JPH0252602B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a propulsion tube in which an FRP collar is embedded, and its purpose is to first manufacture an FRP collar in a centrifugal force forming mold used for body molding. The object of the present invention is to provide a method for continuously integrally molding the FRP collar and the reinforced concrete part of the main body by setting a reinforcing bar cage, pouring concrete, and compacting it by centrifugal force.

In recent years, the proportion of sewage pipe beams made up of propulsion pipes has been rapidly increasing to address traffic conditions and residents' complaints. A steel plate collar-embedded propulsion tube has already been developed to meet the needs of long-distance propulsion, curve propulsion, etc. However, although these steel plates with collars are very reliable in terms of material strength and other properties, they have the disadvantage of rusting. It is generally said that the degree of rust in steel structural materials buried underground is 0.03 mm/year, but in reality, even with a 4.5 mm thick collar, local corrosion occurs and small holes occur within 10 years after being buried. Some cases are open. This is thought to be caused by electrolytic corrosion caused by stray currents in the soil. Currently, to prevent this rusting and local corrosion, the inside and outside surfaces of steel collars are painted with paint such as epoxy tar, but the thickness of the paint film is 0.1 to 0.2 mm.
In particular, the outer surface is worn or scraped off by contact with sand, phosphorus, etc. in the soil during propulsion.
100% painting effect cannot be expected.

In order to eliminate this drawback, the present invention uses an FRP collar which is stable in terms of material and has reliable mechanical properties, and continuously performs the molding of this collar and the molding of a concrete pipe.

The present invention will be described below with reference to illustrated embodiments.

As shown in Fig. 1, the concrete pipe of the present invention has FRP on one side of the pipe end of the main concrete part 1.
A collar 2 made of steel is embedded and serves as a socket, and the opposite side serves as a socket 3.

Embedded color 2 is as shown in Figure 2.
One FRP ring 4, 4' is set at the innermost part of the collar and one at the middle part of the collar, and is integrated with the collar body 1. After these rings 4, 4' are embedded, they act as anchor rings, and among them, the innermost ring 4' acts as a weir member during collar molding. These rings 4,
Two or more 4' can be provided. Numeral 4 is a sealing material such as water-swellable rubber, which prevents water from entering from the outside of the concrete body 1 through the concrete contact portion of the embedded collar 2.

FIG. 3 shows the cross-sectional structure of the FRP collar 2, which is composed of a resin layer 6 and a mixed layer of resin and chopped strands 7 of glass fiber. These thin layers 6 on the inner and outer surfaces improve the sliding with the rubber gasket 8 when the tubes are joined, and reduce the frictional resistance with the soil during propulsion.

For example, the layers 6 and 7 are formed from a combination of the following materials.

(a) Combination of resin (unsaturated polyester resin, epoxy resin, etc.) and glass fiber net (b) Combination of resin and continuous glass fiber (b) Combination of resin and glass fiber (continuous fiber) Such an FRP collar-embedded propulsion tube is manufactured as follows. .

First, as shown in FIG. 4, the rings 4 and 4' are placed inside the formwork 10, and then the auxiliary formwork 11 is attached to the end plate 9 of the formwork 10. Next, resin is poured between the ring 4' and the end plate 9 using a feeder 12. Next, chopped strands of glass fiber are fed into the feeder 13. Thereafter, the resin and glass fibers are added simultaneously or alternately to finish to a predetermined thickness. The innermost layer is made of resin only. After the feeding process, a centrifugal force of about 25 to 50 G is applied for several minutes to defoam and harden the material.

After the collar forming is completed, the rotation of the formwork is temporarily stopped, the water-stopping rubber 5 is pasted in place, the reinforcing bar cage 14 is placed inside the formwork 10, and the iron ring 15 for forming the concrete body is attached to the end plate. Attach to 9. From then on,
According to the general manufacturing method for centrifugal reinforced concrete pipes, concrete of a predetermined mix is poured and finished to the predetermined dimensions.

According to the present invention, two-thirds of the work required for demolding and assembling a conventional embedded collar mold is performed on a pipe making machine, and the conventional steel collar is set in the formwork. In the working time (several minutes to 10 minutes)
By forming FRP collars and subsequently forming concrete pipes, it is possible to reduce the total number of work hours, improve quality, and reduce costs.

[Brief explanation of drawings]

Fig. 1 is a longitudinal cross-sectional view of the FRP collar-embedded reinforced concrete pipe according to the present invention, Fig. 2 is an enlarged longitudinal cross-sectional view of the collar embedded part, Fig. 3 is an enlarged cross-sectional view of the collar, and Figs. 4 and 5. FIG. 2 is a schematic vertical cross-sectional view of the formwork during the manufacturing process of the present invention. 2...Color, 4,4'...Ring, 6...Resin layer,
7...Mixed layer of resin and glass fiber pieces, 11...Auxiliary formwork.

Claims (1)

[Claims] 1 Place one or more rings at a predetermined position within the formwork, supply resin and fibers while rotating the formwork, and use centrifugal force to integrate the rings into one.
A continuous manufacturing method for a reinforced concrete pipe for propulsion, characterized by forming an FRP collar, then pouring concrete while rotating a formwork to form a concrete pipe body.