JP7169188B2 - structural member - Google Patents

Description

TECHNICAL FIELD The present invention relates to a structural member (for example, a deformed reinforcing bar, etc.) used as a structural steel material for concrete structures.

Reinforcing bars used in reinforced concrete structures are structural reinforcing materials that bear the tensile force generated in the reinforced concrete due to the load in the reinforced concrete structures, and examples thereof include deformed reinforcing bars and deformed wires.
In the prior art, in order to fix the reinforcing bars in the concrete, contrivances such as adding unevenness to the surface of the round steel reinforcing bars are applied to increase the adhesion between the reinforcing bars and the concrete (see Patent Documents 1 and 2). ).
In addition, a structural member with improved adhesion to concrete by twisting multiple high-strength, low-elongation fibers (see Patent Document 3), and a technique for increasing the surface area of a structural member by winding a resin material around a fiber-reinforced plastic wire. has also been proposed (see Patent Document 4).

However, with conventional deformed reinforcing bars and the like, the adhesion to concrete is increased compared to the case of so-called round bars, but it is difficult to say that the reinforcing bars and concrete are integrated.
Chemical fibers such as carbon fibers are selected as the high-strength, low-elongation fibers, but the chemical fibers have low adhesion to concrete, and it is difficult to ensure sufficient adhesion to concrete.
Therefore, a structural member that integrates with concrete has been demanded, but has not yet been proposed.

In addition, for example, when connecting deformed reinforcing bars in a large reinforced concrete structure to make it longer, the deformed reinforcing bars are attached to a specified length at the joint and lashed with a number wire, and a special connector is used to secure the deformed reinforcing bars. It was necessary to perform the work of butting each other and connecting with a sleeve, and (in the case of steel bars with a large diameter) the work of pressing the butted parts. These lengthening operations have the problem of increasing required labor and cost.
Furthermore, there is also the problem that the cross-sectional area of the concrete is reduced at locations where the lap joints concentrate. At the same time, there is also the problem that when the lap joints are concentrated, they become obstacles during concrete placement.
In addition, in the case of deformed reinforcing bars with a large diameter, crimping by a qualified person is required, and inspection after crimping is also required. Therefore, a large amount of labor is required, which increases the construction cost.

Here, for the safety of the building, in the places where the tensile stress generated in the reinforced concrete structure is large, the cross-sectional area of the structural members is partially increased to reduce the stress per unit area generated. is sometimes more effective.
However, in a reinforced concrete structure, it is difficult to partially increase the cross section of the structural steel material to suppress the stress in a portion where a large tensile stress is generated.
In addition, it is necessary to bend the ends (ends of the reinforcing bars) of the reinforcing bars in the reinforced concrete structure in order to cope with the pull-out force, which requires labor and cost.

JP 2006-104884 A JP 2011-190571 A Japanese Utility Model Laid-Open No. 07-001127 JP-A-05-318452

The present invention has been proposed in view of the above-described problems of the prior art, and enables the integration of structural members and concrete, making it easier to join (lengthen) the structural members. To provide a structural member capable of solving problems caused by jointing of structural members, easily increasing the cross-sectional area, and eliminating the need for bending for fixation at the ends.

The structural member of the present invention is composed of a plurality of structural members each having a rectangular cross-section and a long spiral shape (a shape obtained by twisting a long member with a rectangular cross-section). The pitch of the spiral in the long spiral is at least three times the maximum coarse aggregate of concrete, and the same cross-sectional shape and the pitch of the spiral is A plurality of the same structural members are superimposed so as to be in surface contact, and the superimposed regions are held by a holding member .
Here, the twisting direction of the spiral (the direction in which the long member is twisted) may be the same (twisting) direction, or the twisting direction may be reversed in the middle.

The structural member of the present invention may be made of metal, or may be made of resin or other materials as long as it has the tensile strength necessary for a structural member.
In particular, it is preferable to use a non-oxidizing (corrosive) material (so-called "new material") such as carbon fiber.

Further, in the method of joining structural members having a rectangular cross section and a long spiral shape according to the present invention, a plurality of structural members having the same cross section and the same spiral pitch are superimposed so as to be in surface contact. and holding (tightening) a holding member (for example, wire) at a predetermined position of the overlapped area.

