JP2010024671A - Spray equipment and spray method for repairing material for concrete - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide spray equipment excellent in mobility suitable for relatively small-scale repair of a concrete structure, and a spray method for a repairing material for concrete, using the spray equipment. <P>SOLUTION: This spray equipment M comprises a material tank 1, a connecting implement 10, a hose 4 fitted with a nozzle 5, and a pressurized air supply device 20 such as an air compressor; and a disc-shaped inner lid 6 composed of a flexible member is arranged on the top surface of the repairing material S housed in the material tank 1. A radial slit directed to a peripheral edge from the center is formed in the inner lid 6. The repairing material is charged into the material tank 1; the material tank 1 is sealed with a lid portion 1B; and subsequently, pressurized air is supplied to a pressurized air introduction port 2 and a pressurized air receiving portion 13a from the pressurized air supply device 20. The repairing material S is pushed out into the connecting implement 10 under the pressure of the pressurized air acting through upper air piping P1, and blown out in an atomized state from a nozzle 5 at the leading end of the hose 4 under the pressure of the pressurized air acting through lower air piping P2, so as to be sprayed on a target construction surface. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a spraying device excellent in mobility suitable for repairing a concrete structure on a relatively small scale, and a method for spraying a repair material for concrete using the same.

  In concrete structures such as viaducts, railway bridges, and road bridges, there is a problem that a part of the concrete is deteriorated due to various factors, and in some cases, the surface part is peeled off. In order to repair such a deteriorated portion of concrete, a cross-section repair by a plastering method in which a repair material is applied to the deteriorated portion using a trowel or a cross-section repair by spraying a mortar material is performed.

If the construction area for cross-sectional repair is large, build a scaffold, transport the mortar to the construction site with a pressure pump and a pressure hose, and use compressed air supplied from an air compressor to remove the mortar with a spray gun. A method of spraying on the repair surface is adopted. However, when the construction area is medium or small, or when construction sites are scattered, the construction method for large-scale construction is uneconomical. Therefore, Patent Document 1 proposes a concrete repair material spraying apparatus and method suitable for cross-sectional repair with a construction area of 4 m ² or less.

  The concrete repair material spraying device described in Patent Document 1 is filled with a repairing mortar material in a cylindrical body provided with a nozzle at one end, and at the same time extruding the mortar material from the nozzle by pressing with an extrusion means from the other end, The mortar material is ejected with compressed air supplied from an air compressor through an air pipe connected to a nozzle, and sprayed to a target repair location.

JP 2002-316074 A

  The repair material spraying device described in Patent Document 1 performs spraying work in a state where an operator holds a heavy tubular body filled with mortar material. For this reason, the burden on the worker is large, and it is necessary to learn to spray the repair material at an appropriate position. The dimensions of the cylindrical body and the total weight when filling the mortar are limited to such an extent that the worker can hold it alone (about 4 to 5 kg). Specifically, the inner diameter of the cylindrical body is 60 mm, the length is 400 to 500 mm, and the amount of mortar material that can be filled is about 1.1 to 1.4 liters. Therefore, since the amount of mortar that can be sprayed in a single repair operation is relatively small, it may be necessary to repeat the work of filling the cylindrical body with mortar material several times before completing the required repair operation. There are many problems that work efficiency is not good.

  The present invention solves the above-mentioned conventional problems, reduces the burden on the operator, can increase the amount of repairable material that can be sprayed in a single operation, and small and medium-scale repair work A concrete repairing material spraying apparatus and a spraying method capable of exhibiting a suitable mobility are provided. The spraying device according to the present invention is characterized in that, as described in claim 1, a material tank having a pressurized air introduction port at an upper portion and a material discharge port at a lower portion is connected to the material discharge port of the material tank. And a connecting tool having a pressurized air inlet, a hose having a base end connected to the material delivery port of the connecting tool and a nozzle attached to the tip, a pressurized air inlet of the material tank, and a connecting tool. That is, it is composed of a pressurized air supply device that feeds pressurized air to each of the pressurized air receiving ports.

