JPH0524734Y2 - - Google Patents

Description

[Detailed explanation of the invention] (Field of the invention) This invention is designed to appropriately maintain the clearance between the upper and lower main reinforcements that touch the rising part of the cost reinforcement at the bottom of the beam when the main reinforcements on the side surfaces of reinforced concrete beams are arranged in two stages. Regarding the overlap bar spacer on the side of the beam to ensure that the space is maintained.

(Prior Art) When a large bending stress occurs in a cross section assumed at the beginning of structural design, the number of main reinforcement bars in a reinforced concrete beam increases. Because reinforcing bars need to be spaced at regular intervals due to the filling properties of concrete, adhesion, and other reasons, reinforcing bars cannot be lined up in just one level for the width of the beam, and are often arranged in two or three layers. . Assuming a beam cross section that does not result in overlapped reinforcement will not only increase the floor height, but also reduce the number of floors due to increased building weight and building height restrictions, which will be uneconomical. Overlap reinforcement will be placed on the initially assumed beam cross section.

When using two or more layers of overlapping reinforcement, the spacing between the upper and lower main reinforcements determined by the design standards should be set to 1.5d so that the stress center distances D' and D'' in Figure 6 do not fall below the design values.
Therefore, strict construction management is required at the site.

For the upper end reinforcement of the beam, an S-shaped iron wire spacer 2 as shown in Figure 6 is commercially available, so if you use an S-shaped spacer with a size determined by the main reinforcement diameter, accurate clearance can be maintained. No problem. On the other hand, when overlapping reinforcement is arranged at the lower end of the beam, there is currently no suitable spacer, so the upper main reinforcement 1'' that is in contact with the rising side surface 3' of the reinforcement 3, as shown in Figure 6, is reinforced with a binding wire. The beam was constructed by simply tying it together with annealed steel wire 4 of about No. 18 wire, and as a result, the gap (1.5d) between the upper and lower main bars was not constant, and the reinforcing bars of the beam assembled at the top of the beam were dropped into the formwork. Due to the vibrations caused when the beams are installed, the binding wires often loosen and fall down as shown in broken line 5. Such inaccurate construction methods pose quality control problems, and if the strength of the beams varies, it is difficult to maintain the structure in the event of an earthquake. It is also possible that the effects of

In order to maintain a proper clearance between the upper and lower main reinforcements 1 and 1'' at the place where the upper and lower main reinforcements 1 and 1'' of the lower part of the beam contact the rising side surface 3' of the cost reinforcement 3, the applicant previously proposed the following method as shown in FIG. Devised a stacked spacer (Jitsugan No. 61-10309). This stacked spacer 10
0 is an upper recess 112 that supports the upper main reinforcement 1″
and a lower recess 113 placed on the lower main reinforcement 1 are vertically connected via a straight portion 114, and similarly, an upper recess 112' and a lower recess 113' are connected via a straight portion 114', and are opposed to each other. Only one leg of each of the lower recesses 113, 113' is connected by a connecting part 115, and an arcuate recess 116 that rests on the rib 3 is connected to this connecting part 115.
is formed. The side facing the connecting portion 115 is not provided with a connecting portion because it interferes with the rising portion of the ribs 3. The stacked reinforcement spacer of this shape is shown by the two-dot chain line in Fig. 8 as the upper and lower main reinforcements 1,
As a result of test construction at the location of 1" and cost reinforcement 3, it was found that the upper main reinforcement on the side of the beam was somewhat unstable, and in the case of a large beam, it was necessary to install the cost reinforcement 3 while lying on the slab formwork. Although the performance of the beam is satisfactory since it is necessary to bind the beam and the overlap bar spacer 100, improvements are needed in terms of workability.

(Purpose of the invention) The purpose of the invention is to eliminate the need to tie the ribs and spacers together, to allow for easy placement and to be inexpensive.
Moreover, it is an object of the present invention to provide a stacked reinforcement spacer for the side surface of a reinforced concrete beam, which can maintain the clearance between the upper and lower main reinforcements at the lower end of the beam to an appropriate size.