The structural member of the present invention has a rectangular cross-section and a long helical shape. It is characterized in that it is engagable with a correction member that is to be fitted. In this case , it is preferable to use the correcting member so as to partially form a circular cross section.
Here, it is preferable that the axial length of the correction member is 1.5 to 2.0 times the long side of the cross section of the structural member.
Further, it is preferable that the axial ends (both ends or either end) of the correcting member have a sharp shape. This is to make it easier to insert the correction member into the gap between the structural member and the reinforcing bar (reinforcing bar, distributing bar, etc.).

The method for holding the structural member having a rectangular cross-section and a long helical shape (structural member according to claim 2) and the reinforcing bars is as follows:
When holding (for example, tightening) the structural member and a reinforcing bar having a curved surface (for example, in the form of a round bar) in combination (for example, orthogonally), the above Engaging the structural member with a compensating member (compensating member described in claim 2) whose cross-sectional shape is constituted by a part of the remaining portion after removing the cross section of the structural member,
A curved surface (including an arc) formed by engaging the structural member and the correcting member (having the same radius of curvature as the circumscribed circle) is held in contact with the curved surface of the reinforcing bar or the like ( For example, it is characterized by solidification).

According to the present invention having the above configuration, a reinforced concrete structural member is formed by continuously twisting a long member (for example, a steel bar) having a rectangular cross section into a long helical shape. When used as a concrete, the concrete follows the spiral into the recess of the spiral and integrates with the structural member.
As a result, the tensile stresses acting on the structural members within the concrete structure (members to which tensile forces are applied, such as rebars in reinforced concrete) are directly propagated to the cone-shaped concrete area around the spiral structural member. As a result, it is possible to resist the tensile force acting on the structural member.
In addition, the present invention has the advantage that since the joint surfaces are configured in a spiral shape, simple lashing will not displace (do not shift) even in the vertical direction.

Therefore, according to the present invention, the helical shape of the structural member not only increases the adhesive force between the concrete and the structural member, but also structurally integrates the structural member and the concrete, thereby constructing a concrete structure that is resistant to tensile force. can be done.
Further, according to the present invention, since the structural member and the concrete are integrated, the bending for fixation at the ends, which is necessary in the structural member according to the prior art, is unnecessary in the structural member of the present invention. Therefore, the process of bending the ends is not necessary, and the man-hours and labor are reduced accordingly.

In addition to that, it is possible to continuously twist a long member having a rectangular cross section, or to form a long spiral shape, even if it is a metal material, it can be used as a non-metal such as resin or carbon fiber. Even if it is a material, it can be easily performed by a conventionally known technique.
Therefore, the structural member of the present invention is very easy to manufacture.

According to the present invention, a plurality of structural members having the same cross-sectional shape and the same helical pitch are superimposed so as to be in surface contact, and a predetermined portion of the superimposed region is held by a holding member (for example, a wire). For example, the structural members are prevented from being separated from each other by tightening or simple lashing to prevent slippage, so that the structural members can be joined easily and reliably. Then, when the cast concrete hardens, the superimposed spirals are integrated and the joint maintains sufficient resistance against the tensile force acting on the structural member.
In addition, since it is possible to easily join, labor saving of joining (joint) can be achieved.

Alternatively, according to the present invention, a plurality of structural members having the same cross-sectional shape and the same helical pitch are superimposed so as to be in surface contact, thereby increasing the cross-sectional area of the structural member in the concrete structure. (For example, in a place where an increase in the cross-section of a reinforcing bar is required in reinforced concrete), if the structural members of the present invention are superimposed and held (for example, lashed) so that the required thickness dimension is obtained, the cross-sectional area of the structural member can be increased. It is possible to easily and reliably increase the cross-sectional area of the structural member at the location where the
As a result, the degree of freedom in designing the structure increases.

