JP2005068931A - Reinforcing construction method of concrete structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce a weight increase and construction cost caused by reinforcement; and to shorten a construction period, by reducing a quantity of material being used by reducing the thickness, while reducing the thickness of a covering layer, when reinforcing a concrete structure. <P>SOLUTION: A groove 6 for fitting a vertical directional reinforcement 7 is formed in a surface part of a pier; the vertical directional reinforcement 7 is fitted in and fixed to this groove 6; and a reinforcing layer by the vertical directional reinforcement becomes a state of biting inside the pier. Even when the pier is strained by a horizontal load in an earthquake, since the vertical directional reinforcement 7 exhibits tensile resistance while following displacement of this pier, clearance is not generated between the reinforcing layer and concrete. Thus, the reinforcing effect can be maintained over a long period by further integrating the vertical directional reinforcement 7 and the existing pier. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for reinforcing a concrete structure in which a reinforcing bar is newly embedded and fixed to an existing concrete pier.

  It is important for the concrete piers of the bridge to satisfy the horizontal strength in the event of an earthquake, and it is necessary to ensure earthquake resistance. Conventionally, RC (Reinforced Concrete) winding method, steel plate winding method, carbon fiber / aramid sheet reinforcing method, PC (Prestressed Concrete) winding method, etc. are known as seismic reinforcement methods for concrete piers. (For example, refer to Patent Document 1).

  The RC hoisting method is to fix the vertical reinforcement on the surface of the pier in parallel with the main reinforcement arranged inside the pier, and fix the reinforcement by overlapping the reinforcement in the direction perpendicular to the main reinforcement. A reinforcement structure is constructed by forming a frame and placing concrete. In addition to the reinforcing method by RC winding, a reinforcing structure for covering the polymer mortar after the main reinforcing bar and the band reinforcing bar are fixed on the concrete pier surface is also constructed.

  If the reinforcing structure is RC-wrapped or polymer-reinforced mortar as described above, the integration of the existing pier and the reinforcing bar fixed in the direction of the bridge axis is strengthened by winding concrete or polymer mortar. The reinforcing effect is maintained for a long time.

JP-A-9-59934 (paragraphs 0002-0004)

  In the above-mentioned reinforcement structure, after reinforcing reinforcing bars are fixed on the concrete pier surface, the concrete pier diameter is significantly increased by the concrete winding layer or polymer mortar coating layer by winding concrete or polymer mortar. become. The increased thickness is 25 cm or more in the concrete winding layer and 5 cm or more in the polymer coating layer. For this reason, there is a risk that the building limit will be exceeded or the river volume will be hindered due to the increase in pier diameter. In addition, the weight of the pier is greatly increased by increasing the winding thickness.

  Moreover, since a concrete winding layer forms a formwork after fixing a reinforcing bar on the surface of a bridge pier, and puts concrete into this, a construction period becomes long. Further, in the case of the polymer mortar coating layer, it is necessary to cover the reinforcing bar fixed on the concrete surface to a thickness that completely covers the reinforcing bar, so that the amount of the polymer mortar coating material used is enormous and the construction cost is high.

  An object of the present invention is to reduce the thickness of a coating layer when reinforcing a concrete structure, and to reduce the amount of material used by reducing the thickness, thereby reducing the increased weight and construction cost associated with reinforcement and shortening the construction period. There is.

  The method for reinforcing a concrete structure according to the present invention is a method for reinforcing a concrete structure in which a reinforcing bar is fixed to the surface of the concrete structure and is reinforced, and the reinforcing bar is fitted on the surface of the concrete structure. A groove is formed, and a reinforcing rod is fitted into the groove and fixed.

  A groove for fitting the reinforcing rod is formed in the surface portion of the concrete structure, and the reinforcing rod is fitted into this groove and fixed, so that the reinforcing layer by the reinforcing rod penetrates into the concrete structure. It becomes an existing configuration. This reinforcement layer can prevent the deformation of the concrete structure due to the horizontal force by exhibiting a high tensile resistance against the horizontal load at the time of the earthquake acting on the concrete structure.

