JPH0723603B2 - Construction method of sheath for PC cable - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for constructing a PC cable sheath used for constructing a PC paving slab.

[0002]

2. Description of the Related Art In recent years, for example, a width of 7.
A PC paving slab having a length of 5 m and a length of about 100 m is used. P
The C pavement plate has high strength and durability, can withstand the harsh conditions at the time of aircraft departure and arrival, keep the road surface such as runways without being affected by local subsidence, repair replacement, etc. It is easy to perform and can be completely restored.

In such a PC paving slab, longitudinal and transverse sheaths are arranged, after the concrete is poured and cured, the PC cable is inserted into the sheath and the PC cable is tensioned to introduce prestress into the concrete. Generally, a PC cable sheath has a length of 4 to 5 m, and a joint sheath is used for connecting the sheaths. FIG. 4 shows this. For example, the sheaths 10 and 11 are arranged at predetermined positions in the structure, and the diameter between the sheaths 10 and 11 is larger than that of the sheath of the main body.
They are connected via a joint sheath 14 having a length of about cm. This connection is performed by using the rib screws 12 and 13 provided in the sheaths 10 and 11 and the joint sheath 14
One of the sheaths is rotated and screwed into the rib screw 15 of FIG. Since the PC cable sheath should not be infiltrated with cement paste or water at the time of pouring concrete, vinyl tape 16 is wrapped around both ends of the joint sheath to seal it.

[0004]

[Problems to be Solved by the Invention]
In the conventional method of arranging each book in a grid pattern on the ground at the PC pavement installation site, bundling the intersections, and placing concrete, (a) the sheaths are installed one by one at the site, so It takes a lot of days to lay, and it is difficult to avoid inefficient work by human power. (B) The construction period is long because it is easily affected by weather conditions and other factors. (C) Mechanization and high efficiency are not easy. There are problems such as.

In order to solve such a problem, the present invention manufactures and stores a prefabricated sheath unit assembled in advance into a lattice in a size that can be manufactured in a processing plant.
We developed a technology to transport this to the site and lay it on the PC pavement construction position in a short period of time. In this way, the new technical idea makes it possible to (a) facilitate mechanization of manufacturing a prefabricated sheath unit in a factory, and (b) store intermediate products to mechanize on-site laying work and lay in a short time. , (C) Minimize factors such as weather
(D) The quality, dimensions, etc. will be made accurate, and (e) the sheath unit will be arbitrarily manufactured in parallel with the construction of the site ground, etc., to rationalize the entire construction process.

[0006]

In order to achieve the above-mentioned object, the present invention arranges a large number of straight vertical and horizontal sheaths for a PC cable on a floor of a sheath unit processing site in a straight lattice or a diagonal lattice pattern, For example, every other intersection of the lattice array is staggered in a zigzag arrangement, and each fulcrum is rigidly connected to produce a mesh-shaped prefabricated sheath unit that can be integrally transported. The vertical sheaths are arranged and laid out in a straight line on the ground at the position, and a connecting tube made of a heat shrink tube is externally fitted to the ends of adjacent vertical sheaths to be connected, and this connecting tube is heated. Shrink, PC
A method for constructing a sheath for a PC cable, characterized by forming a sheath for paving slab.

[0007]

According to the present invention, the PC cable sheaths are arranged in advance in a factory in a straight lattice, a diagonal lattice or the like and assembled, and the assembled prefabricated sheath unit is brought into the field and these units are connected to each other to form a PC pavement. This is a construction method for laying a plate sheath. In the prefabricated sheath unit according to the present invention, it is impossible to connect the sheath units with the conventional joint sheath because the individual sheaths cannot be rotated.

Therefore, this method uses a heat-shrinkable tube made of special synthetic rubber that shrinks when heat is applied to connect the prefabricated sheath units to each other and to improve the watertightness. For this reason, the conventional work of winding a vinyl tape becomes unnecessary. When the opening width of the connecting portion between the PC cable sheaths is large, the present invention can be carried out by arranging a sleeve pipe made of a thin steel pipe between the sheaths without impairing a required function. Further, instead of the thin steel pipe sleeve, a joint sheath having a rib screw portion with a margin may be used to cover the heat shrinkable tube.

As the heat-shrinkable tube, a special synthetic rubber having a heat-shrinking property as well as a special rubber having a self-shrinking property and a self-fusion property may be used.

[0010]

EXAMPLE FIG. 3 is a laying diagram showing the concept of an example of the present invention. At the processing site, the two prefabricated sheath units 1 produced are arranged so that the vertical sheaths 2 are aligned. The actual sheath unit 1 for PC pavement construction at an airport has vertical and horizontal dimensions of 7.5 m x 7.5 m, and the vertical sheath 2 and horizontal sheath 3 are arranged at a pitch of 30 cm, and the intersections 4 of the vertical and horizontal sheaths are bound together. It is rigidly connected by metal fittings, and the construction of about 100 m in the longitudinal direction is laid at a time.

Details of the connecting portion 5 of the vertical sheath are shown in FIGS. In the example shown in FIG. 1, the connecting pipe 6 is fitted into the outer diameter of the connecting portion of the vertical sheath 2 and heat-contacted. The example shown in FIG. 2 shows a case where the gap between the connecting portions is large. A thin steel plate sleeve 7 is fitted into the connecting portion 5 of the vertical sheath 2, and a connecting pipe 6 is fitted onto the outer diameter of the thin steel plate sleeve 7. It is in close contact with both ends of the vertical sheath 2. The connection pipe 6 is a heat-shrinkable tube made of a special synthetic rubber having a cylindrical shape having a diameter larger than that of the thin steel plate sleeve 7 and heat-shrinked to be closely attached.

The method of the present invention can be applied not only to PC paving slabs for airfields, but also to road pavement and construction of bottom plate slabs such as large-scale water tanks.

[0013]

Therefore, the present method has the following excellent effects. (1) Stock production of prefabricated sheath units is possible regardless of the weather on site, which contributes to shortening the overall construction period, improving productivity and saving labor. (2) By using the special synthetic rubber, the work of winding the vinyl tape in a low posture is unnecessary, and the worker can be freed from the troublesome work. (3) The use of special synthetic rubber can surely prevent the infiltration of cement paste and water, which enables high-quality construction.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of an example.

FIG. 2 is an explanatory diagram of an example.

FIG. 3 is a cross-sectional view of the sheath connecting portion of the embodiment.

FIG. 4 is a cross-sectional view of a conventional sheath connecting portion.

[Explanation of Codes] 1 Prefabricated sheath unit 2 Vertical sheath 3 Horizontal sheath 4 Intersection point 5 Connection part 6 Connection tube 7 Sleeve 10, 11 Sheath 12, 13, 15 Rib screw 14 Joint sheath 16 Vinyl tape

Claims (1)

[Claims] 1. A mesh capable of being integrally transported by arranging a large number of straight vertical and horizontal sheaths for a PC cable on the floor of a sheath unit processing site in a straight lattice or a diagonal lattice, and connecting the intersections of the lattice arrangement rigidly. -Shaped prefabricated sheath unit is manufactured, and a large number of the prefabricated sheath units are arranged and arranged so that each vertical sheath is aligned on the ground where the PC paving plate is installed, and the ends of adjacent vertical sheaths to be connected are arranged. A connecting pipe made of a heat-shrinkable tube is externally fitted to the portion, and the connecting pipe is heated to shrink to form a PC paving plate sheath.
Construction method of sheath for C cable.