JPH07122322B2 - Fireproof coating - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a fire-resistant coating material for wet spraying for forming a fire-resistant coating on beams and columns of various steel frame buildings.

[Conventional technology]

It is widely practiced to apply a fireproof coating to a steel frame portion of various buildings by a spraying method. As the coating material used for that purpose, it is possible to carry out construction by wet spraying in which all raw materials are mixed with water in advance and sprayed in a paste form, without environmental deterioration due to dust scattering,
It is advantageous because it has good workability.

A typical example of a fire-resistant coating material for wet spraying is Japanese Examined Patent Publication No. 50-24.
It is described in Japanese Patent No. 973 and its composition is as follows.

Rock wool 20 to 75% by weight Hydraulic inorganic adhesive 25 to 60 〃 Surfactant 0.1 to 1.0 〃 Thickener 0.1 to 1.0 〃 In addition to this, lightweight aggregates such as vermiculite and perlite are added to reduce weight. Sometimes

As the hydraulic inorganic adhesive, Portland cement, alumina cement, blast furnace cement, gypsum, gypsum plaster (JIS A6904), etc. are used.

These conventional refractory coating materials are generally sprayed on the surface of the steel frame after completion of the steel frame assembly of a building, and then, it usually takes about 24 hours to cure.

On the other hand, in the vicinity of a factory or a construction site, a fireproof coating pre-attachment construction method has recently been developed in which a fireproof coating is applied to a steel frame surface before assembly, and the steel frame subjected to the fireproof coating is used for assembly (for example, JP-A-61- No. 98841), and the advantages such as the reduction of work at high places and the shortening of the construction period are drawing attention.

However, in the case of the fireproof coating pre-construction method, it is not possible to spend a long time for curing in a narrow work space after spraying the coating material, and it is desired that the transportation and assembly can be performed quickly, so after spraying, It is necessary that the material be capable of forming a refractory coating that exhibits high adhesion strength and surface strength in about 3 hours and can be handled during transportation and assembly. However, the conventional wet-spraying fire-resistant coating material made on the premise of spraying after the steel frame is assembled is too slow to be used in the fire-resistant coating pre-construction method, and therefore it is not possible to use the pre-construction method. The features cannot be fully utilized.

When cement is used as the hydraulic inorganic adhesive, attempts to accelerate the hardening after spraying by changing the cement to a quick hardening type or by using a cement hardening accelerator together have not been successful. This is because the gypsum used in combination with cement delays the hardening of the cement, so the hardening time does not become as short as in the case of cement alone (the cement alone lacks the initial adhesive force to the steel frame, The ironing workability is also poor, and the drying shrinkage rate is large and cracks are likely to occur in the coating layer.The combined use of gypsum is effective in solving these problems.)

Needless to say, it is not necessary that the curing after spraying is quicker, and after mixing the spraying material with water, pumping by pumping and ensuring a minimum of 30 minutes of fluidity retention time for spraying. Moreover, adjustment to suitable curing properties must be achieved without incurring the deterioration of performance required as a fireproof coating material, which is also a problem that cannot be easily solved.

[Problems to be Solved by the Invention]

Therefore, the present invention provides a fireproof coating material having physical properties and curing characteristics suitable for the prefabricated method, and also excellent in the performance of the fireproof coating finally formed, and it is possible to make full use of the features of the prefabricated method. Is what you are trying to do.

[Means for Solving the Problems]

The fire-resistant coating material provided by the present invention, which has achieved the above object, is a rock-wool, a hydraulic inorganic adhesive, and a fire-resistant coating material for wet spraying composed mainly of water, and as a hydraulic inorganic adhesive, Portland cement and the Portland cement. It is characterized in that 100 to 300 parts by weight per 100 parts by weight of gypsum plaster whose initial setting time is adjusted to 10 to 50 minutes is mainly used and also contains sodium silicate.

By adopting the hydraulic inorganic adhesive having the composition as described above, the fire-resistant coating material of the present invention has the optimum curing characteristics for the pre-attachment method and exhibits sufficient performance in spraying workability and fire resistance.

The most characteristic component of the fire-resistant coating material of the present invention is gypsum plaster with an initial setting time of 10 to 50 minutes. The gypsum-based material used in the known fireproof coating material is
Plaster plaster for plastering (JIS A690), which is an anhydrite that starts immediate hardening when mixed with water, or a plaster for 1 hour or more
4; calcined gypsum is the main raw material, and admixtures, thickeners, setting retarders, etc. are appropriately mixed in this). Gypsum plaster, which is out of JIS standard and has an initial setting of 10 to 50 minutes, is not usually marketed. However, in such a gypsum plaster, the mixing ratio of the auxiliary agent such as a setting retarder is adjusted so that the initiation of setting is slightly faster than that of an ordinary gypsum plaster, and the composition is particularly different from that of a normal gypsum plaster. It's not different. By using this early setting gypsum plaster in an amount equal to or more than that of Portland cement, the setting property of the entire fire-resistant coating material depends exclusively on the setting property and the compounding ratio of the gypsum plaster.

