JP3859365B2 - Buried formwork - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a buried form that is used as a form for placing concrete and remains as a surface layer of a concrete structure without being demolded after the concrete is hardened.
[0002]
[Prior art]
When constructing a concrete structure, it is common to build a plywood formwork, place ready-mixed concrete inside it, disassemble the plywood formwork and demold it after hardening the concrete. In order to save labor for mold removal and improve workability, the use of buried molds is increasing.
[0003]
On the other hand, deterioration and corrosion are regarded as problems after construction of concrete structures, for example, concrete structures built in beach areas and hot springs, or in corrosive environments such as chemical plants and sewage treatment facilities. In concrete structures, etc., there are concerns that salt, sulfur, sulfuric acid, etc. may invade from the surface of the structure and corrode internal reinforcing bars, which may cause the surface concrete to peel off and elute early. Countermeasures are being considered.
[0004]
As a countermeasure against such deterioration and corrosion of a concrete structure, a construction technique using an embedded formwork is employed. In this construction technology, by providing durability (chemical and physical resistance) to the embedded formwork itself, by blocking external deterioration factors for the concrete placed in the embedded formwork with the embedded formwork, Improves the durability of concrete structures.
[0005]
In addition, as a means for improving the durability of a concrete structure, a resin lining technique for forming a fiber reinforced plastic layer on the surface of an existing concrete structure is also widespread.
[0006]
[Problems to be solved by the invention]
As mentioned above, the use of embedded formwork is increasing for the purpose of saving labor, improving workability or improving durability, but the embedded formwork is thicker and heavier than conventional plywood formwork. For this reason, improvement in workability is insufficient. Moreover, since it is necessary to use expensive synthetic resin etc. in order to improve the durability of an embedded formwork, this is more expensive than a plywood formwork.
[0007]
On the other hand, in the case of resin lining technology, the quality is not constant because the completed state depends on the working environment at the construction site or the skill level of the construction engineer. For example, the resin lining cannot be constructed in a wet environment, and if the construction engineer is immature, defects such as pin holes are likely to occur in the lining portion.
[0008]
Therefore, the problem to be solved by the present invention is to provide an embedded formwork that is capable of constructing a concrete structure that has good workability and low cost, and that is excellent in quality stability and durability.
[0009]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, an embedded formwork of the present invention comprises a panel-shaped core material formed of resin mortar and a surface reinforcement layer formed of glass fiber reinforced plastic on both surfaces of the core material. The concrete fixing protrusions are arranged on one side of the mold body.
[0010]
By adopting such a configuration, the mold body has a sandwich structure of a relatively inexpensive resin mortar core material and a surface reinforcing layer made of glass fiber reinforced plastic with excellent strength and durability. In addition, it is possible to reduce the thickness and weight without impairing the durability (chemical / physical resistance), and it is possible to provide a buried mold having excellent durability at low cost. In addition, since the concrete fixing protrusions are arranged on one side of the mold body, the integration with the concrete is good.
[0011]
By using the buried form having such a configuration, it is possible to block external factors that corrode and deteriorate concrete, and to improve the durability of the concrete structure. In addition, since the embedded formwork can be manufactured in the factory, precast products reduce the restrictions on the work environment at the construction site, and the completion status is not affected by the level of skill of the construction engineer. The property is good, and the quality stability of the constructed concrete structure is also excellent.
[0012]
Here, the blending ratio of the resin mortar forming the core material is within the range of 10 to 20% by weight of the synthetic resin, 10 to 20% by weight of the filler, and 60 to 80% by weight of the fine aggregate depending on the construction conditions. It is desirable to adjust. By setting it as such a mixture ratio, cost reduction can be aimed at, maintaining the intensity | strength as an embedded formwork. If the blending ratio of the synthetic resin is less than 10% by weight, the fluidity at the time of molding is poor, the thickness of the core material becomes uneven, and if it exceeds 20% by weight, material separation occurs at the time of molding, resulting in warping deformation of the product. Also, the cost will increase. If the blending ratio of the filler is less than 10% by weight, the dispersion of the fine aggregate will be uneven and cause the strength to vary, and if it exceeds 20% by weight, the fluidity at the time of molding will be poor and the thickness of the core will be small. It becomes non-uniform. Further, if the blending ratio of the fine aggregate is less than 60% by weight, the rigidity of the product is lowered, and the amount of resin is relatively increased, resulting in an increase in cost. If it exceeds 80% by weight, the fluidity at the time of molding is increased. Unfortunately, the thickness of the core material is uneven.
