JPH0555643B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method for constructing a composite structure by laying a precast concrete composite slab on a bridge, elevated road, elevated track, building frame, etc., and a method thereof. Regarding fixtures.

[Conventional technology]

The technology of forming concrete composite slabs on girders is widely used in bridges, expressways, buildings, frames, etc.

It is also known to use precast concrete as this concrete slab (Japanese Patent Application Laid-open No. 102405-1983).

In addition, many existing structures with concrete slabs mounted on girders require replacement of the slabs due to age-related deterioration. In particular, existing structures with cast-in-place concrete slabs constructed on steel girders tend to have significant cracking and deterioration. In the case of replacing existing floor slabs like this, complete replacement work must be carried out in a short period of time, such as nighttime construction, in order to eliminate traffic restrictions as much as possible.
It is absolutely impossible to construct a composite slab by removing the existing slab, attaching dowel bars, or reusing the existing dowel bars and pouring concrete.

Therefore, various rapid construction methods using precast concrete slabs have been developed.

For example, such a technique is disclosed in "Prestressed Concrete", Vol. 29, No. 4 (July and August 1987 issue), edited by Prestressed Concrete Technology Association, pages 36 to 44. Figure 6 shows the attachment part between the girder and the deck slab using this technology. In this technique, after removing the old slab, in order to match the installation heights of the old slab and the new slab 31, an angle iron 32 is installed along the side of the flange 6a of the main girder 6 at a portion corresponding to the height of the old slab hatch.
A precast deck slab 31 is attached thereon, a main girder flange 6a is drilled from the upper surface of the deck, and the deck and main girder are connected through this hole with high-tensile bolts 33.

The connecting bolts 33 are finally tightened after the vertical tightening of the floor slab 31 is completed and the space above the main girder flange 6a is filled with non-shrinkage mortar 34 and hardened.

Such a method requires time and effort to adjust the height of the deck slab, and the main girder flange 6
It requires a large-scale mechanical device, effort, and time to eliminate the holes in the hole a, and it is not easy to sufficiently fill the space between the steel girder 6 and the deck slab 31 with mortar 34.

In addition, the steel girder and deck slab are bolted together by friction, making it difficult to use as a composite girder.

[Problem to be solved by the invention]

When installing concrete slabs on girder materials, especially when replacing existing slabs, using precast concrete slabs allows for quick and short construction times, minimal traffic restrictions, and highly reliable construction. It has the advantage of being able to

In this case as well, there are still issues that need to be rationalized.

For example, in the conventional method of connecting the deck slab and girder with high-tensile bolts, it is necessary to drill holes in the steel girder flange to match the holes in the deck slab on site, which requires equipment, labor, and time. On-site work such as adjusting the height of the floor slabs is not easy, and it is difficult to reliably and accurately install composite floor slabs in a short period of time.

Therefore, significant traffic restrictions cannot be avoided when replacing existing floor slabs.

Furthermore, it is not possible to maintain the completely composite state of the structure before construction.

The present invention aims to provide a method for synthesizing a precast concrete slab on a girder and a girder that solves these problems.

In addition, the present invention is particularly advantageous when replacing an existing composite deck slab with concrete constructed on a girder, by using a precast concrete slab to minimize traffic restrictions and quickly and quickly increase the height of the deck relative to the girder. The purpose of the present invention is to provide a method that enables the construction of a composite floorboard in which adjustment of the girder and the combination of the girder and the floorboard can be performed using a single fixture.

Further, the present invention aims to provide a fixing tool that is most suitable for constructing the above-mentioned precast concrete composite deck slab.

[Means to solve the problem]

The present invention is a method for installing a precast concrete deck slab on a girder, which is characterized by the following technical means when laying a precast concrete deck slab for a composite girder on a girder.

(a) A plurality of precast concrete floor slabs are manufactured; (b) The slab has several headbands on its outer diameter, and a female-threaded tubular embedded body is embedded and fixed in a through-hole on the upper and lower surfaces. and a male threaded inner cylinder having a mortar filling groove that is screwed into the female thread, and a fixing device for fixing the girder and the floor slab is embedded in a portion of the deck that contacts the girder, (c) the precast Place the concrete slab on the girder and position the slab by adjusting the height of the fixtures on the girder. (d) Insert the PC steel material through the slab and post-tension it in the direction of the girder. (e) connect and fix the fixtures to the girder; (f) after fixing, connect the through hole and the space between the top surface of the girder and the bottom surface of the deck plate through the through hole; It is characterized by being filled with non-shrinking mortar.

The fixture used to carry out the method of the invention described above consists of a combination of the following technical means.

A tubular body with several headbands on its outer diameter, which is embedded and fixed in a through-hole on the upper and lower surfaces of a precast concrete slab, and an embedded body with a female thread; The inner cylinder has a mortar penetration groove in the threaded portion and a mortar penetration hole in the lower end wall.

The fixture may be made of steel or other metal, hard rubber or other polymeric material, or a composite material combining these materials.