  The reinforcing bar may be a deformed reinforcing bar conventionally used, but it is desirable that the surface is subjected to rust prevention treatment. The material of the rod is preferably carbon fiber. Carbon fiber rods do not generate corrosion such as rust, and have high tensile strength while being lightweight. Further, materials other than deformed reinforcing bars and carbon fibers can be used as long as they have the same strength. Furthermore, the groove formed in the surface part of the concrete structure can be most efficiently exhibited the tensile strength of the reinforcing rod fitted in the groove by matching the direction with the main reinforcement of the existing concrete structure. it can.

  Here, after inserting the reinforcing rod into the groove, a wedge-shaped anchor is driven into the gap between the inner surface of the groove and the reinforcing rod to restrain the reinforcing rod, and the resin is injected into the gap for reinforcement. It is desirable to fix the rod. This step is preferably performed after core punching of the footing portion and after the press-contacting step is completed. By inserting a wedge-shaped anchor into the gap between the inner surface of the groove and the reinforcing rod and fixing it with resin, the reinforcing rod and the inner wall of the groove can be secured without strictly controlling the accuracy of the fitting size of the reinforcing rod and the groove. Can be firmly fixed by surface contact.

  As a specific process for carrying out the above-mentioned construction method, a step of forming a groove for fitting the reinforcing rod body on the surface portion of the pier with a cutting tool, and an inner surface of the groove after fitting the reinforcing rod body into the groove A step of driving a wedge-shaped anchor into the gap between the reinforcing rod and restraining the reinforcing rod; a step of injecting resin into the gap between the inner surface of the groove and the reinforcing rod and fixing the reinforcing rod; And a step of coating the surface with a resin.

  By the step of forming the groove and the step of constraining the reinforcing rod fitted in the groove with the wedge-shaped anchor, the reinforcing layer biting into the concrete surface can be formed. In addition, by injecting resin into the gap between the inner surface of the groove and the reinforcing rod body and fixing the reinforcing rod body, the resin penetrates into the cracks that have occurred in the concrete structure and the crack progresses. Can be suppressed.

  The following effects can be achieved by the present invention.

(1) A method of reinforcing a concrete structure in which a reinforcing bar is fixed to the surface of a concrete structure to reinforce, and a groove for fitting the reinforcing bar is formed on the surface of the concrete structure. By inserting and fixing the reinforcing rods, the reinforcing layer bites into the concrete structure, and even when the attached concrete structure is distorted by a horizontal load during an earthquake, the reinforcing rod is Since the tensile resistance is exhibited while following the displacement of the structure, there is no gap between the reinforcing layer and the concrete. For this reason, further integration of the reinforcing rod and the existing concrete structure is achieved, and the reinforcing effect can be maintained for a long time. Moreover, since the reinforcing rod is fitted in the groove on the surface portion of the concrete structure, the thickness of the coating layer can be extremely reduced, and the amount of material used can be reduced. As a result, the amount of material used can be reduced, and the increased weight and construction cost accompanying reinforcement can be reduced and the construction period can be shortened.

(2) After the reinforcing rod is fitted in the groove, a wedge-shaped anchor is driven into the gap between the inner surface of the groove and the reinforcing rod to restrain the reinforcing rod and to inject the resin into the gap. By fixing the body, it becomes a reinforcing layer that efficiently exhibits the tensile strength against the concrete regardless of the accuracy of the fitting size of the reinforcing rod body and the groove. Further, by interposing the resin between the concrete structure and the reinforcing rod, no shearing force is generated on the reinforcing rod, and the shearing force does not break. Furthermore, this resin also acts as a repair material for cracks generated in the concrete structure, and the reinforcing effect of the concrete structure is further improved.

(3) A step of forming a groove for fitting the reinforcing rod body into the surface portion of the concrete structure with a cutting tool, and after fitting the reinforcing rod body into the groove, the inner surface of the groove and the reinforcing rod body The step of constraining the reinforcing rod by inserting a wedge-shaped anchor into the gap, the step of fixing the reinforcing rod by injecting resin into the gap between the inner surface of the groove and the reinforcing rod, and covering the surface with the resin By including the process to do, the fixation of the reinforcing rod and the construction for preventing peeling can be performed efficiently.

