Treatment device for residual concrete from fiber-reinforced concrete and method for treating residual concrete from fiber-reinforced concrete

Abstract

The present invention provides a treatment device for fiber-reinforced concrete residue that can extract fibers from the residue of fiber-reinforced concrete at construction sites, and separate and process each material. [Solution] A fiber-reinforced concrete residue treatment device comprising: a cage into which the fiber-reinforced concrete residue is placed; a first water tank housing the cage; and a second water tank receiving drainage from the first water tank; the first water tank is provided with an agitation pump for agitating the water stored in the first water tank; an upper drain pipe communicating with the first water tank is provided on the upper side of the first water tank; the second water tank receives the supernatant water from the first water tank discharged from the upper drain pipe as drainage; and a fiber collection basket with a mesh size smaller than the length of the fibers contained in the fiber-reinforced concrete is provided between the outlet of the upper drain pipe and the second water tank.

Description

Technical Field

[0001] The present invention relates to a residual concrete processing apparatus for fiber-reinforced concrete and a method for processing residual concrete that can be used at a construction site.

Background Art

[0002] Fiber-reinforced concrete is obtained by mixing short fibers into ordinary concrete, thereby improving strength, durability, and crack resistance. Its applications are diverse and it is utilized in various fields that require high durability and special performance, such as tunnel lining, road paving, bridge decks, building floor slabs, and seismic reinforcement.

[0003] In tunnel lining concrete, fiber-reinforced concrete is adopted to prevent the concrete on the inner wall of the tunnel from deteriorating and peeling due to the passage of time and environmental influences. This fiber-reinforced concrete is used by mixing fibers into ordinary concrete in a truck mixer at the site. The type of fiber used is non-steel fiber, specifically, polypropylene fibers are used. This improves the integrity of the concrete, significantly reduces the risk of peeling and falling, and enhances the safety and durability of the tunnel.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The construction of tunnel lining concrete is challenging because the arched shape of the tunnel creates uneven surfaces on which the concrete is sprayed. Furthermore, the concrete is poured from below in an upward-blowing manner within the enclosed end plates, making it difficult to accurately calculate the amount of concrete to be poured in advance. In addition, if concrete is not poured continuously after the initial pouring, it can lead to quality problems such as pipe blockage, insufficient filling, and cold joints. Therefore, concrete is ordered to ensure that there is no shortage of concrete. Due to these factors, leftover concrete is generated at tunnel lining construction sites.

[0006] While leftover concrete from regular concrete can be returned to the plant, leftover fiber-reinforced concrete cannot be processed at the plant and must be handled on-site. The processing method involves solidifying all of the leftover fiber-reinforced concrete and then breaking it into smaller pieces using a breaker or similar tool. However, it must be disposed of as "rubble," which incurs higher disposal costs, rather than as concrete rubble like regular concrete. Therefore, two temporary storage sites are required for leftover concrete: one for regular concrete and one for fiber-reinforced concrete. Furthermore, when breaking down hardened fiber-reinforced concrete into smaller pieces, the fibers within the concrete scatter, requiring manual collection. Therefore, there is a need for a method to separate and recover the fibers, aggregates, and other materials from fiber-reinforced concrete before it hardens.

[0007] A fiber extraction device described in Patent Document 1 is known as a device for separating fibers from fiber-reinforced concrete. However, this fiber extraction device is specialized for separating fibers, and it is difficult to separate and process other materials such as aggregate, cement, and sand.

[0008] The present invention aims to provide a fiber-reinforced concrete residue treatment device and a fiber-reinforced concrete residue treatment method that can extract fibers from the residue of fiber-reinforced concrete at a construction site and separate and process each material. [Means for solving the problem]

