KR20150005179A - Vacuum grouting method for filling post-tensioned concrete grout in sheath tube of post-tensioned bridge - Google Patents

Abstract

A vacuum grouting method for filling a sheath tube of a bridge constructed by a post-tension method with post-tensioned concrete grout is provided to densely fill a sheath tube after completely removing air remaining in the sheath tube using an intermediate exhaust unit, prevent an accident of collapse of a bridge due to break caused by corrosion of tension PC steel after completion of the bridge by, when the sheath tube of the bridge constructed by a post-tension method is constructed, inspecting quality of grouting according to data transmitted from a previously installed sensor for measuring remaining air during a vacuum grouting work, extend service life of bridge, and also reduce the scale of PC grout injection equipment by using a small single mixer to control opening and closing with a closing and opening handle.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum grouting method for a post-tension bridge,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum grouting method, and more particularly, to a vacuum grouting method in which a sheath tube of a bridge constructed by post-tensioning is filled with a PC (Post-tensioned Concrete) grout, ) Construction method.

Recently, prestressed concrete bridges using PS (Pre Stressed) steel (stranded wire or steel bar) are being actively applied to highways, national roads and provincial roads. These prestressed concrete bridges are classified into a pre-tension method and a post-tension method depending on the introduction time of the prestress. Here, the prestress is a method of applying tensile stress to compensate for weak defects of concrete Quot; refers to a force that increases tensile stress by applying a compressive force to a portion in advance.

Specifically, the pre-tension method refers to a method of providing a compressive force to a structure by a method in which a prestress is introduced by curing the concrete in a tense state of a PS steel material, and a post- Tension method is a method of filling the sheath pipe according to the linear shape of the designed bridge and then hardening the upper concrete and then introducing the prestress into the hydraulic jack by inserting the PS steel into the sheath pipe. It is a method of filling a hollow space in a sheath tube with grout after the tension of the steel to complete the bridge.

Among the two methods of introducing the prestress, the pre-tension method is a state in which the tensile PS steel (stranded wire or steel bar) and the concrete are in close contact with each other without any gap. In the post-tensioning method, the tensile PS steel The grouting in the sheath pipe to be protected with the tensile PS steel (stranded wire or steel bar) may become poor with time.

Therefore, the construction of the prestressed concrete bridges is mostly done by Post-Tension method. Therefore, sufficient grouting must be done to protect the PS steel (strand or steel bar) in the sheath pipe as well as to exhibit its performance.

1 (a) is a vertical cross-sectional view of a post tension bridge, and Figs. 1 (b) and 1 (c) are cross-sectional views of the post tension bridge according to the prior art, Fig. 1D is a cross-sectional view of the BB line of Fig. 1A as an incline. Fig. 1C is a sectional view of the PSC girder bridge and the PSC beam bridge.

As shown in FIG. 1A, a sheath pipe 20 is inserted in a post tension bridge 10 according to a conventional technique. For example, as shown in FIGS. 1B and 1C, a PSC girder bridge 10a And a plurality of sheath tubes 20 are inserted in the PSC beam bridge 10b. 1 (d), a PS steel material (strand or steel bar) 30 is inserted into the sheath pipe 20 and filled with PC (Post-tensioned Concrete) grout 40. As shown in FIG.

PC (Post-tensioned Concrete) Grouting is a method of tightening a strand inserted in a sheath tube or duct and tightening the duct using a cementitious material in order to protect it from external harmful substances such as chloride Filling work.

Particularly, it is known that a post-tension (PC) structure, for example, a PC bridge 10, has a higher durability performance than a reinforced concrete (RC) structure because it artificially controls a crack by artificially compressing it. However, in recent years, it has been recognized that the service life of the PC structure (10) is directly related to the corrosion prevention of the stranded wire (30) through the case of corrosion of the PC structure in overseas. In order to ensure the durability of the PC structure 10, many improvements have been made to the design, materials, details and construction methods. In particular, the grout 40, which is the last means of protecting the PS steel (strand or steel bar) ) Is recognized as the most efficient process for preventing the corrosion of the PS steel (stranded wire or steel bar) 30 and its importance is emphasized. This is because if the sheath pipe 20 is completely filled with the pores of the grout 40, it is possible to separate the PS steel material (strand or steel bar) 30 from the external harmful substances, so that corrosion does not occur.

