JP2007277827A - Fireproof structure of building - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fireproof structure of a building using a slate (corrugated sheet) as an external facing material, which can enhance fireproof performance of a joint section, considered to be a weak point of a conventional fireproof structure, by using a simple structure advantageous in terms of construction cost. <P>SOLUTION: In this fireproof structure of the building using the slate (corrugated sheet), based on JIS A 5430, as the external facing material, an external facing bed material as a calcium silicate board with a thickness of 15 mm or more, which is set at 0.8 based on JIS type 2 or have equivalent physical properties, or a cemented excelsior board with a thickness of 20 mm or more and physical properties specified by JIS A 5404 is anchored to the outdoor side of horizontal furring strips which are installed at predetermined intervals in the structural skeleton of the building; a joint board, which is composed of a calcium silicate board with a thickness of 6 mm or more, set at 0.8 based on JIS type 2 or having equivalent physical properties, is anchored to the outdoor side of the joint section between the external facing bed materials; and the slate (corrugated sheet) is anchored onto the external facing bed material and the joint board. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a fire prevention structure of a building, and more particularly to a fire prevention structure of a building using a slate (corrugated sheet) (non-asbestos corrugated sheet) as an exterior material.

  Slate (corrugated sheet) is a building material that has been widely used as an exterior material in factories and warehouses. The conventional raw material composition of slate (corrugated sheet) was mainly composed of cement as matrix raw material and asbestos (fiber asbestos) as fiber raw material, but with the recent non-asbestos conversion, cellulose as fiber raw material Organic fibers such as pulp are used. The heating condition in the fire performance test / evaluation method of the building standard method for evaluating the fire performance of a fire prevention structure of a building having such a slate (corrugated sheet) as an exterior material is conventionally shown by a curve b in FIG. It was a thing. Under this fire test condition, a fire prevention structure as shown in FIG. 10 was adopted as a fire prevention structure of a building using a slate (corrugated sheet) as an exterior material, and was certified as a fire prevention structure. That is, in the fire prevention structure of the building shown in FIG. 10, the exterior base material fastening bracket is made by using a wood cement board with a thickness of 15 mm or more as the exterior base material (22) on the outdoor side of the lateral trunk edge (21). (23) and slate (corrugated sheet) (26) with a standard thickness (6.3 mm) on the exterior side of the exterior base material (22) through the packing (27) and the washer (28). It is fastened with the exterior material fastening bracket (29).

However, with the revision of the Building Standards Act in 2000, the heating conditions in the fireproof performance test / evaluation method were revised as shown by the curve a in FIG. 9, and the heating conditions became more severe. This heating condition is a heating curve according to ISO834, and is represented by T = 345log ₁₀ (8t + 1) +20 [wherein T represents temperature (° C.) and t represents time (minute), respectively], When the back surface temperature rise is 180K or less during the 30-minute test, the test is accepted. Under such test conditions, in the conventional fire prevention structure as shown in FIG. 10, the joint portion of the exterior base material (22) becomes a weak point, and the back surface temperature of the exterior base material (22) is suppressed to a judgment temperature or less to prevent fire. It was not possible to obtain a certification as a structure. In order to enhance the fireproof performance of the joint portion of the exterior base material (22), (A) the exterior base material is made thicker; (B) the exterior base material has a two-layer structure and the joint portions of each layer overlap. There have been considered measures such as (C) performing a phase-out process on the edge of the exterior base material; (D) inserting a heat expansion material or the like on the outdoor side of the joint.

  However, the measures described in the above (A) to (D) have problems in terms of construction cost and material cost. Therefore, at present, a fire prevention structure is adopted as shown in FIG. 11 and is certified as a fire prevention structure. That is, in addition to the fire prevention structure shown in FIG. 10, a gypsum board having a thickness of 9.5 mm or more is arranged as an interior material (25) on the indoor side of the lateral trunk edge (21), and the exterior base material (22). By filling rock wool (24) into the hollow portion formed between the interior materials (25), the performance of the fire prevention structure based on the revised Building Standards Law is satisfied, and it is certified as a fire prevention structure. (Non-Patent Document 1).

