US20050120660A1

US20050120660A1 - Plastic micro packer and construction method using it

Info

Publication number: US20050120660A1
Application number: US10/508,028
Authority: US
Inventors: Chun-Man Kim; Samyong Chung; Sung-Woo Park
Original assignee: Samsung Corp
Current assignee: Samsung C&T Corp
Priority date: 2002-03-16
Filing date: 2003-03-14
Publication date: 2005-06-09
Also published as: WO2003078762A1; JP3981666B2; JP2005520955A; AU2003215929A1; KR20020030054A; KR100458992B1

Abstract

Disclosed are a plastic micro packer for repairing cracks of structure and a method for repairing middle or low pressure cracks using the plastic micro packer: The micro packer is connected to a hole formed in a crack to inject, repairing solution into the crack of a concrete structure, and includes: a hollow rubber sleeve having a screw portion formed on the inner surface thereof; a hollow packer body having a screw coupling portion screwed with the screw portion and a nozzle portion connected to a repairing solution injector; and a cove; member connected to the nozzle portion to prevent leakage of repairing solution. The screw portion of the rubber sleeve has a wide top and a narrow bottom, and thereby, is closely contacted to the hole while the lower portion of the screw portion is expanded in a radial direction when the screw: coupling portion is screwed with the screw portion. A flange portion is formed at the front end of the rubber sleeve to prevent excessive induction of the rubber sleeve into the hole.

Description

TECHNICAL FIELD

The present invention relates to a plastic micro packer and a middle- or low-pressure crack repairing method using the same, and more particularly, to a plastic micro packer and a middle- or low-pressure crack repairing method using the same, which have a simple and improved structure to allow economical construction.

BACKGROUND ART

In general, cracks may occur in the outside or the inside of concrete structures or buildings due to various causes, i.e., dry contraction, temperature change, water leakage or others. Furthermore, in places where lots of loads are applied, such as floors of underground parking lots, or in places where waterproofing layer and finishing concrete layer of general floor slabs are constructed weakly, the finished concrete layers often come off even though they are not exposed to the outside of the structure or building. Most of cracks caused by normal dry contraction of concrete do not have any influence on the structure or building, but cracks occurring by excessive dry contraction or other causes may have severely bad influences on the structure or building.
Water and air may enter the cracks and the come-off portions of the structure or building, and the water and air entering facilitate efflorescence of concrete of the structure or building and incur corrosion of reinforcing rods, and thereby life of the structure or building is reduced and safety is deteriorated.
As a method for repairing the cracks formed in the surface of the concrete structures or buildings, packers have been used.
The method for repairing the cracks using the packer includes the steps of installing a tube-type metallic packer in the crack by press-fit, connecting the packer and an injector, which is filled with repairing solution, to a tube, and providing repairing solution through the tube at high pressure to fill the crack with repairing solution.
FIG. 1 of Korean Utility Model Registration No. 0172536 shows an example of a conventional packer for repairing cracks. In order to install the packer, first, a hole of a predetermined size is formed in a crack, and the packer is inserted into the hole as shown in FIG. 1. When a worker rotates an injection member 2, an interval between a lock head 3 and a nut member 4 becomes narrower, and a sleeve 5 is expanded in a radial direction. The outer circumference of the expanded sleeve 5 is in contact with the inner circumference of the hole of the crack, and the crack is filled with repairing solution by connecting an injector 6 to the injection member 2.
However, the conventional packer has a complex structure because of a check valve 1 for preventing backflow of the repairing solution.
Furthermore, work is difficult and inconvenient because tightening force generated when the worker rotates the injection member 2 expands the sleeve 5.
Moreover, because the sleeve 5 expanded after the worker rotates the injection member 2 is contacted to the crack, the contact level or force is imperfect. For a wide contact area between the sleeve 2 and the cracked part, the sleeve 2 must be formed long and the hole for inserting the sleeve 2 must be formed deep. As a result, the conventional packer is not economical due to an excessive working period of time.
Additionally, if the crack formed in the hole where high pressure acts is filled with pulverized powder generated during the perforation by a drill, repairing solution provided by the packer cannot be injected smoothly, and excessive pressure is loaded inside the hole, and thereby, the concrete structure or building can be destroyed.