[Effect]

Since the method of the present invention is configured as described above, a plurality of prestressed precast concrete slabs can be easily constructed on a girder, and the height of the girder can be easily and precisely adjusted. This makes it possible to completely synthesize the girder and deck slab without the need for dovetail bars, etc., and filling with mortar is easy and complete, allowing high-quality construction to be carried out quickly and in a short period of time. It is also possible to start traffic without filling the mortar if necessary.

The fixture used to carry out the present invention consists of an embedded body having several headbands on its outer diameter and buried through a concrete slab, and an inner cylinder screwed into the embedded body and having a mortar penetration groove and a mortar penetration hole. The height is adjustable and can be easily combined with the girder.
Further, mortar can be sufficiently filled from above, and a composite girder can be quickly and reliably formed by combining the prestressed precast concrete slab and the girder.

〔Example〕

The present invention was applied to the replacement work of a concrete deck slab with a girder length of 22.50 m on a 6 m wide bridge. This bridge has concrete slabs placed on steel girders.

The replacement process will be carried out between 9:00 pm and 6:00 am the next morning, with one section of 6 m wide x 6 m long being replaced.
It ended in 4 times.

Figure 1a is a plan view of this floor slab, which is a prestressed precast floor slab (2.0m x 6.0m x 18cm).
The floor slab is formed from 11 sheets.

Figure 1b is a side view and Figure 1c is an elevation view showing the width of the bridge.

FIG. 2 is a perspective view illustrating the relationship between the floor slab and the steel girder, and shows the floor slab cut at the position of the fixture.

The joint part of the joint 2 of the prestressed precast slab 1 is filled with non-shrinkage mortar and made of φ19.3mm PC
The floor slabs are integrated by tightening them with steel material 3.

Fixtures 100 are embedded in each of the floor slabs 1a, 1b, and 1c in a portion corresponding to directly above the steel girder 6, respectively. This fixture 100 has the shape shown in FIG. 3, and the attachment portion to the steel girder 6 is shown in FIG. 2, and a partially enlarged sectional view thereof is shown in FIG.

The entire work process for floor slab replacement work is as follows.

(b) Install suspended scaffolding.

(b) Giant breaker, truck crane,
Pavement and old concrete will be removed using dump trucks, backhoes, hand breakers, etc.

(c) Pour the concrete on the steel girder 6, gas cut the dowel bars, and clean the top surface of the steel girder 6 with a grinder, wire brush, etc.

(d) Lay the precast deck slab 1 on the steel girder 6, adjust the height position of the deck by adjusting the fixtures 100, and insert the PC steel material 3 into the sheath provided on the deck.

(E) Fill the joints between precast plates with non-shrinkage mortar, and after hardening, apply stress.

(f) Weld the fixture 100 and the steel girder 6.

(g) A quick-hardening non-shrinking mortar 7 is placed and grounding is performed inside the sheath and at the fixing end.

Next, embodiments of the fixture of the present invention will be described in detail below with reference to FIGS. 3 to 5. FIG. 3 is a perspective view showing an embodiment of the fixture 100 of the present invention, FIG. 3a is a perspective view of the female threaded embedding body 40, FIG. c is the embedded body 40 and the inner cylinder 5
0 is a perspective view showing a state in which the Fourth
The figure shows a precast concrete slab 1 placed on a steel girder 6 using an embedded body 40 embedded in the precast concrete slab 1 and an inner cylinder 50 screwed thereto, and filled with mortar 7. FIG. FIG. 5 is a detailed view of the part.

As shown in FIG. 3, the fixture 100 of the embodiment consists of an internally threaded embedded body 40 and an inner cylinder 50 that is screwed into this internal thread.As shown in FIG. It is embedded in 1.

As shown in FIG. 3a, the female threaded embedding body 40 is
It has a female thread 41 inside, as shown in FIG.
It is reliably embedded and fixed in the precast concrete floor slab 1 so as to form the inner walls of the upper and lower surface through holes of the floor slab 1. For this purpose, a plurality of headbands 42 are fixed to the outer diameter portion embedded in the concrete. As shown in FIG. 3a, this headband 42 is made by fitting a ring-shaped steel material with an arbitrary cross section onto the implant body, and
It is firmly fixed by welding the entire surface. This embedded body 40 is embedded in the precast concrete slab 1 during manufacture, and has a height lower than the thickness of the slab, is embedded within the thickness of the slab, and its upper and lower sides are The through hole is open.

The male threaded inner cylinder 50 is a hollow cylinder with a male thread cut on its outer diameter, and when this cylinder is twisted within the implant 40, it moves forward and backward in the direction of the thread pitch. This threaded portion is provided with a groove 54 into which mortar will later enter. There are 1 to 2 grooves 54 in the longitudinal direction of the inner cylinder.
It is preferable to provide one strip in the circumferential direction. As shown in FIG. 4, when the inner cylinder 50 is placed on the girder 6 and twisted, the floor slab 1 moves in the vertical direction, and the height of the floor slab 1 relative to the girder 6 can be precisely and finely adjusted. It is preferable to provide the upper edge of the male threaded inner cylinder 50 with a notch 53 in which a handle or the like for twisting is engaged.
Further, it is preferable that the inner cylinder 50 has a diameter/height ratio of 0.6 or more, and the lower end of the inner cylinder 50 can be easily welded 55 by inserting a welding rod into the hollow portion from above. Note that when the girder 6 or the inner cylinder 50 is made of other than steel, the inner cylinder 50 and the girder 6 can be fixed together with an adhesive. Therefore, the height adjustment and connection between the girder and the floor slab can be easily and reliably performed without requiring dowel bars or the like.