For example, in recent years, a number of cases of corrosion of prestressed concrete bridges have been identified as the most important cause of the collapse of prestressed concrete bridges. In Korea, the condition of prestressed bridges with 30 to 40 years of bridge completion has been continuously maintained, such as cracks, whitewash, and reinforcing steel exposed. PSC girder bridges or PSC beam bridges have been completed After more than the elapse of the time, the increase of the design load and the deterioration of the bridge depend on only the external reinforcement method of the bridge without investigating the state of the tensile PS steel inside the bridge.

On the other hand, Corrosion of Reinforce Concrete (RC) structures means oxidation phenomenon that occurs due to reaction with chlorides penetrated in reinforced concrete. In such an RC structure, before the structural defects are caused by corrosion, RC structures suffer from usability problems such as occurrence of rust and peeling, and most of them do not directly affect the safety of the structure. However, the corrosion of the PC structure 10 refers to a phenomenon of hydrogen embrittlement, which is a type of stress corrosion caused by penetration of hydrogen atoms into reinforcing metal molecules. This phenomenon occurs mainly in high-strength steels, and when such damage is accumulated, brittleness is destroyed without visual warning such as rust or crack such as corrosion phenomenon. Therefore, when the PC structure 10 is corroded, it is difficult to evaluate the damage, but accumulation of damage may directly affect the safety of the structure.

Recently, for the grout filling, for example, Japanese Laid-Open Patent Publication No. 2002-309777, Japanese Laid-Open Patent Publication No. 2005-133397, Japanese Laid-Open Patent Publication No. 2006-132201 and Japanese Laid-open Patent No. 2010-222809 A vacuum grouting method is being developed.

FIG. 2 is a view for explaining filling of grouting in a sheath pipe of a post tension bridge according to a conventional technique, and FIG. 3 is a photograph illustrating defects in a sheath pipe of a post tension bridge according to a conventional technique.

In the case of the post tension bridge 10 according to the related art, as shown in FIG. 2, the grout 40 may be unfilled at the curved portion of the sheath pipe 20, There is a possibility that corrosion of the stranded wire 30 occurs in the sheath tube 20 as shown in Fig.

In this grouting operation, it is necessary to thoroughly control the quality of the material and the construction method. However, insufficient grout filling may cause voids in the sheath pipe 20 to cause corrosion of the tensile PS steel 30 Resulting in problems. In addition, the water-cement ratio of the grout is specified to be 50% at maximum. However, there is no reason to judge the grout work and it is uncertain, and since the ratio of water is increased to facilitate the work, bleeding phenomenon occurs, There is a problem that it can occur.

Japanese Unexamined Patent Publication No. 2002-309777 (published on October 23, 2002), entitled "Injection charging method of grout in a duct of a PC structure, injection filling device of a grout and duct for confirming grout filling" Japanese Unexamined Patent Publication No. 2005-133397 (published May 26, 2005), entitled "Grout injection apparatus and grouting method in cable sheath pipe of PC structure" Japanese Unexamined Patent Publication No. 2006-132201 (published on May 25, 2006), entitled "Grouting in a cable sheath pipe including a vacuum process for a PC structure" Japanese Unexamined Patent Publication No. 2010-222809 (Publication date: October 7, 2010) Title of invention: "Method of refilling grout in cable sheath pipe in existing PC structure"

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems and an object of the present invention is to provide a vacuum grouting method in which a sheath pipe of a bridge constructed by a post tension method is filled with PC (Post-tensioned Concrete) grout, The present invention is to provide a vacuum grouting method for filling the post tension bridge inside the sheath pipe, which can fill the inside of the sheath pipe after the residual air is completely removed.

According to another aspect of the present invention, there is provided a method of controlling a grouting quality of a bridge after completion of a bridge by performing a grouting quality control according to data transmitted from a residual air measurement sensor installed during a vacuum grouting operation when a bridge constructed by a post- The present invention is to provide a vacuum grouting method for internal filling of a sheath tube of a post tension bridge capable of preventing an accident that a bridge is collapsed due to corrosion, and to prolong the life of a bridge.