[0013]
Moreover, the compounding ratio of the glass fiber reinforced plastic forming the surface reinforcing layer ranges from 20 to 40% by weight of a synthetic resin, 30 to 70% by weight of a filler, and 10 to 30% by weight of a glass fiber depending on construction conditions. It is desirable to adjust within. By setting it as such a mixture ratio, the intensity | strength and durability of an embedded formwork can be improved. When the blending ratio of the synthetic resin is less than 20% by weight, the resin is insufficiently impregnated into the filler and the glass fiber, resulting in a large variation in strength, and when it exceeds 40% by weight, the cost is increased. When the blending ratio of the filler is less than 30% by weight, warpage deformation occurs in the product due to curing shrinkage at the time of molding, and when it exceeds 70% by weight, impregnation of the resin into the glass fiber is insufficient and the strength is lowered. Further, if the blending ratio of the glass fiber is less than 10% by weight, the strength is insufficient, and if it exceeds 30% by weight, the glass fiber is not sufficiently impregnated and pinholes are generated on the product surface.
[0014]
Moreover, it is desirable to adjust the ratio between the thickness of the core material and the total thickness of the surface reinforcing layer within the range of 1: 1 to 8: 1 according to the construction conditions. By setting it as such a ratio, cost reduction can be implement | achieved, without impairing the rigidity and intensity | strength calculated | required by an embedded formwork. If the ratio of the thickness of the core material to the total thickness of the surface reinforcing layer is less than 1: 1, that is, if the thickness of the core material and the surface reinforcing layer in the thickness of the mold is comparable, the rigidity as the mold is insufficient, In addition, the cost increases. On the other hand, if the ratio of the thickness of the core material to the total thickness of the surface reinforcing layer is more than 8: 1, that is, if the thickness of the surface reinforcing layer is small compared to the core material, the strength as a mold is insufficient, and the core material is on the surface. The variation in the protruding strength is also increased.
[0015]
Here, the thickness of the core material can be 4 to 16 mm, and the total thickness of the surface reinforcing layer can be 2 to 8 mm. By setting the total thickness of the core material and the surface reinforcing layer in such a range, it is possible to reduce the thickness and weight suitable for the actual construction site, so that the workability and workability are further improved. If the thickness of the core material is less than 4 mm, the rigidity decreases, and if it exceeds 16 mm, the overall thickness increases and the cost increases. Moreover, since the strength is insufficient when the total thickness of the surface reinforcing layers is less than 2 mm and the cost is increased when the total thickness exceeds 8 mm, the above range is desirable.
[0016]
Further, in the embedded form of the present invention, gravel, sand, a net-like body or the like can be used as the concrete fixing protrusion. As a net-like body, a three-dimensional structure such as a ramen structure, a coil structure, or a loop structure has a better adhesion to concrete than a flat plate. By using such a material as a concrete fixing protrusion, integration with the concrete placed in the embedded formwork is promoted.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing a buried mold according to the first embodiment, FIG. 2 is an explanatory view showing a method for manufacturing the buried mold of FIG. 1, and FIG. 3 is a cross-sectional view showing a usage state of the buried mold.
[0018]
As shown in FIG. 1, the embedded form 10 of the present embodiment includes a formwork body 13 including a panel-like core material 11 and surface reinforcing layers 12 formed on both surfaces of the core material 11. The concrete fixing projections 14 are dispersedly arranged on one side of 13. The core material 11 is formed of resin mortar, the surface reinforcing layer 12 is formed of glass fiber reinforced plastic, and crushed gravel is used as the concrete fixing protrusion 14. As a means for fixing the concrete fixing protrusion 14 to one side of the mold body 13, a synthetic resin or a synthetic resin to which a filler is added is used.
