Fireproof Partition Wall

The present disclosure relates to fire-resistant partition walls.

Fire-resistant partition walls having a one-hour fire-resistance rating, being capable of preventing the temperature of a non-heated surface from increasing to or above a temperature at which a combustible contacting the non-heated surface may burn when fire heat due to a fire is applied to a heated surface for one hour, are known. Conventional fire-resistant partition walls thus having a fire-resistance capability of one hour are formed by screwing two walls to studs formed of light-gauge steel installed at predetermined intervals such that the studs are sandwiched between the two walls.

Each of the two walls has a multilayer structure of at least two base layers (which are formed of a fire-resistant covering member) and at least two top layers (which are formed of a fire-resistant covering member), such as base layer reinforced gypsum boards, top layer reinforced gypsum boards, and the like. Accordingly, the fire-resistant partition wall as a whole has a structure of four or more surface members. In each of the two walls on both surfaces of the studs, multiple fire-resistant surface members (base surface member and top surface member) are vertically and horizontally arranged to form lateral joints and vertical joints. When a room fire breaks out, the surface members are exposed to fire heat to shrink, so that gaps are formed in the joints that are formed by gaplessly abutting the surface members with each other. Therefore, in the case of a single surface member, heated air leaks out through the gaps in the joints. Accordingly, it is common to form a fire-resistant partition wall having two layers on both surfaces (four layers in total, two layers on each surface) like in the above-described fire-resistant partition wall, and offset the joint positions between the base layer and the top layer of each of the two walls, thereby preventing heated air from leaking out through gaps in the joints.

Here, consideration is given to a fire-resistant partition wall having a single layer on both surfaces (two layers in total, one layer on each surface) for better constructability. Generally, surface members are arranged such that there are studs on the back side of the vertical joints of the surface members, and accordingly, there is no risk that heated air leaks out through vertical joints when a room fire breaks out.

In contrast, there are no studs on the back side of substantially all lateral joints. Therefore, there is a risk that heated air leaks out into the partition wall through lateral joints. Such leakage of heated air through lateral joints may degrade the fire-resistance capability of the fire-resistant partition wall. Furthermore, when a fire-resistant partition wall having a one-hour fire resistance rating is developed, normally, a one-hour fire resistance test is conducted by applying heat for one hour, and the fire-resistant partition wall will be distributed on the market after passing this fire resistance test. The leakage of heated air through lateral joints makes it difficult to pass this one-hour fire resistance test.

Here, Patent Document 1 proposes a partition wall structure that can improve fire-resistance capability and facilitate construction work. Specifically, the partition wall structure includes: studs; a pair of partition walls each including a base layer member and a coated top layer member; and an extension member extended on the outer side of at least one of the partition walls.

However, according to the partition wall structure as described in Patent Document 1, each of the paired walls provided across the studs from each other (in which a single wall is a partition wall) includes two fire-resistant covering members, which are a base layer member and a coated top layer member. In addition, one of the partition walls has the extension member. Therefore, the partition wall structure as a whole has five fire-resistant covering members and accordingly has a problem in that more construction time and effort is required. Furthermore, as described above, Patent Document 1 does not specifically describe a joint base member attached to parts corresponding to lateral joints. Therefore, it is assumed that the partition wall on each side has at least two layers of fire-resistant covering members in order to prevent heated air from leaking to the inside of the partition walls through lateral joints.

