JP3038449U - Double steel pipe filled with fireproof coating material - Google Patents

Abstract

(57) 【Abstract】 PROBLEM TO BE SOLVED: Even among steel materials as structural materials, hollow steel pipes such as square steel pipes and round steel pipes are lightweight even if a fireproof coating material is applied, regardless of the strength of the fireproof coating material. To obtain a double steel pipe filled with a fireproof coating material, which is excellent in the precision of the fireproof coating thickness and is capable of providing an aesthetic coating excellent in surface finish. SOLUTION: A gap between a structural steel pipe and a coating steel pipe of a double steel pipe having a double structure by using a larger coating steel pipe in which a necessary thickness of a fireproof coating is added to the structural steel pipe. In addition, the structure is filled with a fireproof coating material.

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 The present invention relates to a steel pipe used as a structural material.

[0002]

[Prior art]

 Conventionally, steel materials are often used as structural materials in buildings. Especially in recent years, there are many examples of using round steel pipes and square steel pipes for reasons of design and structural strength. In many cases, steel materials generally used as structural materials for buildings are required to have a structure having fire resistance, and in such a case, the surface of the steel material is generally covered with a fire resistant coating material. The fireproof coating material is a material that is coated on the structural material in order to prevent the strength of the structural material from decreasing due to high heat in the event of a fire. A wet type in which a fire-resistant coating layer is formed by drying and curing, and a dry type material that has been previously formed into a plate shape or a mat shape are applied to the construction site. There are two types of dry type, which are attached with adhesive, stud pins, and nails, etc. with appropriate dimensions.

[0003] In most cases, such a fire-resistant coating material is coated on a structural steel material that has already been built on site. However, on-site construction is rationalized and quality is ensured. Alternatively, for the purpose of eliminating dangerous work at the site and improving the work environment, a method of introducing steel materials to the construction site after the fire resistant coating material has been applied to the steel materials in the steel frame processing plant or in the steel material stockyard, etc. (Prior advance construction method) is also adopted. On the other hand, these fire-resistant coating materials are not generally said to be particularly excellent in aesthetic appearance in terms of their hue and texture, and in addition, since many coating materials have weak strength, they are not visible. Or, as for the fire-resistant coating material that is directly touched by human hands, various finishing materials are currently provided on the surface of the coating material.

[0004]

[Problems to be solved by the device]

 However, for example, in the case of the preceding tipping method as described above, the refractory coating material formed on the surface may be peeled off or chipped due to vibration or impact during transportation. Also, when a wet type fireproof coating material is applied on site, the material is scattered during spray coating on the steel surface, which creates a poor working environment and it is not easy to control the coating layer thickness. It was necessary to measure and confirm at multiple sites with a thickness meter. On the other hand, in the case of dry type refractory coating materials, especially in the case of coating round steel pipes, in the case of molded products such as calcium silicate plate, a molding die that matches the dimensions and shape of the steel material is prepared in advance. It was necessary to mold them together at the factory, and it took a great deal of time to process them. In addition, the fire-resistant coating material molded in the factory in this way may be chipped or damaged before it is attached to the steel material at the construction site. In addition, in order to avoid the problem of scattering of the wet type fireproof coating material, a waste formwork with a gap between it and the steel material is provided in advance, the fireproof coating material is allowed to flow into the gap, and the formwork is removed after drying and curing. An injection method has also been proposed, but other problems such as the disposal of the waste formwork and the lack of smoothness of the surface of the fire-resistant coating material formed after demolding occurred. In recent years, concrete-filled steel pipes, in which concrete is poured into steel pipes, have been drawing attention as a composite structure that combines a concrete structure and a steel structure. From the viewpoint of fire resistance, this structure has a characteristic that the steel material temperature is hard to rise because the heat capacity of the filled concrete is large even though the steel material is located on the surface. Therefore, in this structural material, it may not be necessary to separately cover the steel material on the surface with a fire-resistant coating material, in which case the above-mentioned problems caused by the fire-resistant coating material appearing on the surface (hereinafter referred to as "representation"). Has the advantage of not occurring. However, since this structure itself is much heavier than the steel structure, especially when trying to carry out a pre-emptive construction method in which the concrete is pre-filled with concrete and then carried to the site, the load capacity and the lifting capacity are increased. At present, it is inevitable that the applicable dimensions will be considerably limited in terms of the limits of the above. For this reason, in most cases, a method of injecting concrete into a steel pipe that has been built on-site at a high pressure is adopted, and in such a case, a high-tech Is required, and there are many technically difficult aspects. Further, in order to have a steel pipe concrete structure that does not require such a fireproof coating, it is limited to a structure / part having a small axial force ratio (working load / proof strength) because of the balance between heat capacity and applied load. Therefore, even with the same structure, it is usually necessary to additionally provide a fire-resistant coating material on the surface of the steel pipe, and therefore the above-mentioned problems of the fire-resistant coating material cannot be essentially solved.

