JP4069038B2 - Concrete pipe forming method and concrete frame - Google Patents

Description

  The present invention relates to a method for forming a conduit for detecting and repairing cracks such as cracks and cracks inside a concrete frame (hereinafter collectively referred to as “cracks”).

  It is important to maintain a predetermined strength of a concrete frame constituting a building such as a tunnel, a building, or a pile in order to ensure safety. For this purpose, it is desirable to detect and quickly repair abnormalities such as cracks caused by drying and secular changes of concrete frames and cracks caused by earthquakes.

  However, cracks in the concrete frame also occur inside, and such internal cracks are difficult to detect from the outside of the concrete frame. Therefore, conventionally, for example, a method of monitoring the internal state by embedding an optical fiber sensor in a concrete frame in advance is conceivable (for example, see Patent Document 1).

Moreover, it is difficult to repair cracks inside the concrete frame from the outside as well as the detection. Therefore, conventionally, for example, means as described in Patent Document 2 below has been proposed. The means of Patent Document 2 is to embed a relatively fragile pipe inside a concrete frame, cause a crack in the pipe at the same time as a crack in the concrete frame, press a repair material into the pipe, and pass through the crack in the pipe. This is to repair a crack in the concrete frame (for example, see Patent Document 2).
Japanese Patent Laid-Open No. 2001-66117 JP-A-5-302434

  However, in the method using the optical fiber sensor described in Patent Document 1, when the optical fiber sensor fails, the optical fiber sensor is taken out from the inside of the hardened concrete frame and replaced with a new optical fiber sensor. There is a problem that it is difficult to do. In particular, when the concrete frame ages, the possibility of cracking increases and the need for monitoring to detect cracks and other abnormalities increases. Nevertheless, the optical fiber sensor itself also becomes aging and prone to failure. This problem becomes even more serious.

  Moreover, the method of embedding a pipe as described in Patent Document 2 has the following problems. That is, there is a case where cracks do not occur at the same time between the concrete frame and the pipe because, for example, a gap is formed between the concrete frame and the pipe when the concrete frame is cured.

  Therefore, the main object of the present invention is to construct a concrete case capable of inserting and removing an optical fiber sensor and an ultra-small camera as required, or to reliably repair internal cracks, and such a concrete case. It is to provide a means to do.

In order to achieve the above-mentioned purpose, the occurrence of cracks in the concrete frame is detected, and a thin line (pore) that can repair the cracks by injecting repair material is formed inside the concrete frame . . That is, in the concrete pipe forming method according to the present invention, when the concrete frame is constructed, the narrow tube formed of a material that dissolves in a predetermined fluid is connected so that the internal space of the narrow tube communicates with the outside of the concrete frame. After the concrete of the concrete frame is hardened, a predetermined fluid is injected from the outside of the concrete frame into the internal space of the thin tube, the thin tube is dissolved, and the dissolved thin tube material is taken out of the concrete frame, It is characterized in that a thin line pipe is formed in a concrete frame.

  According to this method, the thin pipe is removed from the inside of the concrete housing, and a thin line-shaped pipe line communicating with the outside is formed. When a crack occurs in such a concrete frame, the crack appears on the inner wall surface defining the pipe line. Therefore, the crack can be detected from the inside of the pipeline and can be repaired.

  It is preferable that the thin tube is made of resin and the predetermined fluid is an organic solvent. In this case, the resin material is relatively easy to mold into a thin tube, and since it does not have a fragile property, it is easy to handle even after it is molded into a thin tube. In particular, the thin tube may be made of polystyrene, and the predetermined fluid may be a limonene solution. According to this, since natural limonene is used, it is safe and there is no fear of environmental pollution.

  Further, after covering the thin tube with an outer tube formed of an elastic material and taking out the dissolved thin tube material from the internal space to the outside, the inside of the outer tube is further depressurized to contract the outer tube. The outer tube may be taken out of the concrete frame to form a thin line in the concrete frame.

  In this way, even if the predetermined fluid that dissolves the thin tube has an adverse effect on the concrete case, the predetermined fluid is directly applied to the concrete case due to the presence of the outer tube after the thin tube is dissolved. Because it does not touch, it will not adversely affect the concrete frame.