In view of the above, Patent Document 2 proposes a partition wall that includes as small a number as possible of fire-resistant covering members to have good constructability and effectively prevents leakage of heated air through lateral joints to have a good fire-resistance capability. This partition wall includes: multiple studs installed at predetermined intervals; and a first wall and a second wall that are a pair of walls provided across the multiple studs from each other, the first wall and the second wall being formed of vertically and laterally arranged multiple gypsum boards. Each of the first wall and the second wall is a single-layer wall of the multiple gypsum boards, vertical joints and lateral joints are formed in each of the first wall and the second wall, and the studs are on the back side of the vertical joints. A joint base member having a fire blocking capability is provided at the lateral joints. The joint base member includes a back piece contacting a back surface of the gypsum boards and a projecting piece projecting from the back piece in a thickness direction of the gypsum boards. A transverse cross section of the joint base member perpendicular to a longitudinal direction thereof has a T-letter shape. The gypsum boards, the joint base member, and the studs are not screwed with a common screw, and are screwed in two different screw-fastening forms. In this partition wall, one of the screw-fastening forms is such that the gypsum boards are screwed to only the studs and are not screwed to the joint base member, and the joint base member is fixed to a position of the lateral joints by being inserted between the gypsum boards and the studs. Meanwhile, the other screw-fastening form is such that the gypsum boards are screwed to the studs and to the joint base member with different screws, and the joint base member is fixed to a position of the lateral joints by being inserted between the gypsum boards and the studs.

Patent Document 1: Japanese Patent Application Publication No. 2009-191494

Patent Document 2: International Publication No. WO2020/070938

According to the partition wall described in Patent Document 2, it is possible to use as small a number as possible of surface members to achieve good constructability and prevent leakage of heated air through lateral joints to increase a fire-resistance capability. The partition wall described in Patent Document 2 has two different screw-fastening forms as described above. However, in the former form in which the joint base member is not screwed to the gypsum boards, there is a concern that constructability will decrease when the partition wall is constructed with the joint base member being inserted between the studs and the gypsum boards. Meanwhile, in the latter form in which the joint base member is screwed to the gypsum boards at a position offset from the intersection between the gypsum boards, the studs, and the joint base member, two back pieces, i.e., upper and lower back pieces, included in the joint base member are respectively screwed to upper and lower gypsum boards, there are many screw-fastening positions, and there is a concern that the number of parts will increase and constructability will decrease.

The present disclosure provides a fire-resistant partition wall that prevents leakage of heated air through lateral joints to have a good fire-resistance capability and good constructability.

According to the present disclosure, it is possible to provide a fire-resistant partition wall that prevents leakage of heated air through lateral joints to have a good fire-resistance capability and good constructability.

Hereinafter, the fire-resistant partition wall according to the embodiment will be described with reference to the attached drawings. In the present specification and drawings, substantially the same components may be designated by the same reference symbols, and thus duplicate description thereof may be omitted.

Fire-Resistant Partition Wall according to Embodiments

Examples of the fire-resistant partition wall according to the embodiments will be described with reference toto. In the following, description will be given of fire-resistant partition walls in which reinforced gypsum boards are applied as gypsum boards forming the surface members. However, gypsum boards other than the reinforced gypsum boards may be applied in the fire-resistant partition walls according to the embodiments. Here,is a perspective view of an example of the fire-resistant partition wall according to the embodiment, illustrating a part thereof in a cutaway manner.is a transverse cross-sectional view, looking at the cross section in which the surface members and the studs are fastened together with the first fixing member in the direction of the arrows II-II of.is a perspective view of the joint base member.is a perspective view illustrating the first wall on which the joint base member is provided on the back side of lateral joints, where the surface members, the joint base member, and the stud are not fastened at the three-member intersecting position with the fixing member.is a longitudinal cross-sectional view, looking at the cross section in which the surface members and the stud are fastened together with the first fixing member in the fire-resistant partition wall according to the embodiment.

The fire-resistant partition wallas illustrated inis applied in steel frame buildings, (RC) (Reinforced Concrete) buildings, wooden buildings, and the like, and is applied in general detached houses, apartment complexes, factories, warehouses, and the like.

The fire-resistant partition wallis a fire-resistant partition wall provided with a single-layer wall on both surfaces thereof, and includes multiple studsinstalled at predetermined intervals “u” and a pair of a first wallA and a second wallB provided across the studsfrom each other. The intervals “u” at which the studsare installed may be constant or may change in the middle. The intervals “u” may be set to 303 mm, for example.

