JP3582971B2 - Reinforcement construction method for concrete structures - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to reinforcement of concrete structures such as bridges, for example, in particular, for repairing cracked bridge decks and walls, and additionally for reinforcing existing structures by adding new reinforcing bars. TECHNICAL FIELD The present invention relates to a jig for use, a reinforcing structure using the same, and a reinforcing construction method.
[0002]
[Prior art]
In a road bridge constructed of a concrete structure, a dynamic load due to the passage of a vehicle is repeatedly received, so that the load on the floor slab of the bridge is considerably large among the main members of the road bridge. If the bridge itself repeats excessive loads, impact loads, or greatly exceeds the service life of the bridge itself, cracks will occur on the underside of the floor slab, and these cracks will run vertically and horizontally across the underside. It becomes a fine mesh until it comes off, causing concrete to come off.
[0003]
Since the occurrence of such cracks causes corrosion or breakage of the reinforcing steel in concrete, it is generally considered preferable to reinforce the floor slab at the initial stage of the occurrence of cracks. As the repair work of the floor slab, a resin injection method of injecting epoxy resin or the like into a crack, and a cross section repair method of repairing a hollow portion or a concrete peeling portion generated in the floor slab with cement mortar have been conventionally performed. .
[0004]
However, most of these construction methods are mainly for the purpose of repairing damaged parts, and are effective in preventing the progress of corrosion of reinforcing bars, etc., but construction to increase the strength of the structure itself Can not respond. On the other hand, construction for repair and reinforcement suitable for existing concrete structures including bridges and the like and jigs for this purpose have already been developed, for example, those described in Japanese Patent No. 2521644. Is an example.
[0005]
In the reinforcement structure described in this publication, for example, if the construction target is a floor slab of a bridge, mesh reinforcing bars woven in a lattice shape are arranged along the lower surface of the floor slab, and the reinforcing bars of the mesh reinforcing bars are substantially orthogonal to each other. An anchor pin is driven into the floor slab along the intersecting portion to line the rebar with the lower surface of the floor slab. A tapered portion is formed on the head side of the anchor pin, and the tapered portion is driven so as to hit a portion where the reinforcing bar intersects, so that a prestress is applied to the reinforcing bar. An operation of sealing the entire reinforcing bar with resin mortar is performed.
[0006]
In the case of construction using such pins and mesh reinforcing bars, a structure can be obtained in which the mesh bars are integrally joined to the floor slab. And stable reinforcement is maintained.
[0007]
[Problems to be solved by the invention]
However, in the operation of placing anchor pins, after many drilling holes are drilled in advance in the floor slab with a drill or the like corresponding to the grid arrangement of the mesh reinforcing bar, the anchor pins are driven into these placing holes. Become. In the conventional anchor pin, the outer shape of the tip end of the pin bulges and deforms as the pin is pressed in, and this deformation gives a locking force to the driving hole. Therefore, if a large number of anchor pins are driven into a repaired slab that has cracks and has deteriorated in strength, the impact force at the time of driving will act on cracks that have already occurred in the slab. As a result, cracks are promoted during construction.
[0008]
In addition, in order to suppress the growth of cracks due to the driving of the anchor pins, it is possible to respond to the problem by increasing the driving pitch of the anchor pins, for example. However, when the casting pitch is long, the restraining points of the rebar on the floor slab are reduced, and not only the joining strength of both is reduced, but also the prestress load on the rebar by the anchor pin becomes insufficient. there is a possibility.
[0009]
Furthermore, in the construction where the mesh reinforcing steel is fixed to the floor slab with anchor pins and then the resin mortar is applied to cover the mesh reinforcing steel, if the existing bridge is used, the construction surface faces downward. It is easy to peel off from the surface. For this reason, a cavity-shaped gap is often left between the resin mortar and the bottom surface of the floor slab, or the resin mortar is not filled between the mesh reinforcing bar and the floor slab. As described above, if there is a gap between the floor slab and a region where the resin mortar is insufficiently filled, the degree of reinforcement at this portion is deteriorated.
[0010]
Further, the resin mortar is also applied to the cracks generated on the bottom surface of the floor slab, but since the construction surface faces downward, the cracks are likely not to be sufficiently filled. For this reason, there is a possibility that cracks will grow even after the repair work, and it will be necessary to perform repair again.