Another object of the present invention is to provide a vacuum grouting method for filling a post tension bridge in a sheath pipe, which can reduce the size of PC grout injection equipment by using a small single blender controlled by opening / .

As a means for achieving the above-mentioned object, the vacuum grouting method for filling the sheath tube of the post tension bridge according to the present invention is a method for filling a sheath tube of a post-tensioned bridge A vacuum grouting method comprising the steps of: a) closing an exhaust port and an intermediate exhaust port respectively formed in an exhaust port and an upper surface of a sheath pipe and sealing the interior of the sheath pipe; b) vacuum depressurizing the inside of the sheath tube by operating a vacuum pump installed at a rear end of the sheath tube; c) feeding pressurized PC (Post-tensioned Concrete) grout through a single mixer whose opening and closing is controlled through an opening / closing handle; d) activating an injection pump to inject said PC grout into said sheath tube via an injection hose; e) stopping the vacuum pump when the PC grout reaches the discharge hose and stopping the injection of the PC grout; f) discharging the residual air in the sheath tube by opening the exhaust port and the intermediate exhaust port; g) closing the exhaust port and the intermediate exhaust port and re-injecting the PC grout; h) refilling the inside of the sheath tube to complete filling of the PC grout, wherein the intermediate exhaust is connected to the sheath tube to exhaust residual air in the sheath tube.

In the step (f), the residual air measurement sensor is installed in the inlet and outlet of the sheath pipe and the intermediate exhaust port, and the volume of the sheath pipe is measured by air pressure to confirm an appropriate amount of PC grout.

Here, the single mixer in the step c) may be a small mixer that stirs the PC grout with one mixer and controls the opening and closing of the PC grout through the opening and closing handle to feed the PC grout.

Here, the reduced pressure state in the sheath tube is checked by the first and second pressure gauges provided at the inlet and the outlet of the sheath tube in step b), and the pressure inside the sheath tube is reduced to -0.08 to -0.09 MPa .

In step e), the first and second pressure gauges may be adjusted to a range of -0.08 to -0.09 MPa, the PC grout may be discharged through the discharge hose, and the injection of the PC grout may be stopped.

In the step f), the intermediate exhaust port is installed where the residual air is most generated in order to remove the residual air, and a vacuum pump or a vacuum device is connected to the intermediate exhaust port to remove the residual air in the sheath pipe .

In the step (h), the inside of the sheath tube is re-pressurized to 0.5 MPa.

According to the present invention, in a vacuum grouting method in which a sheath pipe of a bridge constructed by a post tension method is filled with a PC (Post-tensioned Concrete) grout, residual air in the sheath pipe is completely removed using an intermediate vent, And the like.

According to the present invention, by performing the grouting quality control according to the data transmitted from the pre-installed residual air measurement sensor during the vacuum grouting operation during the construction of the bridge constructed by the post-tensioning method, It is possible to prevent the collapse of the bridge in advance and prolong the life of the bridge.

According to the present invention, opening and closing are controlled through the opening / closing handle and the size of the PC grout injection equipment can be reduced by using a small single mixer.

1 is a view for explaining a sheath tube of a post tension bridge according to the prior art.
FIG. 2 is a view for explaining grouting unfilling in a sheath pipe of a post tension bridge according to a conventional technique.
3 is a photograph illustrating defects in a sheath tube of a post tension bridge according to the prior art.
4 is a schematic view for explaining a vacuum grouting method for filling the post tension bridge inside the sheath pipe according to the embodiment of the present invention.
5 is a view for explaining a vacuum grouting method for filling a post tension bridge in a sheath pipe according to an embodiment of the present invention.
6 is a flowchart of a vacuum grouting method for filling a post tension bridge inside a sheath pipe according to an embodiment of the present invention.
7A and 7B are a front view and a side view, respectively, of a mixer used in a vacuum grouting method for filling a sheath tube of a post tension bridge according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, which will be readily apparent to those skilled in the art. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and similar parts are denoted by like reference characters throughout the specification.