  In the concrete pipe forming method according to the present invention, when a concrete frame is constructed, a narrow tube formed of an elastic material and filled with fluid is exposed so that the end of the narrow tube is exposed to the outside of the concrete frame. After the concrete of the concrete frame has hardened, the fluid in the narrow tube is allowed to flow out of the concrete frame from the end, the narrow tube is contracted, and the contracted narrow tube is taken out of the concrete frame, A thing characterized by forming a thin line pipe line in a concrete frame is also considered.

  In this method, the thin tube can be removed from the concrete frame without dissolving it to form a thin line.

  Furthermore, the present invention also relates to a concrete frame having a pipe line formed by the above method.

  According to the concrete pipe forming method and the concrete frame as described above, only when it is necessary to detect the state inside the concrete frame, a sensor such as an optical fiber sensor is inserted into the pipe line and the detection is completed. Since the sensor can be taken out later, another optical fiber sensor can be used even if the optical fiber sensor fails.

  Moreover, the crack of the concrete frame itself can be detected directly rather than estimating the crack of the concrete frame itself by the crack of the narrow tube, and the crack of the concrete frame can be detected reliably. In the case of crack repair, it is possible to repair the cracks of the concrete frame directly, not through the cracks in the narrow tube, and to repair the cracks with certainty.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a partial cross-sectional perspective view of a concrete frame 10 obtained by the concrete pipe forming method of the first embodiment of the present invention. The concrete housing 10 includes a reinforcing reinforcing bar 12 and a plurality of pipe lines 14 (only two are shown in FIG. 1). The reinforcing bars 12 are appropriately arranged according to the shape of the concrete frame 10. The pipes 14 are formed so as to meander up and down along a vertical plane, and are parallel to each other and have the same shape. Moreover, both ends of the pipe line 14 are opened on the upper surface of the concrete housing 10 and communicated with the outside. Note that FIG. 1 is cut along one of the conduits 14.

  Next, the concrete pipe forming method of the present embodiment will be described with reference to FIGS. FIG. 2 is a view showing a state before placing concrete at the same position as FIG. First, the formwork 16 is assembled in accordance with the concrete placement shape, a concrete placement space 18 is defined, and the reinforcing bars 12 are arranged in the space 18. Also, a plurality of identical thin tubes 20 formed so as to meander along one plane are prepared. As will be described below, the thin tube 20 is preferably made of polystyrene. Such thin tubes 20 are arranged side by side in parallel in the space 18 and are appropriately supported by the mold 16 and the reinforcing bars 12. At this time, both ends of the thin tube 20 protrude from the surface of the concrete housing 10 when the concrete housing 10 is formed (state of FIG. 2).

  Next, concrete is placed in the mold 16, and after a predetermined time has passed and the concrete has hardened, the mold 16 is removed. FIG. 3 shows the state at this time. The ends A and A ′ of the narrow tube 20 protrude from the concrete housing 10 and the other portions are embedded in the concrete housing 10.

  Subsequently, a limonene solution that dissolves polystyrene is introduced into the inside of the narrow tube 20 from the ends A and A ′ of the thin tube 20 using the injector 22 or the like. In this embodiment, the reason why polystyrene is used as a capillary material and limonene solution is used as a solvent is that polystyrene has a property of dissolving in limonene solution, and limonene solution is less likely to adversely affect the environment. This is because it is preferable as a solvent because the used solution can be easily discarded. Polystyrene is also relatively inexpensive, easy to mold, moderately elastic and rigid, and therefore has the advantage of being able to withstand vibration during construction and concrete placement pressure. The combination of the thin tube material and the solvent is not limited to this, and any combination of other materials and a fluid that dissolves the material may be used. Further, the fluid is not limited to a liquid and may be a gas. For example, as a capillary material, vinyl chloride resin, vinylidene chloride resin, polyvinyl alcohol, vinyl acetate resin, ABS, polyethylene, acrylic resin, nylon, acetal resin, epoxy resin, etc. can be adopted, and as a solvent, Acetone, benzene, alcohol, toluene, lacquer, water vapor and the like can be used. The same applies to the following second and third embodiments.

