Blocking material for steam vents in steel pipe concrete columns

Abstract

To prevent leakage of concrete from a steam vent hole formed by penetrating inner and outer circumferential surfaces of a steel pipe constituting a steel pipe concrete column after concrete is placed, and to allow passage of steam generated within concrete in the event of a fire, to improve safety against separation due to lateral pressure of concrete.SOLUTION: A closing material 1 comprises: a plug material 2 which is meltable in the event of a fire and which has a main body portion 21 having a cross-sectional area capable of inscribing a steam vent hole 51 and a length exceeding the overall length of the steam vent hole 51 and having a cutout portion 22 formed from an outer peripheral surface side toward the center; and a spring material 3 which has a held portion 31 held by the main body portion 21, an intermediate portion 32 which is continuous with the held portion and positioned at a position corresponding to the cutout portion 22, and a locking portion 33 which is continuous with the held portion and can be locked around the steam vent hole 51 from an inner peripheral surface 5a side toward an outer peripheral surface 5b side of a steel pipe 5. At least one of the intermediate portion 32 and the locking portion 33 can be contracted toward the center side of the main body portion 21 of the plug material 2 when inserted into the steam vent hole 51.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a plugging material for a steam vent hole of a concrete-filled steel tube column, which has a function of allowing steam generated from the concrete during a fire to pass through while preventing the outflow of concrete after placement through a steam vent hole formed through the inner and outer peripheral surfaces of the steel tube constituting the concrete-filled steel tube column.

Background Art

[0002] For the steel tube of a concrete-filled steel tube column in which concrete is filled in the steel tube, when the concrete reaches a high temperature during a fire in a structure, measures such as forming steam vent holes are obligatory to prevent the destruction of the steel column due to the expansion of the water contained in the concrete into steam (see Non-Patent Documents 1 and 2).

[0003] If the steam vent hole is not filled with a filling material (plug), the concrete will enter the steam vent hole during the filling (placement) of the concrete. Therefore, after the concrete is filled, it is necessary to remove the concrete clogged in the wall thickness part inside the steam vent hole using tools. In this regard, it is necessary to fill some filling material in the steam vent hole before filling the concrete.

[0004] When filling the steam vent hole with a filling material (plug) before filling the concrete in advance, the filling material is mainly classified into cases where it is a wooden or plastic plug that easily disappears (burns out) in a fire (see Non-Patent Document 2, Patent Documents 1 and 2), and cases where it is a steel bolt or the like that is removed after the concrete hardens (see Non-Patent Document 2, Patent Documents 3 to 5).

[0005] Examples where the filling material disappears during a fire include a method of inserting a sponge-like permeable member into a through hole formed in the center of the filling material and infiltrating rosin into the permeable member after the concrete is filled to confirm the filling status of the concrete (Patent Document 1), and a method of inserting the filling material into the steam vent hole after confirming the filling of the concrete (Patent Document 2). [Prior art documents] [Non-patent literature]

[0006] [Non-Patent Document 1] "Regarding the establishment of necessary safety technical standards for the structural methods of concrete-filled steel pipe buildings or structural parts of buildings," Ministry of Land, Infrastructure, Transport and Tourism Notification No. 464 [Non-Patent Document 2] "Technical Guidelines and Commentary for Concrete-Filled Steel Tube (CFT) Construction," Japan Building Center, Chapter 2 [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2001-262833 (Claim 1, paragraphs 0012-0023, Figures 1-6) [Patent Document 2] Japanese Patent Publication No. 2004-124426 (Claim 5, paragraphs 0028-0031, Figures 4 and 5) [Patent Document 3] Japanese Patent Publication No. 2002-206312 (Claim 2, paragraphs 0020-0030, Figures 1-3) [Patent Document 4] Japanese Patent Publication No. 2003-166309 (paragraphs 0009-0011, Figures 1-3) [Patent Document 5] Japanese Patent Publication No. 2013-194383 (Claims 1-5, paragraphs 0038-0044, Figure 1, Figure 2) [Overview of the project] [Problems that the invention aims to solve]

[0008] In Patent Document 1, a through-hole formed axially and continuously in the center of the filler material and a notch formed on the inner circumferential surface of the steel pipe are used to insert the filler material into the steam vent hole. This allows the claw portion formed on the outer circumference (edge) of the inner circumferential surface of the steel pipe to engage with the inner circumferential surface of the steel pipe, while the outer surface of the filler material is fitted in close contact with the inside of the steam vent hole (paragraphs 0013, 0014). In this example, the entire outer surface of the filler material is in close contact with the inner circumferential surface of the steam vent hole, and the claw portion is engaged with the steel pipe. Therefore, it is considered that the filler material is stable against being pulled out due to lateral pressure during concrete filling.

[0009] However, since the lateral pressure of the concrete also acts on the permeable member inserted into the through-hole of the filler, and the permeable member maintains its inserted state solely by the frictional force while compressed (paragraph 0013), it cannot be said that there is no possibility that the permeable member may detach from the filler due to the lateral pressure.

[0010] In Patent Document 2, the condition of the concrete filling is checked before inserting the filler into the steam vent hole (paragraphs 0019, 0030), making it difficult to prevent or completely prevent leakage from the concrete steam vent hole. It is thought that leakage of the slurry can be prevented if the filler is inserted immediately after confirming that the concrete is filled, or if the confirmation is ignored and the filler is inserted before the concrete is filled.

