JPS648145B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a precast concrete horizontal frame member using a method for constructing a precast concrete horizontal frame member for an SRC girder.

Conventionally, when installing precast concrete horizontal members such as small beams and slabs to SRC girders when integrally installed with cast-in-place concrete, the horizontal members were reinforced with assembled steel reinforcement and ribbed shapes. ,
Even if unsupported processing such as burying PC steel wires is performed, the horizontal members 1 should be supported by supporting supports 2 placed at their ends, as shown in Figure 1. At this point, it must be aligned with SRC girder 3 (Figure a). This means that even if the horizontal member 1 itself has the ability to be unsupported, its ends cannot be
This is because it is impossible to load and support the SRC girder reinforcements 3 in a typical manner, and after pouring and curing the cast-in-place concrete 4, the supports 2 are removed (Figure b).

Note that direct loading of the SRC girder reinforcements 3 of the horizontal members 1 onto the steel frame 3a is impossible due to the presence of the stirrups 3b.

In addition, unless the lower surface of the horizontal members 1 is placed in the beam as much as possible, the thickness of the slab will affect the floor height, so direct loading onto the flanges of the steel frames 3a of the horizontal members 1 is prohibited. Not usually done.

However, horizontal frame material 1 that can be erected without support
It is irrational that they are unable to demonstrate their abilities and have no choice but to rely on shoring.

The present invention was made in view of the above circumstances,
The gist of this is that when horizontal precast concrete horizontal members such as beams and slabs are integrally attached to SRC girders using cast-in-place concrete without shoring, they must be supported entirely with shoring. A supporting metal fitting that can be inserted between the stirrups is embedded in the horizontal member in advance so that it can be supported by the steel frame of the SRC girder, and the horizontal member is installed using this, and then, By folding the cast-in-place concrete in this state and making the horizontal members and cast-in-place concrete into an integrated structure, it is possible to construct the floor without supporting it, which streamlines the construction process.

Details of this will be explained below based on the drawings.

That is, as shown in FIG. 2a, the support metal fittings 5 for inserting between the stirrup bars embedded in predetermined positions at both ends of the horizontal member 1 allow the horizontal member 1 to be moved without being affected by the stirrups 3b of the SRC girder bars 3. It can be loaded onto the steel frame 3a.

The supporting hardware 5 is made of angle iron or channel steel, and its shape and required quantity are determined depending on the load to be supported.

After installing the horizontal members 1, cast-in-place concrete 4 is poured to create a slab structure that is integrated with the girders (b
Figure) Figure 3 shows the basic shape of the horizontal member 1 when it is implemented as a slab.

In other words, 6 in the figure shows a precast concrete cast-off form slab, which is shaped with ribs 7, etc. of embedded PC steel wires (not shown) at regular intervals, and the supporting hardware 5 is attached to the ribs 7. It is arranged with directionality on the axis line extension of.

Therefore, in the supporting hardware 5 in the above structure,
A large stress is applied due to the self-weight of the horizontal member 1, the weight of additional cast-in-place concrete, and the work load during construction, and the concrete surrounding the supporting hardware 5 is also subject to a large stress locally. Therefore, in order to safely support these loads, it is necessary to arrange appropriate reinforcing bars near the supporting hardware 5.

FIG. 4 shows a simple and
Demonstrates effective reinforcement measures.

That is, in a, stress concentration in the vicinity of the support hardware 5 is dealt with by winding reinforcing bars 8 in a spiral shape around the support hardware 5 and restraining the concrete 9. In b, an Ω-shaped reinforcing bar 10 is arranged across the support hardware 5 to prevent cracks 11 occurring diagonally from the support hardware 5. c shows an embodiment in which a and b are combined and reinforced depending on the magnitude of the load acting on the support hardware 5, thereby making it possible to construct a safe and economical support hardware. I can do it.

Therefore, in the present invention configured as described above, various effects as listed below can be achieved.

(1) After assembling the reinforcing bars of the SRC girders, the horizontal members can be installed by direct loading onto the steel frame, and cast-in-place concrete can be placed without the need for any shoring, and the horizontal members and SRC girder can be made into an integrated structure.

(2) By adopting the specified reinforcing means, a simple and sufficiently safe reinforcement method can be used to withstand the construction load acting on the supporting hardware of the horizontal members necessary for implementing this method. As a result, it becomes possible to design the support portion with excellent economic efficiency.

(3) If floor slab formwork is used as the horizontal member in this method, the slab should have excellent vibration and deflection properties by streamlining the slab formwork and providing fixity to both ends of the slab. I can do it.

[Brief explanation of the drawing]

Figures 1a and b are procedural diagrams of the conventional construction method, Figures 2a and b are explanatory diagrams of the construction procedure of the present invention, and Figures 3a and b are diagrams of the present invention implemented using slab formwork. The plan view, front view, and FIGS. 4a, 4b, and 4c are explanatory diagrams of reinforcing the supporting hardware in the present invention. 1...Horizontal member, 2...Shoring, 3...SRC girder reinforcement, 4...Cast-in-place concrete, 5...Support hardware, 3a...SRC girder, 3b...Stirrup, 8...Spiral reinforcing bar, 10...Reinforcement bar.

Claims (1)

[Scope of Claims] 1. A horizontal member made of precast concrete that has been reinforced at both ends and has protruding supporting hardware for inserting between stirrup bars, is attached to the steel frame of an SRC girder via the supporting hardware. A method for erecting a precast concrete horizontal member for an SRC girder, characterized in that it is erected on top of an SRC girder, and cast-in-place concrete is poured without support to integrate it with the girder. 2. A horizontal member made of precast concrete, characterized by having support metal fittings for inserting stirrup bars protruding from both ends after being reinforced. 3. According to claim 2, the supporting hardware is made of angle-shaped steel or groove-shaped steel for insertion between stirrup bars, the periphery of the supporting hardware is reinforced with spiral reinforcing bars, and the supporting hardware is made to protrude from both ends. Horizontal members made of precast concrete. 4. According to claim 2, the supporting metal is made of angle-shaped steel or groove-shaped steel for insertion between stirrup bars, the periphery of the supporting metal is reinforced with Ω-shaped reinforcement, and the supporting metal is made to protrude from both ends. Horizontal members made of precast concrete. 5. Claim 2, in which angle-shaped steel or groove-shaped steel is used as a supporting metal for inserting between stirrup bars, the periphery of the supporting metal is reinforced with spiral reinforcement and Ω-shaped reinforcement, and the supporting metal is made to protrude from both ends. Horizontal members made of precast concrete as described in .