DISCLOSURE OF INVENTION

Accordingly, the present invention is directed to a plastic micro packer and a middle- or low-pressure crack repairing method using the same that substantially obviate one or more problems due to limitations and disadvantages of the related art.
An object of the present invention is to provide a plastic micro packer, which has a simple structure and is constructed conveniently, and a middle- or low-pressure crack repairing method using the same.
Another object of the present invention is to provide a plastic micro packer being favorable even on edged portions, which are hard to construct, and a middle- or low-pressure crack repairing method using the same.
A further object of the present invention is to provide a plastic micro packer, which prevents stop of cracks by pulverized concrete powder generated when holes are made for inserting the packer to inject repairing solution smoothly, and a middle- or low-pressure crack repairing method using the same.
A still further object of the present invention is to provide a plastic micro packer and a middle- or low-pressure crack repairing method using the same, which can allow construction even though the holes for inserting the packer are shallow so as to reduce damage of structure or building.
Another object of the present invention is to provide a plastic micro packer and a middle- or low-pressure crack repairing method using the same, which can allow a worker to check whether or not repairing solution is injected into cracks. Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention.
The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
To achieve the above objects, in one aspect of the present invention, there is provided a plastic micro packer, which is connected to a hole formed in a crack to inject repairing solution into the crack of a concrete structure, including: a hollow rubber sleeve inserted into the hole, the rubber sleeve having, a screw portion formed on the inner surface thereof; a hollow packer body having a screw coupling portion screwed with the screw portion and a nozzle portion connected to a repairing solution injector; and a cover member connected to the nozzle portion to prevent leakage of repairing solution.
Because the screw portion of the rubber sleeve has a wide top and a narrow bottom, the lower portion of the screw portion is closely contacted to the hole of the concrete structure while being expanded in a radial direction when the screw coupling portion is connected to the screw portion. As a result, separation of the rubber sleeve is prevented during a high pressure injection.
A wrench coupling portion is formed on the circumference of the center of the packer body to screw the packer body to the rubber sleeve using a tool, such as a wrench.
The cover member includes a stopper connected to the nozzle portion, a round connection ring coupled to the screw coupling portion loosely, and a flexible connection cord for connecting the stopper and the connection ring to each other.
In another aspect of the present invention, there is also provided a method for repairing middle or low pressure cracks using a plastic micro packer includes the steps of: first forming a number of holes in cracks of a concrete structure in uniform diameter and depth and at uniform intervals; second forming deeper holes in the first holes using a core drill having a hollow-type core bit to form a concrete core portion, which passes cracks, on the bottom surface of the hole; cutting the concrete core portion attached inside each hole by applying impact to the concrete core portion; cleaning pulverized concrete powder or dust along the holes and cracks; connecting a hollow rubber sleeve to the inner surface of the hole, the hollow rubber sleeve having a screw portion; connecting a hollow packer body to the rubber sleeve, the hollow packer body having a screw coupling portion screwed to the screw portion of the rubber sleeve and a nozzle portion connected to a repairing solution injector; injecting the repairing solution into the crack through the nozzle portion; stopping the nozzle portion with a cover member after the infection of the repairing solution; and cutting and finishing the packer body and the rubber sleeve protruding from the surface of the concrete structure after the injected repairing solution is hardened.
The method for repairing middle or low pressure cracks using the plastic micro packer further includes the steps of: mounting check windows communicating with the cracks between the holes after the connection of the packer body to the rubber sleeve, the check window having a repairing solution space; and sealing the cracks along the cracks between the check windows and the holes to prevent leakage of the repairing solution.
In the sealing step, a sealing tape is adhered along the cracks.

BRIEF DESCRIPTION OF THE DRAWINGS

Further objects and advantages of the invention can be more fully understood from the following detailed description taken in conjunction with the accompanying drawings in which:
FIG. 1 is a sectional view showing a state in which a conventional packer assembly is constructed;
FIG. 2 is an exploded perspective view of a packer according to the present invention;
FIGS. 3 a and 3 b are sectional views of essential parts of the packer of FIG. 2;
FIGS. 4 a to 4 g are briefly sectional views showing a method for repairing cracks according to the present invention;
FIG. 5 a is an exploded perspective view of a check window according to the present invention;
FIG. 5 b is a sectional view showing a state in which the check window is installed;
FIGS. 6 a and 6 b are plan views showing a state in which the packer and the check window are installed on the surface of a structure:
FIG. 7 is a block diagram showing the construction method according to the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