[0011] However, the filler is formed at the end on the inner circumferential surface side of the steel pipe, and is only held in place in the steam vent hole by the frictional force due to the elasticity of the retaining piece that locks onto the inner circumferential surface of the steel pipe and the intermediate piece that partially protrudes axially from the outer circumferential surface of the filler (paragraph 0021), and there is a gap between the outer circumferential surface of the part other than the intermediate piece and the inner circumferential surface of the steam vent hole (Figure 1). For this reason, the filler itself is in a state where it can move within the steam vent hole, and there are concerns about its safety against detachment due to lateral pressure from the concrete.

[0012] Based on the above background, this invention proposes a form of sealing material for steam vents that enhances safety against detachment due to lateral pressure on the concrete. [Means for solving the problem]

[0013] The sealing material for a steam vent hole in a steel pipe concrete column according to claim 1 is a sealing material that is inserted from the outer surface side of the steel pipe into a steam vent hole formed by penetrating between the inner surface and outer surface of the steel pipe constituting the steel pipe concrete column, and seals the steam vent hole from the inner surface side of the steel pipe until the concrete filling into the steel pipe is completed and the concrete loses its fluidity. A plug material having a melting point that allows it to melt in the event of a fire, a cross-sectional area that can be inscribed within the steam vent hole and a length that exceeds the total length of the steam vent hole, and a main body having a notch formed symmetrically with respect to the axial center from the outer surface toward the center, The stopper material comprises a holding portion that is held by the main body portion, and a portion that is continuous with the holding portion and positioned at a location corresponding to the notch portion of the stopper material. , elastically deformable toward opposing sides The middle section and this each The structure comprises a spring material that is continuous with the intermediate section and has a locking portion that can engage with the steam vent hole from the inner circumferential surface side to the outer circumferential surface side of the steel pipe, The surface of the notch of the plug material has a shape that can accommodate the intermediate portion of the spring material when it is elastically deformed. The spring material is held in the main body of the plug material at the holding portion, with the locking portion positioned in the notch portion of the plug material, and at least one of the intermediate portion and the locking portion of the spring material contracts toward the center of the main body of the plug material when inserted into the steam vent hole. Afterwards, restore The constituent element is that it is possible.

[0014] "Having a melting point that allows it to melt in the event of a fire" means that the plug material has a melting point of around several tens to 100°C, which allows it to melt to the point where it can at least not retain its original shape in the event of a fire and release the blockage of the steam vent. Molded products such as synthetic resins and solid special waxes are mainly used for plug materials, but the material is not particularly limited as long as it has a melting point that satisfies the conditions and is workable enough to form a notch. The plug material only needs to substantially block the steam vent until the concrete filling of the steel pipe is complete and the concrete loses its fluidity, and in the event of a fire in the structure, it melts to promote the release of moisture contained in the concrete through the steam vent.

[0015] "Having a cross-sectional area that can be inscribed in the steam vent hole" means that, in the state where the plug material is inserted into the steam vent hole, the outer peripheral surface of most parts of the main body of the plug material can contact the inner peripheral surface of the steam vent hole except for the notch part, and the main body has a cross-sectional area that can substantially cover the inner peripheral surface of the steam vent hole. The state where most parts of the main body are inscribed in the steam vent hole includes the case where the main body contracts from the outer peripheral side toward the axial center side. The "part that contracts from the outer peripheral side toward the axial center side" when the main body contracts only needs to be at least a part of the main body in the axial direction. "A plug material having a length exceeding the total length of the steam vent hole" means that when inserted into the steam vent hole, at least one of the inner peripheral surface side and the outer peripheral surface side of the steel pipe in the axial direction of the plug material has a length protruding from the steam vent hole.

[0016] Since the outer peripheral surface of most parts of the main body of the plug material can contact the inner peripheral surface of the steam vent hole, even if the outer peripheral surface of the main body does not completely adhere to the inner peripheral surface of the steam vent hole and there is a slight gap between the outer peripheral surface of the steam vent hole, after the concrete is filled, the mortar can enter the gap and harden as it is, so the occurrence of the gap does not hinder the filling property of the concrete. Therefore, the function of concrete blocking that the blocking material should perform from the insertion into the steam vent hole to the completion of the concrete filling is exerted.

[0017] Since the main body of the plug material has a cross-sectional area that can be inscribed in the steam vent hole, when the concrete is filled into the steel pipe in the state where the plug material is inserted into the steam vent hole from the outer peripheral surface side of the steel pipe, the outflow of the concrete from the steam vent hole to the outside of the steel pipe is blocked. It is only necessary that the outflow of the concrete is substantially blocked, and a slight leakage is allowed.

[0018] "A notch is formed from the outer peripheral side symmetrically with respect to the axial center" means that, for example, as shown in Fig. 1-(b), a notch 22 is formed from the outer peripheral surface side of the plug member 2 toward the center side at a position symmetric with respect to the axial center of the plug member 2 in the main body portion 21. At a position corresponding to the notch 22, an intermediate portion 32, which is a portion continuous with the held portion 31 and the locking portion 33 of the spring member 3, is arranged. When the closing member 1 is inserted into the vent hole 51 shown in Fig. 4, the surface of the notch 22 is inclined, for example, so that the intermediate portion 32 can contract toward the center side of the plug member 2 or so that the intermediate portion 32 can fit in (Claim 5 ). "The intermediate portion 32 is arranged at a position corresponding to the notch 22" includes that the intermediate portion 32 of the spring member 3 is arranged so as to fit into the notch 22 and that it is arranged so as to face (oppose) the notch 22.