Ministry of Land, Infrastructure, Transport and Tourism

  However, fastening the interior material (25) to the interior side of the horizontal trunk edge (21) and further filling the rock wool (24) is a big problem in terms of construction cost and construction efficiency. Therefore, the fireproof performance was revised without using non-asbestos slate (corrugated sheet), which is more disadvantageous than asbestos, as an exterior material, constructing interior material on the indoor side, and filling rock wool, etc. Therefore, it is desired to provide a fire prevention structure for a building that can satisfy the fire prevention structure of the Building Standard Act.

  Accordingly, an object of the present invention is to use a slate (corrugated sheet) as an exterior material, which is advantageous in terms of construction cost and can improve the fire prevention performance of the joint, which has been considered a weak point of the conventional fire prevention structure, by a simple structure. It is to provide a fire prevention structure of the building that was.

  That is, the fire prevention structure of a building according to the present invention is a fire prevention structure of a building using a slate (corrugated sheet) defined in JIS A 5430 as an exterior material, and is installed in a structural frame of the building at a predetermined interval. A calcium silicate plate having physical properties equivalent to those of a type 2 0.8 calcium silicate plate defined in JIS A 5430 and having a thickness of at least 15 mm, or JIS The exterior base material selected from the wood wool cement board which has the physical property prescribed | regulated to A5404, and has a thickness of at least 20 mm or more is fastened, and JIS A 5430 is provided on the outdoor side of the joint portion between the exterior base materials. Type 2 0.8 calcium silicate plate or a joint made of calcium silicate plate having a physical property equivalent to this and a thickness of at least 6 mm or more A board is fastened, and the slate (corrugated board) is fastened on the exterior base material and the joint board.

  Moreover, the fireproof structure for a building according to the present invention is characterized in that the exterior base material is fastened to the lateral trunk edge by the exterior base material fastening bracket.

  Furthermore, the fire prevention structure for a building according to the present invention is characterized in that the joint plate is fastened by a joint plate fastening bracket.

  Furthermore, the fireproof structure for a building according to the present invention is characterized in that a T-shaped jointer is installed on the indoor side of the joint portion between the exterior base materials.

  Moreover, the fireproof structure of a building according to the present invention is characterized in that a slate (corrugated sheet) is fastened to a lateral trunk edge by an exterior material fastening bracket.

  Furthermore, the fireproof structure for a building according to the present invention is characterized in that the exterior material fastener is composed of a screw, a hook bolt and a nut, or a channel bolt and a nut.

  According to the fire prevention structure of the building of the present invention, the non-asbestos product slate (corrugated sheet), which is disadvantageous over the asbestos product, is used as an exterior material, and the joint has been regarded as a weak point of the conventional fire prevention structure. The fire prevention performance of the part is advantageous in terms of construction cost and can be improved by a simple structure.

Here, "Type 2 0.8 calcium silicate board as defined in JIS A 5430" as defined in this specification is composed of calcareous raw materials, silicate raw materials, fibers other than asbestos, and admixtures. Apparent density: 0.6 g / cm ³ or more and less than 0.9 g / cm ³ , bending strength: 10.0 N / mm ² or more, length change rate due to water absorption: 0.15% or less, thermal conductivity: 0 .18 W / m · K or less, flame retardancy: means a calcium silicate plate having flame retardant grade 1.

“Wool cement board having physical properties specified in JIS A5404 and having a thickness of at least 20 mm” means that the maximum length of the wood material is 450 mm or less and the bulk specific gravity of the product is 0.7 or more. Hard wood wool cement board, for example, having a thickness of 20 mm, bending fracture load: 800 N or more, deflection: 5 mm or less, flame retardancy: flame retardant second grade, and maximum length of wood raw material is 450 mm or less An ordinary wood wool cement board having a bulk specific gravity of 0.4 to less than 0.7, for example, having a thickness of 20 mm, bending fracture load: 500 N or more, deflection: 9 mm or less, thermal resistance: 0.18 m ^2. K / W or more, flame retardancy: means having flame retardant grade 2.