The present invention will now be described in detail in connection with preferred embodiments with reference to the accompanying drawings. For reference, like reference characters designate corresponding parts throughout several views.
As shown in FIG. 4 b, a plastic micro packer for repairing cracks of a concrete structure according to the present, invention is coupled to a hole 101 formed in a crack 110 to inject repairing solution 200 into the crack 110. The crack 110 communicates with the bottom surface of the hole 101.
Referring to FIGS. 2 and 3, the packer 10 is coupled to the hole 101, and includes a hollow rubber sleeve 30 having a screw portion 31 formed on the inner surface, a hollow packer body having a screw coupling portion 11 screwed with the screw portion 31 and a nozzle portion 12 connected to a repairing solution injector 300 (see FIG. 4 d), and a cover member 20 connected to the nozzle portion 12 to prevent leakage of the repairing solution 200.
The screw portion 31 of the rubber sleeve 30 has a wide top and a narrow bottom. As a result, as shown in FIGS. 3 b and 4 e, when the screw coupling portion 11 is screwed, the lower portion of the screw portion 31 is closely contacted to the hole 101 of the concrete structure while expanding in a radial direction, and therefore, the rubber sleeve 30 is not separated from the hole 101 when the repairing solution is injected at a uniform pressure. Furthermore, a flange portion 32 is formed at the front end of the rubber sleeve 30 to prevent excessive insertion of the rubber sleeve 30 into the hole 101.
A wrench coupling portion 13 protrudes from the circumference of the center of the packer body 15 to be screwed with the rubber sleeve 30 using a tool, such as a wrench (not shown in the drawings). The packer body 15 is made of plastic material.
The cover member 20 includes a stopper 21 connected to the nozzle portion 12, a round connection ring 22 connected to the screw coupling portion 11 loosely, and a flexible connection cord 23 for connecting the stopper 21 and the connection ring 22 to each other.
As shown in FIG. 4 c, the packer 10 is installed in the hole 101 of the concrete structure 100 by inserting the rubber sleeve 30 into the hole 101 formed in the concrete structure 100 and connecting the screw coupling portion 11 of the packer body 15 to the rubber sleeve 30 using the wrench (not shown in the drawings). At this time, as shown in FIGS. 3 b and 4 d, because the screw portion 31 of the rubber sleeve 30 has the wide top and narrow bottom, the lower end of the rubber sleeve 30 is expanded when the packer body 15 is inserted, thereby, being closely contacted to the inner surface of the hole 101.
As shown in FIG. 4 d, after the connection of the packer 10 to the structure, the injector 300 is connected to the nozzle portion 12, and the repairing solution 200 is injected to the crack 110 at middle or low pressure of about 100 kg/cm². The packer maintains a stable state in the hole to the injected pressure.
As shown in FIG. 4 e, after the finish of the injection, the cover member 20 is connected to the nozzle portion 12 to prevent leakage of the injected repairing solution 200.
As described above, the packer 10, which is made of rubber or plastic material, is economical, and has a simpler structure than the conventional packer having a check valve because the packer 10 according to the present invention prevents leakage of the repairing solution 200 by the cover member 20.
Moreover, because the screw portion 31 of the rubber sleeve 30 has the wide top and the narrow bottom, the rubber sleeve 30 is closely contacted to the hole 101 to prevent separation of the rubber sleeve 30 when the packer body 15 is connected to the screw portion 31, and thereby, the packer 10 of the present invention has a stable structure.
A method for repairing cracks of the concrete structure using the packer 10 having the above structure will be described as follows.
Referring to FIGS. 4 to 7, first, a worker checks width, size, state and location of the crack and thickness of the concrete structure, and then, checks a location to install the packer of the present invention.
Next, as shown in FIG. 4a, the worker forms a number of first holes 101 in the crack 110 of the concrete structure 100, the holes 101 having diameter of about 10 mm and depth of about 10˜15 mm and being formed at intervals of about 25˜45 cm by a drill 120. At this time, the cracks 110 inside the holes 101 are stopped by pulverized concrete powder.
Then, as shown in FIG. 4 b, second holes 101 of about 15˜20 mm, which are deeper than the first holes, are formed in the first holes 101 by a hollow core bit 130 mounted on an electronic drill. At this time, a concrete core portion 102 is formed in the second hole 101, and concrete powder pulverized by vibration generated during the second perforation is separated from the crack 110 passing the core portion 102. The worker cleans the concrete powder using a blower (not shown).
In another method, when the crack 110 formed in the hole 101 is stopped by the pulverized concrete powder generated during the first and second perforations, as the injection of the repairing solution 200 is prevented, the concrete core portion 102 is cut by applying impact. In this case, the crack 110 shown in the section of the cut core portion 102 is not stopped by the concrete dust.
In the above condition, the worker cleans the pulverized concrete powder or dust along the hole 101 and the crack 110 formed in the surface of the concrete structure 100 using the blower (not shown).
After that, as shown in FIGS. 4 c and 4 d, the hollow rubber sleeve 30 having the screw portion 31 formed on the inner surface thereof, which has the wide top and narrow bottom, is connected to the hole 101, and the packer body 15 is screwed with the rubber sleeve 30. As shown in FIG. 2, the packer body 15 include the screw coupling portion 11 screwed to the screw portion 31 of the rubber sleeve 30, and the nozzle portion 12 connected to the repairing solution injector 300.
When the packer body 15 is screwed with the rubber sleeve 30, as shown in FIG. 4 d, the lower end of the rubber sleeve 30 is expanded in the radial direction so as to be closely contacted to the inner surface of the hole 101.
After the packers 10 are connected to the holes 101 respectively, as shown in FIGS. 4 c to 6 a, check windows 40 are mounted along the cracks 110 at regular intervals.
As shown in FIGS. 5 a and 5 b, the check window 40 includes a transparent boss 41 having a repairing solution space 41 a communicating with the crack 110 between the holes 101, a flange 42 formed around the boss 41, a double-sided adhesive 45 adhered to the bottom of the flange 42, and a release paper 46.
