Precast concrete structure and precast concrete construction method

Abstract

To provide a precast concrete structure and a precast concrete construction method capable of shortening a process required for installation and reducing the use amount of concrete.SOLUTION: A precast concrete structure comprises: a plurality of precast members formed of precast concrete; first reinforcing bars arranged in a vertical direction in the plurality of precast members stacked in the vertical direction; and second reinforcing bars arranged in the vertical direction in the precast member disposed at a base part among the plurality of precast members, wherein the second reinforcing bar is formed to have higher strength than the first reinforcing bar.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a precast structure using members formed from precast concrete, and a precast concrete construction method. [Background technology]

[0002] The precast construction method, in which precast members formed in advance from concrete are joined on-site to construct a structure, is becoming popular as a construction method that can shorten the construction period. In relation to this, a construction method in which precast members are stacked to form a columnar structure is known (for example, see Patent Document 1).

[0003] According to this method, reinforcing bars (PC steel) are inserted through and fixed to precast members made of precast concrete. Next, the reinforcing bars are extended using connecting members, and the extended reinforcing bars are inserted through other precast members to be stacked above the existing precast members, and then the reinforcing bars are fixed to the existing precast members. This process is repeated in order to form a columnar structure.

[0004] In such a precast structure, the strength of the axial reinforcing bars is the same for each precast member. In a precast structure, the cross-sectional shape is determined by the cross-sectional force of the base, and the same precast members are used in each columnar structure. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2019-19664 A Summary of the Invention [Problem to be solved by the invention]

[0006] When a columnar structure is made up of a large number of precast members, the number of steps for manufacturing the precast members and the steps for manufacturing the joints increases, and the number of steps for installation also increases. In addition, there is a risk of blockage or leakage when joining the precast members with grout. Therefore, in a construction method using precast members, it is desirable to omit as many installation steps as possible and reduce the number of members. According to the technology described in Patent Document 1, there is room to reduce the number of members and omit installation steps.

[0007] An object of the present invention is to provide a precast concrete structure and a precast concrete construction method that can shorten the installation process and reduce the amount of concrete used. [Means for solving the problem]

[0008] In order to achieve the above-mentioned objective, the present invention provides a precast concrete structure comprising a plurality of precast members formed from precast concrete, a first reinforcing bar arranged vertically in a plurality of the precast members stacked vertically, and a second reinforcing bar arranged vertically in a precast member among the plurality of the precast members that is positioned at the base, wherein the second reinforcing bar is formed to have a strength greater than that of the first reinforcing bar.

[0009] According to the present invention, by placing a second reinforcing bar, which is stronger than the first reinforcing bar, in the precast member placed on top of the base, the precast member can be made smaller, and the amount of concrete used can be reduced throughout the entire length of the precast concrete structure.

[0010] In order to achieve the above-mentioned objective, the present invention provides a precast concrete construction method comprising the steps of: fixing a precast member having a second reinforcing bar, the second reinforcing bar being stronger than a first reinforcing bar, arranged vertically to a base; fixing another precast member having the first reinforcing bar arranged vertically above the precast member; and fixing yet another precast member above the other precast member.

[0011] According to the present invention, by arranging a second reinforcing bar having a strength greater than that of the first reinforcing bar in the precast member fixed to the base, the strength of the precast member placed at the base can be made greater than the strength of other precast members installed above. Effect of the Invention

[0012] According to the present invention, it is possible to shorten the installation process and reduce the amount of concrete used. [Brief description of the drawings]

[0013] [Figure 1] 1 is a diagram showing a configuration of a precast concrete structure according to an embodiment of the present invention. FIG. [Diagram 2] FIG. 1 is a comparison diagram between a precast concrete structure and a conventional precast concrete structure. [Diagram 3] FIG. 1 is a diagram showing a part of the process of a precast construction method for constructing a precast concrete structure. [Figure 4] FIG. 1 is a diagram showing a part of the process of a precast construction method for constructing a precast concrete structure. [Diagram 5] FIG. 1 is a diagram showing a part of the process of a precast construction method for constructing a precast concrete structure. [Figure 6] FIG. 1 is a diagram showing a part of the process of a precast construction method for constructing a precast concrete structure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, embodiments of a precast concrete structure and a precast concrete construction method according to the present invention will be described with reference to the drawings.

