JPH0455150B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a fire-resistant coating for protecting steel frames used for columns and pillars in high-rise buildings from fire. (Conventional technology) Most high-rise buildings are constructed of steel frames as pillars and walls, and the surface is covered with decorative boards, which is the so-called steel frame construction (S construction). If a fire were to occur, the steel material would be exposed to temperatures of over 1,000 degrees Celsius and would burn out, so the surface of the steel frame must be coated with fireproof material. Until now, this kind of fireproof coating work has been carried out either by having workers apply the refractory material to the steel frame to a predetermined thickness, or by ejecting the refractory material from the tip of a nozzle and spraying it onto the steel frame. (Problems to be Solved by the Invention) In the above-mentioned fireproof covering work, since the fireproofing material is in powder form, a large amount of the fireproofing material is scattered into the space during the painting or spraying work, and fallen materials are scattered on the floor. It was laminated to a considerable thickness on top. Therefore, various measures have been investigated to protect workers from such adverse environments, such as wearing dust masks to prevent workers from inhaling refractory materials and using robots to perform spraying work. It's been sealed. However, since the work involved essentially spraying powdered refractory material onto steel frames, improvements in the cleaning process for the airborne refractory materials and the refractory materials accumulated on the floor have not been completely achieved. . (Means for Solving the Problems) The present invention aims to completely eliminate the above-mentioned spraying of refractory material onto steel frames, and
4.5-14% by weight of raw coke, based on 100% by weight of the total mixture consisting of 80-35% by weight of aggregate and 80-35% by weight of raw coke;
scaly mica 4.5-9% by weight, borax 5-15% by weight,
A fireproof plate made of a compound containing 5 to 30% by weight of glaze and 20 to 45% by weight of an organic foam adhesive is processed into a rectangular shape that matches the external shape of the steel frame, and the rectangular fireproof plate is placed around the steel frame. The aim is to provide a fireproof coating to the steel frame by placing them between the two and securing them together, thereby creating a cleaner and faster working environment. (Function) In the above compound, cement not only contributes to high strength as a binder but also acts as a fireproof material when heated by fire. In particular, when alumina cement is used as the cement, uniform and fine foaming of the cast molded product is promoted, a flexible and strong fireproof board is obtained, and its fire resistance is increased. Furthermore, raw coke (pitch coke) produces a carbonaceous material with a mesophase crystal structure that is fire resistant and has high high temperature strength in a non-oxidizing atmosphere at a temperature of 250°C or higher, and this material penetrates into the composition of the compound to form the fireproof plate of the present invention. It has the function of being fire-resistant and high-strength. Since scaly mica inherently has low heat conductivity in the thickness direction, even if it is rapidly heated from outside the refractory plate surface, the scaly mica arranged in layers along the refractory plate surface will absorb the heat. Most of the heat does not transfer to the inside of the fireproof board, and it protects the inside of the fireproof board. Borax is added when the temperature is 100°C because borax forms penta- or decahydrates and has polycrystals.
When the temperature exceeds ℃, the endothermic reaction and released water prevent the fireproof board from burning, and when the temperature rises to a high temperature, it reacts with inorganic components such as alumina, silica, lime, and scaly mica, causing moth compounding. to form a binder or high heat barrier. When limestone is used as aggregate, when placed in an environment with elevated temperatures, it thermally decomposes and generates CO ₂ gas, reducing the O ₂ content in the bubbles and remaining in the fireproof board, making it flame retardant. It contributes to the improvement of raw coke and helps the raw coke to become mesophase. Isocyanate-based, urethane-based, and epoxy-based adhesives are used as the organic foam adhesive, and serve to make the fireproof board porous and lightweight. These act as adhesives and shape-retaining agents between the components of the blended composition during the manufacture of the fireproof board and at normal temperatures.
It also acts as a flexibilizing agent for the product. Further, as a foaming agent, for example, a self-foaming foaming agent such as polysilosane may be used. Instead of using one type of glaze, use a combination of several types of glazes, such as those with a relatively high melting point, those with a normal melting point, and those with a low melting point. is preferred. For example, PbO−B ₂ O ₃ type,
B ₂ O ₃ −PbO−Tl ₂ O system, NaO−P ₂ O ₅ system, P ₂ O ₅ −
Select PbO-based, NaO-P ₂ O ₅ -SiO _2- based products, or products with various melting points of Seekel conical composition.
can be used. This low melting point glaze exhibits a fireproofing effect by releasing its crystal water at 100 to 200 degrees Celsius when the fireproof plate is heated due to a fire, etc. Sometimes it has a fireproofing effect. Note that some of the other ingredients can also act as a glaze; for example, borax melts at around 740°C to form glass, so it can act as a fire-resistant glaze at that temperature. . The glaze with a normal melting point or a high melting point may be appropriately selected and used from well-known enamel glazes, ceramic glazes, and the like. The glaze is used by preparing glaze powders with various melting points, for example, 400, 600, 800°C, and mixing them into the building material formulation at the same time. In this case, when heated from the outside, for example, a glaze with a melting point of 400°C will melt and form a glass film when heated to about 400°C, and a glaze with a melting point of 600°C will melt when heated to about 600°C. By forming a glass film with glaze, the interior is protected from external heat. For this reason, the fireproof board has a very large effect in protecting the steel frame from external high-temperature heat, and when heated due to a fire, etc., the glaze is heated and melted to form a glass layer inside the fireproof board, shutting out the heat from the outside world. Therefore, it is possible to provide a fireproof board with excellent fire resistance and heat insulation properties. In addition, the fireproof board made by adding an appropriate amount of water to the above compound and kneading it can be sawed and cut, so the fireproof board can be delivered to the construction site and shaped as needed to match the shape of the steel frame. Cut the fireproof board into an appropriate shape. After each processed fireproof board is attached to a steel frame, the fireproof boards are joined to each other using adhesive, nails, or other fixing means to integrate the fireproof boards. (Example) Fig. 1 and Fig. 2 show the case where the coating method according to the present invention is applied to a pillar, and Fig. 3, Fig. 4, and Fig. 5 show the case where it is applied to a rice cake. . In the figure, 1 is a pillar, a steel frame, 2 is a fireproof plate, and 3
4 is a piece, 5 is a round nail, and 6 is a fixing member such as adhesive. Fireproof board 2 consists of 2000 kg of alumina cement, 400 kg of crushed limestone, and raw coke (softening point approximately 430°C, fixed carbon 88.8%, volatile content 10.7
%, ash content 0.5%), 25 kg of scaly mica, 90 kg of borax (decahydrate), and 250 kg of isocyanate foaming adhesive (water-soluble urethane prepolymer). The resulting mochi-like material is dried at room temperature for 24 hours, and the length
It is formed into a plate shape of 1.8m, width 0.9m, and thickness 40mm. The physical properties of this panel are as follows. Bending strength: 22.5Kg/cm ² Compressive strength: 28.4Kg/cm ² Bulk specific gravity: 1.09 Fire resistance and heat insulation properties were confirmed as follows. That is, a panel with a thickness of 50 mm was produced as described above, and as shown in Fig. 6, from the front side to the back side, the depth (thickness) was 15 mm (first point) and 32.5 mm (first point). Figure 7 shows the results of measuring fire resistance and heat insulation by exposing the front surface of a device with temperature sensors installed at the second point) and back side (third point) to a fire. be. In the figure, line 1 is the time-temperature curve at the first point, line 2 at the second point, line 3 at the third point, line P is the panel surface temperature curve, and line J is defined by the Japanese Industrial Standards (JIS). This is the heating temperature curve for the fire resistance test of the panel. From this graph, the heating surface reaches 1010℃ after 2 hours of heating.
However, the temperature of the fireproof board according to the present invention at the third point near the opposite side hardly rose to 150°C, which is higher than the average and maximum temperature of the pillars and casings as stipulated in Article 107 of the Construction Order of the Building Standards Law. It satisfies both the temperature requirements of 350°C and 450°C, indicating that it has extremely excellent fire resistance and insulation properties. The provisions of Article 107 of the Construction Order mentioned above are considered to be a general guideline for the fire resistance performance of pillars and pillars, but asbestos calcium silicate based fire resistant covering boards have traditionally been used to meet this performance. The plate thickness is as shown in the table below.

