JPH01121450A - Concrete reinforcing member - Google Patents

Abstract

PURPOSE: To provide a concrete reinforcing member capable of improving shearing bearing force by suppressing the generation of local bending stress at the steep bend parts of shearing reinforcing bars. CONSTITUTION: This concrete reinforcing member is composed of at least six frame reinforcements 2 three-dimensionally disposed parallel at specified spaces to one another, and a plurality of shearing reinforcing bars 3 disposed intersecting at a right angle to the respective frame reinforcements 2. The frame reinforcements 2 and shearing reinforcing bars 3 are formed by solidifying a fiber bundle formed of a plurality of continuous fibers bound with resin material. The frame reinforcements 2 are integrally fitted to the shearing reinforcing bars 3 so as to hold both sides of corner parts of the shearing reinforcing bars 3.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a concrete reinforcing member suitable for use as a substitute for reinforcing reinforcing bars etc. buried in various concrete structures.

“Conventional technology” So-called fiber reinforced plastics (hereinafter simply “FRPJ”)
) has the characteristics of being lightweight, having high specific strength, excellent corrosion resistance, good moldability, and a high degree of freedom in shape, and is used in various structural materials. In recent years, taking advantage of the above characteristics, various applications of concrete reinforcing members made by assembling bar-shaped FRP members in the same way as reinforcing bars have been studied as an alternative to reinforcing reinforcing bars buried in various concrete structures. . Such concrete reinforcing members include, for example, a plurality of FRP shaft reinforcements extending in the axial direction of the concrete structure to be constructed, and FRP shear reinforcing bars disposed to intersect with these shaft reinforcements. are integrally molded. Therefore, with this concrete reinforcing member, quality control is easy due to integral molding in the factory, transport and construction work is extremely simplified due to its light weight, and there is no need to take anti-corrosion and rust prevention measures. , etc. can be obtained.

"Problems to be Solved by the Invention" However, the above-mentioned concrete reinforcing members still have the following problems to be considered.

That is, since the shear reinforcing bars are bent at a sharp angle at the intersection with the axial bars, the shear reinforcing bars are bent by applying shear force to the concrete structure in which the concrete reinforcing members are buried. When an axial tensile force is applied to the axial muscle, bending stress is locally generated at the intersection with the axial muscle (that is, the sharp bend). Therefore, the rupture of the shear reinforcing bars at this axial reinforcement intersection becomes sequentially destructive, and the yield strength is much lower than that obtained at all locations.In other words, a decrease in the shear strength of the concrete structure is unavoidable. It was there.

This invention was made in view of the above circumstances, and aims to provide a concrete reinforcing member that can improve shear strength by suppressing the generation of local bending stress at sharp bends of shear reinforcing bars.

"Means for Solving the Problems" In order to solve the above-mentioned problems, the present invention provides a method for constructing a concrete reinforcing member that is buried in concrete and structurally reinforcing the concrete. At least six axial reinforcements arranged three-dimensionally at intervals from each other; and a shear reinforcement reinforcement arranged in an annular shape having at least three corner portions when viewed from the side and intersecting with these axial reinforcements. The axial reinforcement and shear reinforcing reinforcement are molded from continuous fibers hardened with a resin material, and the axial reinforcement is integrated with the shear reinforcement so as to sandwich both sides of the corner portion of the shear reinforcement. It is characterized by being attached to.

"Function" In this invention, when configuring a concrete reinforcing member that is buried in concrete and structurally reinforces the concrete, shaft reinforcements arranged three-dimensionally at intervals are arranged in an annular shape when viewed from the side. Since it is integrally attached to the formed shear reinforcement so as to sandwich both sides of the corner portion of the shear reinforcement, the shear reinforcement can be firmly attached to the concrete in the axial direction via the axial reinforcement.

That is, in this invention, the axial reinforcement has both the functions of reinforcing the concrete in the axial direction and fixing the shear reinforcement to the concrete. At the same time, since no axial reinforcement is provided at the corner portion of the shear reinforcing bar, this corner portion can be bent at an arbitrary bending radius.

"Embodiments" Hereinafter, embodiments of the present invention will be described with reference to the drawings.

1 and 2 are diagrams showing a concrete reinforcing member (hereinafter simply referred to as reinforcing member) which is a first embodiment of the present invention. This figure shows an example in which the present invention is applied to a rectangular prism-shaped reinforcing member that is preferably embedded in a rectangular column. In these figures, this reinforcing member, which is indicated by the symbol l as a whole, has eight axial reinforcements 2 that are three-dimensionally arranged in parallel with each other at predetermined intervals, and each of these axial reinforcements 2 has an intersection C1. It is generally composed of a plurality of shear reinforcing bars 3 arranged to intersect with each other at substantially right angles. The shear reinforcing bars 3 are arranged at predetermined intervals in the axial direction of the shaft bar 2.

More specifically, the shear reinforcement 3 is formed into a square annular member having four corner portions 4 bent at approximately right angles when viewed from the side, and the axial reinforcement 2 is These corner portions 4 are integrally attached to both sides. Therefore, these eight axial reinforcements 2 include four axial reinforcements 2a located on the top or bottom surface of the beam in the erected state, and four axial reinforcements 2a located on the side surface of the beam in the erected state. 2
It is distinguished into b.