[0009] To achieve the above objective, the fiber-reinforced concrete residue processing device of the present invention comprises a cage into which the fiber-reinforced concrete residue is placed, a first water tank housing the cage, and a second water tank receiving drainage from the first water tank. The first water tank is provided with an agitation pump for agitating the water stored in the first water tank, and an upper drain pipe communicating with the first water tank is provided on the upper side of the first water tank. The second water tank receives the supernatant water in the first water tank discharged from the upper drain pipe as drainage. A fiber collection basket with a mesh size smaller than the length of the fibers contained in the fiber-reinforced concrete is provided between the outlet of the upper drain pipe and the second water tank. The cage may be suspended from the frame via a suspension device having a height-adjustable mechanism, and the first water tank may be movable from inside the frame, which is directly below the cage, to outside the frame. Two of the aforementioned stirring pumps may be installed in the first water tank, facing each other with the cage in between. Each of the cages consists of a box-shaped body with a mesh bottom and side mesh, and an open top. The mesh size of the side mesh may be larger than the mesh size of the bottom mesh. The cage may have an inclined section between the bottom mesh and the side mesh. The cage may also have a rod vibrator that is inserted through the side mesh. The cage may have a protruding opening that is inserted through the side mesh and sprays water into the cage.

[0010] Furthermore, a method for processing fiber-reinforced concrete residue using the fiber-reinforced concrete residue processing device of the present invention, which was made to achieve the above objective, comprises: the fiber-reinforced concrete residue processing device having a cage into which the fiber-reinforced concrete residue is put; a first water tank housing the cage; and a second water tank receiving drainage from the first water tank. The method involves lowering the cage, which is suspended from a frame, and placing it in the first water tank, which is filled with water and located directly below the cage inside the frame, and then putting the residue into the cage. The process comprises: an input step; a separation step of operating a stirring pump installed in the first tank to mix the water in the first tank with the remaining concrete in the cage; and a fiber recovery step of receiving the supernatant water from the first tank, which is discharged from an upper drain pipe connected to the first tank and installed on the upper side of the first tank, in the second tank, and recovering the fibers contained in the supernatant water using a fiber recovery basket with a mesh size smaller than the length of the fibers contained in the fiber-reinforced concrete, installed between the outlet of the upper drain pipe and the second tank. After the sorting step, the apparatus may include an aggregate discharge step in which the cage is lifted upward from the first water tank and the aggregate inside the cage is discharged. The aggregate discharge process may involve moving the first water tank from inside the frame to the outside, moving the first water tank below the lifted cage to create space, parking a dump truck in that space, and transferring the aggregate inside the cage to the dump truck for transport. The separation process may be carried out by operating two agitation pumps, each placed opposite the cage in the first water tank. The two agitation pumps may be operated alternately. The fiber-reinforced concrete residue treatment device may include a rod vibrator inserted into the cage, and in the separation process, the rod vibrator may be used to vibrate the residue concrete inside the cage. The fiber-reinforced concrete residue treatment device may have a protruding nozzle for spraying water into the cage, and in the separation process, water may be supplied directly to the residue concrete from the protruding nozzle. [Effects of the Invention]

[0011] The present invention provides at least one of the following effects. <1> Since the frame only suspends the cage, the concrete residue treatment device according to the present invention is compact, does not require a large crane or a vast yard for assembly, and can be easily introduced even at construction sites with limited space. <2> By limiting the cage's movement to only the vertical direction, the device falls outside the definition of a crane, reducing the need for final inspections and improving operational efficiency. <3> By sliding the first water tank, space can be secured beneath the cage within the frame for dump trucks to park for transporting aggregates. <4> The first water tank can be slid from inside the frame to the outside, ensuring sufficient working radius for heavy machinery when cleaning the first water tank. <5> By providing a sloping section between the bottom and side mesh of the cage, and eliminating the corners at the bottom, a configuration can be created that makes it difficult for residual concrete to remain. <6> By placing the stirring pumps opposite each other across the cage, the water flow within the cage becomes turbulent, making the separation of residual concrete more efficient. <7> By using a rod vibrator to vibrate the remaining concrete in the central part of the cage, which is less affected by the water flow, it can be made more susceptible to the effects of the water flow. <8> By supplying water directly to the central part of the remaining concrete through the stirring water supply pipe and outlet, the stirring effect of the stirring pump is enhanced. [Brief explanation of the drawing]

