JP2984054B2 - High strength fiber reinforcement - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION << Industrial application >> The present invention relates to a high-strength fiber reinforcing material for reinforcing concrete, and is particularly excellent in construction workability such as transportation to a site and installation at a site. Also, the present invention relates to a high-strength fiber reinforcing material exhibiting a sufficient shape maintaining function.

<< Prior Art >> At present, a spiral bar formed of a steel rod in a spiral shape is widely used as a shear reinforcing bar for a reinforced concrete column or a reinforced concrete beam. The spiral streaks can be contracted like a coil spring by applying a required compressive load, so that the handling is convenient when the spiral streaks are carried in or built into a construction site.

However, at the time of construction at the site, the stretching work when stretching the contracted spiral muscle at the site,
Considering the on-site workability such as tying work with the main bar, it is not appropriate to apply a long bar with a large weight of the spiral bar itself or a spiral bar using a large-diameter steel rod that has a large restoring force after stretching. It was difficult because a stretching load was required.

In order to solve the problems of such reinforcing bars, fiber reinforced plastics (hereinafter, referred to as FRP) obtained by impregnating and curing high-strength fibers, such as carbon fibers and aramid fibers, with an epoxy resin have recently been remarkably developed. Various uses have been studied for use as an alternative reinforcing material for reinforcing bars. (For example, various application trials have been reported in the summary of academic lectures of the Architectural Institute of Japan, September 1983, or in the Nikkei Architecture December 1, 1986 issue.) Compared to the rebar, it has several times more tensile strength, so in FRP reinforcement having the same tensile strength as rebar,
The diameter of the reinforcing bar can be greatly reduced as compared with the reinforcing bar. Therefore, the rigidity of the spiral muscle formed using such FRP, that is, the spring constant when this spiral muscle is regarded as a spring, can be reduced in comparison with the case of the spiral muscle using a reinforcing bar. Therefore, it is possible to simplify the on-site stretching work and the tying work with the main bar.

In addition, since the specific gravity of FRP is about 1/5 of that of steel, it is possible to manufacture reinforcing bars for long objects, which were difficult with steel bars, and to easily install them.

In addition, FRP reinforcement has excellent durability and does not suffer from deterioration due to carbonation of concrete unlike rebar, so it is possible to reduce the cover thickness of concrete compared to rebar, reducing the cross section of members and accompanying members Can also be reduced in weight.

<< Problems to be Solved by the Invention >> However, in the spiral reinforcement as the shear reinforcement formed by such FRP, as described above, its rigidity is smaller than that of the spiral reinforcement using a reinforcing bar. Therefore, there is a problem that it is difficult to maintain a predetermined shape at the time of installation at the site.

The present invention has been made in view of such circumstances, and an object of the present invention is to improve transportability to a site, construction workability at the time of erection at a site, and to maintain excellent shape in addition to this. An object of the present invention is to provide a high-strength fiber reinforcing material exhibiting a function.

<< Means for Solving the Problems >> In order to achieve the above object, the invention of claim 1 impregnates and cures a high-strength fiber such as a carbon fiber or an aramid fiber with a synthetic resin such as an epoxy resin to form a spiral shape. In a high-strength fiber reinforcing material having a formed shear reinforcement, the shear reinforcement is disposed and fixed so as to intersect with the shear reinforcement at a predetermined angle θ on a spiral curved surface formed by the reinforcement. Characterized in that the shape-retaining muscle is elastically deformed when an external force is applied to the shear reinforcement, and when the external force that has been elastically deformed is removed, the shape-retaining muscle attempts to return to the shape before the elastic deformation. And

The invention according to claim 2 is directed to a high-strength fiber reinforcing material having a shear reinforcing bar formed by impregnating and curing a high-strength fiber such as a carbon fiber or an aramid fiber with a synthetic resin such as an epoxy resin to form a spiral shape. , For the shear reinforcement
A shape maintaining muscle is provided and fixed so as to intersect with the shear reinforcement on a spiral curved surface formed by the spiral reinforcement and along the axial direction of the spiral, and the shape retaining muscle applies an external force to the shear reinforcement. It is characterized in that it is elastically deformed and, when the external force that has been elastically deformed is removed, it tries to return to the shape before the elastic deformation.

Further, the invention according to claim 3 is directed to a high-strength fiber reinforcing material having a shear reinforcing bar formed by impregnating and curing a high-strength fiber such as a carbon fiber or an aramid fiber with a synthetic resin such as an epoxy resin to form a spiral shape. , For the shear reinforcement
A shape retaining streak is provided and fixed so as to extend in a radial direction of the spiral so as to extend into a space surrounded by the spiral formed by the spiral, and the shape retaining streak applies an external force to the shear reinforcement. It is characterized in that it is elastically deformed and, when the external force that has been elastically deformed is removed, it tries to return to the shape before the elastic deformation.

