JP6097519B2 - Fireproof reinforcement structure of fireproof coated CFT pillar - Google Patents

Description

  The present invention relates to a fireproof reinforcing structure for a fireproof coated CFT column.

  A concrete filled steel tube (CFT (Concrete Filled Steel Tube)) column in which concrete is filled in a steel tube column is known (see, for example, Patent Document 1). Since the CFT column is filled with concrete in the steel tube column, the CFT column has a larger heat capacity than the hollow steel tube column and is excellent in fire resistance. Therefore, depending on the design conditions, it is possible to omit the fireproof coating of the CFT pillar and to make a non-fireproof coated CFT pillar.

JP-A-10-204993

  By the way, for example, there is a possibility that the fire resistance (required fire resistance) required for the non-fireproof coated CFT column is increased due to a design change or the like.

  In view of the above facts, the present invention aims to improve the fire resistance of a fire-resistant coated CFT column.

The fireproof reinforcing structure of the fireproof coated CFT pillar according to the first aspect includes a fireproof coated CFT pillar that is not fireproof coated, and is disposed around the fireproof coated CFT pillar by post-installation. And post-installation fire-resistant coating means for performing fire-resistant coating.

According to the fireproof reinforcing structure of the fireproof coated CFT column according to the first aspect , the fireproof coated CFT column is fireproof coated by the post-installed fireproof coating means disposed around the fireproof coated CFT column by post-installation. The temperature rise of the fireproof coated CFT column during a fire is suppressed. Therefore, the fireproof performance of the non-fireproof coated CFT column is improved.

The fireproof reinforcing structure of the fireproof coated CFT pillar according to the second aspect is the fireproof reinforcing structure of the fireproof coated CFT pillar according to the first aspect , wherein a finish paint is applied to the outer surface of the fireproof coated CFT pillar, Post-installed fireproof covering means is attached to the fireproof coated CFT pillar from both sides and joined together to surround the fireproof coated CFT pillar over the finish paint, and the pair of base materials And a refractory material provided on the outer surface or the inner surface.

According to the fireproof reinforcing structure of the fireproof coated CFT pillar according to the second aspect , the fireproof material is provided on the outer surface or the inner surface of the pair of base materials. The pair of base materials are attached to the fire-resistant coated CFT column from both sides and joined to each other, whereby the fire-resistant material is disposed around the fire-resistant coated CFT column, and the fire-resistant coated CFT column is fire-coated. Thereby, the temperature rise of the fireproof covering CFT pillar at the time of a fire is suppressed. Therefore, the fireproof performance of the non-fireproof coated CFT column is improved.

  Further, by attaching the pair of base materials from both sides to the fireproof coated CFT column, the fireproof material can be arranged around the fireproof coated CFT column, so that workability is improved.

  Further, the finish paint is covered with the pair of base materials by surrounding the fireproof coated CFT pillar from the finish paint with the pair of base materials. Therefore, since it is not necessary to repaint or peel off the finish paint, workability is improved.

The fireproof reinforcing structure of the fireproof coated CFT pillar according to the third aspect is the fireproof reinforcing structure of the fireproof coated CFT pillar according to the second aspect , wherein the pair of base materials are arranged along the outer surface of the fireproof coated CFT pillar. It is a pair of metal plates arranged, and the refractory material is a refractory paint applied to the outer surfaces of the pair of metal plates.

According to the fireproof reinforcing structure of the fireproof coated CFT pillar according to the third aspect , the fireproof paint as the fireproof material is applied to the outer surfaces of the pair of metal plates as the pair of base materials. By attaching these metal plates to the fire-resistant coated CFT pillar from both sides, the fire-resistant coated CFT pillar is fire-coated with the fire-resistant paint. Therefore, the fireproof performance of the non-fireproof coated CFT column is improved.

  Further, by using, for example, a thin iron plate or the like as the pair of metal plates, an increase in the column cross-sectional area of the fire-resistant coated CFT column including the pair of metal plates and the fire-resistant paint can be reduced.