[0011]
As described above, in the conventional repair work, there is a possibility that the structure such as a bridge may be deteriorated in strength when performing the repair, and even when the construction surface is downward, even if the resin mortar is applied, There is a possibility that a cavity may be formed between the surface and the construction surface, and the required strength compensation may not be achieved.
[0012]
It is an object of the present invention to provide a concrete structure to be repaired and reinforced so that the concrete structure to be repaired and reinforced can be constructed without giving a strong deterioration, and that the growth of a crack that has occurred can be suppressed.
[0013]
[Means for Solving the Problems]
The reinforcing jig for a concrete structure according to the present invention is a reinforcing jig for fixing a reinforcing bar network in which a plurality of reinforcing bars are substantially crossed in a lattice shape on the surface of an existing concrete structure, wherein the reinforcing bar crosses. A head for restraining two rebars in a fixed direction, a rod protruding in the axial direction from the head and capable of being inserted into a driving hole formed in a concrete structure, and a peripheral surface between the rod and the head It is characterized by comprising a taper formed and tapering on the side of the insertion direction, and a synthetic resin injection hole penetrating from the head to the tip of the rod.
[0014]
The reinforcing structure for a concrete structure according to the present invention using this reinforcing jig is provided by the restraining force of the taper from two intersecting reinforcing bars and the restraining force of the rod from the inner peripheral surface of the driving hole. The fixture is connected to the concrete structure side and covered with the coating layer including the reinforcing bar and the reinforcing jig, and the synthetic resin supplied to the injection hole from the outside is filled between the surface of the concrete structure and the coating layer. It is characterized by being solidified.
[0015]
In addition, the reinforcing construction method of the present invention using the reinforcing jig according to claim 1 is a concrete structure corresponding to a position where a tapered peripheral surface abuts both of two intersecting reinforcing bars. A large driving hole is drilled, a rod is inserted into the driving hole, and a reinforcing jig is formed by the restraining force received by the taper from the two intersecting reinforcing bars and the restraining force received by the rod from the inner peripheral surface of the driving hole. Connected to the concrete structure side, covered with a coating layer including a reinforcing steel net and a reinforcing jig, supplied synthetic resin from the outside to the injection hole, and coated this synthetic resin with the surface of the concrete structure from the casting hole It is characterized by being injected between layers.
[0016]
In this reinforcing construction method, at least a groove running in a direction intersecting with a reinforcing bar of a reinforcing bar network is formed in advance on the surface of the concrete structure, and a flow of the synthetic resin along the reinforcing bar is introduced into the groove when the synthetic resin is injected. You may do so.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a schematic view showing an example in which a floor slab of a bridge is reinforced by the construction method of the present invention, and FIG. 2 is a bottom view showing an arrangement of a mesh reinforcing bar and an anchor pin taken along line AA of FIG. .
[0018]
In FIG. 1, a floor slab 1 of a bridge in which ground covers 2 are integrally formed at both ends in the road width direction and in which reinforcing bars are arranged in a slab shape is supported by a bridge girder 3. In order to repair the floor slab 1 which has been existing and has been cracked on its lower surface by repeatedly receiving the dynamic load of the passing vehicle V, the slab 1 is vertically and horizontally arranged in a lattice shape as shown in FIG. The reinforcing bar 4 in which the reinforcing bars 4a and 4b are integrated in advance by welding is fixed and held by the anchor pin 5 as a reinforcing jig in the present embodiment. After the rebar 4 is applied, a coating layer made of mortar resin or the like is applied except for the head portion of the anchor pin 5 as described later. In FIG. Is shown.
[0019]
3A and 3B show details of the anchor pin 5, in which FIG. 3A is a cutaway front view, and FIG. 3B is a plan view of FIG. 3A.
[0020]
The illustrated anchor pin 5 is shown in a posture in which the anchor pin 5 is driven into the floor slab 1 from below in FIG. 1, and as shown in FIG. A head 5a is formed, and a rod 5b is formed from the head 5a toward the upper end. The rod 5b forms a taper 5c with an outer diameter tapered in the upper end side, that is, in the driving direction, between the rod 5b and the head 5a, and has an injection hole 5d having a uniform inner diameter penetrated in the axial direction in connection with the head 5a. Things. A male screw 5e is formed on the outer peripheral surface of the rod 5b on the tip side with respect to the taper 5c, and a portion forming the peripheral wall of the injection hole 5d is radially cut on the tip side to form a slit 5f.