As shown in FIGS. 3 and 4, these axial reinforcements 2 and shear reinforcing reinforcements 3 are made of a fiber bundle T made up of a plurality of continuous fibers 11 bound with a resin material 10. The structure is made by solidifying and molding. More specifically, fiber bundles T made up of a plurality of aligned continuous fibers 11 are arranged three-dimensionally to constitute the axial muscle 2, and the fiber bundles T constituting the axial muscle 2 are By crossing another fiber bundle T, a shear reinforcing bar 3 that crosses the axial bar 2 at the intersection Ct is constructed, and each continuous fiber 11 of these fiber bundles T is bound together by a resin material 10 and integrated. has been made into Note that the intersection between the fiber bundles T (that is, the intersection CI) is such that a fiber group extending in one direction and a fiber group extending in a direction perpendicular to this are
As shown in FIG. 3, it has a cross-sectional shape in which three or more layers are alternately laminated.

As the continuous fibers 11 that form the main body of the axial reinforcement 2 and the shear reinforcing reinforcement 3, glass fibers, carbon fibers, etc., which are lightweight and have high strength, are suitable; however, if necessary, other fibers,
For example, synthetic resin fibers, ceramic fibers, metal fibers, etc. may be used. Further, these fibers may be appropriately combined.

Further, as the resin material 10 for binding the continuous fibers 11 of the fiber bundle T, it is preferable to use a resin that has good adhesion to these continuous edges w111 and has sufficient strength itself, such as vinyl ester resin. However, other resin materials may be used depending on the type of continuous fibers 11 used. Other resin materials include unsaturated polyester resin,
Examples include epoxy resins and phenol resins.

The ratio of the resin material 10 to the continuous fibers 11 is appropriately determined taking into account the type and strength of the continuous fibers 11, the usage pattern of the reinforcing member 1, etc. When the resin material 10 is a vinyl ester resin, consider that the volume ratio of the fibers 11 is about 3θ to 7θ%, and when the fiber 11 is, for example, carbon fiber, the volume ratio is about 2θ to 5θ%. is preferred. That is, if the proportion of continuous fibers 11 is less than the above, the strength of the reinforcing member 1 will be significantly reduced.
However, if the ratio is too high, relatively expensive materials such as carbon fibers are unfavorable from an economic point of view.

Although any method can be used to form such a reinforcing member 1,
For example, a continuous fiber 11 impregnated with a resin (room-temperature curing fluid resin, etc.) is hooked onto pins or the like provided at positions corresponding to the upper and lower ends of the shaft reinforcement 2 in a so-called one-stroke manner. Next, continuous fibers 11 impregnated with the resin are wound around positions corresponding to the shear reinforcing bars 3. At this time, the fiber groups are always alternately laminated in at least three layers at the intersection portion. Further, it is necessary to apply sufficient tension to the continuous fibers 11 to maintain their linearity.

Here, it is of course possible to supply the continuous edge ill manually, but it may also be automatically performed by mechanical means that operates based on a program in which the passing order is set in advance.

Next, the function of the reinforcing member 1 constructed as described above will be explained with reference to FIG. 5.

As shown in FIG. 5, when a load as shown by arrow A in the figure is applied to a concrete structure 6, which is made up of a reinforcing member l buried in concrete 5, the upper surface of the cage 6 is compressed. The lower surface is in tension. Therefore, an axial pulling force is applied to the side portion of the shear reinforcing bar 3 in the section of the reinforcing member 1 where the shearing force acts. However, this shear reinforcing bar 3 has
Since an axial reinforcement 2b extending in a direction perpendicular to the axial direction of the shear reinforcement 3 is provided in front of the corner portion 4, the shear reinforcement 3 is applied to the concrete 5 via the axial reinforcement 2b. Strong axial adhesion is achieved. Therefore, the tensile force acting in the axial direction of the shear reinforcement 3 is transmitted to the concrete 5 via the axial reinforcement 2b, and the shear reinforcement 3
almost no signal is transmitted to the corner portion 4 (that is, the sharply curved portion). As a result, the sequential destructive fractures that conventionally occur near the corner portions 4 of the shear reinforcing bars 3 are suppressed as much as possible, allowing the shear reinforcing bars 3 to fully demonstrate their inherent tensile strength. , the shear strength of the rice cake 6 can be significantly enhanced.

Furthermore, in this reinforcing member 1, by arranging the axial reinforcement 2 on both sides of the corner portion 4 of the shear reinforcement 3, the shear reinforcement 3 is fixed to the concrete 5 in the axial direction. The structure has two functions: axial reinforcement of the concrete structure (column) 6 and anchoring of the shear reinforcing bars 3 to the concrete 5, making the design very rational.

