JPH0450741Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention aims to provide reliable shear strength to the through-holes of beams in reinforced concrete structures or steel-framed reinforced concrete structures. This invention relates to reinforcement hardware for through holes in concrete beams to be installed.

(Prior Art) In general, if a concrete beam with a beam through-hole is not sufficiently reinforced around the through-hole, the shear strength after concrete placement will be sufficient to withstand the destructive action of external forces during an earthquake, etc. This may result in cracks in the concrete wall of the through hole. Therefore, as a rational reinforcing method that can provide the necessary and sufficient shear strength around the through-hole, it is necessary to strengthen the reinforcement inside the stirrup bars installed on the side of the reinforcing bar cage in the concrete wall and on the same horizontal line. Reinforcing metal fittings are attached to opposing positions, a sleeve made of paper tube or steel tube is inserted and installed between the insertion holes formed in both reinforcing metal fittings, and the reinforcing bar cage is housed in the beam form. By pouring concrete into the frame and embedding both of the reinforcing hardware in the concrete to provide reliable shear strength around the through hole formed in the sleeve insertion portion, the concrete wall of the through hole can be strengthened. This prevented cracking in the steel.

Conventionally, reinforcing hardware used for the above purpose is, for example, made by bending reinforcing bars to form an annular ring body that is sufficiently larger than the outer diameter of the sleeve, and around this ring body. A plurality of ring bodies having a diameter larger than the ring body are arranged in multiple layers on the same plane, these ring bodies are connected and fixed via a plurality of connecting rods arranged radially across the ring bodies, and further, The inner end of an appropriately selected connecting rod among the connecting rods was configured to protrude inside the innermost ring body, that is, inside the sleeve insertion hole, and the sleeve was supported by the protruding portion. In addition, in place of the plurality of ring bodies, there are known ones in which reinforcing bars are spirally wound multiple times on the same plane.

(Problem to be solved by the invention) However, in the case of the above-mentioned conventional example constructed by welding reinforcing bars, there is a step between the ring part and the connecting rod, making it bulky and difficult to transport and store. It is inconvenient to handle and economically disadvantageous. In addition, during manufacturing, the reinforcing bars must be bent and the intersections between the ring and connecting rod must be welded, which is disadvantageous in terms of production efficiency and cost, and it is difficult to perform high-precision machining. be. Furthermore, since the protruding part that supports the sleeve extends from the connecting rod, the protruding end is fixed, but since the sleeve usually has dimensional variations during manufacturing, the imaginary circle connecting the protruding parts is If the sleeve has an outer diameter larger than the diameter, there is a risk that the sleeve will deform, causing distortion in the through hole formed. Conversely, if the sleeve has a smaller diameter than the virtual circle diameter, the sleeve may deform. There is a possibility that the insertion position will be biased and the formation position of the through hole will be misaligned. Further, since the protruding portion is made of reinforcing steel, there is a problem in that rust occurs in the portion facing the through hole, and this rust adheres to the sleeve and the through hole.

(Means for Solving the Problems) The present invention has been made to solve the problems of the conventional art, and includes forming an insertion hole for the sleeve in the center of the hardware body made of a metal plate. A plurality of protrusions protruding inward from the periphery of the hole are integrally formed, and a synthetic resin receiving member for supporting the sleeve is fitted into each of these protrusions, and the protrusions are bent. It is characterized in that it is configured to correspond to the outer diameter of the sleeve.

(Function) According to the above configuration, the hardware main body can be formed simply by pressing the metal plate, so productivity is high.
In addition to being able to be molded with high precision, it is not bulky when transported or stored, making it convenient to handle. In addition, by bending each projecting piece so that the diameter of the virtual circle connecting the ends of the receiving member matches the outer diameter of the sleeve to be inserted, even if the sleeve deviates from the specified outer diameter, it can be held in place. It can be inserted and supported reliably. Furthermore,
In this inserted state, the sleeve is supported in contact with the synthetic resin receiving member, so that problems such as rust adhering to the sleeve or the concrete wall of the through hole do not occur.

(Example) Hereinafter, an example of the present invention will be described in detail based on the drawings. In FIGS. 1 and 2, the through-hole reinforcing hardware A according to this embodiment includes a rectangular plate-shaped hardware body 1 formed by pressing a high-strength, thin-walled steel plate. This hardware body 1 has an insertion hole 2 in the center through which a paper tube sleeve S is inserted, and a plurality of annular ribs 3 (three in the figure) concentric with the hole 2 on the outside of the insertion hole 2. ) are formed at equal intervals, and a large number of radial connecting portions 4 are arranged radially between each annular rib 3, and the four corners of the outer periphery are each chamfered at 45 degrees.