[0021]
As shown in FIG. 2, the anchor pins 5 are driven into the floor slab 1 so as to correspond to the portions where the reinforcing bars 4 a and 4 b intersect vertically and horizontally. That is, as shown in FIG. 4, the anchor pin 5 is struck at a corner where the reinforcing bars 4a, 4b cross in a cross shape, and at a position where the peripheral surface of the rod 5b simultaneously contacts these reinforcing bars 4a, 4b. Set up. Then, when the anchor pin 5 is driven into the floor slab 1, the taper 5c comes into contact with the peripheral surfaces of the reinforcing bars 4a, 4b instead of the rod 5b as shown in FIG. When viewed, the outer radius is increased by the taper 5c. Accordingly, the anchor pin 5 pushes the rebars 4a, 4b in the direction of the arrow in FIG. 2, and a tension acts on these rebars 4a, 4b to apply a prestress load. The pre-stress load by such a taper 5c is the same as that of the patent publication mentioned in the section of the prior art.
[0022]
By providing the anchor pin 5 with the taper 5c as described above, if the position of the anchor pin 5 is appropriately adjusted with respect to the lattice-shaped reinforcing net 4 shown in FIG. Uniform tension can be exerted from the center in a direction having an angle of 45 degrees with the lattice, and uniform prestress is applied to the entire reinforcing bar 4. Therefore, when the floor slab 1 is constructed as shown in FIG. 1, even when the floor slab 1 is bent and deformed, the mesh reinforcing bar 4 follows the bending and deformation, and the distance between the anchor pin 5 and the reinforcing bars 4a and 4b is increased. Is prevented from being generated.
[0023]
The procedure for repairing the floor slab 1 with the reinforcing bar 4 using the anchor pins 5 is as follows.
[0024]
First, on the bottom surface of the floor slab 1, as shown in FIG. The groove 1a has, for example, a width of about 3 to 5 mm and a depth of about 5 to 10 mm so that the resin to be injected can flow quickly, and the vertical and horizontal reinforcing bars 4a and 4b of the grid-like mesh reinforcing bar 4. Not only the arrangement direction but also a random arrangement including diagonally running lines. Such a groove 1a can be formed on-site relatively easily and at a uniform depth by using a tool such as a sander.
[0025]
Next, the position of the mesh reinforcing bar 4 is temporarily determined along the lower surface of the floor slab 1, and as described with reference to FIG. 4, the position where the rod 5b of the anchor pin 5 can contact both the reinforcing bars 4a and 4b is centered. Using a stick or the like, ink is printed on the lower surface of the floor slab 1. In this case, a metal rod or the like having the same outer shape as the rod 5b may be used as the centering rod at this time, and the number of the anchor pins 5 to be driven may be appropriately selected according to the size of the mesh reinforcing bar 4.
[0026]
After inking the anchoring position of the anchor pin 5, the net reinforcing bar 4 is separated from the floor slab 1 or the position is temporarily determined by a holding tool, and the inking mark is used as a mark as shown in FIG. The hole 1b is drilled by a drill. The inner diameter of the driving hole 1b is larger than the outer diameter of the rod 5b so as not to block the flow of the injected resin, and the injection hole 5d opened at the tip when the anchor pin 5 is driven exactly is closed. Do not pierce length.
[0027]
When all the drilling work of the driving holes 1b is completed, the position of the reinforcing net 4 is accurately adjusted again, and the positional relationship between the intersection of the reinforcing bars 4a and 4b and the driving hole 1b is adjusted. Temporarily fix along the bottom of the floor slab 1. When the rod 5b of the anchor pin 5 is inserted into the driving hole 1b, the taper 5c comes into contact with the peripheral surface of the reinforcing bars 4a and 4b, and the anchor pin 5 is held by the reinforcing bars 4a and 4b. . That is, as the anchor pin 5 is driven into the driving hole 1b, the taper 5c is engaged with the reinforcing bars 4a, 4b like a wedge, and the taper 5c is circumferentially formed by the reinforcing bars 4a, 4b. Two points on the surface are constrained.
