JP4904577B2 - Fireproof structure of a composite structural member in which a concrete member and a steel member are integrally formed - Google Patents

Description

  The present invention relates to a fireproof structure of a composite structural member in which a concrete member and a steel member are integrally formed.

  For example, a concrete structure (concrete member) inside a wall structure in which a steel plate (steel member) is attached to the wall surface of a concrete wall (concrete member), or an annular steel pipe (steel member) applied to a pillar or pier of a building structure Concrete-filled steel pipe columns filled with) and concrete segments in which steel male joints and female joints (steel members) used for tunnel lining are integrally attached to arc-shaped concrete members, etc. When the composite structural member is exposed to a high temperature of, for example, 1200 ° C. due to a fire, mechanical properties such as strength and elasticity of the concrete member and the steel member are deteriorated by heat, and the structure including the composite structural member may collapse. Occurs. In particular, a steel member with a high thermal conductivity will rapidly increase in temperature with heating, and it will be difficult to release its heat because it is integrally formed with a concrete member with a low thermal conductivity, which will reduce the mechanical properties due to fire. Prominently occurs. In addition, for example, when the heating temperature is lower than 600 ° C., the strength and elasticity of the steel member gradually recover after cooling, but when heated at a temperature higher than this, the strength and elasticity are recovered. In a synthetic structural member in which a steel member is provided in a state where it cannot be expected and suddenly becomes hot at the time of a fire and is not easily dissipated as described above, the mechanical properties of the steel member may be significantly reduced.

On the other hand, for example, in a tunnel, a fireproof panel (heat insulating material, fireproof coating material) such as ceramics is installed so as to cover the surface (tunnel inner surface) of the tunnel lining segment (synthetic structural member). A fireproof panel reduces the amount of heat input to the segment to suppress the deterioration of mechanical properties (see, for example, Patent Document 1).
JP 2001-311395 A

  However, when the above-mentioned heat insulating material is installed in a composite structural member, the amount of heat received by the composite structural member itself can be suppressed, and a decrease in yield strength after a fire can be suppressed, but the installation takes time and effort. There has been a problem in that it causes a decline in performance and economy.

  In recent years, computational fireproof design methods have been introduced, and it has become possible to reduce or omit insulation (fireproof coating) as long as it can be proved that the structure will not collapse for a given fire. When the fireproof coating is reduced or omitted, heating to the synthetic structural member cannot be suppressed, and the mechanical characteristics are deteriorated within a range in which the structure does not collapse. For this reason, the method of improving the fire resistance of a composite structural member, without causing a fall of workability | operativity and economical efficiency was strongly desired.

  In view of the above circumstances, the present invention provides a fireproof structure for a composite structural member in which a concrete member and a steel member that can provide excellent fire resistance without causing deterioration in workability and economy are integrally formed. The purpose is to do.

  In order to achieve the above object, the present invention provides the following means.

The fireproof structure of the composite structural member in which the concrete member and the steel member of the present invention are integrally formed is provided with a cooling fin for releasing the heat that is heated at the time of a fire and conducted through the steel member to the concrete member. And a part of the cooling fin is exposed to the outside from the concrete member .

  Further, in the fireproof structure of the composite structural member in which the concrete member and the steel member of the present invention are integrally formed, the cooling fin is formed in a plate shape or a rod shape, and upstream of the temperature gradient generated in the heated concrete member. It is desirable to extend from the side toward the downstream side.

  Further, in the fireproof structure of the composite structural member in which the concrete member and the steel member of the present invention are integrally formed, the cooling fin is formed so that a contact area with the concrete member is larger than that of the other portion. It is further desirable that a heat dissipation promoting part is provided.

  Furthermore, in the fireproof structure of the composite structural member in which the concrete member and the steel member of the present invention are integrally formed, the heat dissipation promoting portion is formed in a plate shape or a rod shape, and the surface of the concrete member on the side to be heated is It is more desirable to arrange them substantially in parallel.

  Further, in the fireproof structure of the composite structural member in which the concrete member and the steel member of the present invention are integrally formed, a plurality of the cooling fins and / or the heat radiation promoting portions are provided, and the adjacent cooling fins and / or the It is desirable that the spacing between the heat radiation promoting portions be greater than or equal to the maximum dimension of the aggregate of the concrete member.

  Furthermore, in the fireproof structure of the composite structural member in which the concrete member and the steel member of the present invention are integrally formed, the concrete of the concrete member is formed by mixing 0.05% to 0.35% by volume of organic fiber. It is more desirable.

  Moreover, in the fireproof structure of the composite structural member in which the concrete member and the steel member of the present invention are integrally formed, it is more desirable that the water-cement ratio of the concrete is 40% or less.

  Furthermore, in the fireproof structure of the composite structural member in which the concrete member and the steel member of the present invention are integrally formed, it is desirable that the length of the organic fiber is 20 mm or less.

  Further, in the fireproof structure of the composite structural member in which the concrete member and the steel member of the present invention are integrally formed, a heat-insulating fireproof coating material may be provided on the surface of the composite structural member to be heated. .

