JPH0247634B2 - HORIOREFUINPAIPUKANTSUBUNOENSHOBOSHIKOZO - Google Patents

Description

[Detailed description of the invention]

[Technical Field] The present invention relates to a structure for preventing the spread of fire at a pipe penetration part in the floor of indoor piping for water supply and hot water supply using polyolefin pipes. [Prior art] Conventionally, for indoor water supply such as in buildings,
Polyolefin pipes are used as piping materials for hot water supply, etc., because there are concerns that they will be destroyed in the event of a fire, and that the through holes in the pipes after the fire will become a route for the spread of fire and smoke, so polyolefin pipes have excellent advantages that metal pipes do not have. Although it has corrosion resistance, it has not yet been put into practical use. [Summary and Effects of the Present Invention] The summary of the present invention is as shown in the claims. The following facts were found from numerous fire simulation combustion experiments conducted by the present inventor. JIS A for the penetration structure where the void in the floor penetration hole through which the polyolefin pipe penetrates is sealed with fire-resistant material such as rock wool or mortar.
When a combustion test was carried out under the conditions specified in 1304, the pipe section under the floor melted within a few minutes from the start of heating.
It burns, cuts off and falls from the base of the floor through-hole, and the end face of the pipe inside the floor through-hole is exposed to flames. In the above combustion test, the upper end of the pipe was always closed, taking into consideration that the ends of ordinary water pipes and hot water pipes are closed with a bell, but this closure prevents the movement of air within the pipe. In addition, because the pipe inside the through hole is surrounded by fireproof material on the outside, flames and high heat below the floor rise at a relatively slow rate, and therefore the pipe inside the through hole is surrounded by fireproof material. The pipe inside the hole cracks from its tip due to carbonization due to incomplete combustion, gradually falls off piece by piece, and becomes shorter. 20 to 40 minutes after the start of heating, the pipe tip reaches the upper side of the floor through hole, and eventually the pipe tip separates from the surface of the refractory material sealing the gap in the through hole, creating a gap between the two. The small flame emitted from the gap heats the outer surface of the pipe, which has an abundant supply of air. Due to this heating, the pipe above the floor through-hole eventually begins to burn from its outer surface. From the time the above gap occurs until the pipe starts to burn
It takes a relatively long time, 10 to 20 minutes, but once combustion begins, the combustion force increases rapidly, causing the pipe to become shorter, and as a result, the space occupied by the pipe in the through-hole becomes difficult for air to circulate. Become a smoker in order to be free. In contrast, in the present invention, the outer surface of the root of the pipe protruding above the through-hole is protected against fire with a flame-retardant material or fire-resistant material, so the upper surface of the floor through-hole and the lower end of the pipe Even if there is a gap between the pipe and flames coming out from the gap, the heating of the outer surface of the pipe root is alleviated. Alternatively, even if it is heated, it is difficult to burn because the air supply is limited, and the space where the through-hole pipe existed is still covered by the pipe for a long time, so it cannot be turned into a flue. The spread of fire to floors above the floor is prevented for a long period of time. [Specific and detailed explanation of the gist of the present invention] In the present invention, the polymers constituting the polyolefin pipe used as indoor piping material for water supply, hot water supply, etc. include, for example, polyethylene, polypropylene, polybutene, polymethylpentene,
Non-crosslinked polyolefins such as carboxylic acid-modified (grafted or copolymerized) polyethylene, irradiation-crosslinked polyolefins obtained by irradiating the non-crosslinked polyolefins with radiation, and blending organic peroxides with the non-crosslinked polyolefins. A chemically crosslinked polyolefin obtained by heat treatment, a silane grafted product using the non-crosslinked polyolefin, an unsaturated silane compound such as vinyltrimethoxysilane, vinyltriethoxysilane, etc., and an organic peroxide, or Olefins, especially water-crosslinked polyolefins that are crosslinked with water to form a crosslinked structure, such as copolymers made of ethylene and the unsaturated silane compound (e.g.,
JP-A-56-8446, JP-B-Sho 48-1711), etc. The polyolefin pipe according to the present invention may be made of only the polyolefin compound, or may contain antioxidants, carbon black, pigments, and other compounding agents as required. In addition, the water-crosslinked polyolefin may contain a known silanol condensation catalyst such as dibutyltin dilaurate. When a polyolefin-based pipe is composed of a cross-linked polyolefin, especially when it is composed of a water-cross-linked polyolefin, the cross-linking may already be completed at the time of piping work, or it may be in progress or not in progress. It may be. Further, the constituent material of the pipe used in the present invention may be made flame retardant with a flame retardant. The fire resistance performance of the fire resistant material used in the present invention is evaluated by the following fire resistance test. Fire resistance test: A ceramic column with an outer diameter of 50 mm and a length of 30 cm is covered with a test specimen to a thickness of 5 mm by wrapping tape or using a half-cover method, and heated along the fire resistance curve specified in JIS A 1304. . At this time, x