  As described above, according to the fireproof reinforcing structure of the fireproof coated CFT column according to the present invention, the fireproof performance of the fireproof coated CFT column can be improved.

It is an elevation view which shows the fireproof covering CFT pillar to which the fireproof reinforcement structure of the fireproof covering CFT pillar which concerns on one Embodiment of this invention was applied. It is a longitudinal cross-sectional view which shows the fireproof covering CFT pillar shown by FIG. FIG. 3A is a cross-sectional view taken along the line 3A-3A in FIG. 1 showing a state in which the cylindrical covering member is attached to the column head, and FIG. 1B is a sectional view of FIG. It is sectional drawing equivalent to 3A-3A sectional view taken on the line. It is an expanded sectional view of FIG. 2 which shows the generation | occurrence | production part of the local buckling in the column head of a steel pipe column. It is an elevation view which shows the frame comprised with the general concrete filling steel pipe pillar and beam, (A) shows the state before a fire, (B) has shown the state after a fire. It is a model figure which shows the experimental evaluation model used for the fireproof performance evaluation of a general concrete filling steel pipe column, (A) shows the state before loading horizontal force, and (B) is when horizontal force is loaded. The deformation state and stress state of the concrete-filled steel pipe column are shown, and (C) shows a state where local buckling has occurred in the steel pipe column constituting the concrete-filled steel pipe column. (A) And (B) is sectional drawing equivalent to FIG. 2 (A) and FIG.2 (B) which show the modification of the fireproof reinforcement structure of the fireproof covering CFT pillar which concerns on one Embodiment of this invention. (A) And (B) is sectional drawing equivalent to FIG. 2 (A) and FIG.2 (B) which show the modification of the fireproof reinforcement structure of the fireproof covering CFT pillar which concerns on one Embodiment of this invention. (A) And (B) is sectional drawing equivalent to FIG. 2 (A) and FIG.2 (B) which show the modification of the fireproof reinforcement structure of the fireproof covering CFT pillar which concerns on one Embodiment of this invention. (A) And (B) is sectional drawing equivalent to FIG. 2 (A) and FIG.2 (B) which show the modification of the fireproof reinforcement structure of the fireproof covering CFT pillar which concerns on one Embodiment of this invention. It is an elevation view equivalent to FIG. 1 which shows the modification of the fireproof reinforcement structure of the fireproof covering CFT pillar which concerns on one Embodiment of this invention.

  Hereinafter, a fireproof reinforcing structure for a fireproof coated CFT column according to an embodiment of the present invention will be described with reference to the drawings. In addition, the arrow Z suitably shown in each figure has shown the material axis direction (up-down direction) of the steel pipe column.

  FIG. 1 shows, as an example, an existing fire-resistant covered CFT column 10 to which a fire-resistant reinforcing structure (hereinafter simply referred to as “fire-resistant reinforcing structure”) 30 of a fire-resistant coated CFT column according to the present embodiment is applied. Yes. The fireproof coating CFT column 10 includes a steel pipe column 12 and filled concrete 14 filled in the steel tube column 12 and is a fireproof coating that is not provided with a fireproof coating. The steel pipe column 12 is formed of a round steel pipe, and the upper and lower joints 12U and 12L as upper and lower joints, and between these upper and lower joints 12U and 12L. It has the steel pipe main-body part 12B extended. A finish paint 20 (see FIG. 2) such as paint is applied to the outer surface (outer peripheral surface) of the steel pipe column 12 over the entire surface.

  As shown in FIG. 2, a pair of upper and lower inner diaphragms 18 as a pair of upper and lower diaphragms that reinforces the finish joint 12 </ b> U is provided in the finish joint 12 </ b> U. The pair of upper and lower inner diaphragms 18 is formed of a disk-shaped steel plate. The pair of upper and lower inner diaphragms 18 are disposed so as to face in the vertical direction (the material axis direction of the steel pipe column 12), and each outer peripheral portion is joined to the inner side surface of the finishing port 12U by welding or the like. .