[0019]
The blending ratio of the resin mortar forming the core material 11 is 16% by weight of the synthetic resin, 16% by weight of the filler, and 68% by weight of the fine aggregate, and the blending ratio of the glass fiber reinforced plastic forming the surface reinforcing layer 12 is synthetic. 35% by weight of resin, 50% by weight of filler, and 15% by weight of glass fiber. The thickness of the core material 11 is 7 mm, and the total thickness of the surface reinforcing layer 12 is 3 mm. The total thickness of the mold body 13 is 10 mm, and a reduction in thickness and weight of 50% or more is achieved as compared with a conventional embedded mold. The bending strength is 410 kgf / cm ² , and the rigidity is 1.5 times that of the conventional plywood formwork. This also greatly improved the workability and workability at the actual construction site.
[0020]
Since the mold body 13 has a sandwich structure of a relatively inexpensive core 11 made of resin mortar and a surface reinforcing layer 12 made of glass fiber reinforced plastic having excellent strength and durability, it is thin and lightweight, It has sufficient rigidity, strength, and durability (chemical / physical resistance) as an embedded formwork. By using this embedded formwork 10, a low-cost and highly durable concrete structure is constructed. be able to.
[0021]
Here, for comparison, a mold body was manufactured in which the ratio of the thickness of the core material to the total thickness of the surface reinforcing layer was outside the range of the present invention. When the thickness of the core material is 3 mm and the total thickness of the surface reinforcing layer is 7 mm (ratio is less than 1: 1), the flexural modulus is 0.7 × 10 ⁵ kgf although the flexural strength is as large as 560 kgf / cm ^2. / Cm ^2, which is almost the same as the conventional plywood formwork, and no superiority was found. Further, when the thickness of the core material is 9 mm and the total thickness of the surface reinforcing layer is 1 mm (ratio is more than 8: 1), the bending elastic modulus is 1.5 × 10 ⁵ kgf / cm ^{2, which} is a conventional plywood formwork However, the bending strength was 280 kgf / cm ² , and no significant difference was observed as compared with the conventional embedded formwork. Further, the core material was partially exposed to the surface protective layer, and the surface finish was inferior.
[0022]
Next, a method for manufacturing the embedded mold 10 will be described with reference to FIG. As shown in FIG. 2, the mold body 13 is formed by heating and press-molding the surface reinforcing layer 12 made of glass fiber reinforced plastic in close contact with both surfaces of the core material 11 made of resin mortar. Then, if the crushed gravel used as the concrete adhering protrusion 14 is dispersedly arranged on one surface of the mold body 13, the embedded mold 10 is completed. In this case, since the core material 11 and the surface reinforcing layer 12 both contain a synthetic resin as a binder, the adhesion is good and they are completely integrated by heating and pressure molding. Therefore, the durability after molding is also excellent, and the surface reinforcing layer 12 does not peel from the core material 11 after construction.
[0023]
In addition, since the embedded form 10 of the present embodiment is a factory-produced precast product, there are few restrictions on the work environment at the construction site, and the completed state is not affected by the skill level of the construction engineer. Is good, and the quality stability of the constructed concrete structure is also excellent.
[0024]
Next, with reference to FIG. 3, the usage state of the embedded mold 10 will be described. As shown in FIG. 3, when concrete 15 is placed in a space formed by a plurality of embedded molds 10, the embedded mold 10 and the concrete 15 are integrated by the concrete fixing protrusions 14, and the concrete 15 Since external factors such as corrosion and deterioration are blocked, the concrete structure 16 having excellent durability can be constructed.
[0025]
In this case, since the surface reinforcing layer 12 located on the surface side of the embedded mold 10 is formed of glass fiber reinforced plastic, the concrete structure 16 is prevented from being corroded or deteriorated over a long period even in a corrosive environment. be able to.
[0026]
FIG. 4 is a perspective view showing an embedded form according to the second embodiment of the present invention.
In the embedded mold 40 according to the present embodiment, a formwork body 43 is constituted by a panel-like core material 41 and surface reinforcing layers 42 formed on both surfaces of the core material 41. A protrusion 44 is disposed. The core material 41 is formed of resin mortar, the surface reinforcing layer 42 is formed of glass fiber reinforced plastic, and sand is used as the concrete fixing protrusions 44.