[0019] In the case of the example shown in Fig. 1-(b), specifically, at a position corresponding to the notch 22, the surfaces of the notch 22 are inclined from the outer peripheral surface side 5b of the steel pipe 5 toward the inner peripheral surface side 5a of the steel pipe 5 and from the outer peripheral surface side of the plug member 2 toward the center so that the inner peripheral surface 5a sides of the pair of intermediate portions 32, 32 of the spring member 3 shown in (c) can elastically deform toward the opposing sides when inserted into the vent hole 51 (Claim 5 ). In this case, the inclination of the surface of the notch 22 is formed so that when the spring member 3 held by the plug member 2 is inserted into the vent hole 51, the locking portion 33 contacts the inner peripheral surface of the vent hole 51 as shown in Fig. 4-(b), and when the intermediate portion 32 tries to bend with respect to the held portion 31, the deformed intermediate portion 32 can fit into the space of the notch 22. The intermediate portion 32 of the spring member 3 may contact the surface of the notch 22.

[0020] Furthermore, since it is "symmetrical with respect to the center," the notch 22 includes the area from the outer circumferential surface of the main body 21 to the center. For example, as shown by the dashed line in Figure 3, a band-shaped region with a width corresponding to the width of the spring material 3 may be formed as a groove that is continuous in the axial direction from the inner circumferential surface 5a side of the steel pipe to the outer circumferential surface 5b side of the main body 21, or it may be formed as a groove that is continuous in the axial direction from the outer circumferential surface 5b side of the steel pipe to the inner circumferential surface 5a side of the main body 21. In these cases, the notch 22 is formed to penetrate between the opposing outer circumferential surfaces of the main body 21 with the center in between. Here, the "inner circumferential surface side of the steel pipe" is the upper side in Figure 3, and the "outer circumferential surface side of the steel pipe" is the lower side in Figure 3. In these cases, the retained portion 31 of the spring material 3 is inserted axially into the groove shown by the dashed line and held.

[0021] However, in the example shown by the dashed line in Figure 3, even if the main body 21 has a cross-sectional area that substantially covers the inner circumferential surface of the steam vent hole 51, the decrease in the volume of the main body 21 may reduce the restoring force when it shrinks when inserted into the steam vent hole 51 compared to when the volume does not decrease, potentially weakening the tight seal inside the steam vent hole 51.

[0022] From this point of view, when shrinking the main body portion 21, it is desirable that the amount of shrinkage of the main body portion 21 be uniform in the axial direction, and that the notch portion 22 be formed to be inclined from the outer circumferential surface 5b side to the inner circumferential surface 5a side of the steel pipe 5 in the axial direction of the plug material 2 as described above (Claim) 5 In that case, as shown in Figure 1-(b), a retaining portion 24 (notch) is formed in the main body portion 21 so as to be continuously cut from the outer circumference towards the center in a direction perpendicular to the axial direction, and the spring material 3 is held in the main body portion 1 by inserting the retained portion 31 into this retaining portion 24 in a direction perpendicular to the axial direction, etc. (Claim 3).

[0023] Another method for holding the retained portion 31 of the spring material 3 in a position passing through the center of the main body portion 21 is to make a notch 22 as shown by the solid line in Figure 3. This notch is cut from the end face on the inner circumferential surface 5a side of the main body portion 21 to the outer circumferential surface 5b side of the steel pipe, passing through the center and between the outer circumferential surfaces of the main body portion 21, with a width approximately equal to the thickness of the spring material 3. Additionally, a cut approximately equal to the width of the spring material 3 is made perpendicular to the end of this axial cut on the outer circumferential surface 5b side of the steel pipe. In this example, it is not necessary to form a strip-shaped notch 22 with a width like the dashed line, and the volume of the main body portion 21 is not reduced.

[0024] In this case, the retained portion 31 is inserted along the axial notch (cutout portion 22) shown by the solid line, and then oriented in the direction of the orthogonal notch, so that the intermediate portion 32 is held by the main body portion 21 with the intermediate portion 32 facing the axial notch (surface of the main body portion 21). However, grooves or the like are formed on the surface of the main body portion 21 so that the surface of the main body portion 21 does not hinder the deformation of the intermediate portion 32 when the intermediate portion 32 tries to deform toward the center of the main body portion 21 until the spring material 3 has finished passing through the steam vent hole 51.

[0025] In either case, the intermediate portion 32 of the spring material 3, while held by the plug material 2, is positioned to correspond to the notch 22. When the spring material 3 is inserted into the steam vent hole 51 from the outer surface 5b of the steel pipe as part of the sealing material 1, as shown in Figure 4-(b), the intermediate portion 32 or the locking portion 33 of the spring material 3, or both the intermediate portion 32 and the locking portion 33, elastically deform towards the center of the plug material 2 along the surface of the notch 22. When the tip 34 of the locking portion 33 comes out towards the inner surface 5a of the steel pipe 5, the intermediate portion 32 returns to its original shape as shown in (a), and the tip 34 of the locking portion 33 locks into the inner surface 5a of the steel pipe 5.

