JP6873641B2 - Precast concrete floor slab with looped joints - Google Patents

Description

The present invention relates to a precast concrete deck with a looped joint.

As one of the means for connecting the decks of the bridge, for example, as shown in FIGS. 3 and 4, the loop-shaped joint reinforcing bars (loop-shaped joints 3) of the decks 1 and 2 of each other are connected in the direction perpendicular to the bridge axis. Reinforcing reinforcing bars 4 are inserted and arranged in each loop-shaped joint 3 at intervals or overlapped with each other in the width direction T1 of the floor slabs 1 and 2. A structure A for connecting adjacent floor slabs 1 and 2 by placing concrete 6 in the connecting portion 5 is used (see, for example, Patent Document 1).

Further, when applying this type of connection structure A, reinforcing bars are embedded in the deck body 1b and 2b so that both ends of the loop joint 3 protrude from the joint end faces 1a and 2a of the deck body 1b and 2b. Precast concrete decks (including precast PC decks) that are arranged and provided with a loop-shaped joint 3 in advance are often used. That is, in general, the connecting structure A provided with the loop-shaped joint 3 is configured to connect the precast concrete decks 1 and 2 with each other by an RC structure.

Further, the loop-shaped joint 3 is arranged in the vertical direction of the thickness direction T3 of the decks 1 and 2 when viewed from the front in the bridge axis direction T2, and is spaced apart from each other in the width direction T1 in the direction orthogonal to the bridge axis. A plurality of them are arranged. Further, the inner bending diameter dB and the like of the loop-shaped joint 3 are set according to the loop reinforcing bar diameter, the arrangement interval and the like.

JP-A-2009-264040

Here, in the "Road Bridge Specification / Explanation Steel Bridge Edition" (Japan Road Association: March 2012), the minimum deck thickness of the PC deck is 210 mm when the deck span is 4 m.

On the other hand, when the conventional connection structure A of the loop-shaped joint 3 is provided, the minimum deck thickness of the precast PC floor slab is the bending shape (inner bending diameter dB) of the loop-shaped joint 3 and the floor slab arrangement. The minimum floor slab thickness is 240 mm when the floor slab span is 4 m, which is determined by the connection of the streaks and the arrangement margin of the pretension PC steel material (see FIG. 4).

That is, in the connection structure A of the conventional loop-shaped joint 3 and the floor slabs 1 and 2 provided with the connection structure A, the "Road Bridge Specification / Explanation Steel Bridge Edition" (Nippon Road Association: March 2012) It was not possible to meet the specified minimum deck thickness of 210 mm, which severely restricted its application.

In view of the above circumstances, it is an object of the present invention to provide a precast concrete deck slab provided with a loop-shaped joint capable of reducing the minimum deck thickness as compared with the conventional case and improving applicability.

To achieve the above object, the present invention provides the following means.

The precast concrete deck provided with the loop-shaped joint of the present invention is a precast concrete deck provided with a loop-shaped joint for connecting adjacent floor slabs, and the loop-shaped joint is embedded in the deck body. It is formed on the formed main bar, is arranged so as to project outward in the axial direction from the joint end surface of the deck body, and has a predetermined angle with respect to the vertical direction in the thickness direction of the deck in front view from the axial direction. It is characterized in that a part of the loop-shaped joints adjacent to each other is arranged so as to be inclined so as to intersect with each other in a plan view.

In the precast concrete deck provided with the loop joint of the present invention, the precast concrete deck is provided with the loop joint at a predetermined angle, as compared with the conventional case where the loop joint is arranged vertically. The thickness of the concrete can be reduced according to the inclination angle.

This makes it possible to reduce the thickness of the deck and reduce the weight. Then, for example, it is possible to set the minimum deck thickness to the value specified in "Road Bridge Specification / Explanation Steel Bridge Edition" (Japan Road Association: March 2012), and loop joints can be used. It will be possible to expand the scope of application of the precast concrete deck provided (increasing versatility).

It is a side view which shows the connection structure of the precast concrete floor slab and the floor slab provided with the loop-shaped joint which concerns on one Embodiment of this invention. It is a front view which shows the connection structure of the precast concrete floor slab and the floor slab provided with the loop-shaped joint which concerns on one Embodiment of this invention. It is a side view which shows the connection structure of the precast concrete floor slab provided with the conventional loop-shaped joint, and the floor slab. It is a front view which shows the connection structure of the precast concrete floor slab provided with the conventional loop-shaped joint, and the floor slab.

