JP7177421B2 - Embedded formwork for reinforcing stainless steel bars - Google Patents

Description

In the present invention, cement-based mortar (hereinafter referred to as "base mortar") is used as the base material of a concrete-based molded body, and stainless steel reinforcing bars (hereinafter referred to as "stainless steel reinforcing bars") are used as reinforcing materials. It relates to an embedded formwork to which truss-like steel members are arranged in a lattice shape in the direction and processed to have a spire-like mountain on the side on which a concrete frame is to be constructed.

In the construction of a concrete framework, the embedded formwork functions as a forming formwork when the concrete is poured, and after the poured concrete has hardened, it functions as a part of the main body of the concrete framework. It contributes to the rationalization of concrete frame work because it eliminates the need for deframing work such as

The embedded formwork has a function as a forming formwork when pouring concrete and a function of becoming a part of the main body of the building concrete after the concrete hardens. Embedded formwork for forming a concrete framework is required to withstand lateral pressure when concrete is poured. Therefore, a method of mixing short fibers (fibers) made of stainless steel, steel, vinylon, etc. into the base mortar for reinforcement is being implemented.

The embedded formwork must be held so that it does not deform such as bending or bulging against the lateral pressure acting during concrete pouring. For this reason, the surface of the embedded formwork on which the concrete is poured, that is, the surface of the main body of the concrete frame must be supported by an internal support (separator). Internal shoring has threaded ends and is generally fixed by screwing into inserts embedded in the embedded formwork. There is also a method of fixing the ends of the internal shoring from the outside by providing a through hole in the embedded formwork.

In the embedded formwork, the surface part of the side where concrete is to be placed is (a) roughened with a joint treatment agent, (b) coarse aggregate is embedded so that about half is exposed, and (c) uneven grooves. By attaching it to the post-cast concrete at the boundary surface by any method such as providing a (cotter), it is integrated so that it functions as a part of the main body of the concrete frame.

JP-A-2002-26640 JP 2011-84861 A

As described above, since the embedded mold uses short fibers as a reinforcing material, it has low load-bearing performance against tensile stress when cracks occur, and does not have the tenacity to break. The embedded formwork is subjected to the greatest loads during the pouring of the concrete, which acts as the forming formwork. For this reason, it is essential to design the embedded form so that cracks do not occur against the assumed lateral pressure of the concrete. For this reason, it has been difficult to set the thickness of the embedded mold to about 50 mm or less.

When reinforcing steel is used as a reinforcing material for the embedded formwork, the reinforcing steel functions as a member that bears the tensile force after cracking occurs, so the problem of tenacity when short fibers are used as described above is resolved. However, in the method of using reinforcing steel as a reinforcing material, it is necessary to consider the prevention of reinforcing steel corrosion due to the infiltration of corrosive factors through surface cracks. For this reason, it is necessary to set the thickness of the cover concrete from the surface of the embedded formwork to the surface of the reinforcing bars to be large, which increases the plate thickness of the embedded formwork. This indicates that it is difficult to adopt this method for embedded formwork, which is desired to be thin and light from the viewpoint of workability. According to the Japan Society of Civil Engineers Concrete Standard Specifications [Design Edition], the permissible crack width for reinforcing bars made from ordinary carbon steel (hereinafter referred to as ordinary reinforcing bars) is c ( mm), it is calculated by 0.005×c (mm). For example, if the allowable crack width is 0.2 mm and the required reinforcing bar cover thickness is obtained, c=40 mm. Therefore, when arranging ordinary reinforcing bars with a diameter of 10 mm in two directions, the vertical direction and the horizontal direction, as reinforcing materials, the thickness of the embedded formwork must be 40+10+10+40=100 mm or more. In addition, when using embedded formwork in a severe salt-damaged environment, it is necessary to set the thickness of the reinforcing bar cover to be even larger. As a result, the weight of the embedded formwork becomes thicker, resulting in lower workability and higher transportation costs. It wasn't.

The inserts embedded in the embedded formwork for the purpose of connecting the embedded formwork with the internal shoring must have a large embedment depth in order to increase the resistance to the pull-out load acting on them. Since the embedding depth of ready-made inserts is about 30 mm or more, the thickness of the embedded form must be set to 50 mm or more in consideration of securing a covering of 20 mm or more from the outside of the embedded form.