Therefore, the problem to be solved by the present invention is that even in a steel material as a structural material, a hollow steel tube such as a square steel tube or a round steel tube is lightweight even if a fireproof coating material is applied, and It is an object of the present invention to obtain a double-walled steel pipe filled with a fireproof coating material, which is excellent in the accuracy of the fireproof coating thickness and has an excellent surface finish, regardless of the material strength of the fireproof coating material, and which enables a beautiful coating.

[0006]

[Means for Solving the Problems]

 In order to solve such a problem, the present inventors have made earnest studies and, as a result, came to the idea of combining a refractory coating material with a double steel pipe, and completed the present invention. In other words, a double structure was used by using a larger steel pipe for coating with the necessary thickness of the fireproof coating material added to the structural steel pipe. This double steel pipe is a double steel pipe filled with a refractory coating material characterized by a structure in which a gap between the structural steel pipe and the coating steel pipe is filled with a fireproof coating material.

[0007]

[Embodiment of the invention]

 Typical examples of the structural steel pipes used in the present invention include carbon steel pipes for general structure specified in JIS G 3444 and rectangular steel pipes for general structure specified in JIS G 3466. . In some cases, for example, a round tube or a rectangular tube made of stainless steel or aluminum-based material can be used even in a portion where structurally fire resistance is required by applying this structure.

Next, the steel pipe for coating is considered here on the assumption that structural strength is not imposed on the steel structure, and the material is generally described in the section of the structural steel pipe above. There is no problem even if the structural steel pipe or the general structural square steel pipe is used as it is. Of course, a material such as stainless steel or aluminum may be used. As a minimum performance, the strength that is difficult to deform during handling is required, and normally a pipe material thinner than the steel pipe for construction is sufficient. In addition, in consideration of the final finished surface, it is also possible to use a steel pipe or the like which is mirror-finished in advance.

The gap between the structural steel pipe and the coating steel pipe is filled with a fireproof coating material. The width of this gap is less than the thickness of the fireproof coating material required for the structural steel pipe as a fireproof structure. Must be above. Usually, in order to install so that the gap is uniform, a method of fixing the structural steel pipe and the coating steel pipe at both ends of the steel pipe by welding or the like is adopted. This eliminates the need for the troublesome work of confirming the required refractory coating thickness with a measuring pin, etc., as in the case of the conventional spray-type wet refractory coating method. By filling the fireproof coating material, a fireproof coating layer having a uniform thickness can be secured, and construction management becomes extremely easy in view of the fireproof coating.

The fire-resistant coating material used in the present invention is not particularly limited, but a wet type fire-resistant coating material is generally preferable because it fills the gaps of the double steel pipe. In this case, the wet material is filled by pumping or pouring it into the gap between the double steel pipes from the upper end. On the other hand, a dry type fireproof coating material can also be used if it can be inserted into the gap. At this time, the material is not limited to the conventional refractory coating material, and any material having fire resistance may be blown in any shape such as powder, granules, pulverized material, or fibrous material. The fire-resistant coating material-filled double steel pipe of the present invention can be obtained by simply filling the gap by a method such as pouring.

Concretely, as a wet type fireproof coating material, cement mortar, lightweight mortar, fireproof mortar, wet ceramic fireproof coating material, wet rock wool, gypsum fireproof coating material, gypsum plaster, dolomite plaster, etc. Can be given. As described above, the material is not particularly limited to the described materials as long as it is a wet material which has an effect of suppressing the temperature rise of the structural steel pipe due to the fireproof coating and can be injected. In particular, in the conventional fire-resistant coating surface coating method, the fire-resistant coating material must not peel off from the steel surface while it is being heated by fire, etc. However, this structure has a sandwich structure in which the surface is covered with a steel pipe for coating even while the refractory coating layer is heated, so the refractory coating layer does not peel off. Since there is no need to secure the strength to hold the minimum shape, there is an advantage that the types of materials for the refractory coating layer that can be used are greatly expanded as described above.