[0015] As shown in Fig. 1, the precast concrete structure 1 is formed into a columnar structure provided on a base M. The precast concrete structure 1 includes, for example, a plurality of precast members 2, 2A stacked in the vertical direction, and first reinforcing bars 6 and second reinforcing bars 4 arranged in the plurality of precast members 2.

[0016] The base M is a pedestal provided on the floor surface or the like, which supports the precast concrete structure 1. A plurality of reinforcing bars 3 for embedding, formed of second reinforcing bars 4, are embedded in the base M, with their upper ends protruding from the top surface. The lower ends of the reinforcing bars 3 are bent into a hook shape to prevent them from coming loose. The upper ends of the reinforcing bars 3 are inserted into joints 8 provided at the bottom of the precast member 2.

[0017] A joint 8 is formed in a circular hole in the lower part of the precast member 2. The upper end of the reinforcing bar 3 is inserted into the joint 8 and fixed by a filler material such as grout.

[0018] The second reinforcing bars 4 are arranged vertically in the precast member 2 placed on the upper surface of the base M. The upper ends of the second reinforcing bars 4 protrude from the upper surface of the precast member 2. The second reinforcing bars 4 are formed to have a higher strength than the first reinforcing bars 6. The second reinforcing bars 4 are, for example, high-strength reinforcing bars such as SD490 or USD685 that are stronger than the first reinforcing bars. The precast member 2 fixed to the base M is formed with the upper ends of the multiple second reinforcing bars 4 standing up from the upper surface of the precast member 2.

[0019] The upper end of the second reinforcing bar 4 is inserted into a joint 8 formed in the lower part of the other precast member 2A. The upper end of the second reinforcing bar 4 is fixed to the other precast member 2A by a filler such as grout.

[0020] The first reinforcing bars 6 are arranged vertically in a plurality of precast members 2A stacked vertically above the precast member 2 fixed to the base M. The first reinforcing bars 6 are reinforcing bars of a commonly used strength, such as SD345.

[0021] The upper end of the first reinforcing bar 6 is inserted into a joint 8 formed at the bottom of the precast member 2A placed above. The upper end of the first reinforcing bar 6 is fixed to the precast member 2A placed above with a filler such as grout. The precast member 2A with the first reinforcing bar 6 arranged therein is fixed above the precast member 2 fixed to the base M.

[0022] The precast members 2, 2A are, for example, block-shaped members formed in advance from precast concrete in a factory. The precast member 2A has a first reinforcing bar 6 arranged therein, and the precast member 2 has a second reinforcing bar 4 arranged therein.

[0023] 2, the precast concrete structure 100 according to the comparative example is formed to the same height as the precast concrete structure 1. The precast concrete structure 100 is applied to a conventional structure.

[0024] The precast concrete structure 100 is formed by stacking a plurality of precast members 2B on a base MA, the number of which is greater than the number of precast members 2. First reinforcing bars 6 are arranged in the plurality of precast members 2B. In the precast concrete structure 100, the base MA is formed to have a larger cross-sectional area than the base M. Since the first reinforcing bars 6 are arranged in the precast members 2B, the precast members 2B are formed so that they have a larger cross-sectional area than the precast members 2 and are lower in the height direction. The precast concrete structure 100 is formed by stacking a plurality of precast members 2B.

[0025] The precast members 2, 2A of the precast concrete structure 1 have a smaller cross-sectional shape and are thinner than a conventional precast concrete structure 100 in which first reinforcing bars 6 are arranged in all precast members 2B, and are also longer in the vertical direction.

[0026] The precast concrete structure 1 can significantly reduce the amount of concrete used by using precast members 2, 2A that are thinner than conventional precast members 2B. The precast concrete structure 1 can reduce the number of blocks to be stacked and reduce the number of construction processes by using precast members 2, 2A that are taller than conventional precast members 2B.