  The material tank used in the present invention is made of a material having moderate rigidity such as steel, stainless steel, aluminum, and reinforced plastic, and can withstand a predetermined internal pressure (0.5 MPa or more, preferably about 1.0 MPa or more). It shall have pressure resistance. In order to be able to stand on its own, it is desirable to attach appropriate support means such as a stand. The tank capacity is not particularly limited, and may be appropriately determined according to the construction mode. Usually, the range is 15 to 20 liters. The compressed air supply device is typically an air compressor, and the capacity of the pressurized air supply device is sufficient if the air discharge amount is 400 liters per minute or more and the maximum working pressure is 0.7 MPa or more.

  As for the connection device for connecting the material tank and the hose, as described in claim 2, a primary side pipe part connected to the material discharge port of the material tank, and a secondary side pipe part connected to the hose and including the material delivery port And an air supply pipe portion including a pressurized air receiving port, and the secondary side pipe portion is bent at an angle of 90 degrees or less with respect to the primary side pipe portion, and the air supply pipe portion is secondary It is desirable that the side pipe portion be connected coaxially.

  In addition, as described in claim 3, in the middle of the piping connecting the pressurized air supply device and the pressurized air inlet of the material tank, and the pressurized air supply port of the pressurized air supply device and the connector It is desirable to provide a regulator for adjusting the air pressure in the middle of the piping to be communicated.

  If the inner surface of at least the lower side of the material tank is formed in a conical shape with a diameter decreasing downward as described in claim 4, it is manufactured in a disk shape by a flexible member and is formed in the radial direction. It is desirable to arrange the inner lid in which the slit is formed on the upper surface of the spray material stored in the material tank. This inner lid functions as a piston that pushes out the repair material inside the tank, has a thickness of 2 to 5 mm, preferably 3 mm, and is made of, for example, natural rubber (NRB) or synthetic rubber.

  The feature of the concrete repair material spraying method adopted by the present invention is that, as described in claim 5, the material tank has a pressurized air inlet at the top and a material outlet at the bottom. The repair material is pushed out from the material tank into the hose through the connection connected to the material discharge port by supplying pressurized air from the pressurized air inlet into the material tank. At the same time, pressurized air is applied to the extruded repair material, and the repair material is sprayed from the hose tip toward the target.

  In the construction method, as described in claim 6, when the inner surface of at least the lower side of the material tank is formed in a conical shape whose diameter is reduced downward, on the upper surface of the spray material stored in the material tank, An inner lid made of a flexible member in the shape of a disk and formed with a slit in the radial direction is arranged, and the repair material is supplied through the inner lid by the pressurized air supplied from the pressurized air inlet into the material tank. When pushing out from the inside, when the inner lid descends the conical part of the inner surface of the material tank, the inner lid is conically shaped by polymerizing the part sandwiching the slit in the inner lid in accordance with the reduced diameter of the inner surface. It is advisable to adopt a mode of deforming to.

The spraying device according to the first aspect of the present invention and the spraying method according to the fifth aspect include the repairing material stored in the material tank by the pressurized air supplied from the pressurized air inlet at the top of the tank, At the same time as pushing out into the hose through the connecting tool, the repairing material is blown out from the nozzle at the tip of the hose by applying pressurized air to the extruded repairing material through the pressurized air receiving port of the connecting tool.
In the present invention, since the tank portion for storing the repair material and the nozzle portion are connected by a hose through the connection tool, the worker only needs to hold the lightweight nozzle portion. Therefore, the physical burden on the worker is reduced. Further, it is easy to spray the repair material to the target position on the construction surface without requiring skill, so that an accurate cross-section repair work can be performed.
By separating the material tank from the nozzle, the material tank can be a stationary type, so that the tank capacity can be increased. Therefore, when repairing a predetermined construction area, the number of times the repair material is filled can be reduced, or the replenishment work of the repair material can be eliminated, so that the work efficiency is improved.
Since the connection tool is provided with a pressurized air receiving port so that pressurized air acts on the repair material in the hose, the repair material in the hose is pushed out and hardly remains.
Since it is structured to push out the repair material from the material tank to the hose using pressurized air, it is only necessary to prepare a pressurized air supply device such as an air compressor as the power source, and no pressure pump for the repair material is required. Therefore, the configuration is simple. If an engine type air compressor is used, a power source can be eliminated.
Since the communication between the material tank and the pressurized air supply device is made by a deformable member such as a pressure-resistant tube, the material tank and the pressurized air supply device can be separately installed at appropriate locations. Therefore, the length of the hose connecting the material tank and the nozzle can be shortened (about 1 to 2 m) by installing the material tank near the repair site. Thereby, the trouble of hose cleaning can be reduced.
Furthermore, since only the material tank needs to be installed near the repair site, when the repair points are scattered, only the material tank needs to be moved, so that excellent mobility is exhibited.