(Structure of the invention) In order to achieve the above object, according to the present invention, the stacked reinforcement spacers are arranged in upper and lower circles to horizontally surround the rising parts of the ribs from the outside at intervals corresponding to the gaps between the upper and lower main reinforcements. an arc-shaped part, an upper extension part that extends almost horizontally from both ends of the upper arc-shaped part to support the upper main reinforcement, and a downward extension part that extends almost horizontally from both ends of the lower arc-shaped part to rest on the lower main reinforcement. a vertical connection connecting the ends of the upper and lower extensions on one vertically opposite side to each other, and the ends of the other vertically opposite parts of the upper and lower extensions. It consists of upper and lower hook parts formed by bending and extending the upper and lower main reinforcing bars so as to partially surround the upper and lower main reinforcements, respectively, and these parts may be made integrally by bending a wire rod.

(Example) Hereinafter, the present invention will be described in detail with reference to the drawings.

As can be seen from Figures 1 and 3, the overlap bar spacer 10 according to the present invention is used to maintain an appropriate gap between the upper and lower main bars 1 and 1'' that contact the rising portion 3' of the cost reinforcement 3 at the bottom of the beam. The stacked line spacer 10 of this embodiment is integrally formed by bending a single wire.

1 to 3, the overlapped muscle spacer 10 according to the present invention has a rising portion 3' of the costal muscle 3,
Upper and lower arcuate portions 11 for horizontally surrounding the beam from the outside in the beam width direction at a distance corresponding to the gap between the upper main reinforcement (also referred to as overlapped reinforcement) 1 and the lower main reinforcement 1'';
It has 12. Upper extension portions 13 and 14 for supporting the upper main reinforcement 1'' extend inward in the beam width direction from both ends of the upper arcuate portion 11, and
From both ends of the lower arcuate portion 12, downward extension portions 15 and 16 for placing on the lower main reinforcement 1 extend inward in the beam width direction. Further, the ends of the upper and lower extended portions 13, 14, 15, and 16 on one vertically opposed side are connected by a vertical connecting portion 17. In addition, the ends of the upper and lower extended portions 13, 14 and 15, 16 on the other side that are vertically opposite to each other are arranged so as to partially surround the upper and lower main reinforcements 1'', 1, respectively. Upper and lower hook portions 18, 19 are formed by bending and extending.

When making the stacked reinforcement spacer 10, if the vertical connection part 17 is located too far inward in the beam width direction from the center of gravity of the main reinforcements 1, 1'', the strength of the connection part 17 may become weak and there is a risk of bending. Therefore, the connecting part 17
must be located near the main reinforcement. In addition, in order to prevent the stacked bar spacer 10 from falling outward when inserted into the cost bar 3 and placed on the beam lower main bar 1, the center of gravity of the entire stacked bar spacer must be on or at the center of the main bar center line. It is preferable to determine the position of the connecting portion 17 so that it is located inside the line in the beam width direction. However, even if the center of gravity of the overlapped muscle spacer 10 is on the center line of the main reinforcement or near the inside thereof, when the overlapped reinforcement spacer 10 is inserted into the ribs from the outside and placed on the lower main reinforcement 1, the overlapped reinforcement spacer 10 is placed on the outside. Therefore, as shown in Fig. 3, the angle of the upper and lower arcuate parts 11 and 12 that surround the rising part 3' of the ribs is made larger than 180°, that is, the entrance part where the ribs fit into the ribs. It is safe to make 20 smaller than the rib diameter. At the same time, if the inner diameter of the arcuate portions 11 and 12 is made larger than the diameter of the ribs 3, even if the beam size is large, the arcuate portions 11 and 12 of the overlap bar spacer 10 can be placed on the floor slab formwork. By tapping or pushing lightly, the entrance part 20 for fitting with the rib cage 3 opens and fits into the rib cage 3, and then when you release your hand, the overlap bar spacer 10 will fall naturally and the corner part 20 will open. Since it can rest on the main reinforcement 1, the workability is much improved.

Next, a method of using the stacked reinforcement spacer 10 according to the present invention constructed as described above will be explained in the process of placing beam reinforcement.

In Fig. 5, the supports 7 of the beam main bar supports are placed facing the formwork 6 of the slab on both sides of the beam, and the sturdy cross members 8 are stretched across them. Two to three sets of main reinforcements are arranged at intervals where the main reinforcements do not bend significantly, and the beam upper end main reinforcements 1 are arranged on the cross members 8, and the cost reinforcements 3 are suspended from the main reinforcements. After incorporating the required number of main reinforcements into the cost reinforcements at the bottom end of the beam, insert the first stage of lower main reinforcement 1 at the bottom end of the beam.
Tie it to rib 3. Next, the upper and lower arcuate portions 11 and 12 of the stacked reinforcement spacer 10 of the present invention are fitted into the rising portion 3' of the cost reinforcement 3 as described above, and the downward extension portions 15 and 16 are attached to the lower main reinforcement 1 at the lower end of the beam. I'll put it on. After that, the upper main reinforcement 1″ of the two-stage reinforcement is added to the cost reinforcement 3.
Pick up the lower end and place it on the upper extension parts 13 and 14 of the stacked muscle spacer 10. Upper main bar 1″
is partially surrounded by the upper hook part 18, so that it is in a stable condition.

