JP7776389B2 - Joint structure and construction method - Google Patents

Description

The present invention relates to a fire-resistant joint structure and its construction method.

Conventionally, when applying fire-resistant coating to the outer surface of a structural member in a fire-resistant structure, the application is made easier by providing joints in the fire-resistant coating. However, since fire resistance must also be ensured in the joints, a structure is required in which the joints are filled with a joint material that has heat-shielding properties. Known examples of such structures include those in which a fixed-shape joint material such as rock wool is placed in the joints (see, for example, Patent Document 1).

Japanese Patent Application Publication No. 3-122336

However, in cases where the joints are diagonal, it becomes necessary to shape the standard joint material diagonally, which can reduce workability. For this reason, there was a need for a joint structure that could improve workability while also ensuring fire resistance.

The present invention was made in consideration of the above, and aims to provide a joint structure and construction method that can improve workability and ensure fire resistance.

In order to solve the above-mentioned problems and achieve the objectives, the joint structure of the present invention is a joint structure formed in a joint portion of a fire-resistant covering material applied to the outside of a structural member, and is characterized by comprising: a first joint material made of a paste-like, amorphous fire-resistant material with heat-shielding properties that is applied to cover the outside of the structural member at the joint portion; and a second joint material made of a paste-like, amorphous material with deformation-following properties that is applied to the outside of the first joint material.

Another joint structure according to the present invention is characterized in that, in the above-mentioned invention, the joint portion is an oblique joint portion that runs diagonally relative to the thickness direction of the fire-resistant covering material.

Another joint structure according to the present invention is characterized in that, in the above-mentioned invention, the first joint material is a calcium carbonate-based sealant.

The joint structure construction method of the present invention is a method for constructing the above-mentioned joint structure, characterized in that after filling the area outside the structural member of the joint portion with a first joint material, the area outside this first joint material is filled with a second joint material.

The joint structure of the present invention is formed in the joint portion of a fire-resistant covering material applied to the outside of a structural member. It comprises a first joint material that covers the outside of the structural member at the joint portion and is made of a paste-like, amorphous fire-resistant material with heat-shielding properties, and a second joint material that is applied to the outside of the first joint material and is made of a paste-like, amorphous material with deformation-following properties, thereby achieving the effects of improving workability and ensuring fire resistance performance.

Furthermore, according to another joint structure of the present invention, the joints are diagonal joints that run diagonally relative to the thickness direction of the fire-resistant covering material, which has the effect of improving workability and ensuring fire resistance even in diagonal joints.

Furthermore, according to another joint structure of the present invention, the first joint material is a calcium carbonate-based sealant, which is not likely to burn down and has excellent heat-shielding properties, thereby achieving the effect of further improving fire resistance.

Furthermore, the joint structure construction method according to the present invention is a method for constructing the above-mentioned joint structure, in which a first joint material is filled into the area outside the structural member of the joint portion, and then a second joint material is filled into the area outside this first joint material, thereby achieving the effect of improving construction ease and ensuring fire resistance.

FIG. 1 is a cross-sectional view showing a joint structure and a construction method thereof according to a first embodiment of the present invention. FIG. 2 shows a second embodiment of the joint structure and its construction method according to the present invention, where (1) is a plan view and (2) is a cross-sectional view. FIG. 3 shows a third embodiment of the joint structure and its construction method according to the present invention, where (1) is a plan view and (2) is a cross-sectional view. FIG. 4 is a cross-sectional view showing the test specimens used in the fire resistance test, (1) being an example and (2) being a comparative example. FIG. 5 is a diagram showing the results of the fire resistance experiment (temperature transition). FIG. 6 shows an example of a joint structure, where (1) is a plan view and (2) is a cross-sectional view.

Below, an embodiment of the joint structure and its construction method according to the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to this embodiment.

(Embodiment 1)
First, a first embodiment of the present invention will be described.
As shown in Figure 1, the joint structure 100 of this embodiment 1 is a joint structure formed in a joint portion 16 of a fire-resistant coating material 14 provided on the outside of a structural member 12, and comprises a first joint material 18 provided to cover the outside of the structural member 12 at the joint portion 16, and a second joint material 20 provided on the outside of this first joint material 18.

The structural members 12 may be composed of beams made of wooden members, for example. The fire-resistant covering material 14 may be composed of a fire-resistant covering material such as reinforced gypsum board, or a laminated structure of reinforced gypsum board, a fire-resistant sheet, and a wood-based decorative material, for example.