  According to a second aspect of the present invention, the secondary side pipe portion of the connector is formed to be bent at an angle of 90 degrees or less with respect to the primary side pipe portion, and the air supply pipe portion is coaxial with the secondary side portion. Since the repair material does not pass through the air supply pipe part by being connected to, clogging of the air supply pipe part is completely prevented. Moreover, since the secondary side pipe part is bent at an angle of 90 degrees or less with respect to the primary side pipe part, the tip of the secondary side pipe part is directed horizontally or above the horizontal direction, and the effective length of the hose Can be increased.

  According to a third aspect of the present invention, in the middle of the piping connecting the pressurized air supply device and the pressurized air introduction port of the material tank, and between the pressurized air supply device and the pressurized air receiving port of the connector. By providing a regulator in the middle of the piping, even if the pressure of the pressurized air supply device fluctuates or the softness of the repair material increases or decreases, these effects are eliminated and the discharge state of the repair material is stabilized. be able to. In addition, if the supply pressure of the pressurized air supply device is large, the spray pressure of the repair material is too strong and the discharge speed becomes too high as it is, but this is reduced to an appropriate working pressure by a regulator and is suitable for the content of the repair work. The discharge speed can be adjusted.

When the inner surface of at least the lower side of the material tank is formed in a conical shape whose diameter is reduced downward as described in claim 4, an inner lid made in a disk shape by a flexible member is used as a material. By arranging on the upper surface of the spray material stored in the tank, the pressing force of the pressurized air applied to the material tank can be applied uniformly to the repair material via the inner lid. For this reason, the discharge state of the repair material is stabilized.
As the pressurized air is applied to the material tank to push out the repair material, the inner lid also descends in the tank. And since the slit in the radial direction was formed in the inner lid, as described in claim 6, when the inner lid descends the conical portion of the tank, the portion sandwiching the slit in accordance with the reduced diameter of the inner surface Polymerizes and transforms into a cone. As a result, the repair material is reliably pushed out by the inner lid, and the remaining amount of the repair material tank can be reduced.

  FIG. 1 shows a schematic configuration of a spraying apparatus M according to the present invention. This spraying device M is for spraying a repair material S for concrete, such as cement mortar, to a portion that needs to be repaired. The material tank 1 for storing the repair material S and the material discharge port 3 below the material tank 1 Connected connector 10, air that feeds pressurized air to hose 4, material tank 1, and connector 10 each having a base end connected to material delivery port 12 a of connector 10 and having nozzle 5 attached to the tip. It is composed of a pressurized air supply device 20 such as a compressor. A thin disk-shaped inner lid 6 made of a flexible member such as rubber is disposed on the upper surface of the repair material S stored in the material tank 1. The inner lid 6 is formed with a radial slit from the center toward the peripheral edge.

  As shown in FIG. 2, the material tank 1 includes a main body 1A and a lid 1B that closes an upper opening of the main body 1A so that the upper opening can be opened and closed. The main body 1A includes a cylindrical part a1 and a lower part. It consists of a cone-shaped cone part a2 whose diameter decreases toward the top. The lid portion 1B is provided with a pressurized air introduction port 2 for introducing pressurized air, and an upper air pipe P1 communicating with the pressurized air supply device 20 is connected to the pressurized air introduction port 2. . A regulator R1, a stop valve V1, an open valve V2, and a relief valve V3 for adjusting the air pressure are provided in the middle of the upper air pipe P1, and a pressure is provided between the regulator R1 and the primary side of the open valve V2. Gauges G1 and G2 are attached.