[0026] Thus, the notch 22 of the plug material 2 is formed so that when the intermediate portion 32 of the spring material 3 attempts to elastically deform toward the center of the plug material 2, the intermediate portion 32 fits into the notch 22 and the locking portion 33 can enter into the steam vent hole 51. Since the spring material 3 consists of a continuous retained portion 31, an intermediate portion 32, and a locking portion 33, it can be formed, for example, by bending a single elastic metal plate at the division (boundary) positions of each part. However, the material of the spring material 3 is not limited.

[0027] The term "retained portion held by the main body of the stopper material" means that the retained portion 31 of the spring material 3 is held integrally by the main body 21 of the stopper material 2 in some way, including being held by the notch portion 22 or the retaining portion 24 as described above, and as long as it is inserted into the steam vent hole 51 as a sealing material 1, the spring material 3 is restrained by the main body 21 to the extent that it ensures integrality with the stopper material 2.

[0028] The retained portion 31 of the spring material 3 is held by being inserted into the notch portion 22, which includes an axially formed notch in the main body portion 21 of the plug material 2, or into a notch (retaining portion 24) formed in a direction perpendicular to the axial direction, as described above, thereby ensuring integration with the plug material 2. By ensuring integration between the spring material 3 and the plug material 2, as long as the locking portion 33 of the spring material 3 is locked to the inner circumferential surface 5a of the steel pipe, the spring material 3 ensures high stability when inserted into the steam vent hole 51, thus preventing the plug material 2 from coming out of the steam vent hole 51.

[0029] By ensuring the integration of the spring material 3 with the plug material 2, even if the plug material 2 does not necessarily contract from the outer circumference towards the center and exert a restoring force when the sealing material 1 is inserted into the steam vent hole 51, it can maintain its position inserted into the steam vent hole 51, and the plug material 2 itself can also be stabilized in its inserted state within the steam vent hole 51. Therefore, the sealing material 1, in which the spring material 3 is integrated with the plug material 2, gains high stability against detachment when inserted into the steam vent hole 51, thereby improving safety against detachment due to lateral pressure of the concrete 6 when inserted into the steam vent hole 51.

[0030] After the spring material 4 is inserted into the steam vent hole 51, as shown in Figure 4-(a), when the tip 34 of the locking portion 33 comes out toward the inner circumferential surface 5a of the steel pipe 5, the intermediate portion 32 returns to the outer circumference side of the plug material 2 and locks into the inner circumferential surface 5a of the steel pipe 5. As long as the locking portion 33 does not break or otherwise fail, the spring material 3 will continue to lock into the inner circumferential surface 5a of the steel pipe while the tip 34 of the locking portion 33 is locked into the inner circumferential surface 5a of the steel pipe, the sealing material 1 will maintain its inserted state in the steam vent hole 51 and will be stable against coming out of the steam vent hole 51.

[0031] The tip 34 of the locking portion 33 will not detach from the inner circumferential surface 5a of the steel pipe 5 unless the entire locking portion 33 is subjected to an external force directed toward the center of the steam vent hole 51 or melts. Therefore, once it is locked to the inner circumferential surface 5a of the steel pipe, it will not detach from the steam vent hole 51, regardless of whether the spring material 3 is made of metal or not. The spring material 3 should remain in the steam vent hole 51 until the concrete 6 is filled into the steel pipe 5 and the concrete 6 loses its fluidity, allowing the plug material 2 to perform its function of closing the steam vent hole 51. Consequently, after the concrete 6 has lost its fluidity, the spring material 3 has finished its job and may detach from the steam vent hole 51 due to melting or other reasons.

[0032] Specifically, the intermediate portion 33 of the spring material 3 extends from the main body portion 21 of the plug material 2 toward the inner circumferential surface 5a of the steel pipe 5, until it exceeds the inner circumferential surface 5a of the steel pipe 5, and the locking portion 33 bends or curves from the position of the intermediate portion 32 toward the outer circumferential surface 5b of the steel pipe 5 toward the outer circumferential surface 5b of the steel pipe 5, and when the spring material 3 is fully inserted into the steam vent hole 51, the tip 34 of the locking portion 33 toward the outer circumferential surface 5b of the steel pipe 5 locks into the inner circumferential surface 5a of the steel pipe 5 (Claim 2).

[0033] As shown in Figure 4-(b), when the plugging material 1 is inserted into the steam vent hole 51, the intermediate portion 32, or the intermediate portion 32 and the locking portion 33, elastically deform toward the center of the plug material 2 until the tip 34 of the locking portion 33 contacts the inner circumferential surface of the steam vent hole 51, and a restoring force is generated in the intermediate portion 32 toward the radial outer circumferential side of the main body portion 21 of the plug material 2. "Radial direction" refers to the radial direction if the main body portion 21 is cylindrical. As shown in Figure 4-(a), when the tip 34 of the locking portion 33 passes through the steam vent hole 51 (inner circumferential surface 5a of the steel pipe), the intermediate portion 32 returns to its original position toward the radial outer circumferential side of the main body portion 21, and at the same time, the tip 34 of the locking portion 33 locks onto the inner circumferential surface 5a of the steel pipe 5. [Effects of the Invention]