The studsare fitted into respective grooves of an upper runnerand a lower runner, thereby forming a frame structure of the studs, the upper runner, and the lower runner. In the illustrated example, each of the studsis formed of lip channel steel, and the upper runnerand the lower runnerare formed of channel steel. The studsmay be formed of rectangular steel tubes instead of channel steel. The channel steel or rectangular steel tubes applied to the studsare structural steel or steel tubes having, for example, 45 mm×45 mm×0.4 mm or more as width×height×thickness according to the expression of dimensions defined by JIS A 6517. Furthermore, the channel steel applied to the upper and lower runnersandis structural steel of, for example, 45 mm×30 mm through 40 mm×0.4 mm or more.

Each of the first wallA and the second wallB is formed by vertically and laterally providing multiple reinforced gypsum boards(examples of the surface members) having a thickness “s” of 25 mm. That is, by using the reinforced gypsum boardsof 25 mm in thickness, each of the first wallA and the second wallB can be formed of a single layer of fire-resistant covering material, and accordingly, the fire-resistant partition wallas a whole is formed of two layers of the reinforced gypsum boards, i.e., is formed as a fire-resistant partition wall provided with a single-layer wall on both surfaces thereof. Here, according to the fire-resistant partition wallas illustrated in, the first wallA and the second wallB are formed by applying the rectangular reinforced gypsum boardsin a vertical position. However, the first wallA and the second wallB may also be formed by applying the reinforced gypsum boardsin a horizontal position.

The reinforced gypsum boardsare formed by mixing an inorganic fiber material into the core material portions of gypsum boards, and are boards higher in fire-resistance capability than normal gypsum boards. According to JIS A 6901, the thickness standard of the reinforced gypsum boardsis defined as 12.5 mm, 15.0 mm, 16.0 mm, 18.0 mm, 21.0 mm, and 25.0 mm (with a thickness tolerance of 0 mm to +0.5 mm).

According to the fire-resistant partition wall, each of the first wallA and the second wallB is formed of a single layer of the reinforced gypsum boards. Therefore, the reinforced gypsum boardshaving a maximum thickness ofmm are preferably applied.

As these reinforced gypsum boards, “TIGER BOARD (registered trademark) Type Z, 25 mm in thickness” manufactured by YOSHINO GYPSUM CO., LTD. may be applied. TIGER BOARD Type Z (25 mm in thickness) has a planar size of 606 mm in width and 1,820 mm in length, and has a beveled edge.

Thus, the fire-resistant partition wallas a whole has only two layers of the reinforced gypsum boards, i.e., a fire-resistant partition wall provided with a single-layer wall on both surfaces thereof. Therefore, the fire-resistant partition wallis significantly improved in constructability compared to fire-resistant partition walls having four or more layers of fire-resistance covering material as a whole, i.e., a fire-resistant partition wall provided with two layers on both surfaces thereof.

According to the fire-resistant partition wall, the reinforced gypsum boardseach having a width over the three studsinstalled at the predetermined intervals “u” (e.g., 303 mm) (over the distance between the centers of the right studand the left stud) are applied.

Furthermore, the reinforced gypsum boardsare vertically and laterally provided to form multiple vertical jointsand lateral joints. The steel studsare on the back side of the vertical joints. Accordingly, for example, when a fire breaks out from the first wallA side, there is no risk that heated air leaks into the fire-resistant partition wallthrough the vertical jointsof the first wallA. Here, base members, such as studs and the like, which are illustrated as steel members in the illustrated example, may alternatively be wood members to the extent that they have a satisfactory fire-resistance capability.

In contrast, there could be cavities on the back side of the lateral jointsexcept at positions corresponding to the studs, so that heated air could leak into the fire-resistant partition wallthrough the lateral joints. Therefore, a joint base memberhaving a fire blocking capability is provided on the back side of the lateral joints.

Here, the “fire blocking capability” refers to the capability to block leakage of heated air or flame. In addition to materials having a fire-resistance capability by nature and materials that are cured by heat to have a fire-resistance capability, materials such as those that can have a fire blocking capability as a result of remaining as an incinerated mass even if the materials burn with heat are included.

