JPH07180352A - Joint-placing reinforcing structure of concrete - Google Patents

Abstract

PURPOSE:To improve shearing strength in a horizontal joint-placing surface between an existing concrete and a concrete placed thereon without the need for a work, which requires much time, such as leveling of mortar, roughening of existing concrete surface. CONSTITUTION:A joint-placing reinforcing structure 10 of concrete comprises a large number of protruding members 2 which are embedded in the upper surface of a lower concrete 1 to reinforce the shearing strength of a horizontal joint-placing surface between the lower concrete 1 and an upper concrete when the latter is placed on the former, and the member 2 is constituted by an elongated hoop bar 3 formed by bending a reinforcing bar and an air bag 4, as an elevating means, which is detachably attached to one end of the hoop bar 3. The member 2 can be vertically held so as to be elevated from the upper surface of the lower concrete 1, while the upper part of the member is protruded by the air bag 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a concrete casting reinforcement structure for shearing reinforcement of a horizontal joint surface between upper concrete and lower concrete when the upper concrete is jointed.

[0002]

2. Description of the Related Art Generally, when a new concrete is spliced above an existing concrete located below, a leitance generated on the surface of the existing concrete is removed, and before the new concrete is cast, In order to integrate both concretes, mortar is laid on the surface of the existing concrete, and new concrete is placed on the upper surface of the laid mortar to improve the adhesiveness of both concretes and The shear strength is improved.

Further, among the concretes, the high-fluidity concrete having a particularly high fluidity produces less leitance than ordinary concrete, so that the above-mentioned work of removing the leutance and laying mortar are required. It is possible to directly inject new concrete directly onto the surface of the high-fluidity concrete. However,
In fact, the surface of the cast concrete may be flattened due to the high self-leveling effect of the high-fluidity concrete. Therefore, in order to achieve higher integration of both the upper and lower concrete, for example, the surface of the existing concrete should be The aggregate is exposed by spraying air water jets to form irregularities on the concrete surface to roughen the joint surface, or after the lower concrete has hardened to some extent, shear reinforcement or the like is applied to the joint surface. The method of standing up is adopted.

[0004]

However, in any of the above-mentioned methods, the treatment requires a great deal of labor and labor, which is a cause of impeding labor saving and shortening of the construction period for concrete work. It was

The present invention has been made in view of the above-mentioned problems, and the existing concrete and the above-mentioned concrete can be cast without troublesome work such as leveling mortar and roughening the surface of the existing concrete. It is an object of the present invention to provide a concrete joint reinforcement structure capable of easily improving the shear strength on the horizontal joint surface with the concrete to be jointed.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and its gist is to provide a horizontal joint surface between upper concrete when lower concrete and upper concrete are spliced. In order to perform shear reinforcement, there is provided a concrete splicing reinforcement structure comprising a plurality of projecting members embedded in the upper surface of the lower concrete, wherein the projecting members project above the projecting members by means of levitation means provided on the projecting members. Meanwhile, the concrete splicing structure is characterized in that it is vertically erected and held on the upper surface of the lower concrete.

Further, in the concrete splicing structure of the present invention, it is preferable that the projecting member is composed of a steel rod such as a reinforcing bar and a float as a levitation means attached to the upper portion of the steel rod.

Further, the projecting member extends from the outer circumference of the steel rod at the boundary between the steel rod such as a reinforcing bar and the projecting portion of the steel rod and the embedded portion, and thereby bears in pressure contact with the surface of the lower concrete. It can also be configured with an overhanging plate as a floating means.

[0009]

According to the concrete splicing reinforcement structure of the present invention, each projecting member constituting the reinforcement structure is disposed on the surface of the concrete in parallel with the pouring of the lower concrete or immediately after the pouring of the lower concrete. To do. Since the cast concrete or the concrete immediately after casting has a high fluidity, each of the arranged protruding members has its lower part embedded in the concrete due to its weight, and is floated on the surface of the concrete by the floating means. As a result, the projecting member is erected and held in a state where the upper part of the projecting member is projected from the surface of the concrete.

Further, if the projecting member is composed of a steel rod such as a reinforcing bar and a float as a levitation means attached to the upper part of the steel bar, the projecting member disposed in the concrete during the pouring work of concrete. Once buried, it floats by the action of the float, causing its upper part to project onto the surface of the concrete.

Further, when the projecting member is constructed by providing an overhanging plate on the outer circumference of the steel rod, when the upper concrete is spliced over the lower concrete, the work of removing the overhanging plate as a floating means is performed. Make it unnecessary.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the concrete splicing reinforcement method of the present invention will be described in detail below with reference to the drawings. FIG. 1 shows a concrete splicing reinforcement structure 10 according to this embodiment, in which a large number of projecting members 2 are provided on the upper surface of a lower concrete 1 formed by casting high-fluidity concrete having high fluidity. It is erected and held in a floating state, and the upper end portions thereof are projected from the upper surface.