[0034] The plug material constituting the sealing material integrally holds a spring material having a locking portion that engages with the inner surface of the steel pipe when inserted into the steam vent hole. The spring material is positioned at a location corresponding to a notch formed in the plug material, and a restoring force is exerted toward the outer surface of the plug material by the middle portion of the spring material, maintaining the state in which the tip of the locking portion of the spring material is engaged with the inner surface of the steel pipe. This provides the sealing material with high stability against coming loose when inserted into the steam vent hole. Therefore, the safety against detachment due to lateral pressure of the concrete when the sealing material is inserted into the steam vent hole can be improved. [Brief explanation of the drawing]

[0035] [Figure 1] (a) is a perspective view showing an example of a closure material made by combining a plug material shown in (b), which has a sloped surface in the notched portion and a cut (holding portion) formed from the outer circumferential surface of the main body toward the center, with a spring material shown in (c). (b) is a perspective view showing an example of a plug material shown in (a), and (c) is a perspective view showing an example of a spring material shown in (a). [Figure 2] (a) is an elevation view showing a detailed example of the plug material shown in Figure 1-(b), viewed in the direction of the formation of the notch (holding part); (b) is a plan view of (a); (c) is an elevation view showing the spring material shown in Figure 1-(c); and (d) is an elevation view showing a modified example of the spring material shown in (c). [Figure 3]Figure 1-(b) is a perspective view showing an example of notch formation when a notch is formed in the main body of the plug material, passing through the center and continuing in a groove-like manner from the outer surface. [Figure 4] (a) is a longitudinal cross-sectional view showing the sealing material shown in Figure 1-(a) inserted into the steam vent hole from the outer surface side of the steel pipe, with the tip of the locking part of the spring material locked to the inner surface of the steel pipe. (b) is a longitudinal cross-sectional view showing the sealing material shown in (a) being inserted into the steam vent hole. [Modes for carrying out the invention]

[0036] Figure 1-(a) shows an example of the manufacture of a sealing material 1 that is inserted from the outer surface 5b side of the steel pipe 5 into a steam vent hole 51 shown in Figure 4, which is formed by penetrating between the inner surface 5a and outer surface 5b of the steel pipe 5 that constitutes the steel pipe concrete column 4, and which closes the steam vent hole 51 from the inner surface 5a side of the steel pipe 5 until the concrete 6 is filled into the steel pipe 5 as shown in Figure 4-(a) and the concrete 6 loses its fluidity. The upper side of the plug material 2 shown in Figure 1-(b) is the inner surface 5a side of the steel pipe 5, and the lower side is the outer surface 5b side of the steel pipe 5.

[0037] The sealing material 1 comprises a plug material 2 having a main body portion 21 with a notch portion 22 formed from the outer circumferential surface toward the center, in a shape symmetrical with respect to the axial center, and a spring material 3 held by the main body portion 21 of the plug material 2. The plug material 2 is molded from a synthetic resin or the like that has a melting point that allows it to melt in the event of a fire.

[0038] The main body portion 21 of the plug material 2, excluding the notch portion 22, has a cross-sectional area that can substantially circumscribe the steam vent hole 51, as shown in Figure 4-(a). In this relationship, the main body portion 21 of the plug material 2 has a cross-sectional shape similar to, or equivalent to, the shape of the inner circumferential surface when viewed in the axial direction of the steam vent hole 51, and if the inner circumferential surface of the steam vent hole 51 is circular, then the main body portion 21 has a circular cross-sectional shape. The shape of the inner circumferential surface of the steam vent hole 51 and the cross-sectional shape of the main body portion 21 are not necessarily circular.

[0039] The main body portion 21 of the plug material 2 also has a length that exceeds the total length of the steam vent hole 51, and a handle portion 23, which is grasped by a person's hand when the sealing material 1 is inserted into the steam vent hole 51 from the outer surface 5b side of the steel pipe 5, is continuously formed or joined to the main body portion 21. When the sealing material 1 is inserted into the steam vent hole 51 and the boundary portion between the main body portion 21 and the handle portion 23 is located on the outer surface 5b of the steam vent hole 51 of the steel pipe 5 as shown in Figure 4-(a), the portion that transitions from the main body portion 21 to the handle portion 23 acts as a stopper when the plug material 2 is inserted into the steam vent hole 51, so the handle portion 23 is given a larger cross-sectional area than the main body portion 21, as shown in Figure 1-(b), etc.

[0040] The spring material 3 has a held portion 31 that is held by the main body portion 21 of the plug material 2 by clamping or the like, utilizing the elasticity of the main body portion 21 of the plug material 2, an intermediate portion 32 that is continuous on both sides in the longitudinal direction of the held portion 31 and is positioned at a location corresponding to the notch portion 22 of the plug material 2, and a locking portion 33 that is continuous with the inner circumferential surface 5a side of the steel pipe of the intermediate portion 32 and is bent from the inner circumferential surface 5a side to the outer circumferential surface 5b side of the steel pipe 5 as shown in Figure 2-(c), or curved as shown in (d), and can be locked around the steam vent hole 51. The locking portion 33, at the tip 34 which is the end on the outer circumferential surface 5b side of the steel pipe 5, locks to the inner circumferential surface 5a of the steel pipe 5 around the steam vent hole 51 on the outer circumferential surface 5b side, and functions to prevent the plug material 2, into which the spring material 3 is integrated, from coming out of the steam vent hole 51.