[0028]
On the other hand, the rod 5b inserted into the driving hole 1b receives a reaction force received from a contact point with the reinforcing bars 4a, 4b, that is, a force acting in a direction opposite to the direction of the arrow shown in FIG. The position is changed in the driving hole 1b in the direction.
[0029]
Therefore, as shown in FIG. 5, when the head 5a strikes the reinforcing bar 4a and the driving is completed, the taper 5c is restricted at two points by the reinforcing bars 4a and 4b, and the rod 5b moves in the driving hole 1b. When the position is changed, the peripheral surface substantially makes line contact with the inner peripheral surface of the driving hole 1b. As a result, two points of the anchor pin 5 are constrained by the taper 5c and one point is constrained by the rod 5b, and the peripheral surface thereof is held at three points. Held in state.
[0030]
In this manner, the anchor pin 5 does not exert the engaging force by the tip of the rod swelling and deforming due to the swelling like the conventional casting pin for concrete, but the restraining force on the taper 5c by the rebars 4a, 4b. By using it, it can be temporarily fixed. Therefore, when the anchor pins 5 are driven, unnecessary internal stress is not generated on the existing floor slab 1, and the driving pitch of the anchor pins 5 is shortened.
[0031]
Although the rod 5b of the anchor pin 5 is held in contact with the inner peripheral surface of the driving hole 1b, only this portion is substantially in line contact with the rod 5b and the driving hole 1b. A sufficient gap is maintained between them, and there is no hindrance to resin injection described later.
[0032]
After the anchor pin 5 is driven into the driving hole 1b in the manner described above, as shown in FIG. 5, the portion where the injection hole 5d is open is sealed with a removable sealing material 5d-1 using, for example, a sponge. Stop. Then, the coating material 6a is sprayed by a spraying device, and the groove 1a cut on the lower surface of the floor slab 1 is covered with the coating material 6a.
[0033]
As the coating material 6a, for example, a quick-drying material such as a polymer can be used, and the rebar 4a and the floor slab 1 as shown in FIGS. It is constructed so as not to penetrate between the lower surface and the layer thickness thereof is about 2 mm. By the coating with the coating material 6a, the groove 1a cut in the floor slab 1 is closed by the coating material 6a as shown in FIG.
[0034]
When the spraying of the coating material 6a is completed, an intermediate coating material 6b having a suitable waterproof property is applied as shown in FIGS. The intermediate coating material 6b is applied by using a soldering iron, and the thickness thereof is set so that the head 5a is not buried. When ironing is performed, it is preferable to sufficiently fill the upper side of the reinforcing bar 4a, but such filling and coating is difficult from the viewpoint of workability. On the other hand, in the construction of the present invention, even if a cavity is formed and remains, since the injected resin is filled instead as described later, there is no influence on the final construction.
[0035]
After the application of the intermediate coating material 6b, as shown in FIG. 7, the sealing material 5d-1 is extracted from the injection hole 5d, and the epoxy resin 7 is injected from the outside. The injection of the epoxy resin 7 can be performed for each of the anchor pins 5. However, when the number is not so large, a plurality of hoses are branched from the pumping device for the epoxy resin 7 and these are separated from each other. The injection operation may be performed simultaneously by connecting to the injection hole 5d. This simultaneous operation is very preferable in terms of construction because the injection amount and injection pressure of the epoxy resin 7 from each anchor pin 5 can be made uniform.
[0036]
After filling with the epoxy resin 7, as shown in FIG. 9, a top coat 6c is applied to the surface of the middle coat 6b with an iron, and the coating layer 6 is formed by the coat 6a, the middle coat 6b, and the top coat 6c. You.
[0037]
The epoxy resin 7 supplied to the injection hole 5d is blown out from the upper end of the injection hole 5d and sent out into the casting hole 1b, as shown in FIGS. As a result, the epoxy resin 7 quickly flows downward. The epoxy resin 7 that has escaped from the casting hole 1b flows into the groove 1a cut in the lower surface of the floor slab 1 and penetrates into cracks, and the lower surface of the floor slab 1 that is not covered with the coating material 6a. It flows so as to fill the gap between the reinforcing bars 4a and 4b.