[0012] [Figure 1] Perspective view of the residual concrete treatment device for fiber-reinforced concrete according to the present invention. [Figure 2] Perspective view of the cage and stand [Figure 3] Perspective view of the first tank [Figure 4] Diagram illustrating the water flow in the first tank. [Figure 5] Perspective view of the second water tank and fiber collection basket. [Figure 6]Explanatory drawing (1) of the method for treating residual concrete of fiber reinforced concrete of the present invention [Figure 7] Explanatory drawing (2) of the method for treating residual concrete of fiber reinforced concrete of the present invention [Figure 8] Explanatory drawing (3) of the method for treating residual concrete of fiber reinforced concrete of the present invention [Figure 9] Explanatory drawing (4) of the method for treating residual concrete of fiber reinforced concrete of the present invention [Figure 10] Explanatory drawing (5) of the method for treating residual concrete of fiber reinforced concrete of the present invention [Figure 11] Explanatory drawing (6) of the method for treating residual concrete of fiber reinforced concrete of the present invention [Figure 12] Perspective view of the cage according to Example 2 [Figure 13] Explanatory drawing of the method for treating residual concrete of fiber reinforced concrete of the present invention according to Example 2

Mode for carrying out the invention

[0013] Hereinafter, the residual concrete treatment apparatus and the residual concrete treatment method of fiber reinforced concrete of the present invention will be described in detail with reference to the drawings.

[0014] [Example 1] <1> Outline of the residual concrete treatment apparatus The residual concrete treatment apparatus according to the present invention is for separating and taking out fibers, aggregates, cement components, and sand components from the residual concrete of fiber reinforced concrete before curing and processing them. The residual concrete treatment apparatus includes a cage 1 for charging residual concrete, a first water tank 2 for housing the cage 1, and a second water tank 3 for receiving drainage from the upper part of the first water tank 2 (Fig. 1).

[0015] <2> Cage Cage 1 is used to collect leftover concrete and separate and recover the aggregate. Both have a mesh-like bottom net 11 and side nets 12, and consist of a box-shaped body with an open top (Figure 2). Cage 1 may also be rectangular, but in the case of a rectangular shape, leftover concrete tends to remain in the corners of the bottom. Therefore, a sloping section 13 can be provided between the bottom net 11 and the side nets 12 to eliminate the corners of the bottom and create a configuration in which leftover concrete is less likely to remain. The bottom mesh 11 of cage 1 is designed to accommodate the accumulation of aggregate from the remaining concrete, and therefore has a mesh size (e.g., XS30-XS40) that is resistant to the granular shape of the aggregate. The side mesh 12 of cage 1 has a larger mesh size (e.g., XS50-XS60) than the bottom mesh 11 to prevent the fibers of the remaining concrete, which move due to the water flow described later, from becoming entangled and difficult to remove, thereby ensuring reliable separation of the fibers. Cage 1 is suspended from a frame 4 made of steel materials via a lifting device 41. The lifting device 41 has a mechanism, such as a chain hoist, that allows for adjustment of the height of cage 1. The height adjustment by the lifting device 41 may be done electrically or manually. The cage 1 may be moved laterally within the frame 4, or it may be detached from the frame 4 and moved by a crane or the like. However, in this embodiment, by limiting the cage 1 to movement only in the vertical direction, the entire device, including the frame 4, falls outside the definition of a crane, thus reducing the effort required for completion inspections and improving operability. Furthermore, since the frame 4 only suspends the cage 1, the residual concrete treatment device according to the present invention is compact, does not require a large crane or a vast yard for assembly, and can be easily introduced even at construction sites with limited space.

[0016] <3> Tank 1 The first tank 2 is a box-shaped structure with an open top (Figure 3), and is sized to accommodate cage 1 inside. Then, fibers, aggregates, cement, and sand are separated from the remaining concrete inside cage 1. Because cement and sand accumulate at the bottom of the first water tank 2, it is designed to be strong enough to be cleaned with heavy machinery such as a backhoe. Furthermore, to ensure a sufficient working radius for heavy machinery during cleaning, a carrier 21 with wheels and a motor at the bottom is provided and placed on guide rails 42 laid on the floor. It can be slid along the guide rails 42 to move from inside the frame 4 directly below the cage 1 to the outside. In addition, lowering the height of the first water tank 2 makes cleaning easier. The water in the first tank 2 is turbid due to cement and sand separated from the remaining concrete, so it is sent to a turbid water treatment facility (not shown) for treatment.