In addition, a shape memory alloy wire was employed as the shape retention wire.

<Operation> The operation of the present invention is described below. A high-strength fiber having a shear reinforcing bar formed by impregnating and curing a high-strength fiber such as a carbon fiber or an aramid fiber with a synthetic resin such as an epoxy resin to form a spiral shape. In the fiber reinforcement, the shear reinforcement crosses the shear reinforcement at a predetermined angle θ on the spiral curved surface formed by the shear reinforcement or intersects the shear reinforcement along the spiral curved surface and along the axial direction of the spiral. When carrying, for example, a shape-retaining bar fixed and fixed so as to extend in the radial direction of the spiral so as to extend into the space surrounded by the spiral, the shear reinforcing bar is compressed and contracted. When folded, the shape-retaining streaks arranged and fixed in the spiral are elastically deformed. Therefore, the shear reinforcement can be carried into the site in a folded state, and can be easily carried in large quantities.

Also, when building at the site, if the external force that had shrunk the shear reinforcement was removed, the above-mentioned shape-retaining muscle would try to return to its shape before elastic deformation. In addition, a large load is not required for the on-site stretching operation, and not only the workability on-site can be improved, but also the spiral shear reinforcement can be maintained in a predetermined shape.

In particular, in the invention of claim 1 or 2, the shape-retaining muscle is arranged and fixed to the shear reinforcement on the spiral curved surface, so that the shape-retaining muscle exists in the space surrounded by the spiral. Therefore, at the time of building, it is possible to prevent the main reinforcing bars arranged inside the shear reinforcing bars from interfering with the shape-retaining bars, and to carry out the construction smoothly.

On the other hand, according to the third aspect of the present invention, the shape-retaining bars are arranged and fixed to the shear reinforcing bars so as to extend in the radial direction of the spirals so as to extend into the space surrounded by the spirals. By removing the external compressive force, the shape-retaining muscle is stretched so as to expand the shear reinforcement in the radial direction of the spiral, and exhibits a sufficient shape-maintaining function.

In addition, if a shape memory alloy wire is adopted as the above-mentioned shape retaining wire, the shear reinforcing bar carried to the site in a compressed and contracted state is simply heated to a predetermined temperature, and the shape memory alloy wire is in a shape before the contraction. Therefore, it is possible to greatly simplify the work of stretching the shear reinforcing bars on site.

<< Embodiment >> A preferred embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a perspective view showing the high-strength fiber reinforcing material of the first embodiment, FIG. 2 is a side view showing the shape of the high-strength fiber reinforcing material of the second embodiment when it is installed, and FIG. FIG. 4 is a side view showing a state in which the high-strength fiber reinforcement is contracted when being transported, carried in, or the like to the site, and FIG. 4 is a side view showing a shape of the third embodiment when the high-strength fiber reinforcement is erected. is there.

The high-strength fiber reinforcement 1 is composed of a shear reinforcement 2 formed in a spiral shape by impregnating and hardening a long-strength high-strength fiber with a resin, and a shape-retaining streak 3 that is a flexible wire or the like. Have been. Here, the term "wire or the like" includes not only a linear material but also a thin flat material such as a tape, a ribbon, and a band.

As the high-strength fiber used for the shear reinforcement 2, fiber materials such as carbon fiber and aramid fiber having excellent durability are suitable. Further, as a resin for impregnating and curing these high-strength fibers, an epoxy resin is generally employed.

As the shape-retaining streaks 3, a material that elastically deforms, such as a normal steel wire, is used. Further, other than the linear material, a thin flat material such as a tape, a ribbon, and a band may be employed. The material, wire diameter, thickness, width, and the like may be appropriately determined according to the rigidity of the spiral formed by the shear reinforcement 2 to be applied. Alternatively, a material that restores the shape before deformation under a specific temperature condition, such as a shape memory alloy wire, may be used.

In FIG. 1 showing a first embodiment of the present invention,
The shape maintaining muscle 3 is disposed so as to intersect with the shear reinforcement 2 at a predetermined angle θ on the spiral curved surface formed by the shear reinforcement 2, and in this embodiment,
At each point 4 intersecting with the shear reinforcement 2, the shear reinforcement 2
It is stuck to. In addition, the angle θ formed by the shape maintaining muscle 3 and a plane orthogonal to the central axis of the spiral formed by the shear reinforcement 2 may be determined according to the rigidity of the spiral. In the present embodiment, the angle θ is set to 30 °.