Throughout the specification, when an element is referred to as "comprising ", it means that it can include other elements as well, without excluding other elements unless specifically stated otherwise.

[Vacuum Grouting Method for Internal Filling of Sheath Tubes of Post Tension Bridges]

4 is a schematic view for explaining a vacuum grouting method for filling the post tension bridge inside the sheath pipe according to the embodiment of the present invention.

4 (a) shows a PSC girder bridge 300a to which a vacuum grouting method for filling a sheath tube of a post tension bridge according to an embodiment of the present invention is applied, and FIG. 4 (b) shows a PSC BEAM bridge 300b 4C is a view for schematically explaining a vacuum grouting method for internal filling of the sheath tube of the post tension bridge according to the embodiment of the present invention applied to the PSC girder bridge 300a or the PSC BEAM bridge 300b to be.

A plurality of sheath pipes 310 are respectively inserted into the PSC girder bridge 300a and the PSC BEAM bridge 300b as shown in Figures 4a and 4b, And then the sheath pipe 310 is filled with the PC grout 400. As shown in FIG.

Here, PC grouting is one of many work types to be carried out during the construction of prestressed concrete bridges (PSC girder bridges, PSC BEAM bridges). Here, the PC grout 400 is composed of cement, water, and an admixture. At present, it is common to use grout mixed with fluidity and swelling admixture at a water-cement ratio of about 40 ~ 45% at a ratio of 1% of cement mass. Such PC grout should be performed as soon as possible after prestressing.

4C, the vacuum grouting method for filling the sheath tube of the post tension bridge according to the embodiment of the present invention is characterized in that the sheath tube 310 of the post- A vacuum pump 190 is installed at a rear end outlet of the sheath pipe 310 and at least one intermediate exhaust pipe 210 is installed perpendicularly to the sheath pipe 310, The residual air measurement sensor 220 and the intermediate exhaust opening / closing valve 230 are installed in the exhaust port 210. At this time, the intermediate exhaust port 210 is evacuated by the vacuum pump 240 or the vacuum pump, and the residual air can be discharged. The residual air measurement sensor 220 is also installed at the front end inlet portion of the sheath pipe 310 and the rear end outlet portion of the sheath pipe 310.

That is, in order to remove the residual air in the sheath pipe 310, an intermediate exhaust port 210 is installed at a place where the most residual air is expected to occur, and the vacuum air 240 or the vacuum pump is connected to the intermediate exhaust port 210 To remove the residual air, thereby ensuring a tight grout.

In the vacuum grouting method for filling the sheath pipe of the post tension bridge according to the embodiment of the present invention, the volume of the sheath pipe 310 is measured by air pressure to check the proper amount of grout beforehand so that the grout can be grouted Also, it is possible to confirm whether or not the sheath pipe 310 itself or the sheath pipe connection portion is clear.

 In addition, the process control and control unit 250 can systematically control the vacuum grouting operation by integrally controlling and controlling various data of the residual air measurement sensor 220 installed at each weak point and tensile PS steel material.

5 is a view for explaining a vacuum grouting method for filling the post tension bridge internal to the sheath pipe according to the embodiment of the present invention. FIG. 6 is a view for explaining the vacuum grouting method for the post tension bridge according to the embodiment of the present invention, Figure 3 is a flow chart of a vacuum grouting method for internal filling.

5, a vacuum grouting system for internal filling of a sheath tube of a post tension bridge according to an embodiment of the present invention includes a mixer 110, a hopper 120, an injection pump 130, a flow meter 140, First to third valves 151 to 153, an injection hose 161, a discharge hose 162, first and second switching valves 171 and 172, first and second pressure gauges 181 and 182, The vacuum pump 190, the intermediate exhaust port 210, the exhaust port 211, the residual air measurement sensor 220, the intermediate exhaust opening / closing valve 230, the vacuum air (or vacuum pump) . ≪ / RTI >

The mixer 110 is a 2HP inverter grouting blender and is a mixer for stirring the PC grout 400. The mixer 110 stirs the PC grout 400 and controls the opening and closing of the PC grout 400, Or a small mixer that feeds the press. That is, although the conventional mixer 110 uses two mixers, in the case of the vacuum grouting system for filling the sheath tube of the post tension bridge according to the embodiment of the present invention, a compact single mixer 110 can be used A detailed description of the mixer 110 will be given later with reference to FIGS. 7A and 7B.

