JPH0699956B2 - Construction method of reinforced concrete structure - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for constructing a reinforced concrete structure,
In particular, the present invention relates to a method for constructing a reinforced concrete structure in which the lower main rebars of a beam in the constructed reinforced concrete structure are arranged in multiple stages.

(Prior art) When the stress generated in the beam is large, such as when the reinforced concrete structure to be constructed is high-rise or when the beam span in the structure is long, the lower main rebar of the beam is reinforced in multiple steps. It

As one of the construction methods of a reinforced concrete structure including such a beam, a reinforcing bar basket having lower end main reinforcing bars arranged in a plurality of stages is formed by the ground structure, and after arranging this at a predetermined position,
There is a method in which a beam form is arranged and concrete is placed in a space defined by the form. The rebar cage used in this method is assembled in two directions, that is, a cross, a T-shape or an L-shape when viewed two-dimensionally. However, in the above method, since all the beams are made of cast-in-place concrete,
There are problems in labor saving and high quality construction.

In order to solve the above problem, there is a method in which a part of a beam including a column-beam intersection, a so-called panel zone, is used as a precast member (Japanese Patent Laid-Open No. 62-6034). This method contributes to labor saving and quality improvement of the construction by using the panel zone that includes a part of the beam and where the reinforcing bars are intertwined, as a precast concrete member. Therefore, it becomes difficult to manufacture and transport the precast concrete member. From the viewpoint of reducing the number of connections and the stress generated in the beam, it is desirable to connect the main beam reinforcing bars to the center of the span.
However, if the beam main rebar of the precast concrete member is extended to the center of the span, it will be more difficult to transport, and since the weight will increase, a large mechanical equipment is required to lift the precast concrete member, It is uneconomical.

(Problems to be Solved by the Invention) The present invention promotes prefabrication by using precast concrete members that are easy to manufacture, transport, and handle, and at the same time reasonably arranges lower-end main reinforcing bars intersecting each other in multiple stages. An object is to provide a method of constructing a reinforced concrete structure that can be arranged.

(Means for Solving the Problem) In the method for constructing a reinforced concrete structure of the present invention, a pair of concrete beam main parts spaced apart from each other so that their end faces face each other, and both beam main parts are connected to each other. A plurality of first lower ends and a plurality of second lower ends that extend through the lower portion of the beam main body and are separated from each other in the height direction of the beam main body. A precast concrete member including a streak, a plurality of second lower end streaks, and a plurality of stirrup streaks having an upper end projecting above the beam main body is provided at an upper portion of a pillar main body of a structure between the beam main bodies. And a rebar cage for a beam extending in a direction intersecting with the precast concrete member, the rebar cage having a plurality of third lower end rebars is provided at an upper portion of the pillar main body portion in the precast concrete. A plurality of fourth lower end reinforcements are passed through the rebar cage so as to intersect the member and pass between the first and second lower end reinforcements below the third lower end reinforcement, After or prior to this, the precast concrete member may be provided with a plurality of upper beam reinforcements for beams extending parallel to the first and second lower reinforcement lines.

(Advantageous Effects of the Invention) The precast concrete member used in the present invention has an I-shape that includes a pair of reinforced concrete beam main parts that are connected at intervals by first and second lower end reinforcements so that their end surfaces face each other. That is, since it has a structure that spreads in only one direction, it is easier to manufacture and carry out compared to a conventional precast concrete member that spreads in two directions.

The third lower end bar used for forming the beam intersecting with the precast concrete member is arranged at a predetermined position as a reinforcing bar cage formed together with other reinforcing bars. Therefore, the fourth lower end bar for the reinforcing bar cage is simply arranged so as to extend in the direction intersecting with the first lower end bar for the precast concrete member and the fourth lower end bar for the precast concrete member. Can be formed.

(Example) Hereinafter, the Example of this invention shown in drawing is described.

FIG. 1 shows a precast concrete member 10 of the present invention.
It is shown. The precast concrete member 10
It includes a pair of beam main parts 12 made of reinforced concrete that act as beams in a reinforced concrete structure.

The beam main body 12 is arranged at intervals so that the end faces thereof face each other, and a plurality of lower end streaks 14 and 1 for beams are provided.
Connected to each other by 6. Each of the lower end streaks 14 and 16 extends through a portion of the beam main body 12 below the beam main body 12 and separated from each other in the width direction. The lower end streak 14 is disposed below the lower end streak 16.

The beam main body 12 is provided with a plurality of stirrup bars 18 that interconnect the reinforcing bars for the beams. The upper end of each stirrup bar 18 projects upward from the concrete portion of the beam main body 12.

FIG. 2 shows a rebar cage 20 for a beam used together with the precast concrete member 10 when constructing a reinforced concrete structure. When the reinforcing bar cage 20 is formed as a beam of a constructed structure, a plurality of upper end reinforcements 2 extending in parallel to each other in the widthwise direction of the beam above the beam 2 are formed.
2, 24, a plurality of lower end streaks 26 extending in parallel at the lower end of the beam and separated from each other in the width direction of the beam, and upper end streaks 22, 2
4 and multiple stirrup streaks 2 interconnecting the lower stirrup 26
Including 8 and. The dimensions of the stirrup bar 28 are substantially the same as those of the stirrup bar 18 of the precast concrete member 10. The upper end reinforcement 22 or 24 of the rebar cage 20 may not be provided.