In the present embodiment, on the spiral curved surface, the shape maintaining muscle 3 is arranged and fixed to the shear reinforcement 2, so that the shape maintaining muscle 3 does not exist in the space surrounded by the spiral. In addition, at the time of building, it is possible to prevent the main reinforcing bars arranged inside the shear reinforcing bars 2 from interfering with the shape-retaining bars 3 and to carry out the construction smoothly.

In FIG. 2 showing a second embodiment of the present invention,
The shape-retaining muscles 3 are arranged so as to extend in the radial direction of the spiral so as to extend into the space surrounded by the spiral formed by the shear reinforcing muscles 2. At a fixed point 4, it is fixed to the shear reinforcement 2. In addition, the angle θ formed by the shape maintaining muscle 3 with a plane orthogonal to the central axis of the spiral formed by the shear reinforcement 2 may be considered in the same manner as in the first embodiment.

In the present embodiment, the shape-retaining bars 3 are arranged and fixed to the shear reinforcing bars 2 so as to extend in the radial direction of the spirals so as to extend into the space surrounded by the spirals. Shape retention muscle 3 by removing
Are stretched so as to expand the shear reinforcement 2 in the radial direction of the spiral, and exhibit a sufficient shape maintaining function.

For this shape maintenance, the conventional FRP shear reinforcement,
When applied to the production of a concrete member by a centrifugal molding method or the like, it is difficult to maintain its shape in a mold for centrifugal molding, and it is difficult to preferably apply it to such a molding method as it is. . However, in the high-strength fiber reinforcing material 1 of the present embodiment, the shape-retaining streaks 3 arranged so as to extend in the spiral space in the radial direction of the spiral impart “tension” to the shear reinforcing streaks 2. Therefore, the shape can be appropriately maintained.

In FIG. 4 showing a third embodiment of the present invention,
The shape-retaining muscles 3 are disposed on the shear reinforcement 2 so as to intersect the shear reinforcement 2 on a spiral curved surface formed by the shear reinforcement 2 and along the axial direction of the spiral. At four fixing points 4, they are fixed to the shear reinforcement 2.

In the present embodiment, the shape-retaining bars 3 are arranged and fixed to the shear reinforcing bars 2 on the spiral curved surface, so that the shape is formed in the space surrounded by the spiral as in the first embodiment. There is no holding muscle 3,
At the time of erection, it is possible to prevent the main reinforcing bars arranged inside the shear reinforcing bars 2 from interfering with the shape-retaining bars 3 and to carry out the construction smoothly.

Next, the operation of the present embodiment will be described. In any of the embodiments, a high-strength fiber such as a carbon fiber or an aramid fiber is impregnated with a synthetic resin such as an epoxy resin and cured to form a spiral shear. The reinforcement 2 intersects the shear reinforcement 2 at a predetermined angle θ on the spiral curved surface formed by the reinforcement, or intersects the shear reinforcement 2 on the spiral curved surface and along the axial direction of the spiral. Or a shape retaining streak 3 formed of a flexible wire or the like is provided so as to extend in the radial direction of the spiral so as to extend into the space surrounded by the spiral,
Since the high-strength fiber reinforced material 1 was configured by being fixed to the shear reinforcing bar 2 at each fixing point 4, as shown in FIG. When a compressive external force F is applied to the elastic member to cause contraction, the shape retaining muscle 3 fixed to the shear reinforcement 2 is elastically deformed while being twisted or out of plane. Therefore, the high-strength fiber reinforcement 1 can be carried into the site by folding it in a compressed and contracted state,
It can be easily carried in large quantities.

Also, when building at the site, when the compressed external force F is removed after the contracted high-strength fiber reinforcing material 1 is carried into the site, the shape retaining streaks 3 try to restore to the shape before deformation. Unlike a spiral bar using a conventional reinforcing bar, it does not require an on-site stretched large load, not only can improve workability at the site, but also maintain the high-strength fiber reinforcing material 1 in a predetermined shape. can do.

In addition, the rigidity of the above-mentioned shape-retaining muscle 3 and the shape-retaining muscle 3
However, by appropriately selecting the angle θ between the plane perpendicular to the central axis of the spiral formed by the shear reinforcement 2 and the method of setting the fixed point 4, the spring when the shape maintaining muscle 3 is regarded as a spring is selected. Since various constants can be set, the compression of the spiral formed by the shear reinforcing bars 2 can be reduced by selecting an appropriate material for the shape-retaining bars 3 and the arrangement of the spirals formed by the shear reinforcing bars 2 with respect to the rigidity of the spiral formed by the shear reinforcing bars 2. By simply removing the external force F, the high-strength fiber reinforcement 1 can be restored to a predetermined shape.

Also, if a shape memory alloy wire is adopted as the shape retaining wire 3, a predetermined external compressive force F is applied to the high-strength fiber reinforcing material 1 to shrink, transported and carried to the site, and then heated to a predetermined temperature. Since the shape retaining muscles 3 are restored to the shapes before the contraction deformation, the on-site stretching operation can be greatly simplified.