According to the fireproof structure of the composite structural member in which the concrete member and the steel member of the present invention are integrally formed, by providing the cooling fin that releases the heat that is heated at the time of the fire and conducted through the steel member to the concrete member. Even when a steel member with high thermal conductivity is rapidly formed by heating and is integrally formed with a concrete member with low thermal conductivity, the heat can be transferred to the concrete member and the temperature of the steel member is kept low. be able to. Thereby, since it is possible to suppress a decrease in the mechanical properties of the steel member without providing a heat insulating material as in the past, it becomes possible to improve the workability and economy while imparting excellent fire resistance to the composite structural member. .
Furthermore, since a part of the cooling fin is exposed to the outside from the concrete member, in addition to releasing the heat of the steel member to the concrete member, it can also be released to the air outside the concrete member. Thereby, the heat of the steel member can be efficiently lowered, and the deterioration of the mechanical properties of the steel member can be more reliably suppressed.

  Also, the cooling fins are extended from the upstream side to the downstream side of the temperature gradient generated in the heated concrete member, so that the heat of the steel member can be conducted toward the low temperature side of the concrete member. Because the temperature of the cooling fin that the heat of the steel member is conducted to the temperature of the concrete member can be increased, that is, a large temperature gradient in the direction from the cooling fin to the concrete member can be formed. The heat of the steel member can be released to the concrete member through the cooling fin. Thereby, the fall of the mechanical characteristic of a steel member can be suppressed reliably.

  Further, the heat radiation promotion part formed so that the contact area with the concrete member is larger than the other part is provided in the cooling fin, so that the heat conducted to the cooling fin is passed through this heat radiation promotion part. It can be efficiently and reliably discharged to the concrete member.

  Furthermore, since this heat radiation acceleration | stimulation part is arrange | positioned substantially parallel with the surface by the side of a concrete member to be heated, temperature distribution from the heating surface of the synthetic structural member heated directly by a fire to the inside of a concrete member ( The heat radiation promoting part can be arranged substantially parallel to the isotherm), and the heat of the steel member can be released from the heat radiation promoting part to the concrete member until the temperature of the concrete member and the temperature of the heat radiation promoting part become isothermal.

  In addition, a plurality of cooling fins and / or heat radiation promoting portions are provided, and the spacing between adjacent cooling fins and / or heat radiation promoting portions is equal to or greater than the maximum dimension of the aggregate of the concrete member, thereby cooling fins and heat radiation promotion. Even when the portion is attached to the steel member, it is possible to reliably close-pack the fresh concrete to be cast when the composite structural member is constructed. In other words, it is possible to reliably prevent the construction failure of the composite structural member due to the provision of the cooling fins and the heat radiation promoting portion.

  Further, when 0.05% to 0.35% by volume of organic fiber is mixed in the concrete of the concrete member, when this concrete member is heated, the organic fiber creates fine voids in the concrete. The voids can relieve the thermal expansion force of the concrete surface layer and the pressure of the gas expanded inside, thereby preventing the separation and scattering of the concrete surface layer. As a result, the deterioration of the mechanical properties of the concrete member as well as the steel member can be surely suppressed, and the structure provided with such a composite structural member is made of a heat insulating material such as a fireproof panel (fireproof coating material) as in the past. ), The risk of collapse by fire can be eliminated. Moreover, the said effect can be acquired reliably by the water cement ratio of concrete being 40% or less, or the length of an organic fiber being 20 mm or less.

  Furthermore, when a heat-insulating fire-resistant coating material is provided on the surface of the composite structural member to be heated (heating surface), the amount of heat input to the concrete member or steel member can be reduced, so that it is more reliable. It is possible to improve the fire resistance of the composite structural member and by extension, the structure provided with this composite structural member.

  Hereinafter, with reference to FIGS. 1 to 3, a fireproof structure of a composite structural member in which a concrete member and a steel member according to a first embodiment of the present invention are integrally formed will be described. This embodiment relates to a fireproof structure of a wall structure (composite structural member) such as a building structure.

  As shown in FIGS. 1 and 2, the wall structure A of the present embodiment is, for example, a reinforced concrete concrete wall portion (concrete member) 1 and a flat plate shape attached integrally to one wall surface 1 a of the concrete wall portion 1. It consists of a steel plate (steel member) 2 and cooling fins 3 connected to the steel plate 2 and installed in an embedded state inside the concrete wall 1. In this embodiment, the concrete wall portion 1, the steel plate 2, and the cooling fin 3 constitute a fireproof structure A1. Moreover, in the wall structure A of this embodiment, the surface 2a of the steel plate 2 installed on one wall surface (the surface to be heated of the concrete member) 1a of the concrete wall portion 1 is directly exposed to the heat T at the time of a fire. The heating surface 4 is used.

  The cooling fin 3 is formed using the same steel material as the material of the steel plate 2, for example, and is formed in flat form in this embodiment. The cooling fin 3 has one end 3 a connected to the inner surface of the steel plate 2 that is in close contact with one wall surface 1 a of the concrete wall portion 1, and extends toward the inside of the concrete wall portion 1. At this time, the cooling fin 3 extends so as to be substantially orthogonal to the inner surface of the steel plate 2 (one wall surface 1a of the concrete wall portion 1), and the other end 3b in the extending direction is heated by the fire of the concrete wall portion 1. It is arranged closer to the one wall surface 1a than the other wall surface (non-heated surface) 1b. Further, in the present embodiment, a plurality of cooling fins 3 having the same shape and the same size are arranged side by side along the inner surface of the steel plate 2, and the interval between adjacent cooling fins is the maximum aggregate size of the concrete in the concrete wall 1. That's it.