If the structural member according to the present invention is made of a non-metallic material, for example, a chemical fiber such as carbon fiber (so-called "new material"), the feature of the helical shape can be maximized.
For example, since chemical fibers do not rust, the problem of "rust" in reinforcing bars can be solved, making it possible to construct long-life reinforced concrete structures and save labor in maintenance of concrete structures.
Furthermore, it becomes possible to reduce the weight of the concrete structure. At the same time, in the case of bridges, for example, when the weight of the upper structure is reduced, the lower structure can be made smaller. Therefore, according to the present invention, the concrete structure can be made smaller.

Here, since the structural member of the present invention has a helical shape, for example, when it is intended to be held (for example, tightened) perpendicular to a round bar-shaped reinforcing bar (including stirrups, corrugated bars, ties, etc.). , if the edge of the spiral of the structural member of the present invention is not perpendicular to the tangent to the curved surface of the round bar (the normal to the edge of the spiral of the structural member and the curved surface of the reinforcing bar (round bar) If the normal line does not match), the structural member of the present invention cannot fix the reinforcing bar in a fixed position, and the relative position of the structural member and the reinforcing bar may be displaced during assembly. There is a possibility that it will slip.
On the other hand, in the present invention, a correcting member whose cross-sectional shape is formed by a part of the remaining portion obtained by removing the cross section of the structural member from the circumscribed circle (virtual circle) of the cross section of the structural member, and the structural member. When engaged (used in combination), the curved surface formed by engaging the structural member and the correcting member (having the same radius of curvature as the circumscribed circle) and the curved surface of the reinforcing bar can be brought into contact.
Therefore, the compensating material can be handled in exactly the same way as a conventional round structural material (deformed steel bar).

If such contact is made, even if the helical edge of the structural member is not perpendicular to the tangent to the curved surface of the reinforcing bar (round bar) (the normal to the helical edge of the structural member and the reinforcing bar) (Even if the normal line of the curved surface does not match), the relative position of the structural member and the reinforcing bar is prevented from being displaced (shifted), and the spiral structural member and the curved surface It is possible to hold (eg, knot) a reinforcing bar (eg, a round bar) having a
If the spiral-shaped structural member and the reinforcing bar having the curved surface can be held, it is ensured that the reinforcing bar is positioned as designed (the reinforcing bar is positioned as calculated). guaranteed).
In addition, since it is guaranteed that the reinforcing bar is placed at the calculated position, by pre-holding the correcting member on the structural member, the held correcting member can be used as a mark (position) when installing the reinforcing bar. It can be used as a mark for delivery).

1 is a front view of a structural member according to an embodiment of the invention; FIG. 2 is a cross-sectional view of the structural member of FIG. 1 taken along the line XX. FIG. Fig. 3 is a perspective view showing a state in which the structural members shown in Figs. 1 and 2 are spliced; FIG. 5 is an explanatory diagram schematically showing a state in which the structural member according to the embodiment is combined with reinforcing bars without using a correcting member; FIG. 4 is an explanatory view showing a state in which the correcting member is engaged with both surfaces of the structural member, and shows a state in which the engaged structural member and the correcting member have circular cross sections. It is explanatory drawing which shows the state which engaged the correction member with the structural member in the cross section of a correction member and a structural member. FIG. 10 is a diagram showing a correction member; FIG. 5 is an explanatory view schematically showing a state in which the structural member according to the embodiment is engaged with the correcting member and combined with reinforcing bars and the like. FIG. 10 is a cross-sectional view for explaining a proper holding method when holding an auxiliary reinforcement or the like to a structural member. FIG. 10 is a cross-sectional view for explaining an improper holding method when holding the auxiliary reinforcement or the like to the structural member. FIG. 4 is a cross-sectional view for explaining the reason why the correcting member is useful for properly holding auxiliary bars and the like on the structural member.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
In FIG. 1, the structural member 10 is constructed by twisting an elongated strip of material over its entire length into a helical shape.
In the figure, the symbol "SP" indicates the dimension of one pitch of the spiral. The spiral pitch SP is preferably at least 3 to 5 times the maximum coarse aggregate of concrete.