Materials having a fire blocking capability as described above include metal, thermosetting resin, and wood. Metal includes steel, aluminum, SUS (stainless steel), and the like. Thermosetting resin includes phenol formaldehyde resin (PF), epoxy resin (EP), melamine formaldehyde resin (MF), urea formaldehyde resin (UF), unsaturated polyester resin (UP), alkyd resin, polyurethane resin (PUR), polyimide resin (PI), and the like. Furthermore, wood includes Japanese cedar, pine, spruce, quince, oak, beech, and the like, and may be either solid wood or engineered wood. As described above, wood burns to remain as an incinerated mass to be able to have a fire blocking capability.

The fire-resistant partition wallhas the fire-resistance capability of a one-hour fire-resistance rating. A fire-resistant partition wall having a one-hour fire-resistance rating is a partition wall that can pass a one-hour fire resistance test conducted by applying heat for one hour. According to this fire resistance test, a temperature at which a combustible contacting a non-heated surface may burn is set as a reference temperature, and the temperature of the non-heated surface is required not to increase to or above this reference temperature.

More specifically, it is required that no damage that may let out fire (including heated air) be caused on the non-heated surface side by heating, that no damage that impairs structural strength be caused by heating, and that no significant smoke is produced on the non-heated surface side by heating. Furthermore, it is required that the temperature on the non-heated surface side neither exceed an initial temperature plus 140° C. as an average temperature nor exceed an initial temperature plus 180° C. as a maximum temperature.

As illustrated in, the joint base memberhas a T-letter transverse cross-sectional shape, and the reinforced gypsum boardsand the studsare fastened together with screws(an example of the first fixing member) at positions where there are the studsas illustrated in. The applied screws include those having a diameter of 3.5 mm or more and a length of 35 mm or more. The screwsmay be fastened at vertical intervals of 200 mm or less. Meanwhile, as illustrated in, at a three-member intersecting position between the reinforced gypsum board, the joint base member, and the stud, these members are not fastened together with the screws, and at a position offset from the three-member intersecting position, the reinforced gypsum boardis fastened to the studwith the screws. That is, the reinforced gypsum boardand the studare fastened with the screwsbeing absent in the area enclosed by a joint base member area and a stud area as illustrated in. At the three-member intersecting position, the joint base memberis held between the reinforced gypsum boardand the studwithout being fastened with the screws.

As illustrated in, when the joint base memberis not fastened to the studwith the screws, as behaviors in the case of a fire, deformation due to the thermal expansion of the studand deformation due to the thermal expansion of the joint base memberdo not interfere with each other, and thus the reinforced gypsum boardthat is screwed to them can follow the deformations of both thereof. Therefore, it is possible to reduce stress due to the thermal expansion deformation of steel members applied to the reinforced gypsum board. As a result, cracks can be prevented from occurring in the reinforced gypsum boards.

In the fire-resistant partition wall, the reinforced gypsum boardand the joint base memberare not screwed at the three-member intersecting position as described above, while as described below in detail, in an area offset from the three-member intersecting position, one of the two reinforced gypsum boardsthat are next to each other vertically is fastened to a back pieceof the joint base memberwith a second fixing member.

As illustrated in, the joint base memberis formed by bending a single plate material (e.g., a metal plate). According to the joint base memberof the illustrated example, a projecting pieceprojects from two back piecesvia two first bent parts, and the projecting piecehas a U-letter shape including a second bent part.

Furthermore, according to the joint base member, the angle between the back piecesand the projecting pieceis a predetermined angle θ that is less than 90 degrees. Here, the predetermined angle θ that is less than 90 degrees includes approximately 60 degrees through approximately 88 degrees.

As described above, the angle between the back piecesand the projecting pieceis a predetermined angle e that is less than 90 degrees. In this case, for example, when the joint base memberis installed as illustrated inso that the projecting pieceis inserted between an upper end face(smaller cross section) of the lower reinforced gypsum boardand a lower end face(smaller cross section) of the upper reinforced gypsum board, the ends of the back piecescan gaplessly contact the back surfaces of the reinforced gypsum boards.