  On the other hand, the concrete wall portion 1 of the present embodiment is made of 0.05% by volume to 0% by volume of organic fiber such as polyacetal or polypropylene having a concrete water ratio of 40% or less and a diameter of 10 to 200 μm and a length of 1 to 20 mm. .35% by volume mixed. The concrete wall portion 1 provided with such concrete, as described in, for example, Japanese Patent Application Laid-Open No. 2004-323330, decomposes organic fibers and creates fine voids in the concrete when heated by a fire. This void relaxes the thermal expansion force of the concrete surface layer and the pressure of the gas expanded inside, thereby preventing the separation and scattering of the concrete surface layer. Thereby, the concrete wall part 1 is excellent in fire resistance.

  Next, the operation and effect of the fireproof structure A1 of the wall structure A having the above-described configuration will be described.

  When the wall structure A is heated by a fire, for example, the heating surface 4 of the steel plate 2 is exposed to a heat T of about 1200 ° C., and the temperature of the entire steel plate 2 rapidly rises from the high thermal conductivity. . Here, when the cooling fin 3 of this embodiment is not provided (and / or when the organic fiber is not mixed in the concrete wall 1), the heat of the concrete wall 1 integrally formed with the steel plate 2. Since the conductivity is low, the heat T of the steel plate 2 is difficult to be transmitted to the concrete wall portion 1, and the temperature of the steel plate 2 rises according to the amount of heat received and is maintained in a high temperature state. And when the steel plate 2 is maintained at a high temperature of, for example, 600 ° C. to 1200 ° C., the mechanical properties such as strength and elasticity are remarkably lowered, the proof stress of the wall structure A is drastically lowered, and the wall structure A is There is a risk that the provided structure will collapse.

  On the other hand, in the wall structure A of the present embodiment, as shown in FIG. 3, the cooling fins 3 are connected to the steel plate 2, and the cooling fins 3 are embedded in the concrete wall portion 1 while not being heated from the heating surface 4. Since it is extended toward the heating surface 1b, the heat T of the steel plate 2 is quickly conducted to the cooling fins 3 having the same thermal conductivity as that of the steel plate 2, and the inside of the concrete wall 1 (non-heated) Surface 1b side). On the other hand, at this time, since the concrete wall portion 1 is in contact with the heated steel plate 2 with low thermal conductivity, the one wall surface 1a side is heated, and the other wall surface 1b (heating surface 4) is heated from the one wall surface 1a side. A temperature gradient having an isotherm substantially parallel to the heating surface 4 is formed from the side toward the non-heating surface 1b side). However, the temperature of the inside of the concrete wall portion 1 does not increase suddenly due to the low thermal conductivity, and the cooling fin 3 moves from the upstream side to the downstream side of the temperature gradient generated in the concrete wall portion 1. Since it is extended, the temperature of the concrete wall portion 1 becomes lower than that of the cooling fin 3 so as to be located on the other end 3a side of the cooling fin 3 where the temperature T of the steel plate 2 is conducted and the temperature rapidly rises. . For this reason, a large temperature gradient from the cooling fin 3 toward the concrete wall portion 1 is formed from one end of the cooling fin 3 toward the other end, and the heat T of the cooling fin 3 is released into the concrete wall portion 1. . Such heat radiation from the cooling fins 3 to the concrete wall portion 1 is continuously performed until both temperatures become equal. As a result, the steel plate 2 has a decrease in mechanical properties such as strength and elasticity. It will be continuously maintained at a temperature that does not occur.

  Therefore, according to the fireproof structure A1 of the wall structure A in which the concrete wall portion 1 and the steel plate 2 of the present embodiment are integrally formed, the heat T that is heated in a fire and is conducted through the steel plate 2 is introduced into the concrete wall portion 1. By providing the cooling fins 3 to be discharged, the temperature of the steel plate 2 can be kept low. Thereby, since the fall of the mechanical characteristic of the steel plate 2 can be suppressed, without providing a heat insulating material like before, it becomes possible to improve workability and economical efficiency, providing the fire resistance excellent in the wall structure A. .

  Further, the cooling fin 3 is extended from the upstream side to the downstream side of the temperature gradient generated in the heated concrete wall portion 1, so that the heat T of the steel plate 2 is directed toward the low temperature side of the concrete wall portion 1. Since the temperature of the cooling fin 3 through which the heat T of the steel plate 2 is conducted can be increased with respect to the temperature T of the concrete wall 1, that is, the direction from the cooling fin 3 toward the concrete wall 1. Therefore, it is possible to reliably release the heat T of the steel plate 2 to the concrete wall 1 through the cooling fins 3. Thereby, the fall of the mechanical characteristic of the steel plate 2 can be suppressed reliably.

  Furthermore, since the space | interval of the adjacent cooling fin 3 is made more than the largest aggregate dimension of the concrete wall part 1, at the time of construction of the wall structure A, the fluidity | liquidity of concrete is not impaired by the cooling fin 3, and concrete Can be constructed of a suitable wall structure A that is closely packed.