The check window 40 allows the worker to check whether or not the repairing solution 200 is provided into the crack 110 adjacent to the present crack 110 when the repairing solution 200 of middle or low pressure is injected into the present crack 110. That is, when the repairing solution 200 is injected through the packer 10, the repairing solution 200 is induced into the repairing solution space 41 a of the adjacent check window 40 while being provided along the crack 110. As a result, the worker can check whether or not the repairing solution 200 is injected through the check window.
As shown in FIG. 6 a, after the packers 10 and the check windows 40 are installed, the cracks 110 are sealed along the length of the cracks 110.
As shown in FIG. 6 b, the cracks 110 can be sealed with a sealing tape 400 along the length of the cracks 110. In this case, it is preferable that the sealing tape 400 is adhered also to the top surface of the flange 42 of the check window 40 to increase adhesive strength with an adhesive tape 45 of the check window 40. When the repairing solution 200 is injected along the crack 110, the worker can check through the check window 40 whether or not the repairing solution is injected. Additionally, the worker can check the injection of the repairing solution through deformation of the sealing tape 400 by pressure of the injected repairing solution 200, as the sealing tape 400 adhered on the crack 110 of the surface of the structure has elasticity.
Furthermore, the cracks may be sealed with epoxy resin along the length of the cracks, and sealed doubly by adhering the sealing tape 400 onto the top surface of the sealed epoxy resin.
Additionally, the cracks can be sealed with epoxy resin or the sealing tape 400 after the circumferences of the cracks 110 are coated with liquid type urethane-based primer (not shown) to a uniform width of about 100 mm. In this case, the primer cleans the circumferences of the cracks 110 and makes adhesion of the epoxy resin or the sealing tape 400 smooth.
After the adhesion of the sealing tape 400, the packers and the check windows are closely contacted to the floor surface of the concrete structure by a pressurizing tool (not shown).
After that, as shown in FIG. 4 d, the repairing solution injector 300 is connected to the nozzle portion 12, and the repairing solution 200 is injected into the crack 110 at a middle or low pressure of about 100 kg/cm². At this time, the repairing solution 200 is provided along the cracks 110 communicating with each other by the pressure, and is injected until the repairing solution 200 is provided into the repairing solution space 41 a of the check window 40 mounted on the surface of the concrete structure 100.
As described above, when the worker checks through the adjacent check window 40 that repairing solution 200 is provided into the repairing solution space 41 a, as shown in FIG. 4 e, the worker stops the nozzle portion 12 of the packer assembly 10 with the cover member 20, and then, injects the repairing solution 200 through the adjacent packer assembly 10 as described above.
Meanwhile, during the supply of the repairing solution 200 through the packer 10, the repairing solution 200 can be injected until air inside the crack 110 is discharged through the adjacent packer 10. In this case, the discharge of the air inside the crack 110 and the filling of the repairing solution 200 allows more stable repair.
When the injected repairing solution 200 is hardened after a predetermined period of time, the screw coupling portion 11 of the packer 10 is cut as shown in FIG. 4 f, and the sealing tape 400 is removed as shown in FIG. 4 g. Then, the packer body and the flange portion of the rubber sleeve protruding from the surface of the concrete structure 100 are cut by a cutter blade and grounded and finished.
In the method for repairing cracks as the above, it will be appreciated that the first holes 101 may be formed after attaching the check windows 40 and adhering the sealing tape 400.
Furthermore, it will be appreciated that the cracks 110 may be sealed before the packer 10 is installed after the holes 101 are formed.
Industrial Applicability
As described above, the present invention has the following advantages.
First, the packer according to the present invention can be easily constructed onto edge portions or concavo-convex portions, where the construction is complex, when cracks occur, as it has a simple structure.
Second, the conventional packer has a check valve to prevent backflow of the repairing solution, but the present invention adopts the flexible cover member of plastic material, and hereby, the present invention has a simple and improved structure and enables economical construction.
Third, because the packer of the present invention is assembled with simple tools, such as a wrench, even non-skilled person can operate it easily, and working time period is reduced.
Fourth, because the holes 101 are formed in such a manner that the worker first perforates the holes with a general drill and second perforates the holes with the core drill, the working period of time is largely reduced and life of the core drill is extended.
Fifth, because the concrete core portion is formed and cut with the core drill to prevent stop of the cracks by the pulverized concrete dust, the repairing solution is injected smoothly, and thereby, the packer enables easy construction.
Sixth, because the method for repairing the cracks using the packer of the present invention forms the holes 101 to the minimum depth, strength of the concrete structure is not reduced and embedded electric wire pipes are little damaged. Additionally, because the floor surfaces of the holes 101 are maintained at a short distance from the surface of the concrete structure, the holes can be formed at exact places on cracked line with no error.
Seventh, the conventional packer adopts the check valve to prevent backflow of the repairing solution to the outside after the repairing solution is injected, thereby the air inside the crack cannot be discharged, and as a result, the crack cannot be repaired stably. However, the present invention allows discharge of the air from the inside the crack through the adjacent packer during the injection of the repairing solution.
While the present invention has been described with reference to the particular illustrative embodiments, it is not to be restricted by the embodiments but only by the appended claims. It is to be appreciated that those skilled in the art can change or modify the embodiments without departing from the scope and spirit of the present invention.