Ordinary Portland cement is used as Portland cement.

The sodium silicate compounded in the hydraulic inorganic adhesive mainly consisting of the above-mentioned early setting gypsum plaster and Portland cement does not affect the initial setting property of the fire-resistant coating material so much, but causes strength to develop in a short time after setting. To help. The sodium silicate to be used may be in the form of a solution or a powder, but the powdered sodium silicate is easier to mix with other materials, and when water is added and kneaded after mixing. Since it gradually melts and accelerates hardening, it is advantageous to secure the initial fluidity required for pumping. A suitable blending amount is 3 to 5% by weight based on the total solid content (powdered sodium silicate No. 3 equivalent amount).

Although these components are used together in the above-mentioned ratios, the coagulability after mixing with water is significantly affected by temperature, so it is desirable to determine the optimum mixing ratio based on the results of preliminary experiments at the working temperature. This ensures the fluidity necessary for spraying after mixing with other refractory coating material components such as rock wool and water for at least 30 minutes, while after about 3 hours, the strength to withstand normal handling for steel frame assembly. Can be expressed.

Except that the hydraulic inorganic adhesive is composed of the above-mentioned components, the types and blending ratios of the other constituent components of the fire-resistant coating material of the present invention are not particularly limited, and conventional fire-resistant coatings of this kind are not particularly limited. Like the material, it can be arbitrarily selected. However, the particularly preferable components of the fire-resistant coating material to be combined with the above-mentioned inorganic adhesive specified by the present invention are as follows (numerical values are% by weight based on total solid content).

Rock wool 20-30% Surfactant (foaming agent) 0.1-0.3% Thickener 0.3-0.5% Water 110-130% The fire-resistant coating material of the present invention is kneaded into a slurry by kneading all components including water. After that, it can be sprayed on the surface of the steel frame before assembly by a conventional method of wet spraying.

The fire-resistant coating material of the present invention is most suitable for use in the fire-resistant coating material pre-attachment construction method, but the use is not limited thereto. For example, when the spraying material is not pumped for a long distance, the early setting property does not hinder the spraying work, so that it can be used in the fireproof coating post-installation method.

〔Example〕

The present invention will be described below with reference to examples. In each example, the setting / hardening property test was conducted by measuring the needle penetration degree according to JIS R2506 "Test method for refractory mortar consistency". In this test, the needle penetration after 30 minutes should be about 20 mm or more to secure the fluidity necessary for pumping, and if the needle penetration is 3 mm or less, handling of steel frame assembly It can be said that it has developed the strength to withstand.

Examples 1 to 3 Refractory coating material slurries were prepared under various raw material formulations and temperature conditions, and the setting characteristics thereof were investigated. The results are shown in Table 1.

Comparative Examples 1 to 5 Refractory coating material slurries were prepared in the same manner as in Examples 1 to 3 except that the raw material composition was changed as shown in Table 2, and the setting and hardening characteristics thereof were examined. The temperature was 25 ° C., and Comparative Example 2
Only super early strength cement in place of Portland cement
Jet cement (product of Onoda Cement Co., Ltd.) was used.

The results are also shown in Table 2.

[Advantages of the Invention] As described above, the fire-resistant coating material of the present invention is excellent in early strength development required for the pre-attachment method, and has sufficient initial fluidity and fire resistance performance. By taking advantage of the features of the coating pre-attachment method more than ever, it is possible to form a fireproof coating efficiently and safely.

Front page continued (72) Inventor Masahiko Tsunetani 7-6 Suzuya, Yono City, Saitama Prefecture (72) Inventor Shoichiro Shirai 2-25-6 Sugita, Isogo-ku, Yokohama, Kanagawa Prefecture (72) Inventor Ryutaro Yokoyama Isehara, Kanagawa Prefecture 2-9-33 Isehara, Isehara (72) Kozo Takimoto 1-6-9, Aobadai, Midori-ku, Yokohama-shi, Kanagawa Prefecture (56) References Japanese Patent Laid-Open No. 53-9825 (JP, A) Actual 63-67110 (JP) , U) Japanese Patent Publication No. 50-24973 (JP, B1)

Claims (2)

[Claims] 1. A fire-resistant coating material for wet spraying comprising rock wool, a hydraulic inorganic adhesive, and water as main components,
The hydraulic inorganic adhesive is Portland cement and 100 to 300 parts by weight per 100 parts by weight of the Portland cement,
A fire-resistant coating material characterized by containing gypsum plaster whose initial setting time is adjusted to 10 to 50 minutes and containing sodium silicate. 2. The sodium silicate powder is a sodium silicate powder of 3 to 5% by weight based on the total solid content of the hydraulic inorganic adhesive.
Fireproof coating material as described.