JPH07207800A - Floor construction method using precast reinforced concrete girders and steel beam girders - Google Patents

Abstract

(57) [Summary] [Purpose] The weight of the girder is reduced and the load on the girder is reduced by simplifying the connection between the girder and the girder. [Structure] A precast reinforced concrete beam member in which a plurality of plate-shaped pieces are attached on both sides and steel plates with a plurality of connecting bolt holes drilled at the left and right ends are embedded in such a manner that the left and right ends project from the member in the direction orthogonal to the longitudinal direction. As a girder, H-shaped steel having a plurality of connecting bolt holes drilled at both ends of the web between the girders is connected to the girder as a girder through the connecting bolt holes, and an embedded floor formwork is laid on the beam. After arranging the girder upper end reinforcement and slab reinforcement, slab concrete is placed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a floor construction method for reducing the weight of a reinforced concrete building and using an embedded formwork as the floor formwork to simplify the construction.

[0002]

2. Description of the Related Art When constructing a reinforced concrete building, a so-called precast reinforced concrete construction method is used, in which precast reinforced concrete members are used for each member such as columns, beams, walls and floors, and each of these members is assembled on site. It has become more and more popular in recent years from the viewpoints of automation, shortening of construction period, and reduction of construction cost. When the precast reinforced concrete member is used as the beam member in this precast reinforced concrete construction method, the precast reinforced concrete member is used for both the large beam and the small beam.

[0003]

When a precast reinforced concrete member is used as a beam, it is necessary that both ends thereof extend through the beam while being connected to the precast reinforced concrete member which is a girder. In other words, it is necessary to connect the large beams and the small beams so as to ensure the integrity with the large beams while connecting the small beams having a large self-weight so as not to impair the continuity. For this reason,
The connecting portion between the large beam and the small beam is large and complicated. For this reason, the load on the girder is increased, and the girder is inevitably increased in size. As a result, the pillar and the foundation are also inevitably increased in size.

[0004]

According to the present invention, a beam is lightened by using an H-shaped steel in place of a precast reinforced concrete member as a beam, and a steel plate for beam connection is embedded in the precast reinforced concrete member which is a large beam. By doing so, the connection between the girder and the girder is simplified, and the load on the girder is reduced. As a result, it is possible to reduce the size of the girder, and it is also possible to reduce the size of the pillar and the foundation, thus reducing the construction cost.

That is, according to the present invention, a plurality of plate-like pieces are attached to both sides, and a steel plate having a plurality of connecting bolt holes drilled at both left and right ends is embedded in such a manner that the left and right ends project from a member in a direction orthogonal to the longitudinal direction. The precast reinforced concrete beam member is used as a girder, and H-shaped steel with a plurality of connecting bolt holes drilled at both ends of the web between the girders is connected as a girder to the girder through the connecting bolt holes, and the floor is buried on the beam. Lay the formwork,
The floor construction method consists of placing slab concrete after arranging the upper beam and slab reinforcement of the large beam.
In the present invention, precast reinforced concrete members are used for the large beams, and H-shaped steel is used for the small beams, so that construction of a formwork for the beam members is unnecessary. Nevertheless, since constructing a formwork for a floor member runs counter to purposes such as simplification of construction and reduction of construction cost, in the present invention, an embedded formwork for a floor member is used. Is used, and no diversion form is used. As such a buried form, a usual iron plate incorporating a reinforcing bar or an iron plate discarding form is used. Precast reinforced concrete floor slabs are also used as buried formwork,
From the viewpoint of reducing the weight of the slab after placing the slab concrete, it is preferable to use an ordinary iron plate with a reinforcing bar or an iron plate discarding formwork.

Since the H-section steel used as a beam is exposed on the surface even after construction, it is necessary to coat the surface with a refractory material after construction when constructing a refractory structure (most are the same). . After the construction, a method of spraying a refractory material on the exposed surface or pasting a refractory material forming plate is not preferable because it requires assembling a scaffold on the floor of the lower floor. In advance
Except for the joints on the exposed surface of the H-shaped steel, the fire-resistant molded plate is used to cover the joints. To cover the joints, the fire-resistant molded plate is separately slidably attached to the outer periphery of the fire-resistant molded plate. After attaching to the girder, it is preferable that the refractory material forming plate of the joint portion is slid and fixed to the girder so that the joint portion is also covered.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings.

FIG. 1 shows an example of a steel plate with a plate-like piece embedded in a precast reinforced concrete member used as a girder in the present invention. (A) is an elevation view and (b) is A-A of (a). FIG.

A total of eight L-shaped steel pieces 7 are fixed by bolts 8 to both sides of a steel plate 6 having an opening 10 in the center. The left and right ends of the steel plate 6 are provided with four connecting bolt holes 9 on one side and a total of eight connecting bolt holes 9. This steel plate with plate 5
L-shaped steel pieces 7 are all buried in the left and right connecting bolt holes 9
Is embedded in the precast reinforced concrete member in such a manner that the portion of is projected outward. The number of L-shaped steel pieces 7 fixed to the steel plate 5 with plate-shaped pieces and the number of connecting bolt holes 9 to be drilled are appropriately increased or decreased depending on the size of the precast reinforced concrete girder 2 and the size and length of the H-shaped steel 3 which is a girder. To be done. A precast reinforced concrete girder 2 is placed in the center of the steel plate 6.
The opening 10 is provided in order to maintain the continuity of the concrete in the longitudinal direction, but since the continuity of the concrete in the longitudinal direction is temporarily maintained by the concrete above and below the steel plate 6, it is not necessary to forcibly provide the opening 10. Good.