[Table] Comparing the above table and the performance of the coated plate according to the present invention, the plate thickness is 15 mm for 1 hour, 32.5 mm for 2 hours, and 50 mm (estimated value) for 3 hours. It can be seen that it is possible to use a thin plate material within the range of 5 mm. This results in a large cost difference in the case of high-rise or super-high-rise buildings. The fireproof board 2 is a flat plate of specified dimensions that is brought to the construction site and cut into multiple rectangular shapes using a saw or the like to match the shape of the steel frame 1 to be applied. Waste board 3 used for
It is attached to the steel frame surface using the auxiliary member of piece 4. Next, the fireproof boards 2 are joined together to form an integral piece, but since the fireproof board according to the present invention can be cut as described above and can also be driven with nails, it can be cut like ordinary wood using round nails. can be easily worked on. Further, the composition of the fireproof board according to the present invention can be easily integrated by simply kneading the powder with water, adhering the mixture between each fireproof board, and foaming them under pressure. Furthermore, it is possible to collect the swarf generated when cutting a flat plate into a predetermined rectangular shape at a construction site and reuse it as a lightweight aggregate for cement, which is extremely economical. (Effects) Since the fireproof coating method according to the present invention uses a fireproof material made of the above-mentioned compound, the fireproof board has excellent fire resistance, is lightweight, has high bending strength, and is flexible. It is also excellent. Therefore, by using a thin covering plate, costs can be reduced, and even in the event of an earthquake, the deformation of the pillars and casings will be easily followed and no cracks will occur in the fireproof layer. Furthermore, since the fireproof board can be sawed, nailed, and cut, it is easy to install, and the work site is free from scattering of cuttings, and cleaning is sufficient during the woodworking process. Therefore, the fireproof coating work can be carried out easily and safely in a short period of time.