  Furthermore, “slate (corrugated sheet) as defined in JIS A 5430” means that the raw material is composed of fibers other than cement and asbestos and an admixture, thickness: 6.3 ± 0.6 mm, bending fracture load: 1470 N As mentioned above, water absorption: 30% or less, water permeability: water droplets should not be formed on the back surface, flame retardancy: flame retardant first grade slate corrugated sheet (small wave) and bending fracture load: 3920 N or more, water absorption: 30% or less Water permeability: No water droplets should be formed on the back surface. Flame retardancy: means a flame retardant first grade slate corrugated plate (large wave). “Small waves” means the number of mountains: 11.5 mountains, the depth of the valley: 15 mm or more. “Big waves” means the number of mountains: 7.5 mountains, the depth of the valley: 35 mm. That's all. Moreover, what provided the coating-film layer (decoration layer) on the surface can also be used for a slate (corrugated sheet). In addition, slate (corrugated sheet) uses, for example, cement as a matrix raw material, uses cellulose pulp as a fiber raw material, and further uses one or more synthetic fibers such as vinylon, carbon fiber, and the like in combination. In particular, the combined use of carbon fibers is suitable for improving the fireproof performance of the slate (corrugated sheet). Moreover, it can manufacture by arbitrary well-known methods, such as a papermaking method, using fillers, such as a wollastonite, a mica, a calcium carbonate powder, a silica stone powder, and admixtures, such as a silica fume, as needed.

Next, the fire prevention structure of the building of this invention is demonstrated with figures.
FIG. 1 is a horizontal sectional view in the case where an exterior material [slate (corrugated sheet)] is piled in the fireproof structure of a building of the present invention, and FIG. 2 is a vertical sectional view. The horizontal trunk edge (1) is attached to the structural casing (column) (11) by a horizontal trunk edge attaching material (not shown) attached to the structural casing (column) (11). The exterior base material (2) is fastened to the horizontal trunk edge (1) by the exterior base material fastening bracket (3).
Here, as a horizontal trunk edge (1), the lightweight structural steel for general structures prescribed | regulated to JISG3350 can be used, for example. Further, as the exterior base material (2), a calcium silicate plate having the same physical properties as a type 2 0.8 calcium silicate plate defined in JIS A 5430 and having a thickness of at least 15 mm, or A wood wool cement board having physical properties as defined in JIS A 5404 and having a thickness of at least 20 mm or more is used. Here, it is not preferable that the thickness of the exterior base material (2) is less than the above condition because a predetermined fireproof performance may not be obtained. The upper limit of the thickness of the exterior base material (2) is not particularly limited from the viewpoint of performance, but the material cost increases as the thickness of the fire prevention structure increases, so the performance and cost It is decided by its own balance. Further, as the exterior base material fastening metal fitting (3), screws such as iron or stainless steel, for example, a drill screw or a tapping screw can be used.

  Next, the surface of the vertical joint between the exterior base materials (2) (outdoor side) is covered with the joint plate (5) so that the vertical joint is located at the center of the joint plate (5). Fasten with the bracket (10). Here, the joint plate (5) is composed of a type 2 0.8 calcium silicate plate defined in JIS A 5430 or a calcium silicate plate having a thickness equivalent to at least 6 mm. The When the thickness of the joint plate (5) is less than the above condition, a predetermined fireproof performance may not be obtained. Further, the upper limit value of the thickness of the joint plate (5) is not particularly limited in terms of performance, but the material cost increases as the thickness of the fire prevention structure increases, so the performance and cost It is decided by its own balance. Furthermore, the width of the joint plate is preferably in the range of 60 to 300 mm. Here, when the width of the joint plate is less than 60 mm, it is not preferable because sufficient fireproof performance cannot be obtained or workability is lowered, and even if it exceeds 300 mm, an improvement in performance corresponding to it is obtained. This is not preferable because the cost increases. Further, as the joint plate fastening bracket (10), screws such as iron or stainless steel, for example, a drill screw and a tapping screw can be used.