Basically, the internal shoring that supports the embedded formwork is directly connected to the insert embedded in the embedded formwork. Also, since the insert is fixed to the embedded formwork, the position cannot be changed during construction. For this reason, the internal shoring must be assembled according to the position of the embedded formwork insert. Therefore, the time and effort involved in adjusting the position of the internal shoring during construction hinders improvement in workability.

The integration of the embedded formwork and the post-cast concrete is performed by attaching the joint surface of the embedded formwork, which has undergone surface treatment to ensure adhesion, and the post-cast concrete. It is done in a way that is less resistant. For this reason, when the structure is put into service, separation is likely to occur at the interface between the embedded formwork and the post-cast concrete. When such delamination occurs, deterioration factors of concrete such as moisture and chloride ions permeate through the boundary surface, resulting in deterioration of durability. In addition, when the area of the peeled portion increases, there is a risk that the surface embedded formwork will peel off from the main concrete and fall. These phenomena not only shorten the life of structures, but also reduce safety, so it is necessary to prevent them from occurring.

The present invention is intended to solve the above-described problems of the conventional embedded formwork, that is, to enable the embedded formwork to be thin and light, to save the labor involved in assembling the embedded formwork, to improve workability, and to improve the workability of the embedded formwork. An object of the present invention is to provide an embedded formwork having a function of completely integrating a frame with post-cast concrete to form a part of a building concrete main body.

In order to solve the above-mentioned problems, the stainless steel reinforcement embedded formwork of the present invention is characterized in that stainless steel reinforcement bars with excellent corrosion resistance are arranged vertically and horizontally in a grid pattern inside the main body of the embedded formwork made of a concrete-based molded body for reinforcement. and

Further, the stainless steel reinforcement embedded formwork of the present invention is characterized in that deformed steel bars are used as the stainless steel reinforcement bars arranged vertically and horizontally in the formwork body.

Further, the stainless steel reinforcement embedded formwork of the present invention is characterized in that the surface of the concrete to be placed facing the main body side is subjected to a roughening treatment to make it a rough surface, and is attached to the main concrete body.

Further, in order to solve the above-mentioned problems, the embedded formwork for reinforcing stainless steel reinforcement according to the present invention is characterized in that the truss-like steel material 5a processed to have a spire-like peak is attached to the embedded formwork. Here, the truss-shaped steel material 5a is a stainless steel reinforcing bar or a round steel, and it can be completely fixed to the embedded form by attaching it along the form surface side of the horizontal stainless steel reinforcing bar 4 that intersects the straight part. can.

Further, in order to solve the above-described problems, the stainless steel reinforcement embedded formwork of the present invention is capable of attaching and fixing the assembly steel material 7 to the embedded formwork side of the truss steel material 5a bent into a steeple shape. characterized by Here, the assembly steel material 7 can be a deformed steel bar or a round steel, and the material can be either stainless steel or carbon steel.

Further, in order to solve the above problems, the stainless steel reinforcement embedded formwork of the present invention has an internal support 6 attached to an arbitrary position of the assembled steel material 7 fixed to the embedded formwork side of the steeple part of the truss-shaped steel material 5a . It is characterized by supporting lateral pressure during concrete pouring.

According to the stainless steel reinforcement embedded formwork of the present invention, the internal support 6 is joined to the assembled steel material 7 fixed to the embedded formwork side of the steeple part of the truss-shaped steel attached to the embedded formwork. The load due to the lateral pressure of the concrete acting on the embedded formwork can be transmitted directly to the internal support 6 .

According to the stainless steel reinforcement embedded formwork of the present invention, the space between the truss-like steel material 5a attached to the embedded formwork and the embedded formwork and the space between the assembled steel material 7 fixed to the truss-like steel material 5a and the embedded formwork Since the post-placed concrete is filled in the voids of the holes, the joint force at the interface between the embedded formwork and the post-placed concrete increases. Therefore, it is possible to prevent separation of the embedded formwork and the post-cast concrete by reliably integrating the embedded formwork and the post-cast concrete together with the adhesion effect of the roughening treatment applied to the surface of the embedded formwork.

According to the stainless steel reinforcement embedded formwork of the present invention, separation of the embedded formwork and the post-cast concrete can be prevented as described above. For this reason, it is possible to prevent deterioration factors from entering the inside of the concrete frame from the interface between the embedded formwork and the post-cast concrete, thereby improving durability, and also preventing the embedded formwork from coming off the post-cast concrete.