The joints 16 are oblique joints that run diagonally relative to the thickness direction D (material thickness direction) of the fire-resistant covering material 14. The dimensions of the joints 16 can be, for example, a joint width W of 126 mm or less, a thickness d1 of the first joint material 18 of 30 mm or more, and an oblique angle θ of the joints 16 of 25°. Note that the joints of the present invention are not limited to oblique joints, and may be, for example, joints that run in the thickness direction D of the fire-resistant covering material 14.

The first joint material 18 is made of a paste-like, heat-shielding, unshaped refractory material and is placed in the recessed area defined by the outer surface 12A of the structural member 12 and the side end surface 14A of the fire-resistant covering material 14 in the joint 16. This first joint material 18 can be made of, for example, a calcium carbonate-based sealant. Unlike conventional shaped joint materials, calcium carbonate-based sealants are easy to apply because they do not need to be molded to fit the shape of the joint 16. Furthermore, because the primary material, calcium carbonate, is inorganic, there is no risk of it burning down. Furthermore, because the decomposition of calcium carbonate begins at around 600°C, an endothermic reaction occurs, providing excellent heat-shielding properties. These benefits enable improved application and guaranteed fire resistance, even in diagonal joints that were difficult to apply using conventional technology.

The second joint material 20 is made of a paste-like amorphous material with deformation-following properties, and is placed in the recessed area defined by the outer surface 18A of the first joint material 18 and the side end surface 14A of the fire-resistant covering material 14 in the joint portion 16. This second joint material 20 can be made of, for example, a silicone-based sealant with excellent deformation-following properties.

When constructing the above-mentioned joint structure 100, for example, a fire-resistant coating material 14 is attached to the outer surface 12A of the structural member 12 to form a joint 16, and the area of this joint 16 outside the structural member 12 is filled with a first joint material 18 and smoothed. Then, the area outside the first joint material 18 is filled with a second joint material 20 and smoothed. In this way, the joint structure 100 can be constructed.

However, since applying the second joint materials 18 and 20 becomes difficult as the joint depth increases, when multiple layers of fire-resistant coating material 14 are stacked, it is desirable to fill and apply the first joint material 18 and second joint material 20 into the joint area 16 after each layer of fire-resistant coating material 14 is applied.

According to this first embodiment, it is possible to improve workability and ensure fire resistance. In particular, it is possible to improve workability and ensure fire resistance even in diagonal joints, which were difficult to install using conventional technology.

(Embodiment 2)
Next, a second embodiment of the present invention will be described.
As shown in FIG. 6 , when joining a steel material such as a steel rod 22 diagonally to a structural member 12 (e.g., a beam made of wood), a conceivable structure is one in which the steel rod 22 is inserted diagonally into the structural member 12 through an oblique joint 16 formed in the fire-resistant covering material 14. This example shows a case in which two layers of the fire-resistant covering material 14 are stacked on the outside of the structural member 12. Also shown is a case in which the base portion 16 of the fire-resistant covering material 14 has a substantially rectangular shape when viewed from the front. A joint material is filled into the joint 16 to ensure fire resistance, so as to completely cover the periphery of the steel rod 22. Rock wool 24 is used as the joint material for the joint 16 of the first layer of fire-resistant covering material 14 attached to the structural member 12, and a silicone-based sealant 26 is used as the joint material for the joint 16 of the second layer of fire-resistant covering material 14 attached to the outside of the first layer. This makes it difficult for heat from the joint 16 to be transmitted to the structural member 12.

However, with a structure like the one shown in Figure 6, because steel rods 22 are placed in the diagonal joints 16, processing the rock wool 24 can be time-consuming. Furthermore, it is difficult to fill the rock wool 24 without leaving any gaps, which reduces workability. Therefore, to solve these problems, the joint structure according to the following second embodiment is applied.

As shown in Figure 2, the joint structure 200 of this second embodiment uses a calcium carbonate-based sealant 28 instead of the rock wool 24 in the structure of Figure 6. The calcium carbonate-based sealant 28 corresponds to the first joint material of the present invention, and the silicone-based sealant 26 corresponds to the second joint material of the present invention. In addition, a fire-resistant paint 30 is applied to the portion where the steel rod 22 penetrates the joint portion 16. The gap width W1 between the fire-resistant paint 30 and the fire-resistant coating material 14 can be, for example, 7 mm.

According to the second embodiment, the processing of the rock wool 24 is eliminated, improving workability. Furthermore, the heat-absorbing effect of the calcium carbonate-based sealant 28 allows for heat-blocking performance equivalent to that of the structure shown in Figure 6. Furthermore, the foaming of the fire-resistant paint 30 applied to the steel rod 22 prevents gaps from forming between the steel rod 22 and the joint material. This improves workability and ensures fire-resistant performance.

