Method for filling filling material into joint connecting structural member

Abstract

To provide technology capable of improving fillability by reducing residual air bubbles within and on a top surface of a filling material placed at joints connecting structural members.SOLUTION: A method for placing a filling material into joints connecting structural members comprises: a placing step of placing a filling material into a joint; a mold-closing step of closing a mold defining the joint; and a pressurizing step of further pressure-feeding and pressurizing the filling material into the joint through a placing port provided in the mold. After placing the filling material from above the joint during the placing step, the joint may be closed by the mold during the mold-closing step. Alternatively, after closing the joint during the mold-closing step, the filling material may be placed through the placing port during the placing step. Furthermore, the filling material further pressure-fed into the joint during the pressurizing step may be pressurized from an upstream side using a material other than the filling material. Additionally, a sheet having at least some air permeability may be placed between the mold closing an opening above the joint and the filling material.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a method for filling a joint connecting structural members with a filler material. [Background technology]

[0002] For example, when filling concrete or mortar into the joints (joints) connecting structural members such as deck slabs that make up a steel girder bridge, air entrained during mixing and / or pouring of the filler can rise to the top surface of the joint, resulting in so-called "pockmarks" on the top surface of the joint. To achieve a pockmark-free joint, the top surface of the joint must first be raised (e.g., by a few millimeters) and then cut to a depth that eliminates the pockmarks. Cutting this raised area not only requires a great deal of time and effort, but also generates dust containing cement components, which has significant cost and environmental impacts.

[0003] Therefore, in order to reduce pitting, it is considered to place a permeable sheet between the filler material poured into the joint and the siding. However, because the weight of the filler does not exert upward pressure on the top surface, even if the permeable sheet is placed, a pit-free top surface is formed on the surface, but air bubbles remain just below the top surface. The presence of such air bubbles can cause cross-sectional defects in the joint, which may adversely affect the connection strength between the structural members. In this case, to achieve a pit-free joint, it is necessary to significantly raise the top surface of the joint and then cut deeper into the top surface until the pit-free area is reached, which has significant cost and environmental impacts.

[0004] Meanwhile, in this technical field, with increasing demands for, for example, weight reduction of structural members, reduction in the amount of rebar used, and / or improvement in waterproofing performance, there have been increasing opportunities to use ultra-high strength materials such as ultra-high strength fiber reinforced concrete (hereinafter also referred to as "UFC") (see, for example, the background art described in Patent Document 1). Because such ultra-high strength materials have high fluidity, the upper surface becomes horizontal when simply poured into a joint. Therefore, in construction locations with a slope, such as the road surface of a steel girder bridge, it is necessary to cover the upper surface of the filler poured into the joint with a face form (also referred to as a "face form," "lid form," or "top form") to match the slope of the upper surface to the slope of the construction location.

[0005] However, when a cover frame is placed on top of the filler poured into the joint as described above, it becomes difficult for air bubbles to escape from the top surface of the joint, making the above-mentioned pockmarks more likely to occur. Furthermore, when a filler containing fibers, such as UFC, is used, it is difficult for the collector to adhere, making it difficult to repair pockmarks on the top surface of the joint. Therefore, to achieve a pockmark-free joint, it is necessary to raise the top surface of the joint in advance and then cut it to a depth where pockmarks no longer exist. Cutting this raised area not only requires a great deal of time and effort, but also generates dust containing cement components and iron, further increasing the cost and environmental impact. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-175160 [Patent Document 2] Patent No. 7366806 Summary of the Invention [Problem to be solved by the invention]

[0007] As mentioned above, in this technical field, there is a demand for technology that can reduce the amount of air bubbles remaining on the top surface and inside of filler poured into joints (joints) connecting structural components, thereby improving filling properties.

[0008] The present disclosure has been made in consideration of the above-mentioned problems, and one of its objectives is to provide a technology that can improve filling properties by reducing the amount of air bubbles remaining on the top surface and inside of filler material poured into joints connecting structural components. [Means for solving the problem]

[0009] As a result of extensive research, the inventors have discovered that the above problem can be solved by pouring a filler into the joint connecting structural members and applying pressure to the filler poured into the joint.

[0010] Specifically, the method of filling a joint connecting structural members with a filler according to the present disclosure (hereinafter also referred to as the "method of the present disclosure") includes the following steps: a pouring step, a mold closing step, and a pressurizing step. Note that the order in which the pouring step and the mold closing step are performed does not matter.