  Moreover, the concrete which comprises the concrete wall part 1 mixes 0.05 volume%-0.35 volume% of organic fiber with a water cement ratio of 40% or less, for example, diameter 10-200 micrometers and length 1-20 mm. By forming, the concrete wall part 1 can also be made into the structure excellent in fire resistance.

  The first embodiment of the fireproof structure of the composite structural member (wall structure A) formed by integrally forming the concrete member (concrete wall portion 1) and the steel member (steel plate 2) according to the present invention has been described above. Is not limited to the first embodiment described above, and can be changed as appropriate without departing from the spirit of the invention. For example, in the present embodiment, the cooling fins 3 are formed in a flat plate shape. However, as shown in FIG. 4, the cooling fins 3 may be formed in a rod shape such as a cylindrical rod shape. Are arranged side by side in the vertical direction, it is desirable that the distance between the vertical adjoining is also equal to or greater than the maximum aggregate size of the concrete wall 1.

  In the present embodiment, the surface 2a of the steel plate 2 having the wall structure A is exposed, and the steel plate 2 is directly heated in the event of a fire. For example, as shown in FIG. It may be covered with a heat-resistant fireproof covering material 5. In this case, since the steel plate 2 is prevented from being directly heated by the fireproof covering material 5, the temperature rise of the steel plate 2 can be further suppressed together with the cooling fins 3.

  Furthermore, in the present embodiment, the steel plate 2 is installed only on the one wall surface 1a side of the concrete wall portion 1. However, for example, as shown in FIG. The steel plate 2 provided with the fins 3 may be installed so that it can cope with the case where it is heated by fire from both the one wall surface 1a side and the other wall surface 1b side. Further, in this case, the cooling fins 3 may be formed so that the other ends 3b of the cooling fins 3 attached to both the steel plates 2 on the one wall surface 1a side and the other wall surface 1b side are connected.

  In the present embodiment, the cooling fin 3 is formed of the same material as that of the steel plate 2. However, for example, the cooling fin 3 is formed of a material having a higher thermal conductivity than the steel plate 2, or conversely, the heat conduction is higher than that of the steel plate 2. It may be made of a low-rate material. That is, the material of the cooling fin 3 is not particularly limited as long as the heat T of the steel plate 2 can be conducted early and the heat T can be released to the concrete wall 1.

  Next, with reference to FIG. 7 and FIG. 8, a fireproof structure of a composite structural member in which a concrete member and a steel member according to a second embodiment of the present invention are integrally formed will be described. As in the first embodiment, the present embodiment relates to a fireproof structure B1 of a wall structure (synthetic structural member) B such as a building structure, for example, and the other configurations except for the cooling fins 3 are the first embodiment. It is the same. Therefore, here, the same reference numerals are given to the components common to the first embodiment, and the detailed description thereof is omitted. In the present embodiment as well, the fireproof structure B1 is configured by the concrete wall portion (concrete member) 1, the steel plate (steel member) 2, and the cooling fin 3 as in the first embodiment.

  As shown in FIG. 7, the cooling fin 3 of the present embodiment has a concrete wall portion 1 on the side of the extending direction other end 3 b embedded in the concrete wall portion 1 with respect to the cooling fin 3 of the first embodiment. One heat radiation promotion part 3c formed so that the contact area with the other part is larger than the other part is provided. The heat radiation promoting portion 3c is formed in a substantially rectangular flat plate shape, and is disposed so as to be substantially parallel to one wall surface of the concrete wall portion 1 (the surface on the side heated by the fire of the concrete wall portion 1) 1a. Yes. Thereby, the cooling fin 3 of this embodiment is formed so as to exhibit a T shape in a cross-sectional view, and has a larger contact area with the concrete wall portion 1 on the other end 3b side than the one end 3a side connected to the steel plate 2. Has been.

  As shown in FIG. 8, when the steel plate 2 is heated by a fire, the cooling fin 3 configured in this way conducts its heat T from one end 3a to the other end 3b, and has a large area in the concrete wall portion. Heat dissipation to the concrete wall portion 1 is promoted by the heat dissipation promotion portion 3 c that contacts the 1. Similarly to the first embodiment, based on the fact that a temperature gradient having an isotherm substantially parallel to the heating surface 4 is formed on the concrete wall 1, that is, from one wall surface 1 a of the concrete wall portion 1 to the other wall surface. As the temperature decreases toward 1b, a larger temperature gradient from the cooling fin 3 toward the concrete wall 1 is formed toward the other end 3b from the one end 3a of the cooling fin 3. And the heat radiation promotion part 3c is provided in the other end 3b where this large temperature gradient is formed, so that the cooling fin 3 of the present embodiment is connected to the concrete wall part 1 with respect to the cooling fin 3 of the first embodiment. The amount of heat release increases, and the temperature of the steel plate 2 is lowered more reliably.

  Therefore, according to the fireproof structure B1 of the wall structure B of the present embodiment, the cooling fin 3 is provided with the heat radiation promoting portion 3c formed so that the contact area with the concrete wall portion 1 is larger than the other portions. As a result, the heat T conducted to the cooling fin 3 can be efficiently and reliably released to the concrete wall portion 1 through the heat radiation promoting portion 3c, and the temperature rise of the steel plate 2 can be reliably suppressed. it can. Thereby, it is possible to suppress the deterioration of the mechanical properties of the steel plate 2 without providing a heat insulating material as in the prior art, and it is possible to improve the workability and economic efficiency while imparting excellent fire resistance to the wall structure B.