<< Effects >> As described above in detail in the embodiments, the present invention exerts the following excellent effects.

(1) A high-strength fiber such as a carbon fiber or an aramid fiber is impregnated with a synthetic resin such as an epoxy resin and cured to form a spiral, thereby forming a shear reinforcing bar.
A space surrounded by the spiral so as to intersect with the shear reinforcement at a predetermined angle θ on the spiral curved surface formed by the spiral curved surface and along the axial direction of the spiral on the spiral curved surface. Since it has a shape-retaining streak arranged and fixed so as to extend in the radial direction of the spiral so as to extend into the inside, it is possible to carry this shearing reinforcement into the site in a folded state, and easily carry in a large amount. In addition to the above, when building at the site, since only the external force that has shrunk the shear reinforcement is removed, the above-mentioned flexible shape retaining muscle attempts to return to the shape before elastic deformation, The high-strength fiber reinforcement automatically elongates to a predetermined length, and does not require a large load for on-site stretching work like a conventional spiral bar using steel bars. Not only can improve the work and capable of maintaining the spiral shear reinforcement in a predetermined shape.

(2) Since the shape memory alloy wire is used as the shape retaining streaks, the high-strength fiber reinforced material contracted during transportation or the like is simply heated to a predetermined temperature at the site, and the high-strength fiber reinforced material has a predetermined shape. And the shape can be maintained.

[Brief description of the drawings]

FIG. 1 is a perspective view showing the high-strength fiber reinforcing material of the first embodiment, FIG. 2 is a side view showing the shape of the high-strength fiber reinforcing material of the second embodiment when it is installed, and FIG. FIG. 4 is a side view showing a state in which the high-strength fiber reinforcement is contracted when being transported, carried in, or the like to the site, and FIG. 4 is a side view showing a shape of the third embodiment when the high-strength fiber reinforcement is erected. is there. 1 ... high-strength fiber reinforcement material 2 ... shear reinforcement 3 ... shape retention muscle 4 ... shape retention muscle fixing point θ ... shape retention muscle arrangement angle

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Noriyuki Furuya 4-640 Shimoseito, Kiyose-shi, Tokyo Co., Ltd. Inside Obayashi Corporation Technical Research Institute (72) Inventor Kozo Kimura 4-640 Shimoseito, Kiyose-shi, Tokyo Co., Ltd. Obayashi Technical Research Institute (56) References JP-A-63-189546 (JP, A) JP-A-63-162024 (JP, U) JP-A-63-120117 (JP, U) (58) Fields investigated (Int) .Cl. ⁶ , DB name) E04C 5/00-5/20

Claims (4)

(57) [Claims] 1. A high-strength fiber reinforcing material having a shear reinforcing bar formed by impregnating and curing a high-strength fiber such as a carbon fiber or an aramid fiber with a synthetic resin such as an epoxy resin to form a spiral shape. The reinforcing bars are provided with shape-retaining muscles arranged and fixed so as to intersect with the shear reinforcing bars at a predetermined angle θ on a spiral curved surface formed by the reinforcing bars, and the shape-retaining bars apply an external force to the shear reinforcing bars. A high-strength fiber reinforcing material characterized in that it is elastically deformed when applied, and then tries to return to its shape before elastic deformation when the external force that caused the elastic deformation is removed. 2. A high-strength fiber reinforcing material having a shear reinforcing bar formed by impregnating and curing a high-strength fiber such as a carbon fiber or an aramid fiber with a synthetic resin such as an epoxy resin to form a spiral shape. A reinforcing member provided on the spiral curved surface formed by the reinforcing reinforcement so as to intersect with the shear reinforcing bar along the axial direction of the spiral; A high-strength fiber reinforcing material characterized in that it is elastically deformed when an external force is applied to a muscle, and then tries to return to a shape before the elastic deformation when the elastically deformed external force is removed. 3. A high-strength fiber reinforcing material having a shear reinforcing bar formed by impregnating and curing a high-strength fiber such as a carbon fiber or an aramid fiber with a synthetic resin such as an epoxy resin to form a spiral shape. The reinforcing bars are provided with shape retaining bars fixedly disposed so as to extend in a radial direction of the spiral so as to extend into a space surrounded by a spiral formed by the reinforcing bars, and the shape retaining bars are provided with the shear reinforcement. A high-strength fiber reinforcing material characterized in that it is elastically deformed when an external force is applied to a muscle, and then tries to return to a shape before the elastic deformation when the elastically deformed external force is removed. 4. The high-strength fiber reinforcing material according to claim 1, wherein said shape-retaining streaks are shape memory alloy wires.