  A material discharge port 3 for feeding the repair material S is formed at the lower end of the main body portion 1A (cone portion a2) of the material tank 1, and the connector 10 is connected to the material discharge port 3. The connector 10 includes a primary side pipe part 11 connected to the material discharge port 3, a secondary side pipe part 12 bent at a substantially right angle with respect to the primary side pipe part 11, and a secondary side pipe part 12. It consists of the air supply pipe part 13 connected coaxially. In this example, the connection part Q between the primary side pipe part 11 and the secondary side pipe part 12 is configured to be curved in an arc shape. The angle formed between the primary side pipe part 11 and the secondary side pipe part 12 may be smaller than 90 degrees. An on-off valve V4 such as a ball valve is provided in the middle of the primary side pipe portion 11, and the inflow of the repair material from the material tank 1 into the connector 10 is controlled by operating the lever 14 as necessary. be able to. Further, a stop valve V <b> 5 for opening and closing the pipeline as needed by the lever 15 is also provided at the pressurized air receiving port 13 a of the air supply pipe unit 13. The hose 4 is connected to the material delivery port 12a of the secondary side pipe portion 12. A lower air pipe P <b> 2 communicating with the pressurized air supply device 20 is connected to the pressurized air receiving port 13 a of the air supply pipe unit 13. In the middle of the lower air pipe P2, an air pressure adjusting regulator R2 having a pressure gauge G3 is provided. Moreover, if the secondary side pipe part 12 and the air supply pipe part 13 can be divided | segmented, internal cleaning can be simplified.

  Fastening means 7 is provided between the main body 1A and the lid 1B in the material tank 1 for airtightly fixing the lid 1B to the main body 1A. The fastening means 7 may have a structure as shown in FIGS. 3A and 3B, for example. One end of the rod 7a is pivotally supported on the bracket 8 of the main body 1A by a pin 7b, and a handle 7c and a stopper 7d screwed to the rod 7a are provided on the other end. Each of the main body 1A and the lid 1B is provided with flanges f1 and f2 facing the joint. When the lid 1B can be removed, the rod 7a of the fastening means 7 is in a state of hanging downward from the pin 7b as shown in FIG. When fixing the lid portion 1B to the main body portion 1A, as shown in FIG. 3B, the rod 7a is erected upward and inserted into the receiving portion 9 provided on the lid portion 1B, and then the handle 7c. The stopper 7d is pressed against the upper surface of the receiving portion 9 by rotating the. As a result, the main body 1A and the lid 1B are joined in an airtight manner by pressing the flanges f1 and f2 together.

  For example, as shown in FIG. 5, the nozzle 5 attached to the tip of the hose 4 connected to the secondary side pipe portion 12 of the connection tool 10 includes a tapered nozzle body portion 5 a and a cap nut 5 b and an attachment 5 c. A structure that is used and fixed to the tip of the hose 4 can be considered. The nozzle body 5a is made of synthetic resin, and the diameter of the tip is about 5 to 10 mm. However, these materials and numerical values can be appropriately changed according to the state and physical properties of the spray material used.

The concrete repairing material spraying method by the spraying apparatus M according to the present invention configured as described above is performed as follows.
(Pretreatment process)
Prior to spraying the repair material on the part of the concrete structure where cross-section repair is required, the chipping work is performed to remove the deteriorated or defective parts of the concrete. Thereafter, a primer is applied by spray, roller, brush, or the like, if necessary. Furthermore, when the reinforcing bar is exposed at the repaired part, it is desirable to remove the floating rust and dirt and then apply a rust preventive treatment.

(Adjustment of repair materials)
Next, the repair material is kneaded with water. The softness of the repair material is set based on the temperature during construction and the condition of the construction surface. Usually, it is preferable to use a mini slump value (according to JIS A 1171: 2000 “Testing Method for Polymer Cement Mortar” 6.2 Slump Test) in a range of approximately 30 to 100 mm.

(Preparation of spraying device)
The repair material S kneaded with water is put into the material tank 1 and the inner lid 6 is disposed on the upper surface thereof, and then sealed with the lid portion 1B. The material tank 1 is installed at an appropriate location near the construction site, and the air pipes P1, P2 are connected to the pressurized air inlet 2 of the lid 1B and the pressurized air inlet 13a of the connector 10. Further, the hose 4 is connected to the material delivery port 12a of the connector 10.