When the reinforced gypsum boardsare fixed to the studsin a state where the back surface of the joint base memberis pressed against the stud, the joint base memberensures prevention of formation of gaps (closes gaps) in the lateral joints. Accordingly, the leakage of heated air into the partition wallthrough the lateral jointscan be effectively eliminated.

As illustrated in, according to the joint base member, an overall width t(width in a transverse cross section) of the two back piecesis set to 70 mm or more. Furthermore, the projecting pieceis provided at the middle position of the two back pieces, and the projection length of the projecting pieceis set to be in the range of from 5 mm through 7 mm. Furthermore, a longitudinal length tof the joint base membermay be as long as approximately 1,815 mm, which is over six spans, when the intervals “u” of the studsare approximately 303 mm, for example.

Thus, the joint base memberhas a high aspect ratio with the overall width being 70 mm or more and the overall length being approximately 1,815 mm. Therefore, the joint base memberis prone to be bended during transportation, construction, or the like, and may plastically deform when the joint base memberis made of metal. The joint base member, however, includes the projecting pieceover its entire length at its widthwise center. Therefore, this projecting pieceprovides the joint base memberwith flexural rigidity, thus making it possible to control or prevent its bending or plastic deformation during transportation, construction, or the like.

As illustrated in, the reinforced gypsum boardhas a chamfered partat the back side corner of the lower end face(smaller cross section). A length tof this chamfered partin the thickness direction of the reinforced gypsum boardis set to be in the range of from 7 mm through 9 mm.

Accordingly, when the joint base memberis installed on the back surface of the upper and lower reinforced gypsum boards, the projecting piecewhose projection length tis set to be in the range of from 5 mm through 7 mm can be accommodated in the chamfered part.

Thus, when the projecting pieceis completely accommodated in the chamfered part, the lower end face(smaller cross section) of the upper reinforced gypsum boardand the upper end face(smaller cross section) of the lower reinforced gypsum boardcan gaplessly contact each other as illustrated in, so that there is no gap in the lateral joints.

The above description is given of a chamfered part in the case of applying reinforced gypsum boards in a vertical position. In the case of applying reinforced gypsum boards in a horizontal position, the edges of boards whose sides are covered with gypsum board paper are caused to abut with each other. When the edge bent angle is less than 90 degrees, the gap may be able to be a gap that can accommodate the projecting piece of a joint base member without chamfering. In this case, it is noted that lateral joints are prevented from being open. Even in the case of horizontal position application, chamfering is performed, if necessary. Here, examples of shapes of the edges of boards include a beveled edge and a square edge. Also, the edge bent angle refers to an angle of a side surface covered with gypsum board paper at a board edge.

Again, as illustrated in, one of the two reinforced gypsum boardsnext to each other vertically is fastened to the back pieceof the joint base memberwith the second fixing member.

When the two reinforced gypsum boardsnext to each other vertically are regarded as a surface members' setA, multiple surface members' setsA are next to each other horizontally. One of the two surface members' sets next to each other is such that a lower portion of the upper reinforced gypsum boardis fastened to the upper back pieceincluded in the joint base memberpresent on the back side. Meanwhile, the other of the two surface members' sets next to each other is such that an upper portion of the lower reinforced gypsum boardis fastened to the lower back pieceincluded in the joint base memberpresent on the back side.

In the illustrated example, the two second fixing membersare applied in the upper portion or the lower portion of the reinforced gypsum board.

Here, as the second fixing member, a nail, a screw thread, or the like is applied in addition to the screw. The second fixing memberis driven from a wider-surface side of the reinforced gypsum board, so that the reinforced gypsum boardis fastened to the back piecepresent on the back side.

In the fire-resistant partition wall, as described above, at the three-member intersecting position between the reinforced gypsum board, the back pieceof the joint base member, and the stud, these members are not fastened together into a single piece with a common fixing member (e.g., a nail, a screw, or the like; the same applies hereinafter). Meanwhile, in the area offset from the three-member intersecting position, one of the two reinforced gypsum boardsnext to each other vertically is fastened to the back pieceof the joint base memberwith the second fixing member.