Embodiments of the present invention will be specifically described below with reference to the drawings.
FIG. 1 (a) shows an overall view of a reinforced concrete pier as a concrete structure to which the present invention is applied. 1 is a reinforced concrete footing, and a reinforced concrete column portion 2 is formed on the footing 1. A beam portion 3 made of reinforced concrete is formed on the column portion 2. A reinforcing covering layer 4 is formed on the entire surface of the column portion 2.

  1B is a cross-sectional view taken along line AA in FIG. 1A, and FIG. 1C is an enlarged view of a portion B in FIG. 1B. Inside the column part 2, a reinforcing bar 5 is arranged in the axial direction of the column part 2, that is, in the vertical direction. A groove 6 is formed on the surface of the column portion 2 on the outer side of each reinforcing bar 5 in the same direction as the reinforcing bar 5, and a vertical reinforcing bar 7 as a reinforcing rod is fitted in the groove 6. The vertical stripe 7 is fixed in the groove 6 by filling the inside of the groove 6 with a resin 8 made of an epoxy resin and curing it.

  In the above configuration, the vertical streak 7 is fixed in a state of being fitted in the groove 6 formed on the surface of the column part 2. Moreover, since the resin 8 made of epoxy resin is interposed between the vertical streak 7 and the groove 6, even when the column portion 2 is bent and deformed by a horizontal load at the time of an earthquake, the deformation of the column portion 2 is caused. The distortion force is transmitted to the vertical streak 7 through the resin 8 in the groove 6.

  That is, since the vertical streak 7 is sealed in the groove 6 of the column part 2, even if the column part 2 is displaced due to bending due to a horizontal load at the time of an earthquake, the elastic region of the vertical streak 7 Within the range, the entire surface of the column part 2 has a high tensile stress by absorbing the displacement. Further, since the vertical streak 7 is constrained and sealed by the resin 8 inside the groove 6, it does not float from the groove 6.

Next, with reference to FIG. 2 to FIG. 5, the construction procedure of the reinforcing coating layer 4 will be described.
In FIG. 2A, 1 is a reinforced concrete footing, and 2 is a reinforced concrete column 2. In order to reinforce the pillar portion 2 of this pier, first, the entire surface of the pillar portion 2 is roughened by chipping or sandblasting. A water jet may be used.

  Next, as shown in FIG. 2 (a), the surface of the column part 2 has a width of 50 mm and a depth in a direction parallel to the main reinforcement arranged in the column part 2 by a concrete cutter (not shown) (vertical direction). A cut having a length of about 50 mm is made, and the concrete inside the cut is suspended by an electric pick to form a groove 6.

  Further, as shown in FIG. 2A, a core drilling space 9 for performing core drilling in the footing 1 is provided in the lower part of the column part 2, and further in the vertical direction in the middle of the column part 2. A pressure contact space 10 for performing pressure contact of the muscle 7 is provided. The core drilling space 9 has a size that allows at least a core drill as a drilling tool for performing core drilling to perform a drilling operation. The press-contacting space 10 has a size capable of accommodating at least the press-contacting tool and performing the press-contacting work.

  FIG. 2B is an enlarged view of a portion C in FIG. 2A showing the core drilling space 9, and FIG. 2C is an enlarged view of the portion D in FIG. is there. Both spaces are cut using a concrete cutter and an electric pick in the same manner as the grooves 6. Thereafter, the concrete dust adhering to the surface of the column part 2, the groove 6, the core drilling space 9, and the pressure contact space 10 is removed and cleaned by a method such as high pressure cleaning.

  2 (d), a core drill 11 is installed in the core drilling space 9 provided in the lower part of the column 2 to cut the fixing hole 12 having a diameter of 60 mm and a depth of 600 mm. Make a hole. In this step, it is desirable to grasp the position of the steel material arranged in the footing 1 in advance.

  Next, as shown in FIG. 3A, after the vertical stripe 7 is temporarily fixed in the groove 6, the vertical stripe 7 is inserted into the fixing hole 12 provided in the above process, and E in FIG. As shown in the enlarged sectional view, fixing is performed with a fixing material 13 made of epoxy resin. After the fixing material 13 is cured, a pressure tool is installed in the pressure space 10 to press the vertical stripe 7.