(Blowing work)
With the stop valve V1 of the upper air pipe P1 and the on-off valve V4 and the stop valve V5 of the connector 10 closed, the pressurized air supply device 20 such as an air compressor is started to supply the pressurized air to the material tank 1 and Supply to connector 10. The working pressure of the pressurized air can be set by the regulators R1 and R2, and is practically in the range of 0.3 to 0.4 MPa. However, the result tends to be better when the pressure value of the regulator R2 on the connector 10 side is set not to be lower than the pressure value of the regulator R1 on the lid 1B side. When the pressure setting is completed, the stop valve V1 of the upper air pipe P1 and the stop valve V5 of the connection tool 10 are opened, and the material tank 1 and the secondary side pipe part 12 and the air supply pipe part 13 of the connection tool 10 are opened. After making the pressurized air act, the on-off valve V4 of the connector 10 is opened. As a result, the repair material S in the material tank 1 is pushed out from the material discharge port 3 into the connector 10 by the pressure of the pressurized air acting through the upper lid 6 and the inner lid 6. Then, the repair material S pushed out into the connector 10 is sent to the hose 4 by the pressure of the pressurized air acting through the lower air pipe P2, and ejected in a mist form from the tip of the nozzle 5, so that the target construction surface To be sprayed.

  In this example, when the opening / closing valve V4 of the connection tool 10 is opened and the repair material S is introduced into the connection tool 10, pressurized air is applied to the air supply pipe portion 13 in advance. Moreover, since the air supply pipe part 13 and the secondary side pipe part 12 are formed coaxially, the pressurized air acts on the secondary side pipe part 12 from the upstream side of the flow path. Therefore, there is no possibility that the repair material S flows into the air supply pipe portion 13, and the problem that the connection portion between the lower air pipe P2 and the connector 10 is clogged with the repair material S is completely avoided.

(End processing)
After the required spraying operation is completed, the on-off valve V4 of the connector 10 is closed to stop the outflow of the repair material S from the material tank 1, and then the pressure of the upper air pipe P1 and the lower air pipe P2 Reduce the pressure. The repair material S remaining in the connector 10 and the hose 4 can be discharged from the nozzle 5 by closing the on-off valve V4 of the connector 10 before the pressure in the lower air pipe P2 is lowered. The cleaning operation of the connector 10 and the hose 4 after the completion is simplified. In addition, when the repair work is temporarily interrupted, the repair material S can be removed from the connection tool 10 and the hose 4, so that the cleaning work of the connection tool 10 and the hose 4 performed when the work is resumed can be simplified.

(Inner lid action)
As shown in FIG. 5A, by placing the inner lid 6 on the upper surface of the repair material S accommodated in the material tank 1, the pressure of the pressurized air supplied through the upper air pipe P1 is reduced. Since the surface can be made to act uniformly, the extrusion efficiency of the repair material S is improved.
As the repair material S is sprayed, the storage amount of the repair material S in the material tank 1 decreases. However, since the lower side of the material tank 1 has a conical shape, the inner lid 6 is not deformed. When the upper surface of the repair material S is lower than the upper end of the conical portion a2, the degree of adhesion between the inner lid 6 and the repair material S is reduced, and the extrusion efficiency of the repair material S is deteriorated. However, in the present invention, since the slit 6a in the radial direction is formed in the inner lid 6, when the inner lid 6 descends from the upper end of the conical portion a1 of the material tank 1 as shown in FIG. The inner lid 6 is deformed into a conical shape by overlapping the portion 6b sandwiching the slit 6a in the inner lid 6 in accordance with the reduced diameter of the surface.
As shown in FIG. 5 (C), as the inner lid 6 is lowered, the ratio of the overlapping portions 6b is increased. Eventually, the inner lid 6 discharges most of the repair material S from the material tank 1, and the conical portion a1. A cone shape with an apex angle approximately equal to is reached. By such an action of the inner lid 6, even when the upper surface of the repair material S becomes equal to or lower than the upper end of the conical portion a1, the extrusion efficiency of the repair material S can be kept good.