According to the stainless steel reinforcement embedded formwork of the present invention, the internal support 6 can be fixed at any position on the assembly steel material 7 attached via the truss- shaped steel material 5a attached to the embedded formwork. It is possible to omit the time and effort involved in adjusting the mounting position, and improve workability.

FIG. 2 is a diagram showing the structure of the embedded formwork for reinforcing stainless steel reinforcing bars according to the present invention, the arrangement of stainless steel reinforcing bars for reinforcement, and the arrangement of truss-shaped steel materials processed into a spire shape. FIG. 4 is a diagram showing a method of fixing a truss-shaped steel material processed into a spire shape inside a stainless steel reinforcement embedded formwork according to the present invention. FIG. 2 is a diagram showing a method of attaching an internal support to the truss-like steel material of the stainless steel reinforcement embedded formwork according to the present invention to function as a forming formwork when pouring concrete.

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of an embedded formwork using stainless reinforcing bars according to the present invention will be described below with reference to the drawings.

As shown in FIG. 1, the embedded formwork according to the present invention has a structure in which vertical stainless steel reinforcing bars 3 and horizontal stainless steel reinforcing bars 4 as reinforcing members are arranged in a grid pattern inside an embedded formwork main body 2 made of concrete molding. and The embedded formwork main body 2 can be manufactured in any shape, such as a flat plate, curved surface, corner portion, or the like.

The truss-like steel material 5a is fixed to the embedded formwork according to the present invention, as shown in FIG. This is done by embedding inside the frame body 2 . Here, the truss-like steel members 5a can be arranged in either the vertical direction or the horizontal direction. The truss-like steel material 5a is processed into a shape in which two or more spires are continuous as shown in FIG. 2(a). It is also possible to use what was made independent. Since such a fixing method is adopted, the truss-like steel material 5a or the truss-like steel material 5b can bear the pull-out force acting from the internal support 6 via the assembled steel material 7 in a stable state .

To attach the internal support 6 to the truss-like steel material of the embedded formwork according to the present invention, as shown in FIG. Do it in a fixed way. The internal support 6 can be attached by hooking onto the assembly steel 7 if the end of the steel material is processed into a hook shape or the end of the threaded steel material is connected to a U-shaped bolt via a long nut. can. Fixing of the internal support 6 to the assembly steel material 7 can be performed by any method such as bolting or welding. As shown in Fig. 3, considering the load due to the lateral pressure of the concrete acting on the embedded form body 2, by arranging the required number of internal supports 6, the embedded form body 2 is formed into a mold when pouring concrete. It can function as a frame.

As shown in FIG. 3, the embedded formwork according to the present invention is formed by filling the gap between the assembled steel material 7 attached to the truss-shaped steel material 5a and the embedded formwork main body 2 with post-cast concrete. The poured concrete can be completely integrated.

1: Embedded formwork 2: Embedded formwork main body 3: Vertical stainless steel reinforcing bar 4: Horizontal stainless steel reinforcing bar 5a: Truss-like steel (a type in which the spire is continuous)
5b: Truss-like steel material (a type with a single spire)
6: Internal support 7: Assembled steel

Claims (5)

Stainless steel reinforcing bars are arranged vertically and horizontally in a grid pattern inside an embedded form made of a concrete-based molded body, truss-like steel materials processed into a spire shape are placed along the stainless steel reinforcing bars, and further attached to the spire part of the truss-like steel material. A stainless steel reinforcement embedded formwork characterized by fixing an internal shoring to a prefabricated steel material. The stainless steel reinforcement embedded formwork according to claim 1, wherein the stainless steel reinforcement is a deformed steel bar. 3. A straight part of a truss-shaped steel material formed by processing a straight member to have a steeple part is embedded and fixed in the embedded mold according to claim 1 or 2. embedded formwork with stainless steel reinforcement. The straight part of the truss-shaped steel material embedded in the embedded formwork is attached along the part of the intersecting stainless steel reinforcing bar on the surface side of the formwork, and the assembled steel material is attached to the embedded formwork side of the steeple part of the truss-shaped steel material. The stainless steel reinforcement embedded formwork according to any one of claims 1 to 3, characterized by: 5. The inner support structure according to any one of claims 1 to 4, characterized in that an internal support is fixed at an arbitrary position of the assembled steel material attached to the embedded formwork side of the truss-like steel steeple portion arranged in the embedded formwork. Buried formwork with stainless steel reinforcement.

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