[0011] The pouring process is a process of pouring filler into the joint. The closing process is a process of closing the formwork that defines the joint. The pressurizing process is a process of pressurizing the filler poured into the joint by further pumping the filler into the joint through a pouring port provided in the formwork. The position at which the pouring port is provided in the formwork is not particularly limited, and the pouring port may be provided on the top, bottom, and / or side of the formwork, for example.

[0012] In another embodiment of the disclosed method, the pouring step is followed by a closing step, in which filler is poured from above the joint, which is closed at the bottom by a formwork and has an opening at the top, and the opening of the joint is then closed by a further formwork in the closing step.

[0013] On the other hand, in another aspect of the disclosed method, a mold closing step is performed before the pouring step. In this case, in the pouring step performed after the mold closing step, filler material is poured into the joint through a pouring port provided in the formwork.

[0014] Furthermore, as described above, the pressurizing step is a step of pressurizing the filler poured into the joint by further pumping the filler into the joint through a pouring port provided in the formwork, but the filler further pumped into the joint may be pressed by a filler located upstream. For example, in the above-described embodiment of the disclosed method, when the filler is poured into the joint through a pouring port provided in the formwork in the pouring step performed after the mold closing step, the pressurizing step can be performed by continuing to pump the filler into the joint through the pouring port even after the pouring step is completed. Therefore, in another embodiment of the disclosed method, in the pressurizing step, the filler further pumped into the joint is pressed from upstream by the filler itself.

[0015] On the other hand, instead of pressing the filler material further pumped to the joint by a filler material located upstream as in the above-described embodiment of the disclosed method, the filler material may be pressed by a material other than the filler material, such as water, oil, or air. Thus, in another embodiment of the disclosed method, in the pressurizing step, the filler material further pumped to the joint is pressed from the upstream side by a material other than the filler material.

[0016] Additionally, in another aspect of the disclosed method, a breathable sheet is disposed between the formwork that closes the opening above the joint and the filler material. [Effects of the Invention]

[0017] As described above, in the method for filling a joint connecting structural members (the disclosed method) according to the present disclosure, after the casting step and the mold closing step are performed, a pressurizing step is performed in which the filler poured into the joint is pressurized by further pumping the filler into the joint through a pouring port provided in the formwork. As a result, the disclosed method can reduce residual air bubbles on the top surface and inside of the filler poured into the joint connecting structural members, thereby improving filling properties. Furthermore, in the disclosed method, the filler hardens while remaining pressurized, resulting in residual pressure inside the hardened filler. This residual pressure acts in a direction that expands the inside of the joint (joint), thereby achieving the effect of reducing the likelihood of cracks occurring on the surface of the joint after construction. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a flowchart illustrating the flow of each step included in a method of filling a filler into a joint connecting structural members according to the present disclosure (the method of the present disclosure). [Figure 2] 10 is a flowchart showing another example of the flow of each step included in the method of the present disclosure. [Figure 3] 1 is a schematic cross-sectional view showing an example of a state in which precast PC deck slabs 10, as an example of a structural member, are connected to each other using the method disclosed herein. [Figure 4] This is a schematic diagram showing how filler material is pressure-fed from a concrete pump 40 to a joint 30 through a pipe 41 connected to a pouring port 25 provided in the formwork during the pouring process that takes place after the form closing process. [Figure 5] This is a schematic side view showing an example of a configuration for pressing the filler filled inside the pipe 51 with water pressure, as an example of a case in which, after the casting process and the closing process are completed, the pipe 51 filled with filler is connected to the casting port 25 provided in the formwork 21, and the filler filled inside the pipe 51 is pressed with a material other than the filler from the upstream side, opposite the casting port 25. [Figure 6]This is a schematic top view illustrating the configuration of a shutter valve 60 used as an example of a mechanism for closing the pouring port 25 and maintaining the pressure of the filling material filled inside the joint 30. [Figure 7] 7A and 7B are schematic side and cross-sectional views of the shutter valve 60 illustrated in FIG. 6. [Figure 8] FIG. 8 is a schematic exploded perspective view of the shutter valve 60 illustrated in FIGS. 6 and 7. [Figure 9] 1 is a photograph showing an example of the top surface of a joint filled with ultra-high strength fiber reinforced concrete (UFC) using the disclosed method. [Figure 10] This is a schematic diagram illustrating a wedge-shaped protrusion 13 (also called a "sawtooth shape") as an example of a structure formed at the end of a precast PC deck to increase the contact area between the precast PC deck 10 and the filler by complicating the structure of the end face of the precast PC deck 10 in order to increase the connection strength between the precast PC deck 10 and the filler. [Figure 11] This is a photograph of the top surface of a joint 30 formed by pouring ultra-high strength fiber reinforced concrete (UFC) between precast PC deck slabs 10 with wedge-shaped protrusions 13 formed at the ends, as an example of a structure formed at the ends of the precast PC deck slabs, in order to increase the contact area between the precast PC deck slab 10 and the filler by complexifying the structure of the end face of the precast PC deck slab 10 in order to increase the connection strength between the precast PC deck slab 10 and the filler, and then hardening the concrete with the top surface closed by a frame. [Figure 12] FIG. 10 is a schematic diagram illustrating a state in which a joint 30 is closed using a face-down frame with a water-permeable sheet disposed on the surface facing the filler in the method disclosed herein according to a preferred embodiment. [Figure 13] 10 is a photograph showing the difference in the occurrence of pitting on the upper surface of the bonded portion 30 after hardening depending on whether or not a water-permeable sheet 70 is used. [Figure 14] 1 is a flowchart illustrating the flow of each step included in a method (conventional method) for pouring a filler material into a joint connecting structural members according to conventional technology. [Figure 15]1 is a schematic cross-sectional view showing an example of a state in which precast PC deck slabs 10, which are an example of structural members, are connected to each other by a conventional method. [Figure 16] This is a photograph showing an example of a pockmark that appeared on the top surface of a joint filled with ultra-high strength fiber reinforced concrete (UFC). [Figure 17] This is a photograph showing an example of the top surface of a joint when using a flat frame with a water-permeable sheet arranged on the surface facing the filler. DETAILED DESCRIPTION OF THE INVENTION