  Note that a T-shaped jointer (4) can be installed on the back surface (inner side) of the exterior base material (2) between the joint base materials. Here, the joint joiner (4) is a hot-dip galvanized steel sheet having a thickness of 0.27 mm or more, a paint hot-dip galvanized steel sheet, a hot-dip zinc-5% aluminum alloy-plated steel sheet, a paint hot-dip zinc-5% aluminum alloy-plated steel sheet, It can be composed of a 55% aluminum-zinc alloy-plated steel sheet, a paint-melted 55% aluminum-zinc alloy-plated steel sheet, or the like. In addition, as a jointer (4), what has a shape as shown, for example in FIG. 4 can be used.

  Next, the exterior material (6) is fastened to the horizontal trunk edge (1) by the exterior material fastening metal fitting (9) through the packing (7) and the washer (8). Here, as the exterior material (6), a slate (corrugated sheet) defined in JIS A 5430 can be used. Moreover, as an exterior material clasp (9), a screw, a hook bolt, a nut, or a channel bolt, a nut etc. can be used, for example. FIG. 3A shows a case where a screw (9-a) is used as the exterior material fastening metal fitting (9). In this case, after passing the packing (7) and the washer (8) through the screw (9-a), the exterior material (6), the exterior base material (2), etc. are applied from the surface of the exterior material (6). Pass through and fasten to the side waistline (1). As the screw (9-a), for example, a drill screw having a thread of a tapping screw made of iron or stainless steel, a drilling tapping screw, a tapping screw with a slot, a tapping screw with a cross hole, a hexagonal tapping screw, a hexagon with a flange A tapping screw, a tapping screw with a hexalobular hole, a tapping screw with a flat washer, etc. can be used. As the packing (7), for example, asphalt-impregnated wool felt, asphalt-impregnated cow felt, wool felt, cow felt, polyethylene packing, vinyl chloride packing, polystyrene packing and the like can be used. Furthermore, as the washer (8), an iron or stainless steel one can be used.

FIG. 3 (b) shows a case where a nut (9-b) and a hook bolt (9-c) are used as the exterior material fastener (9). Further, FIG. 3 (c) shows a case where a nut (9-b) and a channel bolt (9-d) are used as the exterior material fastener (9). In these cases, hook bolts (9-c) or channel bolts (9-d) have their tips (bending portions) hooked on the lateral trunk edges (1) and hooked into holes provided in advance in the exterior material (6). The bolt (9-c) or the channel bolt (9-d) is passed through the other end and held with a packing (7), a washer (8) and a nut (9-b). Here, as the nut (9-b), one made of iron or stainless steel can be used.
In addition, what is necessary is just to set the fastening position of an exterior material fastening metal fitting (9) to two or more per 1 side trunk edge. Moreover, only the exterior material located in the overlapped intermediate layer of the exterior material (6) that overlaps both in the horizontal direction and the longitudinal direction can be cut at the corners (measures for reducing gaps caused by the overlap). it can. The space defined by the exterior material (6), the exterior base material (2), and the joint plate (5) acts as a heat insulating layer.

  As described above, FIGS. 1 to 3 show the case where a slate (corrugated sheet) used as an exterior material is piled up, but the fire prevention structure of the building of the present invention is limited to this. However, it is needless to say that the fire prevention structure of the building of the present invention can also be obtained by applying a trough to a slate (corrugated sheet) used as an exterior material.