[0041] Figure 1-(b) shows an example of the manufacturing of a plug material 2 in which a notch is formed as a retaining portion 24 for holding the spring material 3, in a direction perpendicular to the axial direction of the main body 21, extending from the outer circumferential surface of the main body 21 toward the center, into which the retained portion 31 of the spring material 3 is inserted. The notch for this retaining portion 24 is formed to a depth that allows the retained portion 31 to be inserted until its plane center coincides with the axial center of the main body 21. The width of the notch is approximately the thickness of the retained portion 31, or large enough that the retained portion 31 can be inserted in the direction of the depth of the notch while being sandwiched by the main body 21. In Figure 1-(b), the center of the main body 21 refers to the center of the (circular) cross-section perpendicular to the axial direction of the main body 21.

[0042] Figure 1-(b) also shows an example in which notches 22, 22 are formed that are continuous on both sides in the longitudinal direction of the held portion 31 inserted into the holding portion 24 of the main body portion 21, and are inclined in the axial direction of the main body portion 21 to the end face on the inner circumferential surface 5a side of the steel pipe. These notches 22 are formed in a shape corresponding to the state when the sealing material 1 is inserted into the steam vent hole 51 from the outer circumferential surface 5b side of the steel pipe and the intermediate portion 32 of the spring material 3 is elastically deformed toward the center side of the main body portion 21, as shown in Figure 4-(b). Specifically, the surface of the notches 22 is sloped from the outer circumferential surface 5b side of the steel pipe toward the inner circumferential surface 5a side, toward the center from the outer circumferential surface side of the plug material 2 (main body portion 21).

[0043] Figure 1-(c) shows an example of the formation of a spring material 3 that is combined with the plug material 2 shown in (b). The spring material 3 is integrally attached (held) to the plug material 2 as shown in (a) by inserting the held portion 31 into the holding portion 24 (notch) formed in the main body portion 21 of the plug material 2 in a direction perpendicular to the axial direction of the main body portion 21 (width direction of the held portion 31), thereby ensuring integration with the plug material 2. The state in which the held portion 31 is held by the holding portion 24 is stabilized as described above, by the elastic (restoring force) of both axial sides of the holding portion 4 (notch) of the main body portion 21 gripping the held portion 31.

[0044] When the spring material 3 is attached to the plug material 2, the intermediate portions 32, 32, which are continuous from both sides in the longitudinal direction of the retained portion 31, are positioned to correspond to each notch 22 of the main body portion 21. When the spring material 3 is integrated with the plug material 2, each intermediate portion 32 is set in a position corresponding to each notch 22, while remaining in a state where it does not come into contact with the surface of the notch 22, or even if it comes into contact with the surface, it remains in a state where it can be elastically deformed within the notch 22.

[0045] As described above, when the sealing material 1 is inserted into the steam vent hole 51 from the outer surface 5b side of the steel pipe, the tip 34 of the locking portion 33 of the spring material 3 (the tip facing the outer surface 5b side of the steel pipe) comes into contact with the inner surface of the steam vent hole 51, causing the intermediate portions 32, 32 to elastically deform towards the center of the main body portion 21 within the notch portion 22, as shown in Figure 4-(b), and to enter the notch portion 22.

[0046] As the sealing material 1 is pushed towards the inner circumferential surface 5a of the steel pipe, and the tip 34 of the locking portion 33 passes through the steam vent hole 51, the contracted intermediate portion 32 returns to its original state, and as shown in Figure 4-(a), the tip 34 of the locking portion 33 locks to the inner circumferential surface 5a of the steel pipe 5 toward the outer circumferential surface 5b. This state is the state in which the sealing material 1 is installed in the steam vent hole 51, and the outer circumferential surface of the main body portion 21 of the plug material 2 substantially in contact with the steam vent hole 51 and covers the inner circumferential surface of the steam vent hole 51. Figure 4-(a) shows how the outer circumferential surface of the portion of the main body portion 21 of the plug material 2 closer to the knob portion 23 than the holding portion 24 shown in Figure 2 contacts (fits tightly) with the inner circumferential surface of the steam vent hole 51.

[0047] When the tip 34 of the locking portion 33 engages with the inner surface 5a of the steel pipe 5 due to the restoring force of the intermediate portion 32 of the spring material 3 toward the outer circumference of the plug material 2, the restoring force of the intermediate portion 32 and the effect of the outer surface of the knob portion 23 in close contact with the inner surface of the steam vent hole 51 can minimize any gap between the inner surface of the steam vent hole 51 and the outer surface of the plug material 2, even if such a gap exists due to manufacturing errors. Therefore, rattling of the occluding material 1 when it is installed in the steam vent hole 51 can be prevented or suppressed.

[0048] When concrete 6 is filled into the steel pipe 5 with the plugging material 1 installed in the steam vent hole 51 and rises to the level of the steam vent hole 51, the main body 21 of the plugging material 2 substantially prevents the concrete 6 from flowing out of the steel pipe 5. The main body 21 of the plugging material 2 is subjected to lateral pressure from the fluid concrete 6 toward the outer surface 5b of the steel pipe, but the locking portion 33 of the spring material 3, which ensures integration with the plugging material 2, continues to lock into the inner surface 5a of the steel pipe 5, resisting the lateral pressure, so that the plugging material 1 does not come out of the steam vent hole 51 toward the outer surface 5b of the steel pipe.