[0019] Below, we will explain the form for implementing the invention disclosed herein, but before that, we will explain a method for pouring filler material into joints connecting structural members according to conventional technology (hereinafter also referred to as the ``conventional method'').

[0020] Fig. 14 is a flowchart illustrating the flow of each step included in the conventional method. As illustrated in Fig. 14, in the conventional method, in a pouring step performed in step S01, a filler material is poured into a joint, which is a space between structural members to be connected. Next, in a mold closing step performed in step S02, a formwork defining the joint is closed. After that, after a predetermined time has passed and the filler material has sufficiently hardened, the formwork is removed, and the structural members are connected to each other via the joint.

[0021] Figure 15 is a schematic cross-sectional view showing an example of a state in which precast PC decks serving as structural members are connected together using a conventional method. In the example shown in Figure 15, a precast PC deck 10 made of concrete 11 with reinforcing bars 12 placed in appropriate locations is exemplified as a structural member. In Figure 15, the area hatched in a diagonal grid pattern has a wedge-shaped protrusion 13 (also referred to as a "sawtooth shape") formed as an example of a structure formed at the end of the precast PC deck to increase the contact area between the precast PC deck 10 and the filler by complicating the structure of the end face of the precast PC deck 10 and thereby increasing the contact area between the precast PC deck 10 and the filler, with the aim of increasing the connection strength between the precast PC deck 10 and the filler.

[0022] As illustrated in FIG. 14 , in the conventional method, in the pouring process performed in step S01, concrete filler (not shown) is poured into the joint 30, which is the space between the precast PC deck slabs 10 to be connected. In the closing process performed in step S02, the joint 30 is closed using formwork 21 and 22 arranged on the end faces of the precast PC deck slabs 10 and above and below the joint. In the example shown in FIG. 15 , the formwork 21 is fastened to cover and seal the upper surface of the joint 30 using square pipes 23 and single pipes 24 having a predetermined shape and mechanical strength. However, the configuration for fastening the formwork 21 as a flat frame to cover and seal the upper surface of the joint 30 is not limited to the above, and materials other than the square pipes 23 and / or single pipes 24 may also be used. After a predetermined time has passed and the filler has sufficiently hardened, the formwork 21 and 22 are removed, completing the connection of the precast PC deck slabs 10 via the joint 30.

[0023] However, as mentioned above, air entrained during mixing of the filler and / or pouring into the joint may rise to the upper surface of the joint, causing pitting on the upper surface of the joint. In particular, when an ultra-high strength material with high fluidity such as UFC is used as the filler, it is necessary to cover the upper surface of the filler poured into the joint with a frame in order to match the slope of the upper surface to the slope of the construction site, which makes pitting even more likely to occur.