  Next, as shown in the F section enlarged view of FIG. 3C, a wedge-shaped anchor 14 is driven into the gap between the vertical stripe 7 and the groove 6 temporarily fixed in the groove 6 of the column portion 2 to restrain the vertical stripe 7. To do. As shown in FIG. 3C, the wedge-shaped anchors 14 are installed in a staggered manner on both sides of the gap between the vertical stripe 7 and the groove 6. As shown in FIG. 4C, the wedge-shaped anchor 14 has a circular bottom surface, an elliptical top surface, and a hollow interior. As will be described later, the hollow portion 14a serves as an injection port when the resin 8 is injected.

  Next, as shown in FIG. 4 (a), a putty made of a clay-like resin made of epoxy resin is formed in the gaps between all the grooves 6 other than the portion where the wedge-shaped anchor 14 is fitted and the surface of the vertical streak 7. Cover the material 15 to cover it. The epoxy resin putty material 15 seals the gap between the groove 6 and the surface of the vertical streak 7 and integrates them, and also prevents the low-viscosity epoxy resin 8 in the next process from leaking during injection. There is.

  After these steps, as shown in FIG. 4B, the injection device 16 is connected to the inside of the wedge-shaped anchor 14, and the inside of the groove 6 sealed with the putty material 15 is made of epoxy resin as a low viscosity material. Resin 17 is poured. Since this low-viscosity resin 17 has a low viscosity, it fills in the gaps in the grooves 6 and penetrates into the fine cracks 18 generated when the grooves 6 are cut and scraped.

  Further, by injecting the low-viscosity resin 17 from the lower part of the column part 2, the upper wedge-shaped anchor 14 other than the injection part functions as an air vent. After confirming that the low-viscosity resin 17 has reached the wedge-shaped anchor 14 directly above, the first wedge-shaped anchor 14 is sealed with cloth packing to prevent the low-viscosity resin 17 from flowing backward, and then injected from the wedge-shaped anchor 14 immediately above. This is repeated until the wedge-shaped anchor 14 at the top of the column part 2 is reached. Thereby, the low-viscosity resin 17 can be completely filled in the gaps in the grooves 6 while minimizing air contamination.

  Next, as shown in FIG. 5 (a), the vertical stripe 7 arranged in the vertical direction inside the surface of the column portion 2 is attached to the band 19 in a direction perpendicular to the horizontal direction, that is, in the horizontal direction. The attachment is performed by binding the vertical streak 7 with a binding line previously attached to the vertical streak 7. After binding, as shown in FIG. 5 (b), the ends of the band 19 are flare welded to form continuous bars. In addition, although the band 19 may be a deformed reinforcing bar conventionally used, it is desirable that the surface is subjected to rust prevention treatment. The binding wire is preferably made of stainless steel.

  Next, as shown in FIG. 5C, the reinforcing coating layer 4 is formed on the surface of the column portion 2. The reinforcing coating layer 4 is formed by first applying a polymer paste base reinforcing coating material 20 having a rust-preventing performance, and then applying a polymer cement coating material 21. The coating method is brush coating or spraying for the base reinforcing coating material 20, and the polymer cement-based coating material 21 is iron coating or spraying.

  In addition to the covering materials 20 and 21, the reinforcing covering layer 4 can be formed by a method of forming a mold and winding up cement mortar. At this time, it is desirable that the surface of the column part 2 is roughened by chipping or the like in advance. In addition, when forming the coating layer 4 for reinforcement by RC winding method, after forming a formwork, high fluidity concrete is laid.

  The thickness of the reinforcing covering layer 4 thus formed exposed to the surface of the column portion 2 is about 1/8 of the conventional RC winding method and about 1/3 of the polymer mortar winding method. It is possible to reinforce bridge piers that are restricted by inhibition. In addition, since the winding thickness can be greatly reduced, the amount of the coating material used can be reduced by about 2/3 as compared with the conventional polymer mortar winding method, and the construction cost can be greatly reduced.