Next, the construction method of the present invention will be described with reference to FIG.

As shown in FIG. 3 (A), a plurality of columns 32 are built on the floor upper surface 30 of the lower floor at predetermined intervals. In the column 32, a plurality of column main bars 34 extending in the vertical direction and a plurality of hoop lines (not shown) connecting the column main bars to each other are arranged. The upper end portion of the column main bar 34 is projected from the column 32 so that the height position of the upper end of the column main bar 34 is higher than the height position of the beam.

In the precast concrete member 10, as shown in FIG. 3 (A), the space between the beam main parts 12 is the upper part of the pillar 30, and
It is arranged by means of a crane or the like so that the ends of the beam main body 12 on the side of the opposing end faces are placed on the columns 30. In the state where the precast concrete member 10 is arranged on the columns 32, the column main bars 34 of the columns 32 extend upward between the beam main parts 12. A plurality of spacers 36 that form a gap between the beam main body 12 and the pillar 32 are arranged in advance.

Next, as shown in FIG. 3 (B), when the rebar cage 20 is above the pillar 30, it extends between the beam main parts 12 in the direction intersecting with the precast concrete member 10 and the lower end bar 26 has the precast concrete member 10. So that it touches the lower end muscle 16 of
It is arranged by means such as a crane. At this time, it is desirable that the lower end reinforcement 38, which will be described later, is also temporarily fixed to the lower portion of the stirrup reinforcement 28 of the rebar cage 20 as shown in FIG.

In a state where the reinforcing bar cage 20 is arranged as shown in FIG. 3 (B), the reinforcing bar cage 20 is supported by the lower end bar 16 of the precast concrete member 10, and the column main bar 34 projects upward from the reinforcing bar cage 20. There is.

Next, as shown in FIG. 3 (B), the bottom end bar of the rebar cage 20
38 is inserted between the lower end portions of the stirrup bar 28 and the lower end bar 26 and between the lower end bars 14 and 16 of the precast concrete member 10.

Next, as shown in FIG. 3 (C), the upper end bar 40 of the precast concrete member 10 is inserted between the upper end bars 22 and 24 of the reinforcing bar cage 20 at the upper part of the hoop bar (not shown). At the same time, the upper end reinforcement 42 is inserted below the upper end reinforcement 40 and the upper end reinforcement 24 of the reinforcing bar cage 20. As a result, the precast concrete member 10 and the rebar cage 20 are joined as shown in FIG. 3 (D).

The upper end streaks 40 of the precast concrete member 10 are
It may be arranged before the lower end bar 38 of the reinforcing bar cage 20 is arranged.

Next, the formwork and beam main body 12 that define the space for the floor slab.
And a form defining a space between the columns 32, a form defining a connection between adjacent precast concrete members 10, a form defining a space for embedding the exposed rebar of the precast concrete member 10, And, after the formwork which defines the space for the beam extending in the direction intersecting with the precast concrete member 10 is arranged, concrete is poured into the space defined by these formwork.

Thereby, the beam extending in a cross shape, the pillar 32, and the floor slab are integrally formed. After this, columns for the next floor will be built on the new floor. The above steps are repeated for each floor of the structure to be built.

[Brief description of drawings]

1 is a perspective view showing an embodiment of a precast concrete member used in the present invention, FIG. 2 is a perspective view showing an embodiment of a rebar cage for a beam used with the precast concrete member shown in FIG. 1, 3 The figure is an explanatory view of the construction method of the present invention, FIG. 3 (A) is a view showing a state in which a precast concrete member is arranged on a pillar of a lower floor, and FIG. 3 (B) is a reinforcing bar basket on a pillar. Fig. 3 (C) shows a state in which the upper end reinforcements for precast concrete members are arranged, and Fig. 3 (D) shows a state in which the arrangement of all the reinforcing bars for beams is completed. It is a top view shown. 10: Precast concrete member, 12: Beam main part, 14, 16: Lower end bar of precast concrete member (first and second lower bar), 18, 28: Stirrup bar, 20: Reinforcing bar cage for beam, 22, 24: Reinforcing bar upper end bar, 26, 38: Reinforcing bar bottom end bar (3rd and 4th bottom bar), 32: Column, 40, 42: Precast concrete member top bar.

Claims (1)

[Claims] 1. A pair of concrete beam main parts spaced apart from each other so that their end faces are opposed to each other, and a plurality of plurality extending through the lower part of the beam main parts so as to connect both beam main parts to each other. A plurality of first lower end reinforcements and a plurality of second lower end reinforcements that are separated from each other in the height direction of the beam main body, and a plurality of second lower end reinforcements; The precast concrete member having a plurality of stirrup bars having an upper end portion protruding upward is arranged so that the space between the beam main parts is the upper part of the pillar main part of the structure,
A reinforcing bar basket for beams extending in a direction intersecting with the precast concrete member, the reinforcing bar basket having a plurality of third lower end bars is arranged so as to cross the precast concrete member at an upper portion of the column main body, A plurality of fourth lower end reinforcements are passed through the rebar cage so as to pass between the first and second lower end reinforcements below the third lower end reinforcement, and thereafter or prior to the precast concrete member. A method for constructing a reinforced concrete structure, comprising arranging a plurality of upper end reinforcements for beams so as to extend parallel to the first and second lower end reinforcements.