A material that does not burn out even after heating for hours and retains its shape at least to the extent that it has an oxygen blocking effect is referred to as a refractory material that is refractory for x hours. For example, a 10-minute refractory material, a 30-minute refractory material, a 1-hour refractory material, or a 2-hour refractory material each requires 10 minutes of heating (705
℃), heating for 30 minutes (840℃), heating for 1 hour (925℃)
℃) or 2 hours of heating (1010℃). Examples of 10-minute fire-resistant materials include polyimide, fluororesin, heat-resistant organic polymers,
Examples include low melting point metals such as aluminum and glass wool. Examples of 30-minute fire-resistant materials include glass tape, mica, and the like. Examples of 2-hour fire-resistant materials include rock wool, asbestos, ceramic, shirasu balloon,
Examples include earth and sand, alumina, calcium silicate, cement derivatives such as mortar and concrete, and high melting point metals such as iron and titanium. Among these fire-resistant materials, granular, fibrous, woolly,
Alternatively, those that can be cast and solidified are suitable for closing voids in through holes, while those in the form of wool, seals, or tapes are suitable for use by being wrapped around the surface of a pipe. Further, the above-mentioned materials may be used after being formed into a half-split shape or a cylindrical shape. When using a flame retardant material for fire protection on the outer surface of the pipe root, the material must have an oxygen index (measured according to JIS K 7201-1976) of at least
30 flame retardant materials are used. For example, flame-retardant plastics such as plastics and rubbers made flame-retardant with organic and/or inorganic flame retardants, and hard vinyl chloride. Among these, those with an oxygen index of at least 35, especially at least 40 are preferred. [Embodiment] FIGS. 1 to 3 are sectional views of embodiments of the present invention. In these figures, a polyolefin pipe 3, for example, with a diameter of 30 to 200 mm, is passed through a pipe through hole 2 provided in a floor 1 of a building. The gap in the through hole 2 is sealed with a fireproof material 4, and the root portion 31 of the pipe 3 extending above the through hole 2 is protected against fire by a fireproof layer 5 made of a fireproof material or a flame retardant material. has been done. floor 1
If the thickness of the through hole 2 is 70 mm or more, it is not necessarily necessary to seal the void in the through hole 2 with a fireproof material 4 with a thickness equal to the total thickness of the floor 1 as in the embodiment of FIG. It is preferable that the thickness of the refractory material 4 is at least 1/2 of the thickness of the floor 1, although it may be thinner than the floor thickness as in the example. Since the fire-resistant material 4 is often scorched with flames from the initial stage of a fire, a 2-hour fire-resistant material is used. Among these, preferred are cement derivatives such as mortar and concrete, rock wool, or a combination thereof. As mentioned above, the root portion 31 of the pipe 3 is effective only by protecting the pipe surface from heating caused by small flames leaking from a small hole formed in any part thereof or a gap formed at the pipe root on the upper surface of the through hole. Therefore, even if a 10-minute fireproof material is used as the constituent material of the fireproof layer 5, it is sufficiently effective. Also, fire protection may be provided by using the above-mentioned flame retardant materials in place of the fire resistant materials. However, to achieve even more adequate fire protection, 30-minute fire-resistant materials, 1-hour fire-resistant materials, especially 2-hour fire-resistant materials,
Preferably, time-refractory materials are used. The length of the fireproof layer 5 is at least 10 cm from the top surface of the fireproof material 4 or the top surface of the floor 1. The lower end of the fireproof layer 5 does not necessarily need to be in contact with the upper surface of the fireproof material 4, and a gap of several millimeters is acceptable, but the fireproofing of the present invention can be achieved by preventing the pipe 3 from being directly scorched by flames. In order to extend the life of the structure, the lower end of the fire protection layer 5 may be brought into close contact with the upper surface of the refractory material 4, or, in particular, the lower end of the fire protection layer 5 may be placed in the refractory material 4, as in the embodiment of FIG. It is preferable to immerse yourself in it. The fire protection layer 5 may function to insulate and protect the outer surface of the pipe root 31 from flames for a certain period of time, and even if the insulation effect is poor, it may block the supply of air to the outer surface for a certain period of time. It is effective even if it does the same thing. For example, pipes made of iron plates wrapped around the surface of the pipe have no insulation or air-blocking effect, while pipes made of coarse glass cloth wrapped in layers or flame-retardant plastics such as hard polyvinyl chloride has both a heat insulating effect and an air blocking effect, so even a relatively thin fire prevention layer of about 1 to 5 mm has a considerable fire prevention effect. Therefore, items with a thickness of several millimeters or tens of millimeters made of two-hour fire-resistant materials such as rock wool or asbestos, or double-layered structures with a steel plate layer on top of a 30-minute fire-resistant material such as glass tape, are insulated. Fire protection layer 5
