JP2001218346A - Fire preventing structure and material of bridge- extending fiber reinforced plastic tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To cover a fiber reinforced plastic tube(FRP tube) 10 which is extended under the surface of bridge and includes cables therein in view of preventing the fire. SOLUTION: The bridge-attaching FRP tube 10 is externally covered with a fire-preventing tube and a sheet S1, S2. In this case, a tube joint portion is externally wound with the fire preventing sheet S2 and thereafter it is fixed wit a fixing tool and the other part is fixed by fit-inserting the fire preventing tube S1 to the tube 10. The fire preventing materials S1, S2 are formed of silicon glass fiber including the ceramic fiber.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fireproof structure for a reinforced plastic pipe (hereinafter, referred to as an FRP pipe) attached to the lower surface of a bridge and a fireproof material therefor.

[0002]

2. Description of the Related Art FRP pipes containing cables such as power cables and communication cables are made of flame-retardant resin.
It does not burn in normal use, and there is no problem with the cable inside. However, under a bridge such as a river, a bonfire may occur in winter, and the flame may reach the FRP pipe attached to the lower surface of the bridge.

At this time, if the FRP tube is exposed to the flame for a long time, even if the tube material is a flame-retardant resin, it may burn and spread. If the pipe spreads, inconveniences such as damage to the enclosed cable occur, and in the worst case, a power failure and communication failure occur.

[0004] Under such circumstances, Japanese Utility Model Publication No. 61-743.
It is conceivable to adopt the fire protection structure disclosed in Japanese Patent Publication No. 3 which coats a pipe with an inorganic refractory layer via a latex cement layer for a bridge FRP pipe on the lower surface of the bridge.

[0005]

However, the fire prevention structure described in the above publication has an inorganic refractory layer made of cement, gypsum, calcium silicate, or the like via a cement body and a latex cement layer made of cationic rubber latex. It is effective for fire prevention of pipes, but a latex cement layer, cement,
Since the inorganic fireproof layer of gypsum is bonded, the processing cost is high, the pipe body is heavy, and it is necessary to remove the latex cement layer and the inorganic fireproof layer coated on the connection to the bridge etc. There is.

In view of the above circumstances, it is an object of the present invention to provide a fire prevention structure that has good workability and does not spread even when exposed to a long-time flame.

[0007]

In order to achieve the above object, according to the present invention, an FRP pipe is wrapped with a flexible fireproof material. In general, if there is flexibility such as a sheet, the tube can be easily wrapped by inserting, winding, or the like, while it can be easily fixed to the tube by a fixture such as a steel band. As the mode of the fireproof material, not only a sheet-shaped material but also a cylindrical material can be adopted.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As an embodiment of the present invention, there is provided a fire prevention structure which is attached to a lower surface of a bridge and covers a cable, the structure including the FRP tube being covered with a flexible fireproof material. adopt.

More specifically, in the construction, the fire-prevention material comprises a fire-prevention sheet and a fire-prevention tube, and the pipe joint is wound around the fire-prevention sheet and then fixed by a fixing tool. A configuration in which a fire protection tube is inserted and fixed can be adopted.

Various materials can be considered as the material of the fireproof sheet. For example, a material made of silicon glass fiber containing ceramic fiber can be adopted.

[0011]

EXAMPLES shows a construction example of an embodiment in FIG. 1 (a) ~ FIG 1 (f), the fire material S, are prepared S ₁ and the sheet-shaped ones S ₂ that of the tubular. They use a silicon-coated glass cloth for the exterior and ceramic fibers attached to the inside as batting.

[0012] While covering the FRP pipe 10 in this fire material S, in the factory, fitted in advance the FRP pipe 10 a fire tube S ₁ as shown in FIG. 1 (b) from FIG. 1 (a), the FRP Carry the tube 10 to the site. In the field, one F
Fitted with a fire protection fastener a a RP pipe 10 _1, this fixture a, as well as fastened fire tube S ₁ to the tube 10 _1, mounting the FRP pipe 10 ₁ into the bridge.

[0013] Next, FIG. 1 (c), the the FRP pipe 10 ₂ following to be connected one FRP pipe 10 ₁
And by positioning on the same axis, it engages the socket 10a side drawstring e of one pipe 10 ₁ of the socket 10a side and the second tube 10 ₂ from the lever block B. At this time, the fire prevention tube S _{1 at the} locking position is approached to _one side and
Make sure there is no problem in locking the RP tube. In this state, the string e is attracted by the lever block B, and both pipes 1
0 ₁ and 10 ₂ are brought together, the insertion port 10b is inserted into the receiving port 10a, and the two pipes 10 ₁ and 10 ₂ are connected. After this connection, the fire tube S ₁ of the two tubes 10 _2, together with at fire resistance of the fastener a is fastened to the tube 10 _2, mounting the tube 10 ₂ in the bridge by the fasteners a (the (d) ).