In FIG. 2 showing the cross section of the structural member 10, the structural member 10 has a substantially rectangular cross-sectional shape (in the illustrated example, the central portion of the circular cross section is left and both sides are scraped off: see FIG. 6), The aspect ratio (W:D) of the cross-sectional shape is preferably 1:3 to 1:5. However, the aspect ratio (W:D) is changed depending on the structure to be used, taking into account various parameters such as the external force acting on the structure, the required geometrical moment of inertia and cross-sectional area, and the workability of the structure. can do
In structural calculations, the position of the center of the cross section of the structural member 10 having the cross section shown in FIG. 2 is slightly different from that of the round steel having the same area.
In FIG. 2, reference numeral 11 indicates the edge (or short side) of the structural member 10, reference numeral 12 indicates the long side portion, and reference CR indicates the arc of the circular cross section, that is, the circumscribed circle containing the structural member 10. It is indicated by a phantom line. Here, in the cross section of the structural member 10 shown in FIG. 2, the curved portion may be removed to form a rectangular cross section.

The helical structural member 10 is preferably made of a new material such as carbon fiber that will not rust. This is because the weight of the structural member is reduced. In addition, there is no fear of breakage due to rusting, which makes it possible to improve the economic efficiency of maintenance and management and extend the life of the concrete structure.
However, when carbon fiber or the like is used, it is difficult to perform on-site processing, so various processing must be performed in advance at the manufacturing plant.

The helical structural member 10 does not require any special requirements for use and can be used in the same manner as conventional rebar structural members.
A structural member 10 in which a long member (for example, a steel member) having a rectangular cross section is continuously twisted to form a long spiral shape is formed into a reinforced concrete structural member (a member that bears a tensile force like a reinforcing bar). , the concrete enters the recessed portion of the spiral along the spiral, the adhesive force between the concrete and the structural member 10 increases, and the concrete and the structural member 10 are integrated.
As a result, the tensile stress acting on the structural member 10 in the concrete structure is widely propagated to the entire concrete region (the cone-shaped concrete region) around the structural member 10 to resist the tensile force.

Therefore, the helical shape of the structural member 10 increases the adhesive force between the concrete and the structural member 10, and the structural member 10 and the concrete are structurally integrated, so that a strong concrete structure can be constructed.
Further, according to the illustrated embodiment, since the structural member 10 and the concrete are integrated, the fixing bending at the ends, which is required in the conventional structural members, is not required. Therefore, the process of bending the ends becomes unnecessary, and labor is reduced accordingly.

In the illustrated embodiment, joining the structural members 10, 10 together will be described with reference to FIG.
In FIG. 3, two structural members 10, 10 superimposed so as to be in surface contact have the same cross-sectional shape and the same helical pitch. If the two structural members 10, 10 are superimposed so as to be in surface contact, and a predetermined portion of the superimposed region is lashed with, for example, a wire (not shown in FIG. 3: holding member), the structural member 10 , 10 can be joined easily and reliably. In addition, labor saving in joining (joint) between structural members can be achieved.
Note that FIG. 3 shows the state immediately before the two structural members 10, 10 are brought into surface contact for ease of visual recognition and understanding, and the interval between the two structural members 10, 10 is indicated by symbol δ. It is When the two structural members 10, 10 are in surface contact, the distance δ becomes zero (0 mm).

As shown in FIG. 3, if a plurality of structural members 10, 10 having the same cross-sectional shape and the same helical pitch are superimposed so as to be in surface contact, the superimposed plurality of structural members 10 . . . The thickness dimension can be adjusted as appropriate.
For example, in a concrete structure where the cross-sectional area of a structural member needs to be increased (for example, in a reinforced concrete where the cross-sectional area of a reinforcing bar needs to be increased), if the structural members 10 are overlapped and lashed with a wire or the like (not shown), A required cross-sectional area or geometric moment of inertia can be easily and reliably secured. Therefore, the degree of freedom in designing the structure increases.