It is particularly excellent as a constituent material. Pipe root 31 protected by fire protection layer 5
The longer the length, the better, and if it is at least 30 cm, an even better fire prevention effect will be achieved. In the embodiments shown in FIGS. 2 and 3, not only the pipe root 31 but also the pipe root 32 located under the floor 1 are protected against fire by the fire protection layer 6. If a fire-resistant material for at least 1 hour, especially a 2-hour fire-resistant material is used as the fire-resistant material for the fire protection layer 6, the time required for the pipe root 32 to burn out in the event of a fire will be prolonged, or, for example, the pipe root 32 may be burned out. Even if this happens, the cylinder made of the refractory material 6 will remain. In that case, the flame below the floor 1 will pass through the cylindrical body and attack the pipe root 31, but since the cylindrical body acts as a resistance to the passage of the flame, the flame below the floor 1 will pass through the cylinder and attack the pipe root 31. The attack force becomes weaker, and the life of the pipe root 32 is extended accordingly. Second
In the illustrated embodiment, the pipe roots 31 and 32 are fire-protected with the same fire-resistant material as the pipe portion inside the through-hole 2, for example a two-hour fire-resistant material such as rock wool. In the example shown in Fig. 3, the pipe root 31 and the upper half of the pipe inside the through hole 2 are made of fire-resistant material or flame retardant material for 10 minutes to 1 hour, while the pipe root 32 and the upper half of the pipe inside the through hole 2
The inner lower half of the pipe is made of fire-resistant material for 1 to 2 hours, and the case where it is protected against fire is shown. It is also shown that two types of refractory materials 4 and 4', upper and lower, are used to seal the voids in the through holes. Note that the pipe portion inside the through hole 2 is made of fire-resistant material 4.
All you need to do is to surround it with, etc. The length of the pipe root 32 protected by the fire protection layer 6 is preferably at least 10 cm, particularly at least 20 cm. [Experiment example] Structures of experimental examples 1 to 8 of simulated fire spread prevention structures created using 10 cm thick lightweight foam concrete plates as flooring materials,
The following table also shows the results of fire resistance tests conducted under the heating conditions stipulated in JIS A 1304 for each experimental example. Incidentally, the total length of the pipe used in each experimental example was 3 m, and the fire resistance test was conducted with a penetration part in the center, and the upper end of the pipe hermetically sealed with rock wool. As shown in the table, in Experimental Example 1, heating
After 20 minutes, smoke leakage was already observed above the floor, but in Experimental Examples 2 to 8, no smoke leakage was observed even after 1 hour. In addition, in Experimental Example 2,
After 40 minutes, smoke leaked from the upper root of the floor for about 10 seconds, but it stopped immediately. 60~ of Experimental Examples 2~8
During the 120 minutes of heating, only a slight smoke leak of several seconds was observed once or twice, and the fire did not spread to the floor.

【table】

【table】 [Brief explanation of drawings]

1 to 3 are examples of the present invention, in which 1 is a floor, 2 is a through hole, 3 is a polyolefin pipe, 4 is a fire-resistant material that seals the gap in the through hole 2, and 5 is an upper side of the floor. 6 is a fire protection layer that protects the pipe root 31 under the floor from fire.

Claims (1)

[Claims] 1. The void in the floor through-hole through which the polyolefin pipe penetrates is sealed with a fire-resistant material for 2 hours, and at least 10 cm of the outer surface of the root of the pipe extending above the through-hole is free from oxygen. A structure for preventing the spread of fire of a polyolefin in-pipe penetration, characterized by being protected against fire by a flame-retardant material with an index of at least 30 or a fire-resistant material of at least 10 minutes. 2. The fire spread prevention structure according to claim 1, wherein the polyolefin pipe is a polyethylene pipe, a crosslinked polyethylene pipe, a polypropylene pipe, or a polybutene pipe. 3. The voids in the floor through-holes should be filled with cement-inducing material and/or
or sealed with rock wool, and the root portion of the pipe is protected against fire by one or more selected from the group consisting of rock wool, glass wool, glass fiber, asbestos, and iron plate. Or the structure to prevent the spread of fire as described in Section 2.