In addition, the hopper 120 temporarily stores the PC grout 400 formed in the mixer 110. Here, the PC grout 400 can be easily managed using a pre-bonded product so that the PC grout 400 can be grouted without being mixed in the field.

The injection pump 130 injects the PC grout 400 stored in the hopper 120 into the sheath pipe 310 along the supply pipe using the hydraulic pressure and the flow meter 140 measures the hydraulic pressure, (Not shown).

The first valve 151 is connected to the supply pipe to open and close the supply pipe and the second valve 152 is installed at the lower end of the first pressure gauge 181. The third valve 153 is connected to the front end of the vacuum pump 190 And controls opening and closing.

The injection hose 161 is installed at the injection port of the sheath pipe 310 to supply the PC grout 400 and the discharge hose 162 is connected to the sheath pipe 310 to discharge the PC grout 400. [ As shown in FIG.

The first switching valve 171 is installed at the connection portion of the supply pipe and the injection hose 161 and the second switching valve 172 is installed at the connection portion of the discharge port and the exhaust port 221.

The first pressure gauge 181 measures the pressure supplied to the sheath tube 310 and the second pressure gauge 182 measures the pressure exerted from the sheath tube 310.

The vacuum pump 190 is formed at the outlet of the sheath tube 310 to vacuum-form the inside of the sheath tube 310.

The intermediate exhaust pipe 210 is installed at a place where the most residual air is expected to be generated in order to remove the residual air in the sheath pipe 310 and the vacuum pump 240 is connected to the intermediate exhaust pipe 210, The air can be removed, thus ensuring a tight grout. The exhaust port 211 is installed at the outlet of the sheath pipe 310 to exhaust the air in the sheath pipe 310. That is, the exhaust port 211

The residual air measurement sensor 220 is installed in the intermediate exhaust port 210 to measure residual air. The residual air measurement sensor 220 is also installed at the front end inlet portion of the sheath pipe 310 and the rear end outlet portion of the sheath pipe 310.

The intermediate exhaust opening / closing valve 230 is installed in the intermediate exhaust opening 210 to open / close the intermediate exhaust opening 210.

A vacuum air (or vacuum pump) 240 forms a vacuum in the intermediate exhaust port 210 so as to discharge the residual air in the sheath pipe 310.

The process control unit 250 manages the process of the vacuum grouting system for filling the interior of the sheath pipe of the post tension bridge according to the embodiment of the present invention and is connected to the residual air measurement sensor 220, It is possible to control the operation of the vacuum pump 190 and the injection pump 130. At this time, in the vacuum grouting system for internal filling of the sheath tube of the post tension bridge according to the embodiment of the present invention, And a vacuum pump 190 are used.

Further, in the vacuum grouting system for filling the sheath tube of the post tension bridge according to the embodiment of the present invention, it is important to accurately check the volume of the void portion of the sheath tube 310. Therefore, By measuring the volume of the pipe 310 and confirming an appropriate amount of grout in advance, it becomes a closed grout, and it is also possible to confirm whether or not the sheath pipe 310 itself or the sheath pipe connection portion is clear. Further, in the vacuum grouting system for internal filling of the sheath tube of the post tension bridge according to the embodiment of the present invention, opening / closing is controlled through the opening / closing handle to reduce the size of the PC grout injection equipment by using the small single mixer 110 .

5 and 6, the vacuum grouting method for filling the interior of the sheath pipe of the post tension bridge according to the embodiment of the present invention is characterized in that the inner filling of the sheath tube of the post-tensioned bridge A vacuum injecting process, an evacuation process, a re-injection process, and a re-pressurization process. In the vacuum grouting process, In the vacuum grouting method, the discharge process, the re-injection process, and the re-press process are additionally performed as compared with the conventional vacuum grouting process. That is, after the residual air in the sheath pipe 310 is exhausted through the intermediate exhaust port 210, PC grouting is performed.