  Further, the heat radiation promoting portion 3c is formed in a flat plate shape and is disposed substantially in parallel with the one wall surface 1a to be heated of the concrete wall portion 1, so that the heat radiation promoting portion 3c has a temperature distribution in the concrete wall portion 1. The heat T of the steel plate 2 can be applied from the heat radiation promoting part 3c to the concrete wall part 1 until the temperature of the concrete wall part 1 and the temperature of the heat radiation promoting part 3c become isothermal. Can be released.

  As a modification of the second embodiment described above, a fireproof structure of a composite structural member in which a concrete member and a steel member are integrally formed as described below may be employed. In the present embodiment, the heat radiation promoting portion 3c is formed in a flat plate shape, but the heat radiation promoting portion 3c may be formed in a rod shape or a substantially spherical shape, and the concrete wall portion of the cooling fin 3 The shape of the steel plate 2 is not particularly limited as long as the heat T of the steel plate 2 can be efficiently released by increasing the contact area to the steel plate 1.

  In the present embodiment, one heat radiation promoting portion 3c is provided on the other end 3b side of the cooling fin 3. However, as shown in FIG. 9, for example, one end 3a to the other end 3b of the cooling fin 3 is provided. In the range up to, a plurality of heat radiation promoting portions 3c may be arranged in parallel, and in this case, the contact area with the concrete wall portion 1 can be further increased than the cooling fins 3 of the present embodiment. The heat T of the steel plate 2 can be released to the concrete wall 1 more efficiently. At this time, the plurality of heat radiation promoting portions 3c are provided such that the interval between the adjacent heat radiation promoting portions 3c is equal to or larger than the maximum aggregate size of the concrete wall portion 1, so that the heat radiation promoting portion 3c is constructed when the concrete wall portion 1 is constructed. Thus, the fluidity of the concrete is not impaired, and the concrete wall portion 1 can be suitably formed in a dense state.

  Furthermore, in this embodiment, although the heat radiation promotion part 3c of the cooling fin 3 shall be embed | buried in the state distribute | arranged to the one wall surface 1a side rather than the other wall surface 1b of the concrete wall part 1, it shows, for example in FIG. In this way, the cooling fin 3 is formed so that the surface 3d on the other wall surface 1b side of the heat radiation promoting portion 3c is flush with the other wall surface 1b and exposed to the outside, or as shown in FIG. The cooling fin 3 may be formed so that 3c protrudes outside the other wall surface 1b of the concrete wall portion 1 and is exposed. In such a case, as shown in FIGS. Since the heat T of the steel plate 2 conducted through 3 can be released to the concrete wall portion 1 and also to the outside of the concrete wall portion 1 (for example, in the air), the temperature rise of the steel plate 2 can be more reliably suppressed. It becomes possible.

  Next, with reference to FIG. 14 and FIG. 15, a fireproof structure of a composite structural member in which a concrete member and a steel member according to a third embodiment of the present invention are integrally formed will be described. The present embodiment relates to a fireproof structure C1 of a concrete-filled steel pipe column (composite structural member) C used as, for example, a building structure or a bridge column (bridge pier). In addition, the same code | symbol is attached | subjected with respect to the structure which is common in 1st and 2nd embodiment, and the description about the detail is abbreviate | omitted.

  As shown in FIGS. 14 and 15, the concrete-filled steel pipe column C of the present embodiment includes an annular steel pipe (steel member) 10 having a substantially rectangular cross section, and concrete (concrete member) 11 filled in the steel pipe 10. One end 3a is connected to the inner surface 10a of the steel pipe 10, and the cooling fin 3 extends toward the center of the axis O1 of the concrete-filled steel pipe column C. Here, in this embodiment, the steel pipe 10, the concrete 11, and the cooling fin 3 comprise the fireproof structure C1.

  The cooling fin 3 of the present embodiment is provided with a flat plate-shaped heat radiation promoting portion 3c at the other end 3b and is formed in a T-shaped cross section, one for each of the four planar inner surfaces 10a of the steel pipe 10 in a cross-sectional view. It is attached one by one. Moreover, each cooling fin 3 is extended in the direction orthogonal to the inner surface 10a by connecting one end 3a to the center in the width direction of each inner surface 10a of the steel pipe 10, and the heat radiation promoting portion 3c is the concrete filled steel tube column C. It is distribute | arranged to the inner surface 10a side of the steel pipe 10 rather than the axis line O1.

  And the cooling fin 3 comprised in this way, when the outer surface (heating surface 4) 10b of the steel pipe 10 is heated by a fire etc., the end 3a with which heat is connected with the steel pipe 10 similarly to 1st and 2nd embodiment. To the other end 3b, and heat dissipation to the concrete 11 is promoted by the heat dissipation promoting portion 3c. Thereby, the temperature of the steel pipe 10 is maintained at a low temperature.