[0024] FIG. 16 is a photograph showing an example of pockmarks that have appeared on the upper surface of a joint between precast PC decks 10, an example of a structural component, where UFC has been filled between them. As illustrated in FIG. 16, placing a frame over the top surface of the filler poured into the joint makes pockmarks more likely to appear on the upper surface of the joint. Note that the material used as the frame is not particularly limited as long as it is possible to match the slope of the upper surface of the joint to the slope of the construction site. For example, steel plates and plywood (plywood for concrete formwork) can be used as the frame. In FIG. 16, the boundary between the pockmarked joint and the precast PC decks as structural components has a sawtooth shape. This is because a wedge-shaped protrusion (also referred to as a "sawtooth shape") is formed at the end of the precast PC deck to increase the connection strength between the precast PC deck and the filler (see, for example, Patent Document 2). However, as mentioned above, the wedge-shaped protrusion 13 is merely one example of a structure formed at the end of a precast PC deck 10 to increase the contact area between the precast PC deck 10 and the filler material by complicating the structure of the end face of the precast PC deck 10 in order to increase the connection strength between the precast PC deck 10 and the filler material. In other words, the structure formed at the end of a precast PC deck slab for this purpose is not limited to the wedge-shaped protrusion 13. The same applies to Figure 17, which will be referred to in the following explanation.

[0025] Therefore, as mentioned above, in order to reduce pitting, it is possible to place a permeable sheet between the filler poured into the joint and the facing frame. Figure 17 is a photograph showing an example of the top surface of a joint when a facing frame with a permeable sheet placed on the surface facing the filler is used. As shown in Figure 17(a), when the permeable sheet is placed, a pockmark-free top surface is formed at the joint.

[0026] However, when the top surface of the joint shown in Figure 17(a) is cut, air bubbles are present just below the top surface of the joint, as shown in Figure 17(b). As mentioned above, the presence of such air bubbles can cause cross-sectional defects in the joint, which can adversely affect the connection strength between the structural members. Furthermore, to achieve a pockmark-free joint, it is necessary to significantly raise the top surface of the joint in advance and then cut deeper until the pockmark-free area is reached, which has a significant impact on costs and the environment.

[0027] Therefore, as mentioned above, the inventors, after extensive research, discovered that the above problem can be solved by pouring a filler material into the joints connecting structural members and applying pressure to the filler material poured into the joints.

[0028] Hereinafter, a method for filling a joint connecting structural members with a filler (the disclosed method) according to the present disclosure will be described with reference to the drawings. The disclosed method provides a technology that can improve filling properties by reducing residual air bubbles on the top surface and inside of the filler applied to the joint connecting structural members.

[0029] FIG. 1 is a flowchart illustrating the flow of each step included in the disclosed method. As illustrated in FIG. 1, the disclosed method includes a pouring step performed in step S01, a mold closing step performed in step S02, and a pressurizing step performed in step S03. The pouring step is a step of pouring a filler material into the joint. The mold closing step is a step of closing the formwork defining the joint. The pressurizing step is a step of pressurizing the filler material poured into the joint by further pumping the filler material into the joint through a pouring port provided in the formwork. Note that the position of the pouring port in the formwork is not particularly limited; for example, the pouring port may be provided on any of the top, bottom, and / or side surfaces of the formwork. After a predetermined time has passed and the pressurized filler material poured into the joint has sufficiently hardened, the formwork is removed, and the structural members are connected to each other via the joint.

[0030] However, the order in which the pouring step and the mold closing step are performed does not necessarily have to be the order shown in Fig. 1. That is, as illustrated in Fig. 2, after the joint is closed in the mold closing step (step S02), the filler may be poured into the joint through a pouring port provided in the formwork in the pouring step (step S01).

[0031] Fig. 3 is a schematic cross-sectional view showing an example of a state in which precast PC decks, as an example of a structural member, are connected together using the method of the present disclosure. The example shown in Fig. 3 is similar to the example shown in Fig. 15, except that a precast PC deck 10 made of concrete 11 with reinforcing bars 12 protruding from the end faces arranged in appropriate positions and ultra-high strength fiber-reinforced concrete (UFC) 14 is used as a structural member.