In detail, the vacuum grouting method for filling the interior of the sheath tube of the post tension bridge according to the embodiment of the present invention is a process of preparing the injection hole. The vacuum grouting method includes closing the exhaust port 211 and the intermediate exhaust port 210, (S110).

Next, as a preparation for injection, a vacuum pump 190 installed at the rear end of the sheath pipe 310 is operated to vacuum decompress the inside of the sheath pipe 310 (S120). The first and second pressure gauges 181 and 182 provided at the inlet and outlet of the sheath pipe 310 may be used to check the reduced pressure in the sheath pipe 310, Is reduced to -0.08 to -0.09 MPa.

Next, as an injection process, PC (Post-tensioned Concrete) grout 400 is fed by pressure through a single mixer 110 whose opening and closing is controlled through an opening / closing handle (S130). At this time, the single mixer 110 may be a small mixer that stirs the PC grout 400 with a single mixer and controls the opening and closing of the PC grout 400 through the opening and closing handle to feed the PC grout 400.

Next, as an injection process, a PC (Post-tensioned Concrete) grout 400 is supplied through the mixer 110, the injection pump 130 is operated, and the inside of the sheath pipe 310 PC grout 400 is injected (S140).

Next, as the injection process, when the PC grout 400 reaches the discharge hose 162, the vacuum pump 190 is stopped and injection of the PC grout 400 is stopped (S150). Specifically, the PC grout 400 is discharged through the discharge hose 162 to the second switch valve 172, and the injection of the PC grout 400 is stopped. At this time, the first and second pressure gauges 181 and 182 are adjusted to be in the range of -0.08 to -0.09 MPa.

Next, as the discharge process, the exhaust port 211 and the intermediate exhaust port 210 are opened to discharge the residual air in the sheath pipe 310 (S160). For example, the residual air measurement sensor 220 is installed at the inlet and outlet of the sheath pipe 310 and the intermediate exhaust port 210, and the volume of the sheath pipe 310 is measured by air pressure to calculate an appropriate amount of PC grout You can check in advance. At this time, the intermediate exhaust port 210 is connected to the sheath pipe 310 to exhaust the residual air in the sheath pipe 310. Particularly, in order to remove the residual air, the intermediate exhaust port 210 is installed at a place where the residual air is most generated, and a vacuum pump or vacuum air 240 is connected to the intermediate exhaust port 210, Can be removed.

Next, as the re-injection process, the exhaust port 211 and the intermediate exhaust port 210 are closed and the PC grout 400 is re-injected (S170).

Next, as the re-pressurization process, the interior of the sheath pipe 310 is re-pressurized to complete filling of the PC grout 400 (S180). For example, the inside of the sheath tube 310 is re-pressurized to 0.5 MPa.

7A and 7B are a front view and a side view, respectively, of a mixer used in a vacuum grouting method for filling a sheath tube of a post tension bridge according to an embodiment of the present invention.

7A and 7B, a blender 110 used in a vacuum grouting method for filling a sheath tube of a post tension bridge according to an embodiment of the present invention includes a blender drum 111, a handle 112 for opening and closing, But are not limited to, a mixer motor 113, a gear box 114, a stirrer 115, a speed reducer 116, a cover 117, a gauge 118 and a pump 119.

Specifically, mixing, stirring, and feeding are sequentially performed by using two mixers used in a vacuum grouting method according to the related art, thereby increasing the size of the entire equipment. However, as shown in FIGS. 7A and 7B, in the vacuum grouting method for filling the sheath tube of the post tension bridge according to the embodiment of the present invention, the PC grout 400 is stirred with one mixer, A single compacted mixer 110 which is controlled to open and close via a handle and feeds the PC grout 400 by pressure is used.

As a result, in the vacuum grouting method for filling the sheath tube of the post tension bridge according to the embodiment of the present invention, air is injected by an injection pump to calculate an accurate grout expected amount, and a vacuum pump is used to make the interior of the sheath tube It is a technology to fill tightly with high-quality grout. It can systematically control vacuum grouting work by integrally controlling and controlling various data of sensors installed at weak points and tensile PS steels.