The insertion hole 2 has a plurality of (four in the figure) projecting pieces 5 that project inward from the periphery of the insertion hole 2.
are integrally formed with the metal fitting main body 1. Each protruding piece 5 protrudes along the diagonal line of the metal fitting main body 1, and each protruding piece 5 has a receiving member 6 made of synthetic resin.
is fitted. These receiving members 6 support the sleeve S, and have a spherical tip that contacts the sleeve S, and when fitted into each of the projecting pieces 5, each receiving member 6 supports the sleeve S. The dimensions are set so that the diameter of the virtual circle connecting the tips of the sleeves 6 and 6 coincides with the outer diameter of the sleeve, which is equal to or slightly smaller than the prescribed diameter.

In this embodiment, a plurality of annular ribs 3 and radial connecting portions 4 are provided in order to maintain the mechanical strength of the hardware body 1, but in the present invention, a rigid structure with a different shape is used. is also included. Furthermore, the shape of the receiving member 6 is not necessarily limited to a spherical shape, as long as it does not have a sharp shape that may damage or deform the outer peripheral surface of the sleeve S.

Next, an example of constructing a concrete beam using reinforcing hardware A with the above configuration will be described. As shown in FIG. Reinforced beam cage B
After temporarily assembling, place a pair of reinforcing hardware A symmetrically on the same horizontal line at a predetermined position of the stirrup bars 9, and fix arbitrary locations such as the four corners of each reinforcing hardware A to the stirrup bars 9, etc. do. Next, the sleeve S prepared in advance is bridged between the reinforcing metal fittings A in order to pass through them, but in this case, the outer diameter of the sleeve S is
If the diameter is larger than the diameter of the imaginary circle C (see Figure 1) connecting the tips of the
As shown in FIG. 2, each of the projecting pieces 5 is bent equally to tilt the receiving member 6, thereby expanding the diameter of the imaginary circle C, and supporting the sleeve S by each receiving member 6. Therefore, according to this embodiment, even if the sleeve S has dimensional variations with respect to the specified size, it can be easily and reliably fixed and supported at a predetermined position between the reinforcing hardware A.

Rebar cage B with sleeve S constructed in this way
is housed and supported in a pre-assembled beam form D, and then concrete is poured into the slab form E and beam form D, and the entire reinforcing bar cage B is buried in the concrete. be. Thereafter, after the beam formwork D is dismantled, the sleeve S is removed from the formed through hole or left in place as required. Since it is made of synthetic resin, it will not rust, and therefore rust will not adhere to the sleeve S or the concrete wall surface of the through hole.

The reinforcing hardware A of the above embodiment can be applied not only to reinforced concrete beam construction as described above but also to steel frame reinforced concrete construction. In this case, after inserting the sleeve into the through hole provided in the web of the beam steel frame, insert the reinforcing metal fittings A into both ends of the sleeve, fixing each reinforcing metal fitting A to the beam stirrups, etc., and then , the beam formwork will be assembled.

In any of the construction examples described above, the reinforcing hardware A of this example has a shear strength that is applied to the concrete wall around the through hole formed at the insertion position of the sleeve S due to the combination of the three groups of annular ribs and the four groups of radial connecting parts. This will reliably prevent cracking of the concrete wall.

(Effects of the invention) As explained above, according to the invention, by bending the projecting piece and appropriately adjusting the diameter of the virtual circle connecting the ends of the receiving member, it is possible to adjust the diameter of each sleeve with variations in outer diameter. Correspondingly, the sleeve can be inserted and supported reliably, and in this inserted state, the sleeve comes into contact with the resin surface of the receiving member, so that the sleeve or the through hole formed thereby can be inserted and supported. It is possible to prevent rust generated from the hardware body from adhering to the concrete wall. Furthermore,
The main body of the hardware can be formed by pressing a metal plate, so it can be manufactured with high precision and efficiency, and is not bulky during transportation or storage, making it easier to handle and more economical. He became rich.

[Brief explanation of drawings]

Fig. 1 is a front view of reinforcing hardware for a through hole in a concrete beam according to an embodiment of the present invention, Fig. 2 is a sectional view taken along the cutting line - in Fig. 1, and Fig. 3 is a reinforcement fitting of this embodiment. It is a longitudinal cross-sectional view of the main part of the construction example used. 1...Hardware body, 2...Insertion hole, 5...Protrusion piece,
6... Receiving member, S... Sleeve.

Claims (1)

[Scope of utility model registration request] An insertion hole is formed in the center of the hardware body made of a metal plate, into which a sleeve for forming a through hole in a concrete beam is inserted, and a plurality of protrusions that protrude inward from the periphery of this insertion hole are integrally connected. A concrete beam characterized in that a receiving member made of synthetic resin for supporting the sleeve is fitted into each of these projecting pieces, and the projecting pieces are bent to correspond to the outer diameter of the sleeve. Reinforcement hardware for through holes.