[0017] <3.1> Stirring pump A stirring pump 22 is installed in the first water tank 2, and the water stored in the first water tank 2 is stirred using the water flow from the stirring pump 22, thereby separating the fibers, aggregates, cement, and sand from the remaining concrete in cage 1. The stirring pump 22 is installed near cage 1 to direct the water flow directly onto the remaining concrete inside cage 1, efficiently separating the remaining concrete (Figure 4). Furthermore, by installing two stirring pumps 22 facing each other across the cage 1, the water flow inside the cage 1 becomes turbulent, making the separation of residual concrete more efficient. If the stirring pump 22 were placed on the bottom surface of the first tank 2, it would be affected by displacement due to the injection pressure and by the cement and sand content of the residual concrete accumulated at the bottom of the first tank 2. Therefore, it is suspended and fixed to a pump stand 221 that is positioned across the top surface of the first tank 2.

[0018] <3.2> Upper drain pipe Since the fibers used in fiber-reinforced concrete are non-steel fibers, the fibers separated from the leftover concrete will float on the water surface due to their specific gravity. An upper drain pipe 23 is provided on the upper side of the first tank 2, which communicates with the inside of the first tank 2. This allows fibers floating on the water surface to be discharged along with the surface water due to the difference in height.

[0019] <4> Second Tank The second tank 3 is installed below the upper drain pipe 23 and receives the supernatant water from the first tank 2 discharged from the upper drain pipe 23 (Figure 5). A fiber collection basket 31 with a mesh size smaller than the length of the fibers is placed between the outlet of the upper drain pipe 23 and the second tank 3 to separate only the fibers from the supernatant water. For example, when separating fibers contained in lining concrete (fiber-reinforced concrete) in tunnel construction projects by NEXCO companies, if the fibers are mixed with Polystrom (registered trademark) lining concrete (HS4870) manufactured by Dainichi Seikan Co., Ltd., which is classified as PP-1-A of the NEXCO "Quality Standards for Non-Steel Fibers for Tunnel Lining Concrete," the specific gravity of HS4870 is 0.91, which is lighter than the specific gravity of the superimposed water. Therefore, since the fibers float and flow on the surface of the superimposed water, if a mesh with a mesh size smaller than the length of the fibers is used, the fibers will inevitably come into contact with the fiber collection basket 31 when the superimposed water falls into the second water tank 3, so the fibers will be left behind in the fiber collection basket 31 and can be easily collected. When HS4870 is used as the fiber, the length of the fiber is 48 mm, so the mesh used in the fiber collection basket 31 should have a mesh size of 48 mm or less. The supernatant water from the first tank 2, which is received in the second tank 3, is also turbid due to cement and sand separated from the remaining concrete, so it is sent to a turbid water treatment facility (not shown) for treatment.

[0020] <5> Method for disposing of leftover concrete from fiber-reinforced concrete Next, a method for treating residual fiber-reinforced concrete using the residual fiber treatment device of the present invention will be described.

[0021] <5.1> Input of remaining concrete The suspension device 41 is operated to lower the cage 1 suspended from the frame 4, and it is placed in the first water tank 2, which is filled with water and positioned directly below the cage 1 inside the frame 4. Then, the remaining concrete is directly poured from the truck mixer 5 into the cage 1 (Figure 6). At this time, the truck mixer 5 is positioned at a high position using a ramp or the like so that the remaining concrete can be dropped from the chute 51 of the truck mixer 5 into the cage 1 in the first water tank 2.

[0022] <5.2> Separation by water flow After the remaining concrete is placed in cage 1, the stirring pump 22 is operated to generate turbulence that entrains the remaining concrete, mixing the water in the first tank 2 with the remaining concrete in cage 1, thereby separating the fibers, aggregates, cement, and sand from the remaining concrete in cage 1. At this time, the fibers are separated by floating them to the top, so the remaining concrete is kept completely submerged in water. The stirring pumps 22 may be operated simultaneously or alternately (Figures 7(a), (b)). Depending on the amount of residual concrete C in cage 1, the residual concrete C in the center may be less affected by the water flow. By operating the stirring pumps 22 alternately, the residual concrete C will move, making the residual concrete C in the center more susceptible to the water flow. By separating the remaining concrete C, the aggregate remains on the bottom mesh 11 of cage 1 without passing through it, the cement and sand components become turbid with the water, and some of them settle and accumulate at the bottom of the first water tank 2. The fibers, on the other hand, float on the water surface. In order to discharge the fibers by floating them on the water surface, the size of cage 1 and the first water tank 2, the amount of water in the first water tank 2, and the amount of remaining concrete C are appropriately selected so that the remaining concrete C is completely submerged and there is sufficient water on top.