  The introduction of the solvent, that is, the limonene solution into the capillary 20 is preferably performed by applying pressure so that the dissolved capillary material can be easily washed away. When the introduction of the limonene solution is continued, the capillary 20 is dissolved and the dissolved capillary material flows out from the other ends B and B ′. Further, the introduction is continued, and when all of the dissolved capillary material is discharged and only the limonene solution flows out from the other ends B and B ′, the introduction is stopped. In this way, a thin line-shaped pipe line 14 directly formed inside the concrete housing 10 as shown in FIG. 1 is completed. In addition, it is preferable that water is appropriately poured into the thin line 14 and washed to remove the limonene solution and the residue of the thin tube material.

  Next, the advantage of the concrete frame 10 in which the pipe line 14 is formed will be described.

  The concrete housing 10 may generate cracks 24 inside due to various effects such as drying during curing, weakening due to secular change or earthquake damage, and neutralization of concrete (FIGS. 1 and 4). reference). Such a crack 24 appears on the inner wall surface of the pipe line 14 because the pipe line 14 according to the present embodiment is directly formed inside the concrete housing 10. In particular, in the configuration of FIG. 1, since a plurality of pipes 14 are arranged in a meandering shape, when the crack 24 progresses, it immediately appears in one of the pipes.

  When the inside of the pipe line 14 is inspected, the optical fiber sensor 26 is inserted into the pipe line 14 provided on the surface of the concrete frame 10. The optical fiber sensor 26 is connected to a light emitting portion that illuminates the inside of the conduit 14 and a distal end portion 28 that includes an imaging device that captures the state in the conduit, a cable 30 that extends from the distal end portion 28, and the other end of the cable 30. It is conceivable that the operation unit 32 is provided. The operation unit 32 includes a monitor 34, a controller 36, a light source (not shown) and a power source (not shown) provided therein. The distal end portion 28 of the optical fiber sensor 26 is passed through any one of the openings a, a ′, b, b ′ of the concrete housing 10 (opening portion a in FIG. 1) to the back of the conduit 14 of the optical fiber sensor 26. I will put it in. Then, the operation of the controller 36 causes the optical fiber to emit light and illuminates the inside of the conduit 14, so that the inside is photographed by the image sensor and displayed on the monitor 34. The crack 24 is detected from the state of the inner wall of the pipeline 14 displayed on the monitor 34.

  When the crack 24 is detected, the repair material 38 can be introduced from any one of the openings a, a ′, b, and b ′. The repair material 38 is liquid at the time of introduction, but is preferably an epoxy resin that hardens when it reacts with an alkali component of concrete or air. Such a repair material 38 reaches the location of the crack 24 through the conduit 14 as shown in FIG. 4, penetrates into the crack 24, and can block it. In addition, when the diameter of the pipe line 14 and the crack 24 are large, it may be more effective to press-fit non-shrink mortar having a higher viscosity than the epoxy resin. In addition, the reinforcing portion can be formed inside by press-fitting concrete reinforced with fibers or the like, or press-fitting a reinforcing material and epoxy at the same time and then curing. By repairing cracks from the inside in this way, the strength of the concrete frame can be restored, the progress of neutralization can be prevented, and the chloride can be prevented from entering.

  If it is necessary to measure not only the crack 24 but also the temperature, strength, displacement, stress, neutralization, or activation of the inside of the concrete housing 10, a sensor suitable for the application is inserted into the pipe. Thus, the internal state can be measured. Further, when the concrete is mass concrete and the temperature inside the concrete is high, the cooling of the concrete can be performed by flowing a cooling liquid through the pipe 14. Furthermore, a stress material can be inserted into the pipe line 14 to prestress the concrete frame.

  Although FIG. 1 shows what formed the pipe line 14 over the substantially whole concrete frame 10 constructed | assembled, the arrangement | positioning and shape of a pipe line are determined suitably. FIG. 5 is a partial cross-sectional perspective view of the concrete casing 110 showing a modification of the arrangement of the pipe lines in the concrete casing. The said modification shows the shape of the pipe line suitable for a large-scale structure. The concrete frame 110 includes a pile foundation 102 that is driven into the ground to support the load of the building, a foundation slab 104 provided on the pile foundation 102, and a foundation beam. With respect to the concrete frame 110, the pipes are provided on the pile foundation 102 with annular horizontal pipes 114 a arranged at equal intervals in the vertical direction, and a plurality of pipes (see FIG. 5) that extend perpendicularly across the pipes 114 a. Is composed of four pipe lines 114b.