  Therefore, according to the fireproof structure C1 of the concrete-filled steel pipe column C of the present embodiment, the cooling fins 3 are attached to the steel pipe 10, so that the steel pipe 10 having high thermal conductivity is rapidly heated and heated by heating. Even if it is integrally formed with the concrete 11 having low conductivity, the heat can be transferred to the concrete 11 and the temperature of the steel pipe 10 can be kept low. Thereby, it becomes possible to improve workability and economical efficiency compared with what uses the conventional heat insulating material, providing the fire resistance excellent in the concrete filling steel pipe column C. FIG.

  Also in the present embodiment, as in the first embodiment, the organic fiber is mixed in the concrete 11 by 0.05 volume% to 0.35 volume%, or the water-cement ratio of the concrete 11 is set to 40% or less. By setting the length of the organic fiber to 20 mm or less, it is possible to reliably suppress the deterioration of the mechanical properties of the concrete 11 together with the steel pipe 10.

  In addition, as a modification of the third embodiment, a fireproof structure of a composite structural member in which a concrete member and a steel member are integrally formed as described below may be employed. In the present embodiment, one cooling fin 3 is attached to each of the four inner surfaces 10a of the substantially rectangular steel pipe 10 in a sectional view, but a plurality of cooling fins 3 are provided on each inner surface 10a in a sectional view. Moreover, the steel pipe 10 may be formed in the cross-sectional circular shape, for example.

  In this embodiment, the outer surface 10b of the steel pipe 10 of the concrete-filled steel pipe column C is exposed and the steel pipe 10 is directly heated in the event of a fire. For example, as shown in FIG. 10b may be covered with a heat-resistant fireproof covering material 5. In this case, since the steel pipe 10 is prevented from being directly heated by the fireproof covering material 5, the temperature rise of the steel pipe 10 can be further suppressed together with the cooling fins 3.

  Furthermore, in this embodiment, the heat radiation acceleration | stimulation part 3c is provided in the other end 3b of the cooling fin 3, and this heat radiation acceleration | stimulation part 3c is distribute | arranged to the inner surface 10a side of the steel pipe 10 rather than the axis line O1 of the concrete filling steel pipe column C. However, for example, the cooling fins 3 may be formed so as to connect the other ends 3b of the pair of cooling fins 3 arranged to face each other in a cross-sectional view. Moreover, the cooling fin 3 may be provided with a plurality of heat radiation promoting portions 3 as in the second embodiment, and conversely, the heat radiation promoting portions 3c may not be formed.

  Next, with reference to FIGS. 17 to 20, a fireproof structure of a composite structural member in which a concrete member and a steel member according to a fourth embodiment of the present invention are integrally formed will be described. The present embodiment relates to a fireproof structure of a concrete segment (synthetic structural member) that forms, for example, a shield tunnel lining.

  As shown in FIG. 17, the segment D of the present embodiment is formed in an arcuate disk shape having a curvature radius substantially equal to the curvature radius of the excavation surface of the tunnel 20 excavated by, for example, a shield machine. Further, the segment D is formed so that the circumferential length in the circumferential direction is larger than the width in the axis O2 direction of the segment D parallel to the axis O1 of the tunnel 20 in the installed state, and the radial thickness is in the circumferential direction. It is formed uniformly along. The plurality of segments D formed in this manner are provided continuously in the circumferential direction of the tunnel 20 along the excavation surface of the tunnel 20, and are annular segment ring bodies that are supported while covering the excavation surface in the circumferential direction. 21 is formed. Further, the segment ring body 21 is adjacently adjacent to the tunnel O1 in the direction of the axis O1, and the excavation surface excavated by the shield machine is supported while being covered with the plurality of segments D, so that the lining of the tunnel 20 is formed. .

  Further, the segment D of the present embodiment includes a concrete segment main body (concrete member) 22 formed in a circular arc shape, and a steel joint structure (steel member) embedded in the segment main body 22 and integrally formed. 23. The joint structure 23 includes an inter-ring joint 24 and an inter-segment joint 25 that join the segments D adjacent to each other in the circumferential direction of the tunnel 20 and the axis O1 direction. Among these, the inter-ring joint 24 includes a male joint 24a provided on one end face (one end face 22a of the segment main body 22) facing the front end side in the axis O1 direction of one segment D, and the one segment D. It is comprised from the female type joint 24b provided in the other end surface (the other end surface 22b of the segment main body 22) side of the other segment D joined.

  As shown in FIG. 18, the male joint 24 a is formed in a rod shape, with its axis line O 3 direction aligned with the axis O 1 direction of the tunnel 20, and with the rear end side embedded in the segment body 22, The side is provided so as to protrude from the one end face 22a to the outside in the axis O2 direction of the segment body 22. The female joint 24b is formed in a substantially cylindrical shape, with its axis O3 direction aligned with the direction of the axis O1 of the tunnel 20, and the open tip disposed at the same position as the other end surface 22b of the segment body 22. In the state, it is embedded in the segment main body 22. Then, the adjacent segments D are joined together by fitting the protruding end side of the male joint 24a to the female joint 24b.