[0038]
That is, between the portion where the reinforcing bars 4a, 4b are running and the bottom surface of the floor slab 1, there is a large number of gaps left unfilled or filled even if the coating material 6a and the intermediate coating material 6b are filled. Has become. For this reason, the epoxy resin 7 that has flowed out from the lower end of the casting hole 1b is sequentially fed by the injection pressure from the supply device in the direction shown by the arrows in FIGS. Accordingly, the gap between the reinforcing bars 4a, 4b and the floor slab 1 is filled with the epoxy resin 7, and all of the cavities which could not be eliminated by the application of the middle coat material 6b from below with the iron are used for this epoxy resin. 7 for sealing and filling.
[0039]
Further, since the grooves 1a cut in the bottom surface of the floor slab 1 are formed at random, there are portions intersecting with the reinforcing bars 4a and 4b as shown in FIG. For this reason, the epoxy resin 7 flowing along the reinforcing bars 4a and 4b enters the groove 1a from the intersection, and the space of the groove 1a surrounded by the coating material 6a is filled with the epoxy resin as shown in FIG. Is done. Since the groove 1a runs vertically and horizontally, it has a relation of intersecting with the crack C generated in the floor slab 1 as shown in FIG. 4, so that the epoxy resin 7 penetrates from the groove 1a to the crack C. Can be done.
[0040]
That is, although the crack C is covered with the coating material 6a, the crack C has a cross-sectional shape cut out similarly to the groove 1a, so that when the epoxy resin 7 from the groove 1a flows due to the injection pressure, the coating material is coated. 6a can be penetrated into the crack C by spreading it. Further, in a portion where the reinforcing bars 4a, 4b directly intersect the crack C, the epoxy resin 7 supplied along the reinforcing bars 4a, 4b directly enters the crack C. Therefore, even if the manner in which the crack C occurs is irregular, the crack C can be filled with the epoxy resin 7 using the arrangement of the reinforcing bars 4a and 4b and the groove 1a formed at random.
[0041]
As described above, the epoxy resin 7 injected from the injection hole 5d of the anchor pin 5 can be distributed not only in the driving hole 1b but also in a wide area of almost the entire floor slab 1. Therefore, when a curing period is set after injecting an appropriate amount of the epoxy resin 7, the rod 5 b of the anchor pin 5 is firmly fixed in the driving hole 1 b by solidification of the epoxy resin 7, whereby the reinforcing bar 4 is connected. The slab 1 can be stably held.
[0042]
Further, since the solidified epoxy resin 7 remains between the lower surface of the floor slab 1 and the reinforcing bars 4a, 4b, the lower surface of the floor slab 1 can be firmly covered, and only the prevention of corrosion of the existing reinforcing bars in the floor slab 1 is achieved. In addition, the corrosion of the reinforcing steel net 4 newly constructed for reinforcement is similarly prevented.
[0043]
Further, since the crack C is also filled with the epoxy resin 7, the growth thereof can be suppressed even when an impact load or the like is received, and not only the repair but also the reinforcing strength can be sufficiently increased.
[0044]
In the above example, the reinforcement of the floor slab of the bridge is used. However, it is a matter of course that various concrete structures may be used instead.
[0045]
【The invention's effect】
The reinforcing jig used in the present invention can be pre-stressed and connected to the rebar network by taper if properly placed at the intersection of the rebars of the rebar network and cast into a concrete structure. It is also possible to follow and hold the reinforcing steel mesh against the flexural deformation of the concrete structure, and the reinforcing effect can be maintained for a long time. Since the synthetic resin can be filled between the surface of the concrete structure and the coating layer by providing the injection hole for the synthetic resin, the generation of rust and the repair of cracks in the reinforcing net can be sufficiently performed.
[0046]
In addition, if the reinforcing jig is fixed to the concrete structure by solidifying the injected synthetic resin, it is not necessary to obtain the engaging force due to the bulging deformation unlike the conventional anchor pin or the like. By shortening the arrangement pitch of the jigs, the strength can be further increased, and unnecessary deterioration is not applied to the concrete structure at the time of casting, so that the deterioration of the strength can be prevented.