  Since the shapes of the pipes 114a and 114b are different, the arrangement shape of the narrow pipes (not shown) at the time of placing the concrete is different, but the rest is performed in substantially the same manner as the above-described embodiment. Description is omitted.

  In the case of a large-scale building, there are some parts where cracks are difficult to occur and other parts that are less affected by the occurrence. Therefore, it is not efficient to provide the pipe lines 114a and 114b throughout the concrete frame 110. In the case of such a building, cracks are most likely to occur in the pile head 106, and this portion of the crack is particularly undesirable for the upper building. Therefore, in the example (not shown), the conduit 114 is provided not only on the concrete frame 110 as a whole but only on a portion where the crack is easily generated from the pile head 106 of the pile foundation 102 to the foundation slab 104. For this reason, compared with the case where a pipe line is provided over the whole concrete frame 110, the cost and labor for forming a pipe line can be reduced. Despite the fact that the pipes 114a and 114b are not provided in the entire concrete frame 110, it is possible to detect cracks in important parts, and the cracks can be detected and repaired most effectively at a minimum cost.

  Next, a concrete pipe forming method according to a second embodiment of the present invention will be described with reference to FIG. In the second embodiment, the pipe line 214 is formed using a thin tube 220 made of an elastic member, in which water 200 is enclosed.

  First, a liquid, preferably water 200, is pressed into a narrow tube 220 having one end closed. When a sufficient amount of water 200 for increasing the diameter of the thin tube 220 is injected, the other end of the thin tube 220 is also closed to form the thin tube 220 in which the water 200 is enclosed (see FIG. 6A).

  Next, the narrow tube 220 is placed in the concrete placement space to place concrete. Since these procedures are the same as those in the first embodiment, description thereof will be omitted. In addition, since the water 200 is enclosed in the narrow tube 220, the cross-sectional shape is maintained while the concrete tube is not placed by the pressure from the concrete during the placement of the concrete.

  After the concrete is hardened, one end of the narrow tube 220 embedded in the constructed concrete casing 210 is opened, and the internal water 200 flows out of the narrow tube 220. The diameter of the thin tube 220 is reduced with the outflow of the water 200, and a gap is formed between the concrete housing 210 and the thin tube 220, so that the thin tube 220 can be easily pulled out of the concrete housing 210 (FIG. 6 ( b)). And the pipe line 214 is formed by drawing out the thin tube 220 from the concrete housing 210.

  According to the second embodiment, it is not necessary to flow the solvent into the narrow tube 220, and therefore there is no need for waste liquid treatment. Further, since the liquid in the narrow tube 220 is sufficient as water, the conduit 214 can be formed at low cost.

  Next, a concrete pipe forming method according to a third embodiment of the present invention will be described with reference to FIG. In the third embodiment, a resin-made thin tube 320 that is dissolved by a predetermined fluid is surrounded by an outer tube 300 that is an elastic member that is elastically stretched around the periphery.

  Although this point surrounded by the outer tube 300 is different from that of the first embodiment, the arrangement of the narrow tube 320 in the concrete placement space and the procedure of placing concrete are performed in the same manner as in the first embodiment. These descriptions are omitted. FIG. 7A is a partial cross-sectional perspective view showing a state after the concrete is placed and before the thin tube 320 and the outer tube 300 are removed from the inside of the concrete housing 310.

In the state shown in FIG. 7A, a fluid that dissolves the thin tube 320 is introduced into the tube from the end of the thin tube 320. Since the introduction and the method of flowing out the thin tube 320 are the same as the method of dissolving the polystyrene thin tube 20 of the first embodiment with the limonene solution, the description thereof is omitted.
When the thin tube 320 is removed by dissolving it with a predetermined fluid, the diameter of the outer tube 300 as an elastic member shrinks, and a gap is formed between the concrete housing 310 and the outer tube 300 (the state shown in FIG. 7B). The outer tube 300 can be easily pulled out from the outside of the housing 310. And the pipe line 314 is formed by pulling out the outer pipe 300 from the concrete housing 310.