Hereinafter, the fire prevention structure of the building which uses the slate (corrugated sheet) of this invention as an exterior material is further demonstrated by an Example.
Example 1
In the fire prevention structure of the building shown in FIGS. 1 and 2, C-100 × 50 × 20 × 2.3 mm is used as the horizontal trunk edge (1), and the grooved steel corresponding to the structural frame (column) (11) It attached to the frame for test bodies comprised at a space | interval of 865 mm. Next, a type 2 0.8 calcium silicate plate (thickness 15 mm) defined in JIS A 5430 is used as the exterior base material (2), and a stainless steel screw is used as the exterior base material fastening bracket (3). (A countersunk head, diameter: φ4 mm, length: 40 mm), and a calcium silicate plate was fastened to the lateral trunk edge with a screw. The fastening pitch was 303 mm in the horizontal direction and 865 mm in the vertical direction.
Next, a type 2 0.8 calcium silicate plate (thickness 6 mm, width 220 mm) defined in JIS A 5430 is used as the joint plate (5), and stainless steel is used as the joint plate fastener (10). Use screws (deck head, diameter: φ4 mm, length: 40 mm), and place the joint plate (5) on the surface (outside) of the vertical joints between the calcium silicate plates that are exterior base materials. It covered so that it might be located in the center of a joint board (5), and it fastened with the screw | thread.
Further, a T-shaped joint joiner (4) having the shape shown in FIG. 4 was installed on the back surface (inner side) of the joint portion between the calcium silicate plates which are exterior base materials. Here, the joint joiner (4) was composed of a hot-dip galvanized steel sheet having a thickness of 0.27 mm.
Next, as an exterior material (6), a slate (corrugated sheet) prescribed in JIS A 5430 [large corrugated sheet (length: 1820 mm, width 950 mm, thickness: 6.3 mm, number of mountains: 7.5 mountains, Valley depth: 35 mm)], vinyl chloride packing as packing (7), stainless steel washer as washer (8), hexagonal tapping screw (stainless steel, diameter: φ6 mm) as exterior material fastener (9) , Length: 115 mm), and a slate (corrugated plate) was fastened to the lateral trunk edge with a hexagonal tapping screw through packing and a washer. The fastening pitch was 390 mm.
As described above, a 3200 mm × 3200 mm test body of the fireproof structure of a building of the present invention was assembled.

The test specimen was placed in a heating furnace, and a fire prevention test was conducted on a heating surface of 3050 mm × 3050 mm under a heating condition of T = 345 log ₁₀ (8t + 1) +20 [T = temperature (° C.), t = time (min)]. When the back surface temperature rise was measured with nine thermocouples installed on the back side of the heating surface of the body, any thermocouple has sufficient fire prevention performance at 180 K or less even after 30 minutes from the start of the test. It was confirmed. In addition, the temperature change obtained by the thermocouple installed in the joint part and the back surface of the general part is shown in FIG. In FIG. 5, “a” indicates a temperature change in the joint portion, and “b” indicates a temperature change in the general portion.

Example 2
As an exterior base material (2), an ordinary wood wool cement board (thickness: 20 mm) having the physical properties defined in JIS A5404, and as an exterior base material fastening bracket (3), a stainless steel screw (counter head, diameter: The same configuration as in Example 1 except that a hexagonal tapping screw (made of stainless steel, diameter: φ6 mm, length: 135 mm) was used as the exterior material clasp (9) as φ4 mm and length: 50 mm). A test body having a fireproof structure for a building according to the present invention was assembled.
About the obtained test body, when the fireproof test was done by the method similar to Example 1, the back surface temperature rise of a test body is 180 K or less even after 30 minutes progress from a test start, and has sufficient fireproof performance. It was confirmed that In addition, the temperature change obtained by the thermocouple installed in the joint part and the back surface of the general part is shown in FIG. In FIG. 6, “a” indicates a temperature change in the joint portion, and “b” indicates a temperature change in the general portion.

Comparative Example 1
Except that the joint plate (5) was not fastened, a building fireproof test body having the same configuration as in Example 1 was assembled. About the obtained test body, when the fireproof test was done by the method similar to Example 1, after 22.5 minutes passed from the start of a test, a joint part will open, temperature will rise, and a test will be stopped after 27.5 minutes Therefore, satisfactory fire prevention performance could not be obtained. In addition, the temperature change obtained by the thermocouple installed in the back surface of the joint part is shown in FIG.