  In addition, a filling hole 18A is formed at the center of each inner diaphragm 18, and the filled concrete 14 is filled into the steel pipe column 12 through these filling holes 18A. Similar to the upper end portion 12U, a pair of upper and lower inner diaphragms 18 as a pair of upper and lower diaphragms are provided inside the lower end portion 12L.

  A pair of upper steel beams 16 as steel beams are joined to both sides of the upper end portion 12U. The upper steel beam 16 is formed of an H-shaped steel, and has a pair of upper and lower upper flange portions 16A and a lower flange portion 16B, and a web portion 16C that connects the upper flange portion 16A and the lower flange portion 16B. doing. The ends of the upper steel beam 16 in the material axis direction are formed on the outer surface of the upper end 12U so that the pair of upper and lower upper flange portions 16A and 16B are continuous with the pair of upper and lower inner diaphragms 18 respectively. It is abutted and joined by welding. A slab made of reinforced concrete (not shown) is constructed on the upper steel beam 16.

  Similar to the upper end portion 12U, a pair of lower steel beam 17 as a steel beam is joined to both sides of the lower end portion 12L. The lower steel beam 17 is formed of an H-shaped steel, and includes a pair of upper and lower upper flange portions 17A and 17B, and a web portion 17C that connects the upper flange portion 17A and the lower flange portion 17B. Have. The ends of the lower steel beam 17 in the material axis direction are arranged on the outer surface of the lower end portion 12L so that the pair of upper and lower upper flange portions 17A and 17B are continuous with the pair of upper and lower inner diaphragms 18 respectively. And is joined by welding. A slab made of reinforced concrete (not shown) is constructed on the lower steel beam 17.

  The column head portion 12BU and the column base portion 12BL in the steel pipe main body portion 12B are fire-resistant coated with cylindrical covering members 40U and 40L as post-construction fire-resistant covering means. The tubular covering members 40U and 40L are required for the non-fire-resistant coated CFT pillar 10 due to structural design change (for example, application change or plan change) after finishing paint 20 is applied to the outer surface of the steel pipe pillar 12. When the fire resistance is increased, the steel pipe body 12B is provided around the column head 12BU and the column base 12BL according to the required fire resistance. That is, the tubular coating members 40U and 40L are finished by post-processing so that the required fire resistance performance of the non-fire-resistant coated CFT pillar 10 that has been increased by design change or the like is satisfied after the non-fire-resistant coated CFT pillar 10 is finished. The column head 12BU and the column base 12BL are covered with fireproof coating from above. In addition, since the cylindrical covering member 40U that fire-coats the column head 12BU and the cylindrical covering member 40L that fire-coats the column base portion 12BL have the same configuration, the configuration of the cylindrical covering member 40U will be described in detail below. The description of the configuration of the cylindrical covering member 40L is omitted.

  As shown in FIGS. 3A and 3B, the cylindrical covering member 40U is formed in a cylindrical shape having a circular cross section by joining a pair of base members 42 together. The pair of base members 42 are formed of a thin metal plate made of stainless steel and have a substantially semicircular cross section along the outer surface of the column head 12BU of the steel pipe main body 12B. A fireproof paint 44 as a fireproof material is applied to the outer surfaces of the pair of base materials 42 over the entire surface. The term “fire resistant paint” as used herein refers to a fire resistant coating material that forms a foamed layer by heating in the event of a fire and delays the temperature rise of a steel material or the like. The pair of base members 42 are arranged along the outer surface of the column head portion 12BU so as to surround the column head portion 12BU of the steel pipe main body portion 12B from above the finish paint 20, and the respective opening side end portions 42A are butted together. Are joined together by welding. As a result, the pillar head 12BU is covered with the fireproof coating 44 over the entire circumference from the top of the finish paint 20.

  Next, the operation of this embodiment will be described.