Furthermore, as shown in FIGS. 3b and 5, the inner cylinder 50
Since a mortar injection hole 52 is provided at the lower end of the mortar 7, as shown in FIG. 4, when filling the empty space with mortar 7, the space between the deck slab and the girder can be easily and completely filled with mortar.

As described above, the fixing device of the present invention can perform high-quality construction quickly and in a short time.

As a specific example of the fixture of the present invention, an example of a deck slab on a steel girder using steel fittings is shown in FIG.

The dimensions of the example are as follows.

Floor slab: 2m x 6m x 160mm thick Embedded body with female thread: Inner diameter 100mm x height 100mm Steel inner cylinder with female thread: Steel pipe 89.1mmφ x height 140mm x thickness
5.5mm Notch: Height 40mm x Width 35.3mm x 4 Thread grooves: Longitudinal direction 30mm x 2 threads, Circumferential direction 1 thread The male threaded steel inner cylinder 50 is a hollow tube, and the female thread is embedded with a screw. The height of the deck 1 and the steel girder 6 is adjusted by moving up and down inside the body 40. The lower end of the male threaded steel inner cylinder 50 is fixed to the steel girder 6 by welding 55, and the entire inner circumference can be continuously welded, making the welding work easy and reliable.
In this case, a welding rod is inserted from the upper surface of the deck 1 through the hollow part of the inner cylinder 50 to perform welding. Further, as shown in FIG. 3b, a mortar penetration hole 52 is provided near the lower end of this male threaded steel inner cylinder and in a portion penetrating the thread groove, and as shown in FIG. When filling, the space between the steel girder 6 and the deck slab 1 is also filled with mortar at the same time.

〔Effect of the invention〕

According to the present invention, it has become possible to easily construct a precast concrete composite deck slab on a girder. That is, by firmly connecting and fixing the fixtures embedded in the precast concrete deck and the girder, it is easy to completely synthesize the girder and the deck. In addition, the relative positioning of the girder and the floor slab is extremely easy, and filling with mortar is easy and complete, making construction simple, reliable, and labor-saving, and allows for high-quality construction in a short period of time.

Therefore, it is possible to do this not only when laying a composite slab on a newly constructed girder, but also to minimize traffic restrictions when removing an existing old slab and replacing it with a new slab. It is suitable.

According to the fixture of the present invention, accurate height alignment between the girder and precast concrete is facilitated,
The construction of joining the girder and the concrete slab is easy and reliable, and can be performed in a short time, and mortar filling can be performed extremely easily and completely.

[Brief explanation of drawings]

Fig. 1 shows a floor slab of an embodiment constructed according to the present invention, a plan view, b side view, c front view, and Fig. 2 a partially enlarged cross section showing the relationship between the girder and the mounting hardware. 3 is a perspective view of the fixture, FIG. 4 is a cross-sectional view of the attachment part of the fixture, FIG. 5 is a cross-sectional view of the lower end of the fixture, and FIG. 6 is an explanatory diagram of the prior art. 1... Precast floor slab, 3... PC steel material, 6
...Girder, 40...Embedded hardware with female thread, 50...Cylinder, 100...Fixing tool.

Claims (1)

[Claims] 1. When laying precast concrete deck slabs for composite girders on girders, (a) a plurality of precast concrete deck slabs are manufactured, (b) the deck slabs have an outer diameter A fixing device consisting of a tubular embedded body with a female thread, which has several headbands on the top and bottom and is embedded and fixed in a through hole on the upper and lower surfaces, and an inner cylinder with a male thread and a mortar filling groove that is screwed into the female thread,
(c) arranging the precast concrete floor slab on the girder and adjusting the height of the fixture on the girder to position the deck; (d) Insert the PC steel material into the deck slab and apply stress in the direction of the girder to integrate the deck slab; (e) Connect and fix the fixtures to the girder; (f) After said fixing, A method for constructing a composite girder using a precast concrete slab, characterized by filling the through hole and the space between the upper surface of the girder and the lower surface of the deck slab with non-shrinkage mortar through the through hole. 2 Consists of a tubular embedded body with a female thread that is embedded and fixed in a through hole on the upper and lower surfaces of a precast concrete composite deck slab, and an inner cylinder having a male thread that is screwed into the female thread, and the embedded body has a number of holes on its outer diameter. Has a long headband,
A fixture for fixing a precast concrete composite deck slab to a girder, wherein the inner cylinder has a mortar filling groove in the male threaded portion and a mortar entry hole in the lower end wall.