Claims

1. A plastic micro packer connected to a hole formed in a crack to inject repairing solution into the crack of a concrete structure, the plastic micro packer comprising:

a hollow rubber sleeve inserted into the hole, the rubber sleeve having a screw portion formed on the inner surface thereof;

a hollow packer body having a screw coupling portion screwed with the screw portion and a nozzle portion connected to a repairing solution injector; and

a cover member connected to the nozzle portion to prevent leakage of repairing solution.

2. The plastic micro packer according to claim 1, wherein the screw portion of the rubber sleeve has a wide top and a narrow bottom.

3. The plastic micro packer according to claim 1, wherein a wrench coupling portion is formed on the circumference of the center of the packer body to screw the packer body to the rubber sleeve using a tool, such as a wrench.

4. The plastic micro packer according to claim 1, wherein the cover member includes a stopper connected to the nozzle portion, a round connection ring coupled to the screw coupling portion loosely, and a flexible connection cord for connecting the stopper and the connection ring to each other.

5. A method for repairing middle or low pressure cracks using a plastic micro packer, the method comprising the steps of:

forming a number of first holes in cracks of a concrete structure in uniform diameter and depth and at uniform intervals;

additionally forming deeper holes in the first holes using a core drill having a hollow-type core bit to form a concrete core portion, which passes cracks, on the bottom surface of the hole;

cutting the concrete core portion attached inside each hole by applying impact to the concrete core portion;

cleaning pulverized concrete powder or dust along the holes and cracks;

connecting a hollow rubber sleeve to the inner surface of the hole, the hollow rubber sleeve having a screw portion;

connecting a hollow packer body to the rubber sleeve, the hollow packer body having a screw coupling portion screwed to the screw portion of the rubber sleeve and a nozzle portion connected to a repairing solution injector;

injecting the repairing solution into the crack through the nozzle portion;

stopping the nozzle portion with a cover member after the injection of the repairing solution; and

cutting and finishing the packer body and the rubber sleeve protruding from the surface of the concrete structure after the injected repairing solution is hardened.

6. The method according to claim 5, further comprising the steps of:

mounting check windows communicating with the cracks between the holes after the connection of the packer body to the rubber sleeve, the check window having a repairing solution space; and

seating the cracks along the cracks between the check windows and the holes to prevent leakage of the repairing solution.

7. The method according to claim 6, wherein in the sealing step, a sealing tape is adhered along the cracks.

8. The method according to claim 6, in the sealing step, the cracks are sealed with epoxy resin.