  According to the third embodiment, even if a predetermined fluid that dissolves the narrow tube 320 adversely affects the concrete housing 310, the fluid is not directly applied to the concrete housing 310 because the outer tube 300 is present, and the concrete There is no worry about deterioration of the casing 310 due to the fluid. Further, as in the second embodiment, a method is used in which the thin tube material is peeled from the concrete housing 310 using the contraction of the tube of the elastic member. However, when the concrete is placed, there is a resin thin tube 320 provided inside. Therefore, stronger strength is ensured with respect to the pressure from the concrete than in the second embodiment.

  As mentioned above, although preferred embodiment of this invention was described in detail, it cannot be overemphasized that this invention is not limited to the said embodiment.

It is a partial cross section perspective view of the concrete frame obtained by the concrete pipe formation method of a 1st embodiment of the present invention. It is the partial cross section perspective view which showed the state before concrete placement of the concrete frame of FIG. It is the partial cross section perspective view which showed the state after concrete placement of the concrete frame of FIG. 1, and before thin tube removal. It is sectional drawing of the concrete frame part in which the pipe line was formed and the crack produced. It is a partial cross section perspective view of the concrete frame obtained by the concrete pipe formation method of the alternative of 1st Embodiment. (A) is the figure which showed the state by which water was enclosed in the thin tube of the concrete frame obtained by the 2nd Embodiment concrete pipe formation method of this invention, (b) is water from the inside of a thin tube. It is the figure which showed the state after making it flow out. (A) is the figure which showed the state before the removal of a thin tube and an outer tube | pipe of the concrete frame obtained by the 3rd embodiment concrete pipe formation method of this invention, (b) dissolved a thin tube, It is the figure which showed the state which the outer tube contracted.

Explanation of symbols

10, 110, 210, 310 ... Concrete frame 12 ... Reinforcing bars 14, 114a, 114b, 214, 314 ... Pipe line 16 ... Formwork 18 ... Space 20, 220, 320 ... Narrow tube 24 ... Crack 300 ... Outer tube

Claims (6)

It is a method of detecting the occurrence of cracks in a concrete frame and forming a thin line-like pipe line inside the concrete frame that can repair the cracks by injecting a repair material,
When the concrete frame is constructed, a narrow tube formed of a material that dissolves in a predetermined fluid is disposed so that the internal space of the narrow tube communicates with the outside of the concrete frame,
After the concrete of the concrete frame has hardened, the predetermined fluid is injected into the internal space of the thin tube from the outside of the concrete frame, and the thin tube is dissolved.
A method for forming a concrete pipe, wherein the melted thin pipe material is taken out of the concrete casing and a thin line pipe is formed in the concrete casing. The thin tube is covered with an outer tube formed of an elastic material;
After the melted thin tube material is taken out from the inner space to the outside, the inside of the outer tube is further decompressed to shrink the outer tube, and the shrunk outer tube is taken out of the concrete housing, and the concrete housing The concrete pipe forming method according to claim 1, wherein a thin line pipe is formed in the inside.   The concrete pipe forming method according to claim 1 or 2, wherein the narrow pipe is made of resin, and the predetermined fluid is an organic solvent.   The concrete pipe forming method according to claim 3, wherein the narrow pipe is made of polystyrene, and the predetermined fluid is a limonene solution. It is a method of detecting the occurrence of cracks in a concrete frame and forming a thin line-like pipe line inside the concrete frame that can repair the cracks by injecting a repair material,
Wherein when building the concrete skeleton, the tubules are fluid therein and formed of an elastic material is sealed, the end of the tubules leave arranged so as to be exposed to the outside of the concrete skeleton,
After the concrete of the concrete frame has hardened, the fluid in the narrow tube is allowed to flow out of the concrete frame from the end, the narrow tube is contracted, and the contracted narrow tube is taken out of the concrete frame, A concrete pipe forming method for forming a thin line pipe in a concrete frame. A concrete frame having a pipe formed according to the concrete pipe forming method according to claim 1.

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