[0049] Figures 2-(a) and 2-(b) show detailed examples of the plug material 2 shown in Figure 1-(b). Figure 2-(a) shows the plug material 2 as viewed from the direction in which the spring material 3 is inserted into the retaining portion 24 (notch). The example shown here, excluding the notches 22, 22, shows a plug material 2 in which the cross-sectional area perpendicular to the axial direction of the main body portion 21 is large enough that the outer surface of the main body portion 21 is inscribed within the steam vent hole 51.

[0050] In this example, as shown in Figure 2-(a), the ends of the notches 22, 22 formed on opposite sides of the center of the main body 21 on the holding portion 24 side extend inward from the outer circumferential surface of the main body 21 by about the thickness of the spring material 3 (intermediate portion 32), but this portion may not extend inward from the center. In the example in Figure 2-(a), the part of the notch 22 on the holding portion 24 side that is recessed from the surface of the main body 21 is continuous with the holding portion 24, and the notch 22 is formed extending from the holding portion 24 side of the notch 22 toward the axial tip side of the main body 21 (opposite side of the knob portion 23). The surfaces of the notches 22, 22 do not come into contact with the inner circumferential surface of the steam vent hole 51.

[0051] Figure 2-(c) shows an example of the formation of the spring material 3 shown in Figure 1-(c) when combined with the plug material 2 shown in (a). As shown in Figure 4-(b), this example shows a case where the end of the intermediate portion 32 on the locking portion 33 side (the boundary portion between the intermediate portion 32 and the locking portion 33) is aligned with the end face of the main body portion 21 on the inner circumferential surface 5a side of the steel pipe, or protrudes from the end face toward the inner circumferential surface 5a side of the steel pipe.

[0052] When the end of the intermediate portion 32 on the locking portion 33 side protrudes toward the inner circumferential surface 5a of the steel pipe, as shown in Figure 4-(b), the end of the intermediate portion 32 on the locking portion 33 side can be brought into contact with the inner circumferential surface of the steam vent hole 51 prior to the main body portion 21 of the plug material 2. In this case, the end of the intermediate portion 32 on the locking portion 33 side contacts the inner circumferential surface of the steam vent hole 51 and deforms from the outer circumferential surface side toward the center of the main body portion 21, so the deformation of the intermediate portion 32 can be used to contract the main body portion 21 toward the center. In this example, as the end of the intermediate portion 32 on the locking portion 33 side comes into contact with the inner circumferential surface of the steam vent hole 51, it can approach the outer circumferential surface of the main body portion 21, which is effective when the clearance between the inner circumferential surface of the steam vent hole 51 and the outer circumferential surface of the main body portion 21 is small.

[0053] In the example shown in Figure 2-(a), a portion of the main body 21 near the axial handle 23 is left intact, and a notch 22 is formed near the inner surface 5a of the steel pipe. However, the notch 22 may also be formed along the entire length of the main body 21. When the notch 22 is formed near the inner surface 5a of the steel pipe, a portion of the main body 21 near the handle 23 has a cross-sectional area equal to or greater than the area of ​​the inner surface of the steam vent hole 51, allowing the entire outer surface of that portion to come into contact with the inner surface of the steam vent hole 51, thereby enhancing the effect of preventing concrete 6 (grind) from flowing out.

[0054] Figure 2-(d) shows an example where the end of the intermediate portion 32 of the spring material 3 on the locking portion 33 side is located on the knob portion 23 side of the end face of the main body portion 21 of the plug material 2 on the inner circumferential surface 5a side of the steel pipe, and a portion of the intermediate portion 32 on the inner circumferential surface 5a side of the steel pipe bends or curves outward (towards the inner circumferential surface of the steam vent hole 51) from the outer circumferential surface (notch portion 22) of the main body portion 21. In this example, the tip of the main body portion 21 on the inner circumferential surface 5a side of the steel pipe is closer to the inner circumferential surface 5a of the steel pipe 5 than the end of the intermediate portion 32 on the locking portion 33 side, and the end of the intermediate portion 32 on the locking portion 33 side is located outside the outer circumferential surface of the main body portion 21 of the plug material 2.

[0055] Therefore, if the clearance between the inner surface of the steam vent hole 51 and the outer surface of the main body 21 is small, the inner surface of the steam vent hole 51 will come into contact with the curved portion of the intermediate part 32 near the locking portion 33, pushing the intermediate part 32 outward. For this reason, the example in Figure 2-(d) is suitable for use when there is sufficient or large clearance between the inner surface of the steam vent hole 51 and the outer surface of the main body 21. In this case, the inner surface of the steam vent hole 51 comes into contact with the section of the locking portion 33 from the end of the intermediate part 32 on the locking portion 33 side, causing the locking portion 33 to move toward the notch portion 22, and the intermediate part 32 deforms toward the notch portion 22.

[0056] Figure 3 shows an example, indicated by a dashed line, of a case where the notch 22 is formed by extending from the axial end face of the main body 21 or the knob 23 toward the opposite side, continuously from the outer circumferential surface to the center, and with a width corresponding to the width of the retained portion 31 of the spring material 3. The notch 22 is formed by hollowing out the portion sandwiched between the dashed lines. The retained portion 31 of the spring material 3 is inserted into this notch 22 in the thickness direction and remains in that attached state.