[0027]
FIG. 5 is a perspective view showing an embedded form according to the third embodiment of the present invention.
The embedded form 50 of the present embodiment includes a panel-shaped core material 51 made of resin mortar and a surface reinforcing layer 52 made of glass fiber reinforced plastic formed on both surfaces of the core material 51, and a mold body 53 is formed. On one side of the mold body 53, a concrete adhering protrusion 54 composed of a continuous ramen-like net is disposed.
[0028]
In the case of the embedded form 40 of the second embodiment and the embedded form 50 of the third embodiment, the concrete structure is low in cost and excellent in durability, like the embedded form 10 of the first embodiment. Can be built.
[0029]
【The invention's effect】
According to the present invention, the following effects can be obtained.
[0030]
(1) A formwork body is composed of a panel-shaped core material made of resin mortar and a surface reinforcing layer made of glass fiber reinforced plastic on both sides of the core material, and a concrete fixing protrusion on one side of the formwork body By arranging the body, it becomes a sandwich structure of a relatively inexpensive resin mortar core material and a surface reinforcing layer made of glass fiber reinforced plastic with excellent strength and durability, so rigidity and strength as an embedded formwork In addition, it is possible to reduce the thickness and weight while ensuring durability, and it is possible to construct a concrete structure that is low in cost and excellent in durability. In addition, because it can be manufactured in the factory, there are few restrictions on the work environment at the construction site, and the completed state is not affected by the level of skill of the construction engineer. The quality stability of is also excellent.
[0031]
(2) By setting the blending ratio of the resin mortar forming the core material, the blending ratio of the glass fiber reinforced plastic forming the surface reinforcing layer, the thickness of the core material and the thickness of the surface reinforcing layer within a specific range, While ensuring the strength and durability, the cost can be reduced, and the workability and workability can be improved.
[0032]
(3) Use of gravel, sand, nets, etc. as the concrete fixing protrusions promotes integration with concrete placed in the embedded formwork and blocks external factors that corrode and deteriorate concrete. Thus, the durability of the concrete structure can be further improved.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an embedded mold according to a first embodiment.
FIG. 2 is an explanatory view showing a method for manufacturing the embedded mold shown in FIG. 1;
FIG. 3 is a cross-sectional view showing a usage state of the embedded form in FIG. 1;
FIG. 4 is a perspective view showing an embedded mold according to a second embodiment.
FIG. 5 is a perspective view showing an embedded mold according to a third embodiment.
[Explanation of symbols]
10, 40, 50 Embedded mold 11, 41, 51 Core material 12, 42, 52 Surface reinforcing layer 13, 43, 53 Mold body 14, 44, 54 Protruding body 11a for concrete fixing Core material thickness 12a Surface reinforcing layer Thickness 15 Concrete 16 Concrete structure

Claims (6)

A formwork body is composed of a panel-like core made of resin mortar and a surface reinforcing layer made of glass fiber reinforced plastic on both sides of the core, and a concrete fixing protrusion is placed on one side of the formwork body Embedded formwork characterized by that. The embedding formwork according to claim 1, wherein a blending ratio of the resin mortar forming the core material is 10 to 20% by weight of a synthetic resin, 10 to 20% by weight of a filler, and 60 to 80% by weight of a fine aggregate. The embedded mold according to claim 1 or 2, wherein a blending ratio of the glass fiber reinforced plastic forming the surface reinforcing layer is 20 to 40% by weight of a synthetic resin, 30 to 70% by weight of a filler, and 10 to 30% by weight of a glass fiber. frame. The embedded formwork according to claim 1, wherein the ratio of the thickness of the core material to the total thickness of the surface reinforcing layers is 1: 1 to 8: 1. 5. The embedded formwork according to claim 1, wherein the core material has a thickness of 4 to 16 mm, and the surface reinforcing layer has a total thickness of 2 to 8 mm. The embedded formwork according to claim 1, wherein the concrete fixing protrusion is at least one of gravel, sand, and a net-like body.

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