[0012] As a dry type fire-resistant coating material, calcium silicate board, gypsum board, aerated concrete board, etc., which have been conventionally used as a fire-resistant coating material, are crushed powders, inorganic fibers such as rock wool and ceramic wool. Examples thereof include inorganic powders such as silica sand, ground calcium carbonate, aluminum hydroxide, and the like, lightweight inorganic aggregates such as expanded perlite, vermiculite, shirasu balloon, and ceramic balloon. In actual use, these may be used alone or in combination. Embodiments of the present invention will be described below.

[0013]

【Example】

 A structural steel pipe with a diameter of 267.4 mm and a thickness of 9.3 mm is inserted into a coating steel pipe with a diameter of 355.6 mm and a thickness of 6.4 mm, and the structural steel pipe is located at the center of the coating steel pipe. After arranging as described above, both ends of each steel pipe were sealed and welded with a disc-shaped steel plate. At this time, an injection hole for the refractory coating material and an air vent hole in the gap between the steel pipes were provided in advance in the center of both ends of the coating steel pipe. The double steel pipe thus formed was tilted and fixed in a state where the air vent hole was raised as shown in FIG. Next, the wet rock wool mixed with water was pressure-fed with a mortar pump with a mortar mixer, and was filled from the injection hole of the double steel pipe. The refractory coating material was sequentially filled, and the pumping was stopped when it overflowed from the air vent hole at the end. After that, the double steel pipe filled with the refractory coating material was allowed to stand on flat ground for curing for 30 days. The double-walled steel tube filled with the fireproof coating material produced in this way has a gap of 37.7 mm between the structural steel pipe and the coated steel plate, and the wet rock wool filled in this gap has a fireproof property of 2 hours for this thickness. It was the equivalent.

[0014]

[Effect of the invention]

 The double steel pipe filled with the fireproof coating material thus produced has the following effects as compared with the fireproof coating structure obtained by the conventional fireproof coating method.・ The construction management of the thickness of the fireproof coating is extremely easy.・ Since the thickness including the fireproof coating layer and the surface layer (steel pipe for coating) is the minimum required, the overhanging dimension of the fireproof coating material on the pillar etc. can be kept to the minimum required. -In the construction of fireproof coating, the surface layer is covered with steel pipes even if the preceding pre-construction method is used in the factory, so there is no damage to the fireproof coating layer during the processes such as transportation, lifting, and building. -When considering the finished surface as well, the coating steel pipe becomes the surface, so a highly accurate smooth surface can be obtained. -Since the fire-resistant coating layer does not appear on the surface and the steel pipe serves as the surface layer, the fire-resistant layer will not be damaged even if an object hits it, and it is durable. -Considering the overall construction period, the finishing process such as surface coating can be performed regardless of the fireproof coating construction or the drying process in the case of wet materials, leading to a reduction in the construction period.・ Also, unlike concrete-filled steel pipes where the overall weight becomes extremely heavy, even for steel materials of considerable size, this structure only adds the weight of the minimum required thickness of the fire-resistant coating material and the weight of the coating steel pipe. It is possible to bring it to the site with the fireproof coating applied at the factory, which contributes to shortening the on-site construction period and streamlining.

[Brief description of the drawings]

FIG. 1 is a sectional view of a double steel pipe filled with a refractory coating material of the present invention.

FIG. 2 is an overall view showing an example of a method for manufacturing a double steel pipe filled with a fireproof coating material according to the present invention.

[Explanation of symbols]

 A Structural steel pipe B Fireproof coating material C Steel pipe for coating D Mortar mixer E Pump F Fireproof coating material G Double steel pipe H Air vent hole

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Masahide Hiraka Inventor Masahide Hiraka 2-3-18 Shimoochiai, Shinjuku-ku, Tokyo SK Kaken Co., Ltd. Tokyo Branch (72) Inventor Hideo Motoki 1-chome, Shimizu, Ibaraki-shi, Osaka No. 25-10 SK Kaken Co., Ltd.

Claims (1)

[Utility model registration claims] 1. A structural steel pipe and a coating steel pipe of a double steel pipe having a double structure by using a larger coating steel pipe in which a necessary thickness of a fireproof coating material is added to the structural steel pipe. A double steel pipe filled with a refractory coating material characterized by a structure in which a gap is filled with a refractory coating material.