[0057] The solid line in Figure 3 shows an example where a notch 22 is formed between the outer surfaces of the main body 21, extending from the tip end face towards the handle 23, with a width equivalent to the thickness of the part to be held 31. From the end of the axial notch 22 of the main body 21 on the handle 23 side, a continuous notch approximately the width of the spring material 3 is formed in a perpendicular direction. In this case, the part to be held 31 is inserted in the width direction from the tip of the notch 22, and is rotated 90° with respect to the center of the part to be held 31 in the width direction at the end position on the handle 23 side, thereby achieving the attached state.

[0058] Figure 4-(b) shows the situation when the sealing material 1 shown in Figure 1-(a), in which the spring material 3 shown in (c) is integrally attached to the plug material 2 shown in Figure 2-(a), is inserted into the steam vent hole 51 from the outer surface 5b side of the steel pipe. At this time, the tip 34 of the locking portion 33 of the spring material 3 contacts the inner surface of the steam vent hole 51, pushing the locking portion 33 toward the center of the main body portion 21 of the plug material 2, and the intermediate portion 32 contracts toward the center of the main body portion 21. Part or all of the intermediate portion 32 may also contact the surface of the notch portion 22.

[0059] Figure 4-(a) shows the situation when the sealing material 1 is fully inserted into the steam vent hole 51 from the state shown in (b). At this time, the locking portion 33 of the spring material 3 passes through the steam vent hole 51, and the intermediate portion 32 returns to its original position due to the restoring force from the center of the main body portion 21 toward the outer circumference. Simultaneously, the tip 34 of the locking portion 33 locks into the inner circumferential surface 5a of the steel pipe 5, thereby preventing the sealing material 1 from coming out of the steel pipe 5. [Explanation of Symbols]

[0060] 1...Occluder, 2... Plug material, 21... Main body, 22... Notch, 23... Knob, 24... Holding part 3...Spring material, 31...Holded part, 32...Middle part, 33...Locking part, 34...Tip, 4...Steel pipe concrete column, 5...Steel pipe, 5a...Inner peripheral surface, 5b...Outer peripheral surface, 51...Steam vent hole, 6... Concrete.

Claims

1. A sealing material is inserted from the outer surface side of a steel pipe into a steam vent hole formed by penetrating between the inner and outer surfaces of a steel pipe constituting a steel pipe concrete column, and closes the steam vent hole from the inner surface side of the steel pipe until the concrete filling into the steel pipe is complete and the concrete loses its fluidity. A plug material having a melting point that allows it to melt in the event of a fire, a cross-sectional area that can be inscribed within the steam vent hole and a length that exceeds the total length of the steam vent hole, and a main body having a notch formed symmetrically with respect to the axial center from the outer surface toward the center, The plug material comprises a retained portion held by the main body portion of the plug material, an intermediate portion continuous with the retained portion and positioned corresponding to the notch portion of the plug material, and elastically deformable toward opposing sides, and a spring material continuous with each of these intermediate portions and having a locking portion that can engage with the steam vent hole from the inner circumferential surface side toward the outer circumferential surface side of the steel pipe, The surface of the notch of the plug material has a shape that can accommodate the intermediate portion of the spring material when it is elastically deformed. The spring material is held in the main body of the plug material at the holding portion with the locking portion positioned in the notch portion of the plug material, and at least one of the intermediate portion and the locking portion of the spring material is retracted toward the center of the main body of the plug material when inserted into the steam vent hole, and then restored to its original state, characterized in that the spring material is held in the main body of the plug material at the holding portion, and at least one of the spring material is held in the notch portion of the plug material, and at least one of the spring material is retracted toward the center of the main body of the plug material when inserted into the steam vent hole, and then restored to its original state.

2. The intermediate portion of the spring material is continuous with the main body of the plug material toward the inner surface of the steel pipe until it exceeds the inner surface of the steel pipe, the locking portion is bent or curved toward the outer surface of the steel pipe from the position of the intermediate portion toward the outer surface of the steel pipe, and when the spring material is fully inserted into the steam vent hole, the tip of the locking portion toward the outer surface of the steel pipe locks into the inner surface of the steel pipe, characterized in that the sealing material for a steam vent hole of a steel pipe concrete column according to claim 1.

3. The sealing material for a steam vent hole of a steel pipe concrete column according to Claim 1, characterized in that a holding portion is formed on the main body of the plug material, continuous from the outer circumference to the center of the main body, and to a depth such that the spring material can be inserted until the center of the held portion on the plane coincides with the axial center of the main body, and the held portion of the spring material is inserted into this holding portion and held by the main body.

4. The main body of the plug material is characterized in that a cut is made between the outer surfaces of the main body of the plug material, approximately the thickness of the spring material, in an axial direction from the end face on the inner surface side of the steel pipe to the outer surface side of the steel pipe, passing through the center, and a cut is made perpendicular to the end of the axial cut on the outer surface side of the steel pipe, approximately the thickness of the spring material, and the retained portion of the spring material is inserted and held through these two cuts, as described in Claim 1.

5. The plug material is characterized in that the surface of the notched portion of the plug material is sloped from the outer surface side of the plug material toward the center, extending from the outer surface side of the plug material toward the inner surface side of the steel pipe.

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