  As shown in FIG. 2, for example, when the upper steel beam 16 expands in the material axis direction (horizontal direction, arrow S direction) due to thermal expansion in the event of a fire, a horizontal force F acts on the finishing part 12U, and the steel pipe body A bending moment M is generated in the portion 12B. The bending moment M gradually increases from the intermediate portion 12BM in the material axis direction of the steel pipe body 12B toward each of the column head portion 12BU and the column base portion 12BL in the material axis direction.

  On the other hand, the steel pipe column 12 expands in the material axis direction (arrow Z direction) due to thermal expansion at the time of a fire, but the extension in the material axis direction gradually decreases due to a decrease in strength and rigidity accompanying temperature rise, and a certain temperature. When it reaches, the expansion and deformation in the direction of the material axis stops and it starts to shrink. In this state, when the horizontal force F acts from the upper steel beam 16 to the upper end portion 12U, the column head portion 12BU and the column of the steel pipe main body portion 12B in which a large bending moment M is generated as compared with the intermediate portion 12BM as described above. Local buckling K tends to occur in the side wall portions 12S1 and 12S2 on the compression side (arrow C side) of the leg portion 12BL. In particular, the column head portion 12BU is rigidly joined to the upper steel beam 16 through the upper joint portion 12U, and the column base portion 12BL is rigidly joined to the lower steel beam 17 through the lower joint portion 12L, and When the extension amount (extension amount) of the upper steel beam 16 in the material axis direction is large, the column head portion 12BU and the column base portion 12BL are deformed with a large curvature. If a large degree of compressive stress is generated in the side wall portions 12S1 and 12S2 on the compression side (arrow C side) of the column head portion 12BU and the column base portion 12BL due to this deformation, the side wall portions 12S1 and 12S2 are displaced outward in the out-of-plane direction. Out) Local buckling K occurs.

  When local buckling K occurs in the column head portion 12BU or the column base portion 12BL, the bending rigidity of the fireproof coated CFT column 10 is significantly reduced. In addition, in the portion where the local buckling K occurs in the column head 12BU, as shown in FIG. 4, the side wall 12S1 on the compression side of the steel pipe body 12B that restrains the filling concrete 14 bulges outward, and the filling concrete 14 And a side wall 12S1 is formed with a gap W. As a result, in the part where the local buckling K occurs, the restraining force (restraining effect) of the side wall 12S1 with respect to the filling concrete 14 cannot be obtained, and the compression side edge (outer peripheral part) 14S of the filling concrete 14 is easily crushed. In FIG. 4, the cylindrical covering member 40U is not shown.

  When the compression side edge 14S of the filled concrete 14 is crushed, the displacement in the material axial direction of the fireproof coated CFT column 10 is rapidly increased, and the compression side edge 14S of the filled concrete 14 is crushed along with the sudden increase in displacement in the material axial direction. May further progress, and the fireproof coated CFT pillar 10 may not be able to maintain structural stability.

  Here, “the fire-resistant coated CFT column 10 cannot maintain the structural stability” means, for example, that the vertical displacement (material axis direction) of the fire-resistant coated CFT column 10 is excessive, or This means a state in which the long-term axial force cannot be maintained due to a sudden increase in vertical displacement. Although not described, the same applies to the case where local buckling K occurs in the column base portion 12BL of the fireproof coated CFT column 10.

  Here, the amount of extension in the material axis direction of the upper steel beam 16 described above becomes longer as the required fire resistance performance required for the fireproof coated CFT column 10, that is, the required fire resistance time becomes longer. This required fire resistance time is determined by conditions such as the amount of combustibles in the room, so if there is a design change such as an indoor use change or plan change, the required fire resistance time will be longer than the initial (newly set) time. The fireproof coated CFT pillar 10 may not be able to satisfy the fireproof performance required for the required fireproof time. That is, when the required fire resistance required for the fire-resistant coated CFT column 10 is increased due to the design change, local buckling K tends to occur in the column head portion 12BU and the column base portion 12BL of the fire-resistant coated CFT column 10 and fire resistant. There is a possibility that the coated CFT pillar 10 cannot maintain the structural stability.