[0023] <5.3> Fiber recovery The fibers floating on the water surface are discharged from the upper drain pipe 23 of the first tank 2 along with the supernatant water from the first tank 2. The fibers are collected by a fiber collection basket 31 installed at the outlet of the upper drain pipe 23, and only the supernatant water is stored in the second tank 3 (Figure 8). The supernatant water from the first tank 2, which is stored in the second tank 3, is treated by a turbidity treatment facility (not shown).

[0024] <5.4> Relocation of the first tank Cage 1, with the remaining structural material inside, is lifted upward from inside the first tank 2 by operating the suspension device 41. Then, the motor of the carrier 21 is driven, and the first water tank 2 is slid laterally along the guide rail 42, moving it from inside the frame 4 to the outside (Figure 9). By moving the first water tank 2, space can be secured below the cage 1 inside the frame 4 for a dump truck 6 to park for transporting aggregate.

[0025] <5.5> Discharge of aggregate The dump truck 6 is parked in the space below cage 1, which has become empty after the first water tank 2 is moved, and the aggregate material inside cage 1 is transferred to the dump truck 6 and transported away (Figure 10). The cage 1 is configured to have a retractable bottom net 11, allowing the aggregate to be easily transferred to the dump truck 6 by opening the bottom net 11. If the bottom net 11 is not provided, the aggregate can be transferred to the dump truck 6 by turning the cage 1 upside down on the bed of the dump truck 6.

[0026] <5.6> Cleaning of the first tank At the bottom of the first tank 2, cement and sand from the remaining concrete accumulate. Therefore, regular cleaning is necessary. The stirring pump 22 is removed from the first water tank 2, which has been slid out, and the accumulated cement and sand are discharged and cleaned using heavy machinery such as a backhoe 7 (Figure 11). By sliding the first water tank 2 from inside the frame 4 to the outside, the working radius of the heavy machinery can be secured.

[0027] The present invention's method for treating residual fiber-reinforced concrete separates the residual concrete using the water flow in the first water tank 2. Although this increases the amount of turbid water treated due to the presence of cement and sand, it allows for the separation and recovery of fibers, aggregates, cement, and sand from the residual fiber-reinforced concrete, thus enabling environmentally friendly waste treatment. Furthermore, while conventionally leftover fiber-reinforced concrete had to be disposed of as "rubble," which incurs higher disposal costs, separate collection and processing are now possible, significantly reducing disposal costs.

[0028] [Example 2] <1> Arrangement of rod vibrator and water supply pipe for stirring. The remaining concrete in cage 1 is separated by the water flow from the agitation pump 22, but depending on the amount of remaining concrete in cage 1, the remaining concrete in the central part may be less affected by the water flow. Therefore, a protruding opening 151, connected to a rod vibrator 14 and a stirring water supply pipe 15, is inserted into the central part of the cage 1 through the side mesh 12 (Figures 12 and 13). A rod vibrator 14, a water supply pipe 15 for stirring, and a protruding opening 151 are pre-placed in cage 1, and the remaining concrete is poured in from the top. The rod vibrator 14 vibrates the remaining concrete C in the central part of cage 1, which is less affected by the water flow, making it more susceptible to the water flow. In addition, by spraying agitation water from the protrusion 151 and supplying water directly to the central part of the remaining concrete C, the agitation effect of the agitation pump 22 is enhanced. [Explanation of Symbols]

[0029] 1 Cage, 11 Bottom mesh, 12 Side mesh, 13 Inclined section, 14 Rod vibrator, 15 Water supply pipe for stirring, 151 Outlet 2 First water tank, 21 Carrier, 22 Agitation pump, 221 Pump stand, 23 Upper drain pipe, 3. Second water tank, 31. Fiber collection basket 4. Frame, 41. Lifting device, 42. Guide rail 5 truck mixer trucks, 51 chutes 6 Dump trucks 7 Backhoe C Remaining Concrete