Comparative Example 2
Except that the joint plate (5) was not fastened, a building fireproof structure test body having the same configuration as in Example 2 was assembled. About the obtained test body, when the fireproof test was done by the method similar to Example 1, after 20 minutes passed from the start of a test, a joint part will open, temperature will rise, and a test must be stopped after 26.5 minutes. It was not possible to obtain satisfactory fire performance. In addition, the temperature change obtained by the thermocouple installed in the back surface of the joint part is shown in FIG.

  The fire prevention structure using the slate (corrugated sheet) of the present invention as an exterior material can be suitably used as an outer wall of a building.

In the fire prevention structure of this invention, it is a horizontal sectional view at the time of carrying out the mountain retaining construction of exterior material [slate (corrugated sheet)]. In the fire prevention structure of this invention, it is a vertical sectional view at the time of carrying out the mountain retaining construction of exterior material [slate (corrugated sheet)]. (A)-(c) is a figure which shows the embodiment of the exterior material clasp metal fitting which can be used when the exterior material [slate (corrugated sheet)] is piled in the fireproof structure of this invention. It is a figure which shows the shape of a jointer. It is a figure which shows the temperature change of the joint part and general part in the fireproof performance test in the fireproof structure of the building of this invention obtained in Example 1. FIG. It is a figure which shows the temperature change of a joint part and a general part in the fire prevention performance test in the fire prevention structure of the building of this invention obtained in Example 2. FIG. It is a figure which shows the temperature change of the joint part in the fire prevention performance test in the fire prevention structure of the building obtained by the comparative example 1. FIG. It is a figure which shows the temperature change of the joint part in the fireproof performance test in the fireproof structure of the building obtained by the comparative example 2. FIG. It is a graph which shows the heating conditions in the fireproof performance test and evaluation method of a building standard method. It is a figure which shows the fire prevention structure of the building which used the conventional slate (corrugated sheet) as an exterior material. It is a figure which shows the fire prevention structure of the building which used the conventional slate (corrugated sheet) as an exterior material.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Horizontal trunk edge, 2 Exterior base material, 3 Exterior base material clasp metal, 4 Jointer jointer, 5 Joint plate, 6, Exterior material 7 Packing, 8 Washer, 9 Exterior material clasp metal, 9-a Screw, 9- b Nut, 9-c Hook Bolt, 9-d Channel Bolt, 10 Joint Plate Fastener, 11 Structural Body (Pillar), 21 Horizontal Body Edge, 22 Exterior Base Material, 23 Exterior Base Material Fastener, 24 Rock Wool , 25 interior material, 26 slate corrugated sheet, 27 packing, 28 washer, 29 exterior material clasp.

Claims (6)

  In a fire prevention structure of a building using a slate (corrugated sheet) defined in JIS A 5430 as an exterior material, the outer side of the horizontal trunk edge installed at a predetermined interval on the structural frame of the building, A calcium silicate plate having the same physical properties as a Type 2 0.8 calcium silicate plate defined in 5430 and having a thickness of at least 15 mm or more, or a physical property defined in JIS A 5404 and at least An exterior base material selected from wood wool cement board having a thickness of 20 mm or more is fastened, and a type 2 0.8 silicic acid stipulated in JIS A 5430 is disposed on the outdoor side of the joint between the exterior base materials. Fastening a joint plate made of a calcium silicate plate or a calcium silicate plate having a thickness of at least 6 mm having a physical property equivalent to that of the calcium plate, the exterior base material and the joint A fireproof structure for a building, wherein the slate (corrugated plate) is fixed on a plate.   The fireproof structure for a building according to claim 1, wherein the exterior base material is fastened to the lateral trunk edge by an exterior base material fastening bracket.   The fire prevention structure for a building according to claim 1, wherein the joint plate is fastened by a joint plate fastening bracket.   The fireproof structure for a building according to claim 1, wherein a T-shaped jointer is installed on the indoor side of the joint portion between the exterior base materials.   The fireproof structure for a building according to claim 1, wherein the slate (corrugated sheet) is fastened to the lateral trunk edge by an exterior material fastening bracket.   The fireproof structure for a building according to claim 5, wherein the exterior material fastener is composed of a screw, a hook bolt and a nut, or a channel bolt and a nut.

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