  On the other hand, in this embodiment, as shown in FIGS. 2 and 3, a cylindrical shape is formed from the top of the finish paint 20 so as to satisfy the required fire resistance performance of the non-fire-resistant coated CFT pillar 10 that has been increased by design change or the like. The column head portion 12BU and the column base portion 12BL of the steel pipe main body portion 12B are fire-resistant coated by the covering members 40U and 40L. Specifically, the cylindrical covering members 40U and 40L are formed by joining a pair of base members 42 into a cylindrical shape. A fireproof paint 44 is applied to the outer surfaces of the pair of base materials 42. Therefore, for example, by attaching the pair of base members 42 of the tubular covering member 40U from both sides to the column head 12BU of the steel pipe main body 12B and joining them together, the fireproof paint 44 is disposed around the column head 12BU, The pillar head 12BU is fireproof coated. Similarly, by attaching the pair of base members 42 of the cylindrical covering member 40L from both sides to the column base part 12BL of the steel pipe main body part 12B and joining them together, the refractory paint 44 is formed around the column base part 12BL. The column base 12BL is fireproof coated. In addition, in the joint part of a pair of base materials 42, since the fireproof paint 44 may peel off at the time of joining, the fireproof paint 44 is not previously applied around the joint part, but the fireproof paint 44 is applied after joining. May be.

  Thereby, as a result of suppressing the temperature rise of the column head 12BU and the column base part 12BL at the time of a fire, the fall of the intensity | strength and rigidity of the column head 12BU and the column base part 12BL accompanying a temperature rise is reduced. Therefore, the occurrence of local buckling K of the column head portion 12BU and the column base portion 12BL is suppressed. Therefore, the fireproof performance of the non-fireproof coated CFT pillar 10 is improved.

  Further, as described above, by attaching the pair of base members 42 from both sides to the column head portion 12BU and the column base portion 12BL of the steel pipe main body portion 12B, a fireproof paint is provided around the column head portion 12BU and the column base portion 12BL. 44 is arranged. Therefore, the application | coating operation | work of the refractory paint 44 on the spot can be abbreviate | omitted.

  In addition, when the fire resistant paint 44 is directly applied on the finish paint 20, the fire resistant paint 44 is often peeled off during heating (at the time of a fire), so that sufficient fire resistance cannot be obtained in many cases. In this case, the fireproof paint 44 is applied after the finish paint 20 of the pillar head part 12BU and the pillar leg part 12BL is peeled off, and the construction becomes complicated. On the other hand, in this embodiment, since the fireproof paint 44 is applied to the outer surfaces of the pair of base members 42, it is not necessary to peel off the finish paint 20 of the column heads 12BU and the column bases 12BL. Even if the finish paint 20 is dirty, the pair of base materials 42 surrounds the column head portion 12BU and the column base portion 12BL of the steel pipe main body 12B from above the finish paint 20, so that the finish paint 20 is covered by the pair of base materials 42. Therefore, it is not necessary to repaint or remove the finish paint 20. Therefore, the workability is improved.

  Furthermore, in this embodiment, the pair of base members 42 are formed of thin metal plates. Thereby, the increase in the column cross-sectional area of the fireproof covering CFT pillar 10 including a pair of base material 42 and the fireproof coating 44 can be reduced.

  In addition, in the present embodiment, as described above, the column head portion 12BU and the column base portion 12BL of the steel pipe main body portion 12B in which local buckling K is likely to occur during a fire are covered with the fireproof coating by the cylindrical covering members 40U and 40L. Therefore, the fireproof performance of the non-fireproof coated CFT column 10 can be efficiently improved as compared with the configuration in which the steel pipe main body 12B is fireproofed over its entire length. In addition, it is possible to improve workability, shorten the construction period, and reduce costs.