An experiment for spraying a repair material for concrete was performed under the following conditions.
(Blowing device)
・ Material tank height 600mm / cone height 202mm / maximum inner diameter 254mm / capacity 16.5 liters / steel / wall thickness 6mm
・ Inner lid diameter 240mm / Thickness 3mm / Natural rubber ・ Pressurized air supply device (air compressor)
Output 307 kw / air discharge rate 400 liters per minute / maximum operating pressure 0.99 MPa

(Repair material for concrete)
・ BASF Pozzolith Co., Ltd. polymer cement-based cross-section restoration material “Emaco S99P”
・ Adjustment method A pail can with a capacity of about 20 liters is charged with kneaded water measured according to the target mini slump value. While stirring with a hand mixer, one bag of repair material (25 kg) is gradually added. Kneaded for 2 minutes.

(Primer)
・ Acrylic resin-based water-absorption-preventing base material “Master Seal 520” (main component special acrylic ester) manufactured by BASF Pozzolith Co., Ltd.

[Test method]
(1) Blowing property confirmation test The effect of the softness (mini slump value) of the repair material and the air pressure acting on the material tank and the connecting pipe on the blowing property was examined.
The repair material adjusted by setting the target mini-slump value to any one of 30, 40, 50, and 60 mm by the above adjustment method is put into the material tank, and the inner lid is arranged. The gauge pressure of the regulator R1 of the upper air pipe P1 (hereinafter referred to as the upper pressure) and the gauge pressure of the regulator R2 of the lower air pipe P2 (hereinafter referred to as the lower pressure) are set in the range of 0.2 to 0.35 MPa. The state of spraying of the repair material discharged from the nozzle was visually observed.

The test data is based on the following measurement method.
(Repair material temperature)
The temperature after kneading was measured with an alcohol thermometer.
(Mini slump value: softness of repair material)
According to JIS A1171: 2000 “Testing method for polymer cement mortar” 6.2 slump test.
(Discharge flow rate)
The discharge flow rate per unit time was calculated from the total weight of the repair material charged into the material tank (25 kg per bag + mixed water weight), the discharge time when spraying the repair material, and the remaining amount of the repair material in the material tank.

(2) Compressive strength test The influence of the softness (mini slump value) of the repair material on the compressive strength of the repair material was examined.
(Test method)
Conforms to JIS A 1108: 2006 “Testing method for compressive strength of concrete”.
(Specimen)
A plastic mold with an inner diameter Φ = 5 cm and a depth of 10 cm is filled with a repair material before spraying (immediately after kneading), and a repair material is sprayed and filled with a spraying device. After demolding in the sun, the specimen was aged in the air until the age of 7 days was used as a specimen.
(Unit volume mass)
JIS A 1171: 2000 “Testing Method for Polymer Cement Mortar” 6.3 Based on the unit volume mass test, the plastic simple mold was filled with a repair material before spraying (immediately after kneading), and a spraying device It measured using what filled the repair material by spraying.

(3) Adhesion test The effect of the softness (mini slump value) of the repair material on the adhesion strength of the repair material was examined.
(Specimen)
In accordance with the provisions of JIS A5371: 2004 “Precast unreinforced concrete products”, a ground concrete board 31 having a plane size of 300 × 300 mm and a thickness of 60 mm shown in FIGS. 32, the reinforcing bars (D19) 33a and 33b are placed at the center at a position away from the surface of the ground concrete plate 31 by a predetermined distance d (three types of 10, 15, and 20 mm) as shown in FIG. They are arranged so as to be orthogonal to each other, and this is used as a test substrate 30. And after installing this test board | substrate 30 on a ceiling surface and spraying the said repair material "Emaco S99P" on the surface by this invention spraying apparatus, what was air-cured to the age of seven days is mentioned later. The specimen used for each test was used.

(Interlayer adhesion test)
Conforms to Appendix 2-1 JRWCT A1-2003 “JR West Cross Section Restoration Material / Interlayer Adhesion Field Test” in “Guide for Repairing Concrete Structures [Third Edition] (West Japan Railway Company, April 2003)” It was done.
The measurement points of the interlaminar adhesion strength are the regions indicated by the symbol X in FIG. (A) for each of the three types of specimens with the back-bar spacing d = 10, 15, 20 mm shown in FIG. 7 (C).