2A and 2B show the arrangement and connection of large beams and small beams at the time of construction according to the present invention. FIG. 2A is a plan view and FIG. 2B is a view as seen from arrow A in FIG.

The connection of the girders and the girders and the construction procedure of the present invention will be described with reference to FIG.

(1) A precast reinforced concrete girder 2 is bridged between columns 1.

(2) In the precast reinforced concrete girder 2, a steel plate 5 with a plate-like piece is embedded in the middle portion, both left and right ends thereof project outward, and a connecting bolt hole 9 is drilled in the projecting portion. On the other hand, the webs at both ends of the H-shaped steel 3 which is a beam are similarly provided with connecting bolt holes at positions corresponding to the connecting bolt holes 9. The H-shaped steel 3 is bridged between the precast reinforced concrete girders 2 by overlapping and connecting the bolt holes for connecting the both.

(3) Laying the buried floor formwork 4 on the beam,
The girder upper end reinforcement 12 and the slab reinforcement are arranged.

(4) The slab concrete 13 is poured.

The floor surface is completed as described above.

FIG. 2 shows an example in which one H-shaped steel 3 which is a small beam is bridged over the middle of the girder 2, but a plurality of H-shaped steels 3 may be provided between the girders 2 depending on the structure. At that time, a precast reinforced concrete member in which a plurality of steel plates with plate-like pieces 5 are embedded is used as the large beam 2 connecting the H-shaped steel 3 which is a small beam.

FIG. 3 shows an example in which an exposed surface of an H-shaped steel 3 is covered with a refractory material forming plate as a beam, and (a) is a vertical sectional view of a connecting portion with a girder, (b). 7A is a view from the arrow A of FIG. 7A, and FIG. 8C is a view from the arrow B of FIG.

Wood pieces 18 for locking the refractory material forming plate 14 are continuously or intermittently adhered to the inner surface of the flange of the H-shaped steel 3, and the refractory material forming plate 14 is nailed or screwed to the wood piece 18 from three sides. Most of the exposed surface of the H-shaped steel 3 is covered with a trapezoidal cross section when stopped. An L-shaped steel piece 17 is welded to the H-shaped steel 3 so as to cover the end surface of the refractory material forming plate 14 on the end side, and serves as a guide plate for sliding a sliding refractory material forming plate 15 described later. The sliding refractory material forming plate 15 is a refractory material forming plate for covering the exposed surface of the joint after connecting the H-shaped steel 3 to the girder 2, and is slidably fitted on the outer periphery of the refractory material forming plate 14. Has been. After connecting the H-shaped steel 3 to the girder 2, the sliding refractory material forming plate 15 is slid to the girder 2 side to fix the end surface to the girder 2 by adhesion or the like, and the end portion on the refractory material forming plate 14 side is formed with the refractory material. The plate 14 is fixed with nails or screws.

In FIG. 3A, the sliding refractory material forming plate 15 shows the position before sliding, and the sliding refractory material forming plate 16 shows the position after sliding.

[0021]

As the weight of the girder is light and the connecting portion between the girder and the girder is simplified, the load on the girder can be reduced and the girder can be downsized, and even the pillar and the foundation. The size can be reduced and the construction cost can be reduced.

[Brief description of drawings]

1 shows an example of a steel plate with plate-like pieces embedded in a precast reinforced concrete member used as a girder in the present invention, (a) is an elevation view, (b) is A- of (a)
FIG.

2A and 2B show arrangement and connection of a large beam and a small beam at the time of construction of the present invention, FIG. 2A is a plan view, and FIG. 2B is a view seen from an arrow A in FIG.

FIG. 3 shows an example in which an exposed surface of an H-shaped steel is covered with a refractory material forming plate as a beam, (a) is a vertical sectional view of a connecting portion with a girder, and (b) is (a) ) A arrow view,
(C) is a B arrow view of (a).

[Explanation of symbols]

1 .. Pillars 2. Precast reinforced concrete girders
3 ・ ・ H type steel (small beam), 4 ・ ・ Buried floor formwork, 5 ・ ・ Steel plate with plate-like piece, 6 ・ ・ Steel plate, 7 ・ ・ L type steel piece, 8 ・ ・ Bolt, 9 ・ ・ Bolt hole for connection 10 ・ ・ Opening, 11 ・ ・ Stirrup bar, 12 ・ ・ Large beam top bar, 13 ・ ・ Slab concrete, 14 ・ ・ Refractory material forming plate, 15, 16 ・ ・ Sliding refractory material forming plate, 17 ・ ・ Sliding Dynamic refractory material molded plate guide plate, 1
8 ... Wood piece for locking fireproof molded plate.

Claims (2)

[Claims] 1. A precast reinforced concrete beam in which a plurality of plate-like pieces are attached to both sides, and steel plates having a plurality of connecting bolt holes drilled at both left and right ends are embedded so that the left and right ends project from a member in a direction orthogonal to the longitudinal direction. The member is a girder, and H-shaped steel having a plurality of connecting bolt holes drilled at both ends of the web between the girders is connected as a small beam to the large beam through the connecting bolt holes, and an embedded floor formwork is laid on the beam. The floor construction method that includes placing the slab concrete after placing the upper beam and the slab reinforcement of the large beam. 2. An H-shaped steel having a refractory material covering three peripheral surfaces other than the upper surface of the H-shaped steel except for the upper surface, and a sliding refractory material slidable along the outer periphery of the refractory material at both ends. The floor construction method according to claim 1, wherein is used as a beam.