That is, as shown in FIGS. 2A and 2B, each protruding member 2 has a slender hoop muscle 3 formed by bending a reinforcing bar, and an inner width d of the hoop muscle 3 is substantially equal. A spherical air bag having a diameter, which is detachably attached to one end of the hoop muscle 3 and serves as a floating means.
Composed of and.

The air bag 4 is made of, for example, polyethylene, polypropylene, vinyl, etc., and the buoyancy of the air bag 4 causes the protruding member 2 to be designed to have a specific gravity smaller than that of concrete as a whole. .
Therefore, by arranging the projecting member 2 on the surface of the lower concrete 1 in parallel with the operation of placing the lower concrete 1, or immediately after the lower concrete 1 is placed,
As shown in (a), the projecting member 2 is floated on the surface of the concrete by the action of the air bag 4, and the upper end portion of the hoop muscle 3, that is, the portion where the air bag 4 is mounted is projected from the surface of the lower concrete 1. At the same time, the air bag 4 and the lower part of the hoop muscle 3 are vertically erected in a state of being embedded in the lower concrete 1. If the work of disposing the projecting member 2 on the concrete surface is performed while vibrating the concrete by using a vibrator or the like and liquefying the concrete by the vibration, the standing holding state of the projecting member 2 can be obtained earlier. be able to.

A concrete splicing reinforcement structure 10 in which a large number of the projecting members 2 are erected and held on the concrete upper surface.
According to this, if the air bag 4 of each projecting member 2 is removed after the lower concrete 1 hardens, the upper ends of the respective hoop lines 3 project onto the surface of the lower concrete 1 as shown in FIG. 2 (c). At the same time, a large number of hemispherical concave portions 5 are formed. Therefore, when the upper concrete is spliced above the lower concrete 1 having the projecting hoop reinforcement 3 and the concave portion 5 on the upper surface, each hoop reinforcement 3 serves as a shear reinforcing bar, and each recess 5 shears the horizontal joint surface. It acts as a key, by which shear reinforcement of the horizontal joint surface between the lower concrete 1 and the upper concrete further jointed upward can be easily applied.

When the air bladder 4 is removed, the air bladder 4 is in a state in which the lower part of the air bladder 4 is buried in the concrete due to the weight of the hoop muscles 3. The air bladder 4 is made of polyethylene or the like as described above. Since it is formed of, it can be easily deformed or destroyed, and can be easily peeled off from the concrete surface and easily removed.

FIG. 3 (a) shows another embodiment of the projecting member 2 used in the concrete splicing reinforcement structure 10 of this embodiment. That is, this protruding member 2
Is a steel rod 6 such as a reinforcing bar having a threaded portion at one end, and a cylindrical float 7 formed of a material having a low specific gravity, such as polyethylene, screwed into the threaded portion of the steel rod 6. It is composed of and. This protruding member 2 also has a specific gravity smaller than that of concrete as a whole due to the buoyancy of the float 7, and the upper end thereof, that is, the end to which the float 7 is attached is made to be the upper surface of the concrete. In addition, the float 7 and the lower portion of the steel rod 6 are vertically erected while being embedded in the lower concrete 1.

According to the concrete splicing reinforcement structure 10 constructed by arranging a large number of projecting members 2 on the upper surface of the lower concrete 1 in this way, the float 7 is released from the screwed state after the concrete 1 is hardened. As shown in FIG. 3 (b), the concave portion 5 as a shear key is formed on the surface of the lower concrete 1, and the steel rod 6 as the shear reinforcing bar is downwardly moved from the bottom surface of the concave portion 5 by removing the concave portion 5 from the bottom surface. It is made to project on the concrete 1 upper surface.

The projecting member 2 shown in FIGS. 2 and 3 above.
According to the method, even if these projecting members 2 are once buried in the concrete as the lower concrete 1 is placed, the projecting members 2 are easily floated on the surface of the concrete by the action of the air bag 4 or the float 7 which is a floating means. The upper end can be projected.

Further, FIG. 4 shows another embodiment of the projecting member 2 used in the concrete splicing reinforcement structure 10 of this embodiment. That is, the projecting member 2 is composed of a steel rod 6 such as a reinforcing bar and an overhanging plate 8 as a levitation means extending from the outer circumference of the steel rod 6.