  Here, FIG. 5A shows an example of a frame composed of a column 100 made of a general concrete-filled steel pipe column and beams 102A and 102B. In this frame, for example, as shown in FIG. 5B, when a fire 104 occurs, the beam 102A extends in the material axis direction (arrow J direction), so that the pillar 100 is deformed as shown in FIG. Arise.

  FIG. 6 (A) shows an experimental evaluation model used for fire resistance performance evaluation of a column 110 made of a general concrete-filled steel pipe column. Since this experimental evaluation model shows the deformation state and the stress state as shown in FIG. 6B during heating, the deformation state and the stress state of the column 100 shown in FIG. 5B are appropriately simulated. It is said that you can. Then, when the loading heating experiment was conducted using the experimental evaluation model shown in FIG. 6 (A), the following new knowledge was obtained.

  That is, when the horizontal displacement (horizontal force F) generated at the upper end of the heated column 110 is large or the axial force (long-term axial force) V generated at the column 110 is large, as shown in FIG. It was confirmed that local buckling K occurred in the column head and column base of the steel pipe column constituting the column 110. Further, even when the heating time is relatively short and the concrete filled in the column 110 remains sufficiently proof, the column 110 loses its load supporting ability due to the above-described local buckling K of the column head and column base. It was confirmed that the structural stability could not be maintained.

  When the fireproof coated CFT column 10 according to the present embodiment is specifically described by way of example, the following has been confirmed for the local buckling K. That is, when the column width (diameter) of the steel pipe column 12 is D (see FIG. 3B), the local buckling K in the column head 12BU is the upper end of the column head 12BU (the upper end 12U and the steel pipe body). It is likely to occur in the region from 2D to the intermediate portion 12BM from the boundary portion with the portion 12B), and particularly easily in the region from 1D to 2D. Similarly, the local buckling K in the column base 12BL is within the region from the lower end of the column base 12BL (the boundary between the lower end 12L and the steel pipe body 12B) to 2D from the intermediate portion 12BM. It is easy to generate | occur | produce especially in the area | region from 1D to 2D.

  Accordingly, it is desirable that the covering range H (see FIG. 2) of the cylindrical covering member 40U with respect to the column head 12BU be at least 2D from the upper end of the column head 12BU toward the intermediate portion 12BM. In consideration of workability, material cost, and the like, it is desirable that the covering range H of the cylindrical covering member 40U is at least 1D to 2D from the upper end of the column head 12BU to the intermediate portion 12BM. Thereby, generation | occurrence | production of the local buckling K of the column head 12BU can be suppressed efficiently, reducing the material cost of the cylindrical coating | coated member 40U. The same applies to the covering range H (see FIG. 2) of the cylindrical covering member 40L on the column base 12BL.

  Next, a modification of the above embodiment will be described.

  The cylindrical covering members 40U and 40L in the above embodiment may be appropriately reinforced with a reinforcing member. Specifically, as in the modification shown in FIGS. 7A and 7B, the inner surfaces of the pair of base members 42 in the cylindrical covering member 50U have a plurality of reinforcements as a plurality of reinforcement members. Ribs 52 are provided. The plurality of reinforcing ribs 52 extend in the axial direction of the tubular covering member 50U and are arranged at intervals in the circumferential direction of the tubular covering member 50U, and are joined to the inner surfaces of the pair of base members 42 by welding or the like. ing. A pair of base members 42 are arranged around the column head 12BU with these reinforcing ribs 52 in between. Thus, a space R is formed between the column head 12BU and the pair of base members 42.

  By reinforcing the pair of base members 42 with the reinforcing ribs 52 in this way, the shape of the pair of base members 42 can be easily maintained. When a thin metal plate (thickness of less than 3 mm) is used for the pair of base members 42, depending on the size of the cross section, the pair of base members 42 may be curved and it may be difficult to maintain the shape. At this time, by reinforcing the reinforcing ribs 52, deformation of the pair of base members 42 is suppressed. Rather than increasing the thickness of the pair of base materials 42, the cost is reduced by reinforcing the reinforcing ribs 52, and further improvement in workability can be expected.