(Interface adhesion test)
Conforms to Annex 2-1 JRWCT A1-2003 “JR West Cross Section Restoration Material / Interfacial Adhesion Field Test” in “Guide for Repairing Concrete Structures [Third Edition] (West Japan Railway Company, April 2003)” It was done.
For the measurement of the interlaminar adhesion strength, the portion indicated by the symbol Y in FIG. (A) is used for each of the three types of specimens with the back-bar spacing d = 10, 15, 20 mm shown in FIG. 7 (C).

[Test results]
(1) Spraying property confirmation test The test results are shown in [Table 1].
(Trial number 1-4)
When the upper pressure was set at 0.3 MPa and the lower pressure was set at 0.35 MPa, a good spraying state in which the repair material having a mini slump value in the range of 30 to 60 mm was discharged in a mist form was obtained.
However, when the repair material of Test No. 3 was hard (when the mini slump value was small), the sprayed state tended to fluctuate slightly, but it did not affect the quality after construction.

(Trial number 5-7)
When the upper pressure and the lower pressure were equally set to 0.3 MPa, the target mini slump value was set to 50 mm, and the spraying property was good and there was no problem. (Trial number 5)
In the case where the target mini slump value was set to 30 mm, the repairing material was hard, and thus a phenomenon of discharging while pulsating was observed. (Trial number 6)
In the case of a slightly soft repair material with a mini slump value of 60 mm, a phenomenon was observed in which the repair material was blown away by the momentum of spraying. (Trial number 7)

(Trial number 8)
When the upper pressure is set to 0.2 MPa and the lower pressure is set to 0.35 MPa, the discharge flow rate tends to be insufficient when the repair material is relatively soft with the target mini slump value being 50 mm.

(Trial number 9)
When the upper pressure was set to 0.3 MPa and the lower pressure was set to 0.25 MPa lower than that (mini slump value 50 mm), the repair material could not be blown out.

(Trial numbers 10-12: Comparative example)
As shown in FIG. 6A, when the configuration of the connector 10 is such that the primary side pipe part 11 and the secondary side pipe part 12 are coaxial, and the air supply pipe part 13 is provided in the middle thereof, In general, a good spraying state of the repair material was obtained. (Upper pressure 0.3 MPa, lower pressure 0.35 MPa, target mini slump value 40-60 mm)
However, since the posture of the connector 10 is in the vertical direction and the material delivery port 12a connecting the hose 4 is at the lower end, there is a drawback that it is difficult to ensure the effective length of the hose 4.

(Trial number 13: Comparative example)
As shown in FIG. 6 (B), the connecting device 10 is configured such that the secondary side pipe part 12 is bent at a right angle with respect to the primary side pipe part 11, and the air supply pipe part is located downstream of the bent part Q. When it was set as the structure which provides 13, the favorable spraying state of the repair material was able to be obtained in general. (Upper pressure 0.3 MPa, lower pressure 0.35 MPa, mini slump value 36 mm)
However, there is a problem that the repair material remains in a portion from the on-off valve V4 in the connection tool 10 to the connection portion J of the air supply pipe portion 13 after the spraying is finished.

(2) Compressive strength test The test results are shown in [Table 2].
The target mini slump value is set to 30 ・ 50 ・ 60mm, the softness is hard, the standard and soft repair materials are prepared, and the repair material with the standard softness (target mini slump value 50mm) is applied at the time of spraying. When the compressive strength of the manufactured specimens was measured with different lower pressures, values that gave no problem in construction quality were obtained.

(3) Adhesion test The test results are shown in [Table 3]. The repair material used is the same as that used for the compressive strength test.
(Interlayer adhesion test)
In any condition, the average value is 1.0 N / mm ² or more, which satisfies the specified value.
However, the measured value of only one specimen did not reach 1.0 N / mm ² , which is presumed to be because the specimen was evaluated at the age of 7 days in this test. Usually, it is known that when the material reaches 28 days of age, the strength is improved by about 20 to 30%, so that it is considered that there is no problem in practical use.

(Interface adhesion test)
The average value of 1.0 N / mm ² or more in any conditions, for the individual measurements, and in all 0.85N / mm ² or more, satisfies the specified value.