[0032] Furthermore, when connecting precast PC deck slabs made of ordinary concrete, as illustrated in Figure 15, concrete is used as the filler to be filled in the joints, but when connecting precast PC deck slabs that include parts made of UFC as described above, UFC is used as the filler to be filled in the joints.

[0033] As illustrated in FIG. 1 , in the disclosed method, as in the conventional method, in the pouring process performed in step S01, a filler (UFC in this case, not shown) is poured into the joint 30, which is the space between the precast PC deck slabs 10 to be connected. In the closing process performed in step S02, the joint 30 is closed by formwork 21 and 22 arranged above and below the end faces and joint of the precast PC deck slabs 10. In the example shown in FIG. 3 , the formwork 21 is fastened to cover and close the upper surface of the joint 30 using square pipes 23 and single pipes 24 having predetermined shapes and mechanical strength. However, as mentioned above, the configuration for fastening the formwork 21 as a flat frame to cover and close the upper surface of the joint 30 is not limited to the above, and members other than the square pipes 23 and / or single pipes 24 may be used.

[0034] 1, either the pouring process or the closing process may be performed first depending on the configuration of the structural members and joints and the types of facilities and equipment used in construction. For example, if the lower side of joint 30 is closed by formwork 22 and the upper side is open, filler material can be poured from above joint 30 using, for example, a hopper (not shown). In this case, the upper side of joint 30 is closed by formwork 21 (face-down form) in sequence starting from the portion where the pouring of filler material has been completed, and finally the entire joint 30 can be closed (the formwork is closed to complete the closing process).

[0035] 2, before the casting step is carried out, the joint 30 can be closed in advance (the closing step can be completed) using formwork 21 and 22 arranged on the end faces of the precast PC deck slabs 10 and above and below the joint 30. In this case, in the casting step carried out after the closing step, filler can be pumped from, for example, a concrete pump to the joint 30 through pouring ports provided in at least some of the formwork 21 and / or 22.

[0036] 4 is a schematic diagram showing how filler is pumped from a concrete pump 40 to a joint 30 via a pipe 41 connected to a pouring port 25 provided in the formwork in the pouring process that is performed after the form closing process, as described above. FIG. 4(a) is a top view, and FIG. 4(b) is a side view. As illustrated in FIG. 4, filler pumped from a concrete pump 40 can be poured into a joint 30 between precast PC deck slabs 10 erected on main girders 15 via a pipe 41 connected to a pouring port 25 provided in the formwork.

[0037] In addition to the above, in the disclosed method, after the casting and mold-closing steps, a pressurizing step (S03) is performed. This pressurizes the filler material poured into the joint 30 by pumping the filler material through a pouring port 25 provided in the formwork. The pressure applied to the filler material in this pressurizing step is not particularly limited as long as it can reduce residual air bubbles on the upper surface and inside of the filler material. Typically, a pressure of several hundred kPa is applied to the filler material. Therefore, the formworks 21 and 22 defining the joint 30 must be configured to withstand such pressure. Specific examples of materials that can be used for the formworks 21 and 22 include steel plates and plywood (concrete formwork plywood). As mentioned above, the pressure resistance of the formworks may be enhanced by clamping the formworks 21 and / or 22 to cover and seal the upper and / or lower surfaces of the joint 30 using square pipes 23 and single pipes 24 having predetermined shapes and mechanical strength. However, the configuration for fastening the formwork 21 as a face frame so as to cover and close the upper surface of the joint 30 is not limited to the above, and members other than the square pipes 23 and / or the single pipes 24 may be used.

[0038] The specific method for pressurizing the filler poured into the joint 30 by further pumping the filler into the joint 30 through the pouring port 25 provided in the formwork in the pressurizing step is not particularly limited, as long as it is possible to make the filler poured into the joint 30 more dense and reduce the amount of air bubbles remaining on the top surface and inside of the filler. For example, if the lower side of the joint 30 is closed by the formwork 22 and the upper side is an opening, as described above, the filler is poured from above the joint 30 using, for example, a hopper, and the upper side of the joint 30 is successively closed by the formwork 21 starting from the portion where the pouring of the filler is completed. Finally, the entire joint 30 is closed to complete the mold closing step. After that, a pumping device such as a concrete pump is connected to the pouring port 25 provided in the formwork via piping, and the filler poured into the joint 30 can be further pumped, thereby pressurizing the filler poured into the joint 30. That is, in this case, the filler material that is further pumped to the joint 30 in the pressurizing step is pressed from the upstream side by the filler material itself, thereby pressurizing the filler material that has been placed in the joint 30 .