  On the other hand, in this embodiment, as shown in FIGS. 18 to 20, excavation of the tunnel 20 in a state where the segment D is installed in the portion embedded in the segment main body 22 of each of the male joint 24a and the female joint 24b. Extending toward the surface side (extending from one surface 22c (heating surface 4) side of the segment body 22 forming the inner surface of the tunnel 20 toward the other surface (non-heating surface) 22d of the segment body 22 on the tunnel excavation surface side) Circular and flat cooling fins 30 are provided. The cooling fins 30 are provided in a state where the arc centers are arranged on the axis O3 of each of the male joint 24a and the female joint 24b, and a plurality of cooling fins 30 are arranged in parallel in the direction of the axis O3. At this time, the interval between the cooling fins 30 adjacent in the direction of the axis O <b> 3 is set to be equal to or larger than the maximum aggregate size of the segment body 22.

  When a fire occurs in the tunnel 20 having the segment D configured as described above, the tunnel inner surface 22c (heating surface 4) is heated, and a temperature gradient is formed in the segment body 22 in the radially outward direction. As a result, the temperature of the segment body 22 gradually increases. Then, the heat T reaches the inter-ring joint 24, and the male male joint 24a and the female joint 24b rapidly become high in temperature. At this time, in the present embodiment, the heat T of the male joint 24a and the female joint 24b is conducted to the cooling fin 30 and passes through the cooling fin 30 to the non-heating surface 22d side of the segment body 22, that is, the segment body. Heat T of the ring-to-ring joint 24 is released from the upstream side to the downstream side of the temperature gradient formed in 22. Thereby, the fall of the intensity | strength and elasticity of the ring joint 24 by the heat T by a fire is suppressed.

  Therefore, according to the fireproof structure D1 of the segment D in which the segment body 22 and the joint structure 23 of the present embodiment are integrally formed, by providing the joint structure 23 with the cooling fins 30 extending from the heating surface side to the non-heating surface side. The heat T of the joint structure 23 can be released to the segment main body 22, and it is possible to suppress the deterioration of the mechanical characteristics such as strength and elasticity of the joint structure 23 without installing a refractory panel as in the prior art. become. Thereby, it becomes possible to improve workability and economical efficiency while imparting excellent fire resistance to the tunnel 20.

  Similarly to the first to third embodiments, the interval between the adjacent cooling fins 30 is equal to or larger than the maximum aggregate size of the segment body, so that the segment D is suitably formed even when the cooling fins 30 are provided. can do.

  Further, as in the first to third embodiments, 0.05% to 0.35% by volume of organic fiber is mixed into the concrete forming the segment body 22, or the water / cement ratio of the concrete is set to 40% or less. By making the length of the organic fiber 20 mm or less, the fire resistance of the segment D can be further improved.

  As a modification of the fourth embodiment described above, a fireproof structure of a composite structural member in which a concrete member and a steel member are integrally formed as described below may be employed. In the present embodiment, the cooling fin 30 is described as being attached only to the inter-ring joint 24 in the joint structure 23, but it is desirable that the cooling fin 30 is similarly attached to the inter-segment joint 25.

  In the present embodiment, the cooling fins 30 are formed in a semicircular shape. However, the cooling fins 30 may extend from the heating surface 4 side toward the non-heating surface 22d side and release the heat T of the joint structure 23. For example, it is not necessary to limit the shape.

  Further, in the present embodiment, the segment D is a concrete segment, and the cooling fin 30 is provided in the steel joint structure 24 integrally formed with the concrete segment body 22. However, it may be a composite segment (synthetic structural member D) configured by filling concrete (concrete member) 41 inside a steel box-shaped segment body (steel member) 40 having an inner peripheral side of the convex curved surface opened. In this case, for example, as shown in FIG. 21, a plate-like or rod-like cooling fin 42 is connected to the side wall portion 40a of the steel segment body 40 so that one end 42a is connected to the inside of the concrete 41. By being provided, the heat T that is heated from the exposed surface side of the concrete 41 and conducted through the segment main body 40 during the tunnel fire is cooled. Through the fins 42 can be released into the concrete 41, it is possible to improve the fire resistance of the segment D. Further, in the case where the composite segment is provided with the cooling fins 42 in this way, the cooling fins 42 are connected to the steel segment main body 40 and can release the heat T at the time of fire to the concrete 41. It does not necessarily need to be connected to the side wall part 40a of the segment main body 40, and may be provided connected to the bottom plate part 40b of the segment main body 40 made of steel, for example.