[Brief explanation of the drawing]

FIGS. 1 and 2 show an example in which the fireproof coating method according to the present invention is applied to a column, and FIGS. 3 to 5 are construction drawings in which the method is similarly applied to a column. Moreover, FIGS. 6 and 7 are a layout diagram of a temperature sensor for showing the fireproof insulation properties of the fireproof plate used in the present invention, and experimental data showing the test results thereof. In Figures 1 to 3, 1 is a steel frame, 2 is a fireproof board, 3 is a scrap board, 4 is a piece, 5 is a round nail, 6 is an adhesive, and 7 is a floor.

Claims (1)

[Claims] 1. 20-65% by weight of cement and 80-35% by weight of aggregate.
4.5-14% by weight of raw coke, 4.5-9% by weight of scaly mica, 5-15% by weight of borax, 5-30% by weight of glaze, and 20-45% by weight of organic foam adhesive based on the total amount of 100% by weight of the mixture consisting of: A fireproof coating method for a steel frame, in which a fireproof plate formed from a compound with a weight percentage of . 2. Adhesion is 20~65% by weight of cement and 80~80% of aggregate.
For a total of 100% by weight of a mixture consisting of 35% by weight,
Raw coke 4.5-14% by weight, scaly mica 4.5-9
% by weight, 5 to 15% by weight of borax, 5 to 30% by weight of glaze, and 20 to 45% by weight of an organic foam adhesive. The fireproof covering method for a steel frame according to item 1.