It will be understood by those skilled in the art that the foregoing description of the present invention is for illustrative purposes only and that those of ordinary skill in the art can readily understand that various changes and modifications may be made without departing from the spirit or essential characteristics of the present invention. will be. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. For example, each component described as a single entity may be distributed and implemented, and components described as being distributed may also be implemented in a combined form.

The scope of the present invention is defined by the appended claims rather than the detailed description and all changes or modifications derived from the meaning and scope of the claims and their equivalents are to be construed as being included within the scope of the present invention do.

110: Mixer
120: Hopper
130: Infusion pump
140: Flowmeter
151: first valve
152: second valve
153: third valve
161: Injection hose
162: Discharge hose
171: First switching valve
172: second switching valve
181: First pressure gauge
182: Second manometer
190: Vacuum pump
210: intermediate exhaust
211: Exhaust
220: Residual air measurement sensor
230: intermediate exhaust valve opening / closing valve
240: Vacuum air (or vacuum pump)
250: process control unit
300: Post tension bridge
300a: PSC girder bridge
300b: PSC BEAM bridge
310: Sheath tube
400: PC grout

Claims (5)

In a vacuum grouting method for filling a sheath tube of a post-tensioned bridge,
a) closing the exhaust port 211 and the intermediate exhaust port 210 formed in the discharge port and the upper surface of the sheath pipe 310 and sealing the inside of the sheath pipe 310;
b) Vacuum-depressurizing the interior of the sheath tube (310) by operating a vacuum pump (190) installed at the rear end of the sheath tube (310);
c) feeding the PC (Post-tensioned Concrete) grout 400 through a single mixer 110 whose opening and closing is controlled through the opening and closing handle;
d) injecting the PC grout (400) into the sheath tube (310) through the injection hose (161) by operating the injection pump (130);
e) stopping the vacuum pump (190) when the PC grout (400) reaches the discharge hose (162) and stopping the injection of the PC grout (400);
f) discharging the residual air in the sheath pipe (310) by opening the exhaust port (211) and the intermediate exhaust port (210);
g) closing the exhaust port (211) and the intermediate exhaust port (210) and injecting the PC grout (400) again;
h) Repressurizing the inside of the sheath pipe (310) to complete filling of the PC grout (400)
The intermediate exhaust pipe 210 is connected to the sheath pipe 310 to exhaust residual air in the sheath pipe 310,
The single blender 110 in the step c) is a small blender which stirs the PC grout 400 with a single mixer and controls the opening and closing of the PC grout 400 through the opening and closing handle to feed the PC grout 400,
And the inner pressure of the sheath pipe (310) is re-pressurized to 0.5 MPa in the step (h). The vacuum grouting method for the inner filling of the sheath pipe of the post tension bridge. The method according to claim 1,
The residual air measurement sensor 220 is installed at the inlet and outlet of the sheath pipe 310 and the intermediate exhaust port 210 to measure the volume of the sheath pipe 310 by air pressure to obtain an appropriate amount of PC grout Wherein the post-tensioning bridges are pre-confirmed. The method according to claim 1,
The first and second pressure gauges 181 and 182 installed at the inlet and the outlet of the sheath pipe 310 respectively confirm the reduced pressure state of the sheath pipe 310 and the sheath pipe 310, And the inner pressure is reduced to -0.08 to -0.09 MPa. The vacuum grouting method for the inner filling of the sheath tube of the post tension bridge. The method of claim 3,
In step e), the first and second pressure gauges 181 and 182 are adjusted to be in the range of -0.08 to -0.09 MPa, the PC grout 400 is discharged through the discharge hose 162, And the injection of the grout (400) is stopped. The vacuum grouting method for filling the sheath tube of the post tension bridge. The method according to claim 1,
In the step f), the intermediate exhaust port 210 is installed where the residual air is most generated to remove the residual air, and a vacuum pump or vacuum air 240 is connected to the intermediate exhaust port 210, And the residual air in the sheath pipe (310) is removed. The vacuum grouting method for internal filling of the sheath tube of the post tension bridge.

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