JPS6137688Y2 - - Google Patents

Description

[Detailed description of the invention] This invention is a PRC consisting of a beam made of precast reinforced concrete into which prestress is introduced by pre-tensioning or post-tensioning, and a cast-in-place concrete part that is reinforced and cast on-site. Concerning end joint structure in composite beams.

Conventionally, in this type of end joint structure, Fig. 1A,
As shown in B, the gusset plate b, its anchor reinforcement c, and the anchor plate e that fixes the end of the prestressed steel material d were individually buried in the end of the beam member a, which resulted in a large number of parts. It is inconvenient to manufacture, increases manufacturing cost, and has disadvantages such as the fact that the force generated at the end of the beam is not smoothly transmitted and dispersed to the beam material, making it impossible to utilize the members effectively.

This invention solves these conventional drawbacks all at once,
Due to the small number of parts, the structure is easy to manufacture and costs are reduced, while ensuring sufficient rigidity at the beam end and effectively transmitting prestress.
This provides an end joint structure for PRC composite beams.

Hereinafter, embodiments of the present invention will be described based on the drawings.

Figures 2 and 3 show that the post tension
A PRC composite beam A is shown, which is composed of a pre-stressed precast reinforced concrete beam 1 and a cast-in-place concrete part 3 with the upper end beam main reinforcing bars 2 placed on top of it.
2' is the main beam reinforcement at the lower end embedded in beam material 1, 4...
is a prestressed steel material (a prestressed steel bar is used, but a large number of bundled prestressed steel wires or stranded prestressed steel wires may also be used). The PC steel materials 4 may be arranged either in a straight line or in a catenary line as a post-tension system. In addition, the upper surface of the beam material 1 is designed to prevent slipping between it and the cast-in-place concrete portion 3.
Either finish it in a rough texture as usual, or
As shown in the figure, at the end of the beam, the connecting reinforcing bars 5 surrounding the upper and lower beam main bars 2, 2' are connected to a stirrup 9.
It shall be placed between.

This invention is a PRC composite beam A with such a configuration.
In this case, a jig B for reinforcing the beam end and for joining is embedded in the end of the beam 1 as described below.

That is, as shown in FIGS. 2 to 7, there is an anchor plate 6 with four corners cut off, which fixes the end of the PC steel material 4 by fixing means such as a nut, and the anchor plate 6 forms a T-shape in plan view. A gusset plate 7 protrudes from the center of the surface of the anchor plate 6 so as to have a shape and is integrated by welding, and reinforcing reinforcing bars 8 welded to two upper and lower locations on the back side of the anchor plate 6...
and the reinforcing bars 10 wound around the reinforcing bars 8... constitute the jig B, and most of the reinforcing bars 8... are parallel to the beam material 1 in plan view. However, the gusset plate 7 and the beam material 1
Anchor plate 6 due to the tensile force acting between
In order to prevent the anchor plate 6 from being deformed using the joint with the gusset plate 7 as a fulcrum, the anchor plate 6 is
It is bent straight or with an appropriate curvature toward the center (center of the beam 1). That is, each reinforcing reinforcing bar 8 includes a pair of straight portions 8a parallel to the longitudinal direction of the beam 1, and an inclined portion 8b bent from the tip thereof toward the central portion of the anchor plate 6.
and a welding margin portion 8c located between the tips of these inclined portions 8b and parallel to the plate surface of the anchor plate 6. Reinforcement bar 10...
. . . is a reinforcing reinforcing bar 8 . . . wrapped around it in a hoop shape or spiral hoop shape and fixed with a binding wire, and serves to restrain the concrete.

As described above, according to the present invention, the anchor plate 6 that fixes the end of the PC steel material 4 to the end of the beam 1, and the A gusset plate 7 integrally protrudes from the center of the surface of the anchor plate 6, and a gusset plate 7 integrally protrudes from a plurality of upper and lower locations on the back side of the anchor plate 6, parallel to the longitudinal direction of the beam member 1 in plan view. A pair of straight parts 8
a, a reinforcing reinforcing bar 8 consisting of an inclined part 8b that slopes from its tip toward the center of the anchor plate 6, and a welding margin part 8c for the anchor plate 6, and winding around these reinforcing reinforcing bars 8... Since the end reinforcement/joint jig B composed of the reinforced reinforcing bars 10... is buried, the shear force acting on the gusset plate 7 is transferred to the beam via the anchor plate 6 and reinforcing bars 8... It is transmitted and distributed over a wide range to the material 1, and the bearing surface of the anchor plate 6 is large, and the reinforcing bar 10
The concrete is sufficiently restrained by ..., the prestress is effectively introduced by the prestressing steel material 4, and the rigidity of the beam end can be ensured sufficiently, while the gusset plate 7 and anchor plate 6 and the reinforcing reinforcing bars 8... are integrated, so the number of parts when manufacturing the beam 1 is reduced, making it possible to simplify the structure, save labor in manufacturing, and reduce costs. .

[Brief explanation of drawings]

Figures 1A and 1B are a side view and a plan view of the end of a precast reinforced concrete beam showing a conventional example. Figure 2 and subsequent figures show examples of the present invention.
Figure 2 is a vertical side view of a PRC composite beam, Figure 3 is a cross-sectional plan view of the same as above, Figure 4 is an enlarged cross-sectional view taken along the - line in Figure 2, Figure 5 is an enlarged cross-sectional view taken along the - line in Figure 2,
6 is an enlarged sectional view taken along the line -- in FIG. 2, and FIG. 7 is a perspective view of the main parts. A... PRC composite beam, B... End reinforcement/joint jig, 1... Precast reinforced concrete beam material, 2, 2'... Beam main reinforcement, 3... Cast-in-place concrete part, 7... Gusset plate, 6...
Anchor plate, 4...PC steel material, 8...Reinforcement bar, 8a...Straight section, 8b...Slanted section, 8
c...Welding allowance part, 10...Reinforcement bar.

Claims (1)

[Scope of utility model registration request] Consists of a pre-stressed precast reinforced concrete beam and a cast-in-place concrete section with reinforcement placed on top of it and cast-in-place concrete.
In PRC composite beams, PC is installed at the end of the beam material.
An anchor plate perpendicular to the longitudinal direction of the beam material for fixing the end of the steel material, and a gusset plate integrally protruding from the center of the surface of the anchor plate so as to form a T-shape in plan view together with the anchor plate. and a pair of straight line portions that protrude integrally from a plurality of upper and lower locations on the back side of the anchor plate and are parallel to the longitudinal direction of the beam material in plan view, and a pair of straight line portions extending from the tips of the straight line portions toward the center portion of the anchor plate. An end reinforcement/joint jig consisting of previously sloped sloped parts, reinforcing reinforcing bars with a welding allowance located between the tips of these sloped parts, and reinforcing bars wrapped around these reinforcing bars. An end joint structure in a PRC composite beam characterized by being buried.