(Embodiment 3)
Next, a third embodiment of the present invention will be described.
As shown in Figure 3, the joint structure 300 of the third embodiment is similar to that of the second embodiment, except that calcium carbonate sealant 28 is used instead of the silicone sealant 26, and rock wool 24 is also used as a cushioning material for vibration absorption. Therefore, the calcium carbonate sealant 28 corresponds to the first and second joint materials of the present invention. The calcium carbonate sealant 28 used as a filler for the joint 16 is vulnerable to vibration, and using it alone may cause cracks on the surface of the material, resulting in a decrease in heat-shielding performance. Therefore, the calcium carbonate sealant 28 is used as a filler, and rock wool 24 is also used as a cushioning material for vibration absorption. The rock wool 24 is filled around the space between the side end surface 14A of the second fire-resistant coating material 14 and the calcium carbonate sealant 28.

This third embodiment can improve workability and ensure fire resistance. In particular, by using calcium carbonate-based sealant 28 instead of silicone-based sealant 26, heat-shielding performance is improved and construction costs can be reduced. It also prevents cracking of the calcium carbonate-based sealant 28 due to vibration and a decrease in heat-shielding performance.

(Verification of the effects of the present invention)
Next, a fire resistance experiment conducted to confirm the effects of the present invention will be described.
The specifications of the test specimens used in the fire resistance experiment and the temperature measurement position P near the joint on the unheated side are shown in Figure 4. Figure 4(1) shows the test specimen of the example, and Figure 4(2) shows the test specimen (comparison example) with the prior art rock wool filling specification.

The fire resistance test consisted of placing the test specimens in a fire resistance test furnace and heating them for one hour according to the heating temperature-time curve specified in ISO 834-1. After heating, each test specimen was allowed to cool in the furnace.

As shown in the temperature measurement results in Figure 5, the maximum temperature near the joint on the non-heated side was 125°C for the Example and 188°C for the Comparative Example. Furthermore, no gaps penetrating from the heated side to the non-heated side occurred in the Example. From the above, it was confirmed that the joint structure of the Example has the required fire resistance performance.

As explained above, the joint structure of the present invention is a joint structure formed in a joint portion of a fire-resistant covering material applied to the outside of a structural member. It comprises a first joint material made of a paste-like amorphous fire-resistant material with heat-shielding properties that is applied to cover the outside of the structural member at the joint portion, and a second joint material made of a paste-like amorphous material with deformation-following properties that is applied to the outside of the first joint material, thereby improving workability and ensuring fire resistance.

Furthermore, according to another joint structure of the present invention, the joints are diagonal joints that run diagonally in the thickness direction of the fire-resistant covering material, which makes it possible to improve workability and ensure fire resistance even in diagonal joints.

Furthermore, according to another joint structure of the present invention, the first joint material is a calcium carbonate-based sealant, which is not likely to burn down and has excellent heat-shielding properties, further improving fire resistance.

Furthermore, according to the joint structure construction method of the present invention, a method for constructing the above-mentioned joint structure involves filling the area outside the structural member of the joint portion with a first joint material, and then filling the area outside this first joint material with a second joint material, thereby improving construction ease and ensuring fire resistance.

As described above, the joint structure and construction method of the present invention are useful for joints in fire-resistant covering materials, and are particularly suitable for improving workability and ensuring fire resistance.

12 Structural member 12A Outer surface 14 Fire-resistant coating material 14A Side end surface 16 Joint portion 18 First joint material 20 Second joint material 22 Steel rod 24 Rock wool 26 Silicone-based sealant 28 Calcium carbonate-based sealant 30 Fire-resistant paint D Thickness direction 100 to 300 Joint structure

Claims (4)

A joint structure formed at a joint portion of a fire-resistant covering material provided on the outside of a structural member,
A joint structure characterized by comprising a first joint material made of a paste-like amorphous fire-resistant material with heat-shielding properties, which is arranged to cover the outside of the structural member of the joint portion, and a second joint material made of a paste-like amorphous material with deformation-following properties, which is arranged on the outside of the first joint material. The joint structure described in claim 1, characterized in that the joint is an oblique joint that runs diagonally relative to the thickness direction of the fire-resistant covering material. The joint structure described in claim 1 or 2, characterized in that the first joint material is a calcium carbonate-based sealant. A method for constructing the joint structure according to claim 1 or 2,
A construction method for a joint structure, characterized in that a first joint material is filled in the outer area of the structural member of the joint portion, and then a second joint material is filled in the area outside the first joint material.