  As described above, in the pier made of reinforced concrete to which the present invention is applied, the groove 6 into which the vertical stripe 7 is fitted is formed on the surface portion of the column portion 2, and the vertical stripe 7 is fitted into the groove 6 and fixed. As a result, the reinforcing layer including the vertical streak 7 is in a state of biting into the column part 2, and even when the column part 2 is distorted, the vertical streak 7 exhibits a tensile stress while following the displacement of the column part 2. Therefore, there is no gap between the reinforcing layer and the concrete.

  For this reason, the further integration of the vertical direction stripe | line 7 and the pillar part 2 is achieved, and the reinforcement effect can be maintained over a long term. Moreover, since the vertical direction stripe | line 7 is engage | inserted in the groove | channel 6 of the surface part of the pillar part 2, the thickness of a coating layer can be made very thin and material usage-amount can be reduced. As a result, the amount of material used can be reduced, and the increased weight and construction cost accompanying reinforcement can be reduced and the construction period can be shortened.

  Further, after the vertical stripe 7 is fitted in the groove 6, a wedge-shaped anchor 14 is driven into the gap between the inner surface of the groove 6 and the vertical stripe 7 to restrain the vertical stripe 7 and the resin 8 (putty material 15 is put in the gap. In addition, by injecting the low-viscosity resin 17) and fixing the vertical streak 7, the reinforcing layer efficiently exhibits the tensile strength against the concrete regardless of the accuracy of the fitting dimension between the vertical streak 7 and the groove 6. . In addition, by interposing the resin 8 between the column part 2 and the vertical stripe 7, no shear force is generated on the vertical stripe 7, and no shear force breakage occurs. Furthermore, the resin 8 also acts as a repair material for cracks generated in the column portion 2, and the reinforcing effect of the column portion 2 is further improved. In addition, in this embodiment, since the column part 2 is covered with the polymer cement-based coating material 21, the change in the surface state of the column part 2 appears in the polymer cement-based coating material 21 as it is. Therefore, it is also possible to continuously monitor the change in the surface state of the post-reinforced column part 2.

  The concrete structure reinforcement method of the present invention is useful not only for seismic reinforcement against horizontal loads during earthquakes acting on concrete piers, but also for reinforcement of the concrete underside of bridge concrete girders and other concrete structures. is there. In particular, it is suitable for reinforcing a bridge pier that has a limited increase in winding thickness or a bridge pier that needs to reduce the increased weight.

(A) is an overall view of a reinforced concrete pier as a concrete structure to which the present invention is applied, (b) is a cross-sectional view taken along line AA of (a), and (c) is an enlarged view of a portion B of (b). It is. It is explanatory drawing which shows the construction procedure of this invention. It is explanatory drawing which shows the construction procedure of this invention. It is explanatory drawing which shows the construction procedure of this invention. It is explanatory drawing which shows the construction procedure of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Footing 2 Column part 3 Beam part 4 Reinforcement coating layer 5 Reinforcement 6 Groove 7 Vertical direction reinforcement 8 Resin 9 Core drilling space 10 Pressure welding space 11 Core drill 12 Fixing hole 13 Fixing material 14 Wedge-shaped anchor 15 Putty material 16 Injection tool 17 Low Viscous resin 18 Crack 19 Strip 20 Base reinforcement coating 21 Polymer cement coating

Claims (3)

  A reinforcing method for a concrete structure in which a reinforcing bar is fixed to a surface of a concrete structure to reinforce, and a groove for fitting the reinforcing bar is formed on a surface portion of the concrete structure. A method for reinforcing a concrete structure, wherein the reinforcing bar is fitted and fixed.   After fitting the reinforcing rod into the groove, a wedge-shaped anchor is driven into the gap between the inner surface of the groove and the reinforcing rod to restrain the reinforcing rod and inject resin into the gap. 2. The method for reinforcing a concrete structure according to claim 1, wherein the reinforcing rod is fixed.   A step of forming a groove into which the reinforcing rod is fitted in the surface portion of the concrete structure by a cutting tool; and, after fitting the reinforcing rod into the groove, the inner surface of the groove and the reinforcing rod A step of driving a wedge-shaped anchor into the gap to restrain the reinforcing rod, a step of injecting resin into the gap between the inner surface of the groove and the reinforcing rod, and fixing the reinforcing rod, A method for reinforcing a concrete structure, comprising: a covering step.

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