The overhang plate 8 is made of, for example, a steel plate made of the same material as the steel rod 6, and is integrally formed with the steel rod 6. And this overhanging plate 8
Is supported by the surface of the lower concrete 1 by supporting pressure to expand the installation area for supporting the protruding member 2 on the surface, whereby the concrete has high fluidity like high-fluidity concrete. Also steel rod 6
Is erected upright on the upper surface of the lower concrete 1 without being buried in the concrete.

In the projecting member 2 thus constructed, not only the steel rod 6 but also the overhanging plate 8 can be used as it is as a reinforcing material for the horizontal joint surface. Need not remove the levitation means from the lower concrete 1.

Furthermore, FIG. 5 shows another embodiment of the projecting member 2 used in the concrete splicing reinforcement structure 10 of this embodiment. That is, this protruding member 2
Is one in which the protruding portion and the embedded portion are integrally formed of only synthetic resin such as polyethylene. In the concrete splicing reinforcement structure 10 in which a large number of projecting members 2 having such a configuration are arranged on the upper surface of the cast concrete 1, if each projecting member 2 is removed after the lower concrete 1 hardens, A recess 5 as a shear key as shown in (b) is formed on the surface of the concrete, and the horizontal joint surface is reinforced by filling the recess 5 with the upper concrete.

Further, in the above embodiment, the case where the high-fluidity concrete is used as the concrete to be placed as the lower concrete 1 has been described, but the present invention is not limited to this, and ordinary concrete can be used. For example, the concrete splicing reinforcement structure of the present invention can be adopted in a state of high fluidity immediately after pouring.

[0025]

As described in detail above, according to the concrete splicing reinforcement structure of the present invention, each projecting member constituting the reinforcement structure can be easily formed in a state of being projected from the concrete surface by the levitation means. Can be held upright. And by using a large number of protruding members, horizontal striking between the existing concrete and the concrete spliced above it can be performed without the need for troublesome work such as leveling the mortar or roughening the surface of the existing concrete. It is possible to easily improve the shear strength of the joint surface.If the projecting member is constituted by a steel rod such as a reinforcing bar and a float as a levitation means attached to the upper part thereof,
Even if the projecting member disposed during the concrete pouring operation is once buried in the concrete, the projecting member floats by the action of the floating, so that the upper part thereof can be easily projected onto the surface of the concrete.

Further, the projecting member is provided on the outer periphery of the steel rod.
If the projecting plate is provided as the levitation means, when the upper concrete is spliced above the lower concrete, the splicing work can be performed without removing the levitation means.

[Brief description of drawings]

FIG. 1 is a perspective view of a concrete splice reinforcing structure according to the present invention.

FIG. 2 (a) is a cross-sectional view of a projecting member constituting a concrete splicing reinforcement structure according to the present invention,
(B) is a perspective view of the said protrusion member, (c) has shown the condition which removed the floating means after hardening of the lower concrete.

FIG. 3 is an explanatory view of another embodiment of the projecting member used for the concrete splice reinforcing structure according to the present invention, (a)
Shows a situation where the projecting member is arranged on the upper surface of the lower concrete, and (b) shows a situation where the floating means is removed after the lower concrete is hardened.

FIG. 4 is a cross-sectional view of another embodiment of a projecting member used in the concrete splice reinforcing structure of the present invention.

FIG. 5 is a cross-sectional view of still another embodiment of the projecting member used for the concrete splice reinforcing structure of the present invention.

[Explanation of symbols]

 1 Lower concrete 2 Projection member 4 Air bag (floating means) 6 Steel rod 7 Float 8 Overhang plate

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inori Noritake Takeda 4-640 Shimo-Seido, Kiyose-shi, Tokyo Inside Obayashi Technical Research Institute Co., Ltd. (72) Inventor Masami Kurihara 4-640 Shimoseido, Kiyose-shi, Tokyo Obayashi Corporation Technical Research Institute Co., Ltd.

Claims (3)

[Claims] 1. When the upper concrete is spliced above the lower concrete, in order to shear-reinforce the horizontal joint surface between them, the concrete consisting of a large number of projecting members embedded in the upper surface of the lower concrete. A concrete splice, wherein the projecting member is vertically erected in a state of being levitated on the upper surface of the lower concrete while projecting the upper part thereof by a levitation means provided in the projecting member. Reinforced structure. 2. The concrete joint reinforcement according to claim 1, wherein the projecting member is composed of a steel rod such as a reinforcing bar and a float as a levitation means attached to the upper part of the steel rod. Construction. 3. The projecting member extends from the outer periphery of the steel rod at the boundary between the steel rod such as a reinforcing bar and the projecting portion and the embedded portion of the steel rod, and thereby comes into bearing contact with the surface of the lower concrete. The splicing reinforcement structure for concrete according to claim 1, comprising an overhanging plate as a floating means.