The main reinforcement 1' located in the middle of the beam width and not in contact with the rising part 3' of the cost reinforcement 3 has opposing lower recesses 113, 113' placed on the lower main reinforcement 1 in the stacked reinforcement spacer 100 shown in FIG. A stacked muscle spacer (Utility Model Application No. 60-10309) is used in which both legs are connected by connecting portions. After aligning the spacing between the main reinforcements and tying them together at important points, the entire beam reinforcement is suspended by a crane, and after the cross members 8 are pulled out, they are gently dropped into the formwork.

(Effects of the invention) In this invention, two arcuate parts horizontally surround the rising part of the ribs from the outside with an interval equal to the gap between the upper and lower main reinforcements, and a horizontal arc from both ends of the upper and lower arcuate parts. A connecting part that vertically connects the extending upper and lower extension parts, the vertically opposing parts of the upper and lower extension parts, and the ends of the other vertically opposing parts of the upper and lower extension parts. It consists of upper and lower hook parts bent upward and downward, respectively, so that the upper main reinforcement placed on the upper extension part comes into contact with the rising part of the cost reinforcement by the hook part facing the upper arcuate part. Therefore, the upper arcuate part of the overlap bar spacer is pulled inward in the beam width so that it comes into contact with the rising part of the cost reinforcement, and there is no need to bind the cost reinforcement and the overlap bar spacer, and the vertical The space between the upper and lower main reinforcements is maintained at an appropriate size by the connection part. Furthermore, as mentioned above, the spacer of the present invention can be arranged very easily, has good workability, and is made by bending a single wire, so it is very inexpensive.

[Brief description of the drawings]

Figure 1 is a side view of the overlap bar spacer according to the present invention, Figure 2 is a plan view of the overlap bar spacer of Figure 1, and Figure 3 is the overlap bar spacer with the fitting entrance of the arc-shaped part surrounding the ribs narrowed. Figure 4 is a perspective view of the stacked spacer shown in Figures 1 and 2;
Figure 5 is an explanatory diagram to explain the construction of stacked reinforcement spacers in the process of placing beam reinforcement.
Figure 6 is a cross-sectional view of a beam showing the conventional method of using tie wires to maintain clearance between the upper and lower main reinforcements in a beam with two-stage reinforcement at the upper and lower ends.
FIG. 8 is a side view taken along the line A--A in the figure, and a perspective view of a conventional stacked reinforcement spacer for maintaining the clearance between the upper and lower main reinforcements that contact the rising portion of the ribs at the lower end of the beam. 1...Lower main bar, 1''...Upper main bar, 3...Rice muscle, 3'...Rising portion of cost muscle, 11, 12...
...Upper and lower arcuate portions, 13, 14...Upper extension portion, 15, 16...Downward extension portion, 17...Vertical connecting portion, 18...Upper hook portion, 19...Lower hook portion.

Claims (1)

[Scope of utility model registration request] When the main reinforcement of a beam in a reinforced concrete structure is arranged in two stages, the overlapped reinforcement spacer on the side of the beam is used to maintain an appropriate gap between the upper and lower main reinforcements that touch the rising part of the costar at the bottom of the beam. upper and lower arcuate parts to horizontally surround the upper and lower main reinforcements from the outside at intervals corresponding to the gaps between the upper and lower main reinforcements, and an upper extension part that extends almost horizontally from both ends of the upper arcuate parts to support the upper main reinforcements. , a downward extension extending almost horizontally from both ends of the lower arc-shaped section for resting on the lower main reinforcement, and a vertical section connecting the ends of the upper and lower extension sections on one side that are vertically opposed to each other. upper and lower hook parts formed by bending and extending the ends of the other vertically opposing parts of the upper and lower extension parts so as to partially surround the upper and lower main reinforcements, respectively. A superimposed spacer consisting of and characterized in that these parts are made by bending wire rods.