[0027] Next, each step of the precast concrete method for constructing the precast concrete structure 1 will be described.

[0028] As shown in Fig. 3, a plurality of reinforcing bars 3 are arranged on the floor surface, a formwork is constructed, and concrete is poured to form a base M. On the top surface of the base M, the upper ends of the reinforcing bars 3 are exposed.

[0029] As shown in FIG. 4 , grout is filled into the joint 8 at the bottom of the precast member 2 in which the second reinforcing bar 4 is arranged and into the underside of the precast member 2. The upper end of the reinforcing bar 3 is inserted into the joint 8 of the precast member 2, and the precast member 2 is fixed to the base M. The precast member 2 on the base M does not need to be provided with the joint 8. In this case, the reinforcing bar 3 of the base M is used integrally with the precast member 2 on the base M instead of the second reinforcing bar 4.

[0030] 5, grout is filled into the joint 8 at the bottom of the precast member 2A in which the first reinforcing bar 6 is arranged and into the underside of the precast member 2. The upper end of the second reinforcing bar 4 is inserted into the joint 8 of the precast member 2A, and the precast member 2A is fixed to the upper surface of the precast member 2.

[0031] As shown in Fig. 6, grout is filled into the joint 8 at the bottom of the other precast member 2A in which the first reinforcing bar 6 is arranged and into the underside of the precast member 2. The upper end of the first reinforcing bar 6 is inserted into the joint 8 of the other precast member 2A, and the other precast member 2A is fixed to the upper surface of the existing precast member 2A.

[0032] As described above, the process of fixing another precast member 2A to the upper surface of an existing precast member 2A is repeated multiple times, thereby constructing a precast concrete structure 1.

[0033] As described above, according to the precast concrete structure 1, by arranging the second reinforcing bars 4, which are stronger than the first reinforcing bars 6, in the precast member 2 fixed to the upper surface of the base M, it is possible to make the precast member 2 thinner than in conventional construction methods and to form a smaller cross section of the base M. According to the precast concrete structure 1, by making the precast member 2 thinner, it is possible to reduce the formwork for forming the precast member 2.

[0034] According to the precast concrete structure 1, by thinning the precast members 2, the amount of concrete used can be significantly reduced over the entire axial length of the precast concrete structure 1. According to the precast concrete structure 1, the height of the precast members 2 is formed to be higher than in conventional construction methods, so the number of steps required for installation can be reduced and the construction period can be significantly shortened. According to the precast concrete structure 1, the height of the precast members 2 is formed to be higher than in conventional construction methods, so the number of rebar joints can be reduced and construction costs can be reduced.

[0035] Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment and can be modified as appropriate without departing from the spirit of the present invention. For example, although the precast concrete structure is applied to a columnar structure, it may be applied to a beam member. [Explanation of symbols]

[0036] 1 Precast concrete structure 2 Precast members 3. Steel Bars 4 Second Reinforcement Bar 6 First Reinforcement Bar 8. Joints M base

Claims

1. A plurality of precast members formed of precast concrete; A first reinforcing bar arranged vertically in the plurality of precast members stacked in the vertical direction; and a second reinforcing bar arranged vertically in a precast member arranged at a base among the plurality of precast members, The second reinforcing bar is formed to have a strength higher than that of the first reinforcing bar, The amount of the precast concrete used in the precast member is set to be smaller than that in the case where the strength of the second reinforcing bar is the same as that of the first reinforcing bar. Precast concrete structure.

2. A precast concrete construction method for constructing a concrete structure using the precast member according to claim 1, A step of fixing a precast member having a second reinforcing bar, the second reinforcing bar having a strength higher than that of the first reinforcing bar, arranged vertically to a base; a step of fixing another precast member having the first reinforcing bar arranged vertically above the precast member; Fixing the other precast member above the other precast member; The present invention is characterized in that it comprises Precast concrete construction method.

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