[0014] After this, the two pipe 10 _1, 10 ₂ of the connecting portion (pipe joint), as shown in (f) from FIG. 1 (e), the
Winding a fire sheet S _2, it is fastened to the two side by steel bands b. By this operation, the connection of the pipes 10 ₁ and 10 ₂ and the fire prevention structure are completed, and thereafter, by the same operation, a fire protection bridge extension pipe of a required length is formed.

[0015] In the existing attached pipe of, for fire tube S ₁ can not be mounted, the tube 10 in the same manner as in fire sheet S ₂ the fire tube S ₁ in those rectangular cut into axial linear Wrap and secure. Also, fire tube S ₁ may be fitted to the FRP tube in situ.

[0016]

[Test Example] A combustion test of the FRP pipe 10 using the fireproof material S was performed. That is, as shown in FIG.
The FRP tube 10 covered with the sheet-like fireproof material S was placed thereon, and the flame F was applied from below. Tube 10 has an inside diameter of 25
0 mm, length: 3 m, thickness: 5 mm were used, and the fire source of the flame F was Wes and 1 liter of kerosene. The fireproof material S is an exterior: silicon-coated glass cloth, batting: ceramic fiber, and has a layer thickness of 12.5 mm and 2
As a comparative example, a test of only the FRP pipe 10 (one not covered with the fireproof material S) was also performed as a comparative example. The temperature measurement is shown in FIG.
As shown in the figure, the thermocouples T ₁ and T
_3, T ₂ and the installation, start the measurement immediately after igniting the fire source, the temperature change in the combustion temperature conditions recorded on a data logger for each measurement point, and the status of the test was recorded photographically.

FIG. 3 shows the test results, wherein (a) shows the comparative example, (b) shows the experimental example 1, and (c) shows the experimental example 2. In this experiment, the thermal power reached its maximum 2-3 minutes after ignition,
It began to decrease after 6-7 minutes. The maximum temperature is 80
The temperature reached almost 0 ° C.

According to the test results shown in FIG. 3, in the comparative example, when the tube outer surface temperature T ₂ approaches 450 ° C., the resin starts burning, and the combustion does not reach the tube inner surface.
The inner surface temperature T ₃ rose to 250 ° C. and was visually scorched. After 15 minutes, the flame F was removed.
Self-extinguished. In Experimental Example 1, the maximum tube outer surface temperature T ₂ was 36.
The temperature reached 0 ° C, and no combustion occurred. In addition, the maximum tube inner surface temperature T ₃ was 50 ° C., and the tube outer surface was slightly scorched visually. In Experimental Example 2, the maximum tube outer surface temperature T ₂ was 110 ° C. and the inner surface temperature was 25 ° C., and no abnormality was visually observed in the tube 10. As described above, in the case of only the FRP tube (comparative example), the resin burns, but does not spread. In addition, fireproof material S
Is used, the tube 10 does not burn unless the tube outer surface temperature T ₂ becomes 450 ° C. or more, and it is considered that the tube 10 can be sufficiently used even in the present experimental example 1.

[0019]

According to the present invention, as described above, the workability during construction is good, the fire does not spread even if exposed to a long time flame, etc. Can be protected.

[Brief description of the drawings]

FIG. 1 (a) is a construction drawing of one embodiment.

FIG. 1 (b) is a construction drawing of one embodiment.

FIG. 1 (c) is a construction drawing of one embodiment.

FIG. 1 (d) is a construction drawing of one embodiment.

FIG. 1 (e) is a construction drawing of one embodiment.

FIG. 1 (f) is a construction drawing of one embodiment.

FIG. 2 is an explanatory view of a test, (a) is a schematic front view,
(B) is a sectional view of a main part.

FIG. 3 is a diagram showing a relationship between a combustion time and a temperature change inside and outside a pipe.

[Explanation of symbols]

10 Fiber reinforced plastic pipe (FRP pipe) a Fixture b Steel band S ₁ , S ₂ Fireproof material (fireproof tube, fireproof sheet)

Claims (3)

[Claims] 1. A fire protection structure for a fiber reinforced plastic pipe 10 attached to a lower surface of a bridge and enclosing a cable, wherein the fiber reinforced plastic pipe 10 is externally wrapped with a flexible fireproof material S. Fire protection structure of fiber reinforced plastic tube. 2. A fire structure according to claim 1, wherein said fire material S made of fire sheet S ₂ and fire tube S _1, the pipe joint by the fixture a After outerwrap by winding the fire sheet S ₂ fixed, others fire structure of the bridge添架fiber reinforced plastic pipe, characterized in that secured by fitted the fire tube S ₁ to the plastic tube. 3. A fire protection material for a bridge-supported fiber reinforced plastic pipe according to claim 1, wherein said fire protection material is used for the fire protection structure according to claim 1 or 2 and is made of silicon glass fiber containing ceramic fibers. .