It is a perspective view which shows the fireproof structure of the composite structure member in which the concrete member and steel member which concern on 1st Embodiment of this invention were integrally formed. FIG. 2 is a view taken along line XX in FIG. 1. It is sectional drawing which shows the conduction state of the heat | fever from the cooling fin of the fireproof structure of the composite structure member (wall structure) in which the concrete member and steel member which concern on 1st Embodiment of this invention were integrally formed. It is a perspective view which shows the modification of the fireproof structure of the composite structure member (wall structure) by which the concrete member and steel member which concern on 1st Embodiment of this invention were integrally formed. It is sectional drawing which shows the modification of the fireproof structure of the composite structure member (wall structure) by which the concrete member and steel member which concern on 1st Embodiment of this invention were integrally formed. It is sectional drawing which shows the modification of the fireproof structure of the composite structure member (wall structure) by which the concrete member and steel member which concern on 1st Embodiment of this invention were integrally formed. It is sectional drawing which shows the fireproof structure of the composite structural member (wall structure) in which the concrete member and steel member which concern on 2nd Embodiment of this invention were integrally formed. It is sectional drawing which shows the conduction state of the heat | fever from the cooling fin of the fireproof structure of the synthetic structure member (wall structure) in which the concrete member and steel member which concern on 2nd Embodiment of this invention were integrally formed. It is sectional drawing which shows the modification of the fireproof structure of the composite structure member (wall structure) in which the concrete member and steel member which concern on 2nd Embodiment of this invention were integrally formed. It is sectional drawing which shows the modification of the fireproof structure of the composite structure member (wall structure) in which the concrete member and steel member which concern on 2nd Embodiment of this invention were integrally formed. It is sectional drawing which shows the modification of the fireproof structure of the composite structure member in which the concrete member and steel member which concern on 2nd Embodiment of this invention were integrally formed. It is sectional drawing which shows the conduction state of the heat | fever from the cooling fin of the fireproof structure of the synthetic | combination structural member (wall structure) shown in FIG. 10 to a concrete member. It is sectional drawing which shows the conduction state of the heat | fever from the cooling fin of the fireproof structure of the synthetic | combination structural member (wall structure) shown in FIG. 11 to a concrete member. It is a perspective view which shows the fireproof structure of the composite structural member (concrete filling steel pipe column) in which the concrete member and steel member which concern on 3rd Embodiment of this invention were integrally formed. It is the XX arrow directional view of FIG. It is sectional drawing which shows the modification of the fireproof structure of the composite structural member (concrete filling steel pipe column) in which the concrete member and steel member which concern on 3rd Embodiment of this invention were integrally formed. It is a perspective view which shows the composite structural member (segment) by which the concrete member and steel member which concern on 3rd Embodiment of this invention were integrally formed. It is the YY line arrow directional view of FIG. It is a X1-X1 line arrow directional view of FIG. It is the X2-X2 line arrow directional view of FIG. It is sectional drawing which shows the modification of the fireproof structure of the composite structure member (segment) by which the concrete member and steel member which concern on 3rd Embodiment of this invention were integrally formed.

Explanation of symbols

1 Concrete wall (concrete member)
2 Steel plate (steel member)
DESCRIPTION OF SYMBOLS 3 Cooling fin 3a One end 3b The other end 3c Heat radiation promotion part 4 Heating surface 5 Fireproof covering material 10 Steel pipe (steel member)
11 Concrete (concrete member)
22 Segment body (concrete member)
23 Joint structure 24 Inter-ring joint (steel member)
24a Male joint 24b Female joint 30 Cooling fin 42 Cooling fin A Wall structure (composite structural member)
A1 Fireproof structure B Wall structure (composite structural member)
B1 Fireproof structure C Concrete filled steel pipe column (composite structural member)
C1 fireproof structure D segment (composite structural member)
D1 Fireproof structure T Heat

Claims (9)

It is a fireproof structure of a composite structural member in which a concrete member and a steel member are integrally formed,
The steel member is provided with cooling fins that release heat to the concrete member that is heated during a fire and conducted through the steel member .
A part of the cooling fin is exposed to the outside from the concrete member . In the fireproof structure of the composite structural member in which the concrete member and the steel member according to claim 1 are integrally formed,
The fireproof structure of the composite structural member, wherein the cooling fin is formed in a plate shape or a rod shape and extends from an upstream side to a downstream side of a temperature gradient generated in the heated concrete member. In the fireproof structure of a composite structural member in which the concrete member and the steel member according to claim 1 or 2 are integrally formed,
The fireproof structure of the composite structural member, wherein the cooling fin is provided with a heat dissipation promoting portion formed so that a contact area with the concrete member is larger than other portions. In the fireproof structure of the composite structural member in which the concrete member and the steel member according to claim 3 are integrally formed,
The fire-resistant structure of the synthetic structure material, wherein the heat radiation promoting portion is disposed substantially parallel to a surface of the concrete member to be heated. In the fireproof structure of the composite structural member in which the concrete member and the steel member according to any one of claims 1 to 4 are integrally formed,
A plurality of the cooling fins and / or the heat radiation promoting portions are provided, and an interval between the adjacent cooling fins and / or the heat radiation promoting portions is equal to or greater than a maximum dimension of the aggregate of the concrete member. The fireproof structure of the composite structural member. In the fireproof structure of the composite structural member in which the concrete member and the steel member according to any one of claims 1 to 5 are integrally formed,
The fireproof structure of the composite structural member, wherein the concrete of the concrete member is formed by mixing 0.05% to 0.35% by volume of organic fiber. In the fireproof structure of the composite structural member in which the concrete member and the steel member according to claim 6 are integrally formed,
The fireproof structure of the composite structural member, wherein a water-cement ratio of the concrete is 40% or less. In the fireproof structure of the composite structural member formed by integrally forming the concrete member and the steel member according to claim 6 or 7 ,
The fireproof structure of the synthetic structural member, wherein the organic fiber has a length of 20 mm or less. In the fireproof structure of the composite structural member formed by integrally forming the concrete member and the steel member according to any one of claims 1 to 8 ,
The fireproof structure of the composite structural member, wherein a heat-resistant fireproof coating material is provided on a surface of the composite structural member to be heated.

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