  Further, as shown in FIG. 8A, when the fireproof paint 44 is applied to the inner surfaces of the pair of base members 42, the fire resistance at the time of fire is caused by the space R between the column head 12BU and the pair of base members 42. A foaming space for the paint 44 is secured. For this reason, even when the refractory paint 44 is applied to the inner surface of the base material 42, as shown in FIG. 8B, the refractory paint 44 is appropriately foamed to maintain the structural stability of the fireproof coated CFT pillar 10. I can do it. When the refractory paint 44 is applied to the back side (inner surface) of the base material 42, the front side (outer side) of the base material 42 can be seen more clearly than when the refractory paint 44 is applied to the outer side (outer surface). In particular, the design can be greatly improved because the metal plate (base material 42) can be shown as a representation without applying a finish paint on the front side of the base material 42.

  In addition, in this modification, although the example which arrange | positions the reinforcement rib 52 along the axial direction of the cylindrical coating | coated member 50U was shown, it does not restrict to this. The reinforcing ribs 52 can be arranged along the circumferential direction of the cylindrical covering member 50U, for example.

  Moreover, in the said embodiment, although the example using the fireproof paint 44 was shown as a fireproof material, it is not restricted to this. As the refractory material, for example, a wrapping refractory coating material may be used. Specifically, as in the modification shown in FIGS. 9A and 9B, the inner surface of the pair of base members 42 constituting the cylindrical covering member 60 </ b> U is wrapped around the refractory material as a refractory material. Each of the covering materials 62 is provided.

  The wrapping-type fireproof covering material 62 is formed of a wrapping-type fireproof covering material in which rock wool or the like is formed into a sheet shape. The wrapping fireproof covering material 62 is formed in a substantially semicircular cross section along the inner surface of each base material 42 and covers the entire inner surface of each base material 42. Further, the wrapping fireproof covering material 62 is fixed to the inner surface of each base material 42 by a plurality of screws 64. A pair of base members 42 are arranged around the column head 12BU with the winding-type fireproof covering material 62 interposed therebetween. Thereby, the column head 12BU is covered with the wrapping-type fireproof covering material 62 over the entire circumference from the top of the finish paint 20.

  Thus, by providing the winding-type fireproof coating material 62 on the inner surfaces of the pair of base materials 42, the pair of base materials 42 also functions as a finishing material that covers the winding-type fireproof coating material 62. Therefore, the workability is improved. In particular, the appearance quality can be improved by forming the base material 42 from a metal plate made of stainless steel or steel.

  In addition, as the fireproof material provided on the inner surfaces of the pair of base materials 42, in addition to the wound fireproof covering material 62, a spray fireproof covering material, a board fireproof covering material, a foamable fireproof sheet, or the like may be used. Here, the spray-type fireproof coating material means, for example, spray rock wool, wet spray rock wool, gypsum-based wet spray fire-resistant coating, ceramic-based wet fire-resistant coating, and the like. Examples of board-based fireproof coating materials include gypsum board (including reinforced gypsum board), fiber-mixed calcium silicate board, mortar board, rock wool board, ceramic fiber board, PC board, ALC panel, and extruded cement board. Etc.

  Moreover, in the said embodiment, although the example which formed a pair of base material 42 with the thin metal plate (plate thickness is less than 3 mm) was shown, a pair of base material 42 is a thick metal plate (plate thickness 3 mm or more). You may form with a metal plate. The pair of base members 42 may be formed of a metal plate made of aluminum or titanium in addition to the above-described stainless steel or steel metal plate, or may be formed of a resin plate such as plastic or a wooden plate material. good.