Hereinafter, a precast concrete deck slab provided with a loop-shaped joint according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2. The present embodiment relates to a precast concrete deck of a bridge such as a road bridge or a railway bridge.

As shown in FIGS. 1 and 2, the precast concrete decks 1 and 2 of the present embodiment are formed with a loop-shaped joint 3 for connecting adjacent precast concrete decks 1 and 2. Further, in the precast concrete decks 1 and 2, the main bars (upper and lower main bars) embedded in the concrete of the deck bodies 1b and 2b are axially (bridged) from the joint end faces 1a and 2a of the deck bodies 1b and 2b. (Axial direction) A loop-shaped joint (loop reinforcing portion) 3 is formed by arranging the T2 so as to project outward and substantially U-shaped.

Further, a plurality of the loop-shaped joints 3 are arranged at predetermined intervals in the width direction T1 of the precast concrete decks 1 and 2.

Then, for example, the loop-shaped joints 3 protruding from the joint end faces 1a and 2a of the adjacent precast concrete decks 1 and 2 are overlapped with each other, and the reinforcing reinforcing bars 4 are inserted and arranged in each loop-shaped joint 3 and precast with each other. By placing concrete 6 in the padding / connecting portion 5 between the joint end faces 1a and 2a of the concrete decks 1 and 2, adjacent decks 1 and 2 are connected to each other by a loop-shaped joint 3 and concrete 6. It is integrally connected by the structure (RC structure part) B.

On the other hand, in the precast concrete decks 1 and 2 and the connecting structure B of the decks of the present embodiment, the loop-shaped joints 3 protruding from the joint end faces 1a and 2a of the precast concrete decks 1 and 2 are the precast concrete decks 1 and 2. A plurality of loop-shaped joints are arranged so as to intersect the vertical direction of the thickness direction T3 of the decks 1 and 2 at a predetermined angle θ when viewed from the front in the axial direction T1 of 2. 3 have the same inclination angle θ and are arranged in parallel.

By slanting the plurality of loop-shaped joints 3 at a predetermined inclination angle θ in this way, as compared with the case where the loop-shaped joints 3 are arranged vertically in the conventional manner, the precast concrete deck slab is secured while ensuring the cover of the main bar. The thickness of 1 and 2 can be reduced according to the inclination angle θ.

As a result, in the precast concrete decks 1 and 2 of the present embodiment, the loop-shaped joint 3 can be tilted diagonally to reduce the thickness of the deck and reduce the weight. For example, it has been confirmed that the weight can be reduced by about 13% per precast concrete deck.

In addition, the minimum deck thickness can be set to the value specified in "Road Bridge Specification / Explanation Steel Bridge Edition" (Japan Road Association: March 2012), and a loop-shaped joint 3 is provided. It is possible to expand the applicable range of the precast concrete decks 1 and 2 (improve versatility). As a result, it can be expected that the precast concrete decks 1 and 2 provided with the loop joint 3 will be applied to the large-scale renewal work of the deck in the future.

Further, by slanting the loop-shaped joint 3 at a predetermined inclination angle θ, as compared with the conventional case where the loop-shaped joint 3 is arranged vertically, even if the floor slab thickness is reduced, the floor slabs 1 and 2 And the shear strength, bending strength, etc. of the connecting structure B can be increased.

Although one embodiment of the loop-shaped joint precast concrete deck according to the present invention has been described above, the present invention is not limited to the above embodiment and can be appropriately modified without departing from the spirit of the present invention.

For example, in the present embodiment, the precast concrete deck (deck) according to the present invention has been described as being a bridge deck, but the precast concrete deck (deck) according to the present invention is a building or the like. It may be applied to the deck of other structures. Even in this case, it is possible to obtain the same effect as that of the present embodiment.

1 Precast concrete floor board (floor slab)
1a Joint end face 1b Floor slab body 2 Precast concrete floor board (floor slab)
2a Joint end face 2b Deck body 3 Loop joint 4 Reinforcing bar 5 Connection part 6 Concrete A Conventional floor slab connection structure B Deck connection structure T1 Width direction T2 Axial direction T3 Thickness direction

Claims (1)

A precast concrete deck with a looped joint for connecting adjacent decks.
The loop-shaped joint is formed in a main bar embedded in the deck body, is arranged so as to project outward in the axial direction from the joint end surface of the deck body, and has a thickness of the deck when viewed from the front in the axial direction. It is arranged so as to intersect the vertical direction in the vertical direction at a predetermined angle .
A precast concrete deck having a loop-shaped joint, wherein a part of the adjacent loop-shaped joints is arranged so as to overlap each other in a plan view.

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