Furthermore, this reinforcing member 1 has a structure in which the axial reinforcements 2 conventionally arranged at the corner portions 4 of the shear reinforcing bars 3 are omitted. In other words, conventional concrete reinforcement members, whether the shaft reinforcement is made of FRP or steel, are constructed by crossing the shaft reinforcement with shear reinforcement or by wrapping the shear reinforcement around the shaft reinforcement. , the shear reinforcement is bent at its corner. Therefore, the bending radius of the corner portions of the shear reinforcing bars is formed to be very small, which is one of the factors that causes the aforementioned sequential destructive breakage at the corner portions of the shear reinforcing bars. However, in the reinforcing member 1 of the present invention, the corner part 4 of the shear reinforcing bar 3 is not provided with the axial reinforcement 2, but the corner part 4 is gently bent, and furthermore, the axial reinforcement 2 is placed immediately outside the bent part. As a result, the beam (concrete structure, column) 6 can be
The shear strength of can be further enhanced.

Since this reinforcing member 1 has a structure in which the axial reinforcement 2 and shear reinforcing reinforcement 3 that make up this member are all integrated, it is extremely easy to carry, install, etc., and has excellent construction accuracy. Needless to say, it has excellent advantages such as good performance.

Note that the details of the concrete reinforcing member of the present invention are not limited to the above embodiments, and various modifications are possible.

That is, the total length, material diameter, or mutual distance of the axial reinforcement 2 and shear reinforcing reinforcement 3 may be appropriately determined depending on the size of the concrete structure to be constructed, the required strength, etc. That is, when this concrete reinforcing member is used as a reinforcing member for a passenger car as in the above embodiment, if the axial reinforcement 2b located on the side surface of the beam 6 is not expected to receive much reinforcement in the axial direction, It is also possible to manufacture an economical reinforcing member 1 by slightly reducing the diameter of the shaft reinforcement 2b.

The same applies to the material and shape of the axial reinforcement 2, etc., and as shown in FIG. It's okay. It goes without saying that even with such a configuration, there is no equivalent change in the effects brought about by the aforementioned axial muscle 2.

In the above embodiments, a rectangular reinforcing member was described, but the concrete reinforcing member of the present invention is not equally limited to this, and depending on the required reinforcement state of the reinforcing member,
For example, it goes without saying that the pitch of the intersecting portions may be partially different, that other components including the circumferential direction may be included, and that the shapes may be arbitrary, such as all prisms, pyramids, cylinders, and cones.

Similarly, the concrete structure to which the concrete reinforcing member of the present invention is applied is not limited to beams as in the above embodiments, but can also be suitably used for other architectural/civil engineering structural members such as columns. At this time, when the concrete reinforcing member of the present invention is applied to a column, shearing forces may be applied to the column from multiple directions, so it is preferable that all the eight shaft reinforcements 2 have the same shape.

Note that the continuous fibers 11 include twisted cords, braided cords, and the like.

"Effects of the Invention" As explained in detail above, according to the present invention, when constructing concrete reinforcing members that are buried in concrete and structurally reinforce the concrete, concrete reinforcing members are arranged three-dimensionally at intervals from each other. When viewed from the side, the shear reinforcement is integrally attached to the shear reinforcement so as to sandwich both sides of the corner of the annularly formed shear reinforcement. Strong directional adhesion is achieved. Therefore, when shear force is applied to the concrete structure, the tensile force acting in the axial direction of the shear reinforcement is transmitted to the concrete via the axial reinforcement,
Almost no shear is transmitted to the corners, which are the weak points of the reinforcing bars. As a result, the sequential destructive fractures that conventionally occur near the corners of shear reinforcing bars are suppressed to the utmost, allowing the shear reinforcing bars to fully utilize their inherent tensile strength. Shear strength can be significantly improved.

Further, the concrete reinforcing member of the present invention has a configuration in which the axial reinforcement has two functions: reinforcing the concrete structure in the axial direction and fixing the shear reinforcement to the concrete, and the design thereof is very rational. Furthermore, this reinforcing member has a structure in which the axial reinforcement that was conventionally provided at the corner part of the shear reinforcing bar is omitted, so this corner part can be gently bent, and the axial reinforcement Combined with the prevention of tensile force transmission to the corners, this has the excellent effect of further increasing the shear strength of the concrete structure.

[Brief explanation of the drawing]

1 and 2 are views showing a concrete reinforcing member according to a first embodiment of the present invention, in which FIG. 1 is a perspective view showing the whole, FIG. 2 is a side view of the same, and FIG. 4 is a sectional view of the fiber bundle at the intersection, FIG. 5 is a diagram for explaining the invention in detail, and FIG. 6 is a concrete reinforcing member according to a second embodiment of the invention. FIG. l... Concrete reinforcement member, 2... Axial reinforcement, 3... Shear reinforcement, 4... Corner part, 5... Concrete, 6... Beam (concrete structure, former).

Claims (1)

[Claims] A concrete reinforcing member embedded in concrete to structurally reinforce the concrete, the reinforcing member comprising at least six axial reinforcements arranged three-dimensionally at intervals, and axial reinforcements that intersect with these axial reinforcements. The axial reinforcement and the shear reinforcement are both formed by solidifying continuous fibers with a resin material. and the axial reinforcements are integrally attached to the shear reinforcement so as to sandwich both sides of the corner portion of the shear reinforcement.