[0047]
In the reinforcing structure formed by the reinforcing construction method of the present invention, the reinforcement of the concrete structure can be reliably obtained by the reinforcing mesh prestressed by the reinforcing jig. In addition, the concrete is prevented from peeling due to the generation of voids, and the rust prevention effect of the reinforcing steel mesh is obtained, so that the durability of the structure can be improved.
[0048]
The reinforcing construction method of the present invention, since then take advantage of the reinforcing jig serving also as the fixing of the reinforcing bar network injecting synthetic resin, without requiring a special member required for this injection, also construction Easy to do.
[0049]
By providing the pre-groove on the surface of the concrete structure, it is possible the injected synthetic resin between the surface and the coating layer of the concrete structure by Tsutawa the groove to spread across the surface of the concrete structure Therefore, the synthetic resin can be distributed to the cracks scattered on the surface, and the cracks and the cracks can be repaired.
[Brief description of the drawings]
FIG. 1 is a schematic sectional view showing a bridge in which a slab is reinforced by a reinforcing construction method of the present invention.
FIG. 2 is a bottom view showing the reinforcement reinforcing wire network arranged on the lower surface of the floor slab and the arrangement of anchor pins for fixing the reinforcing reinforcing mesh network, taken along the line AA of FIG. 1;
3A and 3B are details of an anchor pin as a reinforcing jig, wherein FIG. 3A is a cutaway front view and FIG. 3B is a plan view.
FIG. 4 is a bottom view schematically showing the arrangement of anchor pins with respect to the reinforcing bars of the reinforcing bar network.
FIG. 5 is a cross-sectional view of a main part when an application material is applied after an anchor pin is inserted into a driving hole and fixed using a binding force of a reinforcing bar.
6A and 6B are working examples of a groove cut into the bottom surface of the floor slab, wherein FIG. 6A is a schematic view when the floor slab is viewed from obliquely below, and FIG. 6B is a cross-sectional view illustrating the shape of the groove.
FIG. 7 is a cross-sectional view of a main part showing a flow of resin when epoxy resin is injected from an anchor pin having a rod inserted into a driving hole.
8 is a vertical sectional view taken along line BB of FIG. 7;
FIG. 9 is a cross-sectional view of a main part when a resin is filled in a groove of a floor slab by injecting an epoxy resin.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Floor slab 1a Groove 1b Driving hole 2 Ground covering 3 Bridge girder 4 Reinforcing network 4a, 4b Reinforcing bar 5 Anchor pin (reinforcing jig)
5a Head 5b Rod 5c Taper 5d Injection hole 5d-1 Sealing material 5e Male screw 5f Slit 6 Coating layer 6a Coating material 6b Middle coating material 6c Top coating material 7 Epoxy resin

Claims (1)

A reinforcing jig for fixing a rebar network in which a plurality of rebars intersect substantially in a grid on the surface of an existing concrete structure, and a head for restraining two rebars intersecting the rebar net in a fixing direction, A rod protruding from the head in the axial direction and insertable into a casting hole formed in a concrete structure, a taper formed on a peripheral surface between the rod and the head and having a tapered insertion direction, A method for reinforcing a concrete structure using a reinforcing jig for a concrete structure comprising a synthetic resin injection hole penetrated to the tip of a rod ,
A reinforcing bar network in which a plurality of reinforcing bars are crossed substantially in a lattice pattern on the surface of an existing concrete structure is arranged, and a position where the tapered peripheral surface of the reinforcing jig abuts on both of the two reinforcing bars, Drilling a plurality of casting holes larger than the outer diameter of the rod in the concrete structure,
The reinforcing jig is inserted by inserting the rods of the plurality of reinforcing jigs into the respective driving holes, and by using the restraining force of the taper from two intersecting reinforcing bars and the restraining force of the rod from the inner peripheral surface of the driving hole. Is fixed to the surface of the concrete structure by connecting the rebar net to the concrete structure side,
After being covered with a coating layer including a reinforcing mesh and a reinforcing jig,
A synthetic resin is supplied from the outside to the injection hole of the reinforcing jig, and the synthetic resin is injected between the surface of the concrete structure and the coating layer from the casting hole.
Reinforcement construction method for concrete structures.

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