It is drawing which shows schematic structure of the spraying apparatus which concerns on this invention. It is the schematic which shows the structure around the material tank in the spraying apparatus which concerns on this invention. The fastening means in the material tank which concerns on this invention is shown, Comprising: A figure (A) is a front view when a cover part is detachable, A figure (B) is a front view which shows a fastening state. It is the front view which carried out the partial cross section which shows the nozzle part in the spraying apparatus which concerns on this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is for demonstrating the effect | action of the inner lid arrange | positioned in the material tank of the spraying apparatus which concerns on this invention, Comprising: FIG. (A) is front sectional drawing of the material tank before starting a spraying operation, and the plane of an inner lid Figure, Figure (B) is a front sectional view of the material tank in the middle of the spraying work and a plan view of the inner lid at that time, Figure (C) is a front sectional view of the material tank just before the end of the spraying work, and the middle at that time It is a top view of a lid | cover. Fig. (A) is a front view showing a comparative example related to the connector, and Fig. (B) is a front view showing a different comparative example related to the connector. The test substrate used for the adhesive force test of the repair material sprayed by the spraying method concerning this invention is shown, Comprising: A figure (A) is a bottom view, A figure (B) is a front view, A figure (C) is a principal part. It is the front view which expanded.

Explanation of symbols

DESCRIPTION OF SYMBOLS M ... Spraying apparatus 1 ... Material tank 1A ... Main-body part a1 ... Cylindrical part a2 ... Conical part 1B ... Cover part 2 ... Pressurized air introduction port 3 ... Material discharge port 4 ... Hose 5 ... Nozzle 6 ... Middle lid 6a ... Slit 10 ... Connector 11 ... Primary side pipe part 12 ... Secondary side pipe part 13 ... Air supply pipe part 20 ... Pressurized air supply device P1 ... Upper air pipe P2 ... Lower air pipe R1, R2 ... Regulator S ... Repair material

Claims (6)

  A material tank having a pressurized air inlet at the top and a material outlet at the bottom, a connector having a pressurized air inlet connected to the material outlet of the material tank, and a base end portion of the connector From a hose that is connected to the material delivery outlet and has a nozzle attached to the tip, and a pressurized air supply device that feeds pressurized air to the pressurized air inlet of the material tank and the pressurized air inlet of the connector A spraying device characterized by comprising.   The connector includes a primary side pipe connected to a material discharge port of a material tank, a secondary side pipe connected to a hose and including a material delivery port, and an air supply pipe including a pressurized air receiving port. The secondary side pipe part is formed to be bent at an angle of 90 degrees or less with respect to the primary side pipe part, and the air supply pipe part is connected coaxially to the secondary side pipe part. The spraying device described.   The air pressure is adjusted in the middle of the piping connecting the pressurized air supply device and the pressurized air inlet of the material tank, and in the middle of the piping connecting the pressurized air supply device and the pressurized air receiving port of the connector. The spraying device according to claim 1, further comprising a regulator that performs the operation.   At least the inner surface of the material tank is formed in a conical shape whose diameter is reduced toward the lower side, and an inner lid formed in a disk shape by a flexible member and formed with a radial slit is formed in the material tank. The spraying device according to any one of claims 1 to 3, wherein the spraying device is disposed on an upper surface of the stored spraying material.   Repair material for concrete is stored in a material tank with a pressurized air inlet at the top and a material outlet at the bottom, and repaired by supplying pressurized air from the pressurized air inlet into the material tank. The material is pushed out of the material tank into the hose through the connection connected to the material discharge port, and at the same time, pressurized air is applied to the pushed out repair material to move the repair material from the tip of the hose toward the target. A spraying method for repair materials for concrete, characterized by spraying.   The inner surface of at least the lower side of the material tank is formed in a conical shape whose diameter is reduced downward, and is formed into a disk shape by a flexible member on the upper surface of the spray material stored in the material tank, and is a radial slit. When the repair material is pushed out from the material tank through the inner lid by the pressurized air supplied from the pressurized air inlet into the material tank, the inner surface of the material tank has a conical shape. The spraying of the repair material for concrete according to claim 5, wherein when the inner lid descends, the inner lid is deformed into a conical shape by polymerizing a portion of the inner lid that sandwiches the slit in accordance with the reduced diameter of the inner surface. Construction method.