The use of a helical structural member 10 according to the illustrated embodiment in combination with reinforcing bars (stirrups, corbels, etc.) 20 is shown, for example, in FIG.
Since the structural member 10 has a helical shape, for example, when trying to hold (for example, tighten) a round bar-shaped reinforcing bar (including stirrups, corbels, ties, etc.) perpendicular to the reinforcing bar 20, etc. As shown in , if the spiral edge 11 of the structural member 10 is perpendicular to the curved surface of the round bar 20, the structural member 10 can fix the reinforcing bar 20 in place.
In other words, as shown in FIG. 9, if the normal line L10n of the spiral edge 11 of the structural member 10 and the normal line L20n of the curved surface of the reinforcing bar (round bar) 20 match, the structural member 10 can fix the reinforcing bar 20 in place. Alternatively, if the normal L10n of the spiral edge portion 11 of the structural member 10 and the tangent L20t of the curved surface of the reinforcing bar 20 are perpendicular to each other, the structural member 10 and the reinforcing bar 20 are fixed so as not to move relative to each other. can do

However, as shown in FIG. 10, if the helical edge 11 of the structural member 10 is not orthogonal to the curved surface of the round bar 20, it is difficult to fix the reinforcing bars 20 in place. be.
In other words, if the normal L10n of the spiral edge portion 11 of the structural member 10 and the normal L20n of the curved surface of the reinforcing bar (round bar) 20 do not match, the structural member 10 cannot define the reinforcing bar 20. It is difficult to fix in place. Alternatively, if the normal L10n of the spiral edge portion 11 of the structural member 10 and the tangent line L20t of the curved surface of the reinforcing bar 20 are not orthogonal, the structural member 10 and the reinforcing bar 20 are fixed so as not to move relative to each other. It is difficult to
If it is difficult for the structural member 10 to fix the reinforcing bar 20 at a fixed position, the relative positions of the structural member 10 and the reinforcing bar 20 will be displaced (shifted) during the construction of the structure. there is a possibility.

In contrast, in the illustrated embodiment, as shown in FIG. 11, the reinforcing bar 20 can be fixed in a desired fixed position relative to the structural member 10 by combining a compensating member 30 (see, for example, FIG. 7). is.
When the correcting member 30 is used, the curved surface 30cf formed by engaging the structural member 10 and the correcting member 30 (circular arc of the circumscribed circle indicated by symbol CR in FIG. 2) and the curved surface 20cf of the reinforcing bar 20 are brought into contact with each other, the curved surface 30cf and the curved surface 20cf of the reinforcing bar 20 are securely fixed.

Such a correction member 30 is shown in FIGS. 5-7.
5 showing the state in which the compensating member 30 is engaged with the structural member 10, the axial length L3 of the compensating member 30 is 1.5 to 2.5 times the long side 12 of the cross section of the structural member 10 (see FIG. 2). .0 times. However, the length L3 can be changed as appropriate.
Although accurate illustration is omitted, the axial ends (both ends or either end) of the correction member 30 preferably have a sharp shape. This is for making it easier to insert the correction member 30 into the gap between the structural member 10 and the reinforcing bar 30 .

As shown in FIG. 6, the correction member 30 is formed by removing the structural member 10 from the circumscribed circle CR (virtual circle: see FIG. 2) of the cross section of the structural member 10 (two locations: hatched upward to the right in FIG. 6). area shown attached).
Here, the correcting member 30 can be constituted by, for example, a part of any one of remaining portions obtained by removing the structural member 10 from the circumscribed circle CR of the cross section of the structural member 10 .
Alternatively, the correcting member 30 can be configured by two remaining portions hatched upward to the right in FIG. 6 . In other words, the compensating member 30 is constituted by not only a portion of the remaining portion but also the entire remaining portion (two locations) (see FIG. 5), and the portions where the structural member 10 and the two compensating members 30 are engaged are arranged. It is also possible to make the cross-sectional shape of .