Claims

1. A treatment device for residual concrete from fiber-reinforced concrete, A cage for pouring the remaining concrete from the aforementioned fiber-reinforced concrete, A first tank for housing the aforementioned cage, It has a second tank that receives drainage from the first tank, The first water tank is equipped with a stirring pump for stirring the water stored in the first water tank. An upper drain pipe communicating with the first tank is provided on the upper side of the first tank, and the second tank receives the supernatant water from the first tank discharged from the upper drain pipe as the wastewater. A fiber collection basket with a mesh size smaller than the length of the fibers contained in the fiber-reinforced concrete is provided between the outlet of the upper drain pipe and the second water tank. A device for treating leftover concrete from fiber-reinforced concrete.

2. The cage is suspended from the frame via a suspension device having a height-adjustable mechanism. The first water tank is characterized in that it can move from inside the frame directly below the cage to outside the frame. A method for treating residual concrete of fiber-reinforced concrete according to claim 1.

3. The stirring pumps are characterized by being installed in the first water tank, with two pumps facing each other across the cage. A method for treating residual concrete of fiber-reinforced concrete according to claim 1.

4. Each of the aforementioned cages consists of a box-shaped body with a mesh-like bottom net and side netting, and an open top. The mesh size of the side mesh is characterized by being larger than the mesh size of the bottom mesh. A method for treating residual concrete of fiber-reinforced concrete according to claim 1.

5. The cage is characterized by having an inclined section between the bottom mesh and the side mesh. A method for treating residual concrete of fiber-reinforced concrete according to claim 4.

6. The cage is characterized by having a rod vibrator that is inserted and provided through the side mesh of the cage. A method for treating residual concrete of fiber-reinforced concrete according to claim 4.

7. The cage is characterized by having a protruding opening that is inserted from the side mesh of the cage and sprays water into the cage, A method for treating residual concrete of fiber-reinforced concrete according to claim 4.

8. A method for treating residual concrete of fiber-reinforced concrete using a residual concrete treatment device for fiber-reinforced concrete, The fiber-reinforced concrete residue treatment device comprises a cage into which the fiber-reinforced concrete residue is placed, a first water tank housing the cage, and a second water tank receiving drainage from the first water tank. The process involves lowering the cage suspended from the frame and placing it into the first water tank, which is filled with water and located directly below the cage inside the frame, and then pouring the remaining concrete into the cage; A separation step is to operate a stirring pump installed in the first water tank to stir the water in the first water tank with the remaining concrete in the cage, The process comprises a fiber recovery step in which the supernatant water in the first tank, discharged from an upper drain pipe communicating with the first tank and provided on the upper side of the first tank, is received in the second tank, and the fibers contained in the supernatant water are recovered using a fiber recovery basket with a mesh size smaller than the length of the fibers contained in the fiber-reinforced concrete, provided between the outlet of the upper drain pipe and the second tank. Method for disposing of leftover concrete from fiber-reinforced concrete.

9. The invention is characterized by having an aggregate discharge step, after the sorting step, in which the cage is lifted upward from the first water tank and the aggregate inside the cage is discharged. A method for treating residual concrete of fiber-reinforced concrete according to claim 8.

10. The aggregate discharge process is characterized by moving the first water tank from inside the frame to the outside, moving the first water tank below the lifted cage to create space for parking a dump truck, and transferring the aggregate inside the cage to the dump truck for transport. A method for treating residual concrete of fiber-reinforced concrete according to claim 9.

11. The separation process is characterized by operating two agitation pumps, which are installed in the first water tank, facing each other across the cage. A method for treating residual concrete of fiber-reinforced concrete according to claim 8.

12. The two aforementioned stirring pumps are characterized by operating alternately. A method for treating residual concrete of fiber-reinforced concrete according to claim 11.

13. The fiber-reinforced concrete residue treatment device has a rod vibrator that is inserted into the cage, The sorting process is characterized by vibrating the remaining concrete in the cage with the rod vibrator. A method for treating residual concrete of fiber-reinforced concrete according to claim 8.

14. The fiber-reinforced concrete residue treatment device has a protruding nozzle that sprays water into the cage, In the sorting process, water is supplied directly to the remaining concrete from the protruding opening, A method for treating residual concrete of fiber-reinforced concrete according to claim 8.

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