  Moreover, in the said embodiment, although the example which formed the steel pipe pillar 12 with the round steel pipe was shown, it is not restricted to this. For example, as in the modification shown in FIGS. 10A and 10B, the steel pipe column 22 may be a square steel pipe having a substantially square cross section. In this case, according to the cross-sectional shape of the steel pipe column 22, the pair of base members 42 constituting the cylindrical covering member 70 </ b> U are formed in a substantially C-shaped cross section, thereby forming a pair of base members along the outer surface of the steel pipe column 22. 42 can be arranged. In the steel pipe column 22, the length of one side of the square steel pipe corresponds to the column width D of the steel pipe column 22. Furthermore, as the steel pipe column, for example, a square steel pipe having a substantially rectangular cross section may be used. In this case, the length of the short side corresponds to the column width D of the steel pipe column.

  Moreover, in the said embodiment, although the example which coats the pillar head part 12BU and the pillar leg part 12BL of the steel pipe main-body part 12B with fireproof by the cylindrical covering members 40U and 40L was shown, it does not restrict to this. For example, as shown in FIG. 11, the steel pipe main body 12 </ b> B may be covered with a fireproof covering over the entire length by the tubular covering member 40. Compared to the case where only the column head portion 12BU and the column base portion 12BL are refractory reinforced, the cost is higher, but the design property can be greatly improved by refracting the entire length of the steel pipe main body portion 12B. When the non-fire-resistant coated CFT pillar 10 used to represent the surface of the steel pipe main body 12B is not finished with a board or the like, and the steel pipe pillar 12 is finished with fireproof reinforcement in the subsequent work, the entire length of the steel pipe main body 12B is fire-proof reinforced. By doing so, it is possible to use the steel pipe main body 12B as a representation even after the fireproof reinforcement, and to ensure the appearance quality equal to or better than that before the fireproof reinforcement.

  Furthermore, in the said embodiment, although cylindrical covering member 40U, 40L was demonstrated to the example as post-construction fireproof covering means, it is not restricted to this. The post-construction fireproof covering means may be any one that is disposed around the non-refractory coated CFT column 10 by post-construction and that covers the non-refractory coated CFT column 10 by fireproofing. Fire-resistant coating materials such as fire-resistant coating materials, board-based fire-resistant coating materials, and fire-resistant coating materials can be used. That is, the pair of base members 42 can be omitted as appropriate.

  As mentioned above, although one embodiment of the present invention was described, the present invention is not limited to such an embodiment, and one embodiment and various modifications may be used in combination as appropriate, and the gist of the present invention will be described. Of course, various embodiments can be implemented without departing from the scope.

10 Fire-resistant coated CFT pillar 20 Fire-resistant paint 20 Finish paint 30 Fire-resistant reinforcing structure of fire-resistant coated CFT pillar 40U Cylindrical covering member (post-installed fire-resistant covering means)
40L cylindrical covering member (post-installed fireproof covering means)
42 Base material 44 Fireproof paint (fireproof material)
50U tubular covering member (post-fire-resistant covering means)
60U cylindrical covering member (post-installed fireproof covering means)
62 Wrapped fireproof covering material (fireproof material)
70U Tubular covering member (post-construction fireproof covering means)

Claims (3)

A non-fire-resistant coated CFT pillar having upper and lower joint portions and a steel pipe main body portion extending between the upper and lower joint portions ;
A post-installation fire-resistant coating means disposed around the axial end of the steel pipe body by post-construction, and fire-proofing the end instead of the axial middle of the steel pipe main body ;
A fireproof reinforcing structure for non-fireproof coated CFT columns. A finish paint is applied to the outer surface of the fireproof coated CFT pillar,
The post-construction fireproof covering means is
A pair of base materials attached from both sides to the fireproof coated CFT pillar and joined together to surround the fireproof coated CFT pillar from above the finish paint;
A refractory material provided on an outer surface or an inner surface of the pair of base materials;
Having
The fireproof reinforcing structure of the fireproof coated CFT pillar according to claim 1. The pair of base materials is a pair of metal plates disposed along an outer surface of the fireproof coated CFT pillar;
The refractory material is a refractory paint applied to the outer surfaces of the pair of metal plates.
The fireproof reinforcing structure of the fireproof coated CFT pillar according to claim 2.

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