As shown in FIGS. 8 and 11, when the correcting member 30 and the structural member 10 are engaged (used in combination), the curved surface 30cf formed by engaging the structural member 10 and the correcting member 30 ( A curved surface with the same radius of curvature as the circumscribed circle CR (or a cylindrical side surface of a circle with the same radius of curvature as the circumscribed circle CR) is brought into contact with the curved surface 20cf of the reinforcing bar 20 to displace the relative position of the two. It can be fixed without That is, as shown in FIG. 11, the concave curved surface (curved surface 20cf of the reinforcing bar 20) and the convex curved surface (curved surface 30cf formed by engaging the structural member 10 and the correcting member 30) are brought into contact with each other. In this case, the structural member 10 and the reinforcing bar 20 can be held (for example, firmly connected) without being displaced (displaced) in relative position.
If the relative positions of the structural member 10 and the reinforcing bars 20 are maintained (for example, firmly connected) without being displaced (displaced), it is ensured that the reinforcing bars 20 are arranged at the positions as designed, and the positions are calculated as expected. It ensures that the reinforcing bars are positioned.
Here, if the correction member 30 is held in the structural member 10 in advance, the held correction member 30 functions as a mark (a mark for positioning) when attaching the reinforcing bar 20 .

Although illustration is omitted, in the structural member 10 according to the illustrated embodiment, the member whose main purpose is to hold the position of the structural member 10 by the reinforcing bar 20 is made of a new material in which the structural member 10 is shaped like a tape. is also possible. Alternatively, it is conceivable to configure the structural member 10 according to the illustrated embodiment from a composite material of reinforcing bars and new materials.
The structural member 10 according to the illustrated embodiment is effective in reinforcing the periphery of an opening (not shown) of a concrete structure. Alternatively, it is effective to configure the structural member 10 according to the illustrated embodiment as a very long member (not shown) and use it to construct a cylindrical structure.

In the illustrated embodiment, the structural member 10 is formed by continuously twisting an elongated member (for example, steel) having a rectangular cross section to form an elongated helical shape. Also, even non-metallic materials such as resins and carbon fibers can be easily processed by conventionally known techniques.
Therefore, manufacturing of the structural member 10 is easy.

According to the illustrated embodiment, a plurality of structural members 10 having the same cross-sectional shape and the same helical pitch are superimposed so as to be in surface contact, and a predetermined portion of the superimposed region is held by a holding member (for example, a grid line). The structural members 10 can be easily and reliably joined to each other by holding (for example, tightening or simple lashing to prevent slippage) with .
And since it can be joined easily, labor saving of joining (joint) can be achieved.

If the structural member 10 according to the illustrated embodiment is made of a nonmetallic material, for example, a chemical fiber such as carbon fiber (so-called "new material"), the feature of the helical shape can be maximized.
Since chemical fibers do not rust, the problem of "rust" in reinforcing bars can be solved, construction of long-life reinforced concrete structures becomes possible, and maintenance and management of concrete structures can be labor-saving.
Furthermore, it becomes possible to reduce the weight of the structure.

It should be noted that the illustrated embodiment is merely an example and is not intended to limit the technical scope of the present invention.

10... Structural member 11... Edge (short side)
12 Long side portion 20 Reinforcement bar 30 Correction member

Claims (4)

Composed of a plurality of structural members having a rectangular cross section and a long spiral shape,
When used as a structural member of reinforced concrete, the pitch of the spiral in the long spiral is at least three times the maximum coarse aggregate of concrete so that the concrete will follow the spiral and enter the concave portion of the spiral and be integrated with the structural member. ,
A structural member comprising: a plurality of structural members having the same cross-sectional shape and the same helical pitch are superimposed so as to be in surface contact with each other, and the superimposed region is held by a holding member. Engageable with a compensating member whose cross-sectional shape is constituted by a part of the remaining portion obtained by removing the cross-section of the structural member from the circumscribed circle of the cross-section of the structural member that has a rectangular cross-section and is configured in a long spiral shape. A structural member characterized by In a method for joining structural members having a rectangular cross section and a long spiral shape ,
superimposing a plurality of structural members having the same cross-sectional shape and the same helical pitch so as to be in surface contact;
A joining method comprising holding a predetermined portion of the overlapped region with a holding member. In a method for holding a structural member having a long spiral shape with a rectangular cross section and a reinforcing bar,
A correction member having a cross-sectional shape formed by a part of a remaining portion obtained by removing the cross section of the structural member from a circumscribed circle of the cross section of the structural member when holding the structural member and the reinforcing bar having a curved surface. engaging the member;
A holding method comprising contacting and holding a curved surface formed by engaging the structural member and the correcting member with a curved surface of the reinforcing bar.

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