 1 adjacent in the vertical direction Y, they are arranged with a shift of 1 / 2 of the length of the panel body 2.

[0029] Also in this case, since the buffer partition member 4 is arranged between the comp panel 13 and the precast residual formwork panel 1, the self-shrinkage deformation occurring in the process of the fresh concrete 12 hardening is restricted, the tearing force, which is a factor causing cracks, is dispersed, and the transmission of the tearing force to the main body of the precast residual formwork panel is suppressed. Therefore, it is possible to prevent cracks from occurring on the front side surface of the main body of the precast residual formwork panel 1 at a later date after the residual formwork 10 is constructed.

[0030] [Second embodiment] In the present embodiment, a method for constructing the residual formwork in the case where the buffer partition member 4 is provided on the back surface 2a of the panel body 2 after stacking the precast residual formwork panels 1 will be described.

[0031] As shown in Fig. 5, the construction method of the residual formwork according to this embodiment includes a residual formwork construction step of stacking precast residual formwork panels 1 and constructing a precast residual formwork 10 on the front surface of the panel 13, a buffer partition member installation step of providing a buffer partition member 4 at an intermediate position between the connecting fitting 3A on the left side and the connecting fitting 3B on the right side of the panel body 2 after constructing the precast residual formwork 10, a fresh concrete placing step of placing fresh concrete 12 on the back surface 2a of the precast residual formwork panel 1, and a fresh concrete curing step of curing the fresh concrete 12 after placing the fresh concrete 12.

[0032] The construction method of the residual formwork of this embodiment is different from the construction method of the first embodiment in that the buffer partition member 4 is arranged at the same position in the left-right direction X at any stage. The buffer partition member 4 may be provided with a length from the upper stage to the lower stage of the precast residual formwork 10 in the up-down direction Y, or may be provided with a length corresponding to the height of each panel body 2.

[0033] Similar to the construction method of the first embodiment, the construction method of the residual formwork according to this embodiment restricts the self-shrinkage deformation generated in the process of curing the fresh concrete 12 by the buffer partition member 4 arranged between the panel 13 and the precast residual formwork panel 1, and disperses the tearing force, which is a factor causing cracks. As a result, it is possible to prevent the tearing force from being transmitted to the main body of the precast residual formwork panel 1 and prevent cracks from occurring on the front surface of the main body of the precast residual formwork panel 1 after the residual formwork 10 is constructed.

[0034] The buffer partition member 4 can also be provided after constructing the precast residual formwork 10 in the construction method of the residual formwork according to this embodiment. In this case, the buffer partition member 4 can be provided for any panel, so the construction method of this residual formwork has high versatility.

[0035] Although the present embodiment has been described above, other than this, as long as the gist of the present invention is not deviated from, it is possible to select and discard the configurations exemplified in the above embodiment, or to appropriately change them to other configurations.

[0036] In the present embodiment, an example in which the buffer partition member 4 is provided at a position intermediate between the connected fitting 3A and the connected fitting 3B has been described. However, the position where the buffer partition member 4 is provided is not limited to the above position, and it may be provided at any position as long as it is between the left connected fitting 3A and the right connected fitting 3B. Also, the length of the buffer partition member 4 in the vertical direction Y can be appropriately changed.

Explanation of Reference Numerals

[0037] 1 Precast Remaining Formwork Panel 2 Precast Remaining Formwork Panel Body (Panel Body) 2a Back Surface 3, 3A, 3B Connected Fittings 4 Buffer Partition Member 5 Rebar 6 Hook Portion 7 Embedded Portion 10 Precast Remaining Formwork (Remaining Formwork) 11 Separator 12 Fresh Concrete 12A Concrete Layer 13 Steel Sheet Pile Retaining Wall, Companel 13A Protrusion 13B Recess 101 Precast Remaining Formwork Panel 103 Connected Fitting 104 Steel Sheet Pile 110 Precast Remaining Formwork 111 Separator 112 Fresh Concrete C1, C2 Cracks CT, T, t Thickness H Height W Width X Left - Right Direction Y Up - Down Direction Z Front - Back Direction

Claims

1. A method for constructing a remaining formwork using precast remaining formwork panels with connecting fittings provided on the left and right sides of the back surface, comprising: a step of stacking the precast remaining formwork panels; a step of providing a buffer partition member at a position between the left connecting fitting and the right connecting fitting on the back surface of the stacked precast remaining formwork panels; after providing the buffer partition member, a step of placing fresh concrete on the back surface of the precast remaining formwork panels, wherein the buffer partition member restrains the self - shrinkage deformation occurring in the step of hardening the fresh concrete, and disperses the tearing force which is a factor causing cracking, thereby preventing the tearing force from being transmitted to the main body of the precast remaining formwork panel, and preventing cracks from occurring on the front side surface of the main body of the precast remaining formwork panel after the remaining formwork is constructed; A method for constructing a remaining formwork, characterized by the above.

2. A method for constructing a remaining formwork using a precast remaining formwork panel with connecting fittings provided on the left and right sides of the back surface and a buffer partition member provided at a position between the left connecting fitting and the right connecting fitting, comprising: a step of stacking the precast remaining formwork panels; after stacking the precast remaining formwork panels, a step of placing fresh concrete on the back surface of the precast remaining formwork panels, wherein the buffer partition member restrains the self - shrinkage deformation occurring in the step of hardening the fresh concrete, and disperses the tearing force which is a factor causing cracking, thereby preventing the tearing force from being transmitted to the main body of the precast remaining formwork panel, and preventing cracks from occurring on the front side surface of the main body of the precast remaining formwork panel after the remaining formwork is constructed; A method for constructing a remaining formwork, characterized by the above.

3. A precast remaining formwork panel with connecting fittings provided on the left and right sides of the back surface, which is used for constructing a remaining formwork, wherein a buffer partition member is provided at a position between the left connecting fitting and the right connecting fitting on the back surface of the precast remaining formwork panel; A precast remaining formwork panel, characterized by the above.

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