JPH043047Y2 - - Google Patents

Description

[Detailed explanation of the idea]

[Industrial Application Field] The present invention relates to an improvement of a fireproof covering structure for a steel beam of a building. [Prior Art] Conventionally, as fireproof coating structures for steel beams that support building slabs, structures in which fireproof coating materials such as fiber felt are applied directly to the entire surface of the steel beams, and structures in which fireproof coating materials such as fiber felt are applied in a box shape have been used. In addition, as shown in FIG. 3, a structure that is pasted in a substantially figure-eight shape is known. In the direct attachment structure, the fireproof coating is closely attached to the entire surface of the web and upper and lower flanges forming the H-shaped steel beam, so the amount of fireproof coating used is excessive. On the other hand, the box-stacked structure has H
Since it encases a steel frame beam in a box shape, it requires less fireproof coating material than a directly pasted structure, but it is vulnerable to external impacts and is easily damaged. On the other hand, as shown in FIG.
A structure in which c is surrounded by a fireproof sheathing material 3 in a figure 8 shape and fixed with a pin 4 and a washer 5 fixed by welding uses less fireproof sheathing material compared to a directly pasted structure. It also has considerable strength against impact. [Problems to be solved by the invention] However, in the above-described figure-of-eight fireproof coating structure, the fireproof coating material 3 is applied to the central portion of the web 2a of the steel beam, so that the web 2a and The space between the web and the fireproof coating is divided into an upper space extending from the central portion of the web to the upper flange 2b, and a lower space extending to the lower flange 2c. Therefore, as the temperature rises, the lower flange 2c
The temperature in the lower space leading to the building slab 1 is significantly higher than that in the upper space leading to the upper flange 2b which is in thermal contact with the building slab 1, and there is a drawback that sufficient fire resistance performance cannot be obtained. In other words, since the upper flange is in contact with the slab, the heat from the heated upper flange escapes to the slab, which has a large heat capacity, and the temperature rise is smaller than that of the lower flange. There is a tendency for the temperature rise to increase. Incidentally, the fire-resistant covering structure (2-hour fire resistance) for H-type steel beams is divided into three parts: the upper flange, web, and lower flange, and the average temperature of each part must be 350°C or less, so special felt However, there is a problem in that increasing the thickness of the coating significantly reduces economic efficiency and workability. The present invention was developed in order to solve the problems with the structure in which felt fireproof covering material is pasted in a figure 8 shape as a fireproof covering structure for steel beams, and it is economical and easy to construct. The main objective is to provide a fire-resistant coated structure with excellent performance. [Means for solving the problem] The present invention consists of applying felt-like fireproof covering material to steel beams.
In a structure that is pasted and covered in a square shape, the above-mentioned problems can be solved by interposing a piece-like spacer made of an inorganic material between the web of the steel beam and the fireproof covering material applied to it. The aim is to solve the following problems. [Function] In the fireproof covering structure for steel beams having the above configuration, the fireproof covering material applied to the web of the steel frame rises from the web surface due to the interposition of the piece-like spacer, and the upper part reaches the upper flange through the gap. The cavity and the lower cavity leading to the lower flange communicate with each other, and the temperature difference between the upper flange and the lower flange is equalized by air convection, so that the temperature of the lower flange is reduced. [Embodiment] FIGS. 1 and 2 show an embodiment of the present invention, in which members that are the same as or similar to those described above are given the same reference numerals. That is, 1 is a building slab, 2 is an H-shaped steel beam, 2a
2b is a web, 2b is an upper flange, 2c is a lower flange, 3 is a felt-like fireproof covering, 4 is a fixing pin, and 5 is a washer. At the center of the steel web 2a, a required interval is provided in the longitudinal direction. A pin 4 is fixed by welding to the tip of the pin, and a piece-shaped spacer 6 made of rock wool felt is pierced into the pin 4 and pressed against the web surface.Then, the fireproof coating 3 is pierced and a washer 5 is attached to the tip of the pin. , the fireproof covering material 3 is attached in a figure 8 shape in a state raised from the web surface. According to the structure in which the fireproof coating is pasted in a figure 8 shape with the piece-shaped spacer 6 interposed between the web of the steel beam and the fireproof coating as described above, the upper flange 2b is connected from the center of the web. The upper cavity leading to the lower flange 2c and the lower cavity leading to the lower flange 2c communicate with each other through the floating gap formed by the spacer 6, and air convection occurs freely, so that the temperature between the lower flange 2c and the upper flange 2b is lowered. The difference is equalized and the temperature of the lower flange is reduced. The felt-like fireproof covering material may include rock wool felt, or a covering material made of rock wool as a base material and laminated with ceramic fiber felt or ceramic fiber with a metal lath layered on the surface thereof, or a covering material made of glass wool. A suitable covering material is a base material, ceramic fibers are laminated thereon, a wire mesh is layered on top of the base material, and the whole is sewn together with metal wires. In addition to rock wool felt, the piece-shaped spacer is preferably made of an inorganic material such as glass wool felt or a calcium silicate plate. Next, we will discuss the structure of the present invention in which fireproof coating is pasted in a figure-eight shape using the piece-like spacers on the steel beams supporting the building slab, and the conventional structure that does not use the piece-like spacers. The results of the fire resistance test conducted on the following are shown below. H-shaped steel beam 400 x 200 x 8 x 13 x 5400 mm Fireproof covering material Rock wool insulation material (45 mm), ceramic fiber felt (15 mm), polyester non-woven fabric (15 mm)
g/cm ² ) and hexagonal wire mesh (0.55 mmφ) sewn together with wire. Piece-shaped spacer 50mm square (made of rock wool felt)

【table】

[Table] [Effects of the invention] As described above, according to the invention, in a structure in which fireproof coating is attached in a figure-eight shape to the steel beams supporting the building slab, the web of the steel beams By interposing a piece-shaped spacer between the surface and the fireproof coating, the temperature difference between the upper flange and the lower flange is equalized, thereby lowering the temperature of the lower flange (steel material average temperature 350℃ or less, maximum temperature 450℃ or less), there is no need to increase the thickness of the felt fireproof covering material in order to pass the fireproof structure test, and a fireproof covering structure with excellent economy and workability can be obtained. At the same time, it can greatly contribute to the field of construction of fireproof coatings for H-shaped steel beams.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal cross-sectional view of a fireproof covering structure for an H-shaped steel beam showing an embodiment of the present invention, Fig. 2 is a perspective view of the mounting portion of the piece-shaped spacer, and Fig. 3 is a conventional fireproof covering structure. FIG. 1...Building slab, 2...H-type steel beam, 2a...
...web, 2b...upper flange, 2c...lower flange, 3...fireproof covering material, 4...fixing pin,
5... Washer, 6... Piece-shaped spacer.

Claims (1)

[Scope of utility model registration request] In a fire-resistant covering structure that is constructed by pasting fire-resistant covering material in a figure-eight shape to a steel beam supporting a building slab, excluding the slab support surface, the web forming the steel frame and the web that is applied to this A piece-shaped spacer made of an inorganic material is interposed between the fireproof coating material, and the spacer is passed through the gap formed by this piece-shaped spacer,
A fireproof covering structure for a steel beam, characterized in that an upper cavity extending from a spacer part to an upper flange of a steel frame and a lower cavity extending to a lower flange are interconnected.