[0039] On the other hand, if the joint 30 defined by the end faces of the precast PC deck slabs 10 and the formwork 21 and 22 arranged above and below the joint 30 has been closed in advance, then in the subsequent pouring step, a pumping device such as a concrete pump can be connected via piping to the pouring port 25 provided in the formwork to pour the filler into the joint 30, and the pumping device can then be used in the pressurizing step to further pump the filler into the joint 30, thereby pressurizing the filler poured into the joint 30. In other words, in this case too, the filler further pumped to the joint 30 in the pressurizing step is pressed from upstream by the filler itself, thereby pressurizing the filler poured into the joint 30.

[0040] Alternatively, after the pouring process and the closing process are completed by any of the procedures described above, the filler poured into the joint 30 can be pressurized by, for example, connecting a pipe filled with filler to a pouring port 25 provided in the formwork, and pressing the filler filled inside the pipe from the upstream side, opposite the pouring port 25, with a material other than the filler (for example, water, oil, or air).

[0041] FIG. 5 is a schematic side view showing an example of a configuration for pressing the filler material filled inside the pipe 51 with water pressure, as an example of a case in which, after the casting process and the mold closing process are completed as described above, the pipe 51 filled with filler material is connected to the casting port 25 provided in the formwork 21, and the filler material filled inside the pipe 51 is pressed with a material other than the filler material from the upstream side opposite the casting port 25. In the example shown in FIG. 5, the pipes 51 filled with filler material are respectively connected to the casting ports 25 provided in two parts of the formwork 21. A water supply jig 52 is connected to the upstream side, opposite the casting port 25, of each pipe 51 to apply water pressure to the filler material filled inside the pipe 51. Furthermore, although not shown, a high-pressure washer, for example, a "high washer," which sprays high-pressure water, is connected to the upstream side of each water supply jig 52.

[0042] In order to prevent water from getting into the filler filled inside the pipe 51, a water-impermeable member, such as a sponge used to drain concrete remaining inside the pipe, is disposed at the tip of the water feeding jig 52. This prevents water from getting into the filler, and allows the filler poured into the joint 30 to be pressurized by the water pressure applied by the high-pressure washer, which then pumps the filler filled inside the pipe 51 through the pouring port 25 further to the joint 30.

[0043] 5, pipes 51 filled with filler material are connected to the pouring ports 25 provided in the two formworks 21 as described above. However, the number of pouring ports 25 provided for one joint 30 is not limited to the above, and can be determined appropriately depending on various conditions, such as the volume and structure of the joint 30 and the fluidity of the filler material to be poured.

[0044] After the pressure application process is completed as described above, in the disclosed method, as in the conventional method, after a predetermined time has passed and the filler poured into the joint has sufficiently hardened, the formwork 21 and 22 are removed, and the connection between the precast PC deck slabs 10 via the joint 30 is completed.

[0045] While it is technically possible to continue pressurizing the filler poured into the joint 30 using, for example, a concrete pump 40 or a high-pressure washer for the period required for the filler poured into the joint as described above to fully harden, this is not desirable from the standpoint of, for example, saving energy, improving work efficiency, and reducing construction costs. Therefore, after the pressurization step is complete, it is preferable to remove the concrete pump 40 or the high-pressure washer from the joint 30 while maintaining the pressure of the pressurized filler poured into the joint 30.

[0046] Furthermore, as described above, when the pipe 51 filled with filler material is connected to the pouring port 25 provided in the formwork after the casting step and the form-closing step are completed, and the filler material filled inside the pipe 51 is pressed from the upstream side, opposite the pouring port 25, using a material other than the filler material to pressurize the filler material poured into the joint 30, it is necessary to replace the piping 41 leading to the concrete pump 40 connected to the pouring port 25 with the pipe 51. During the period required for this replacement work, it is necessary to keep the joint 30 closed and maintain the pressure of the filler material filled inside.

[0047] Therefore, a shutoff mechanism is provided to close the pouring port 25 and maintain the pressure of the filler material filled inside the joint 30 throughout the period required for the above-mentioned filler material to harden and the period required for the replacement work. Figure 6 is a schematic top view illustrating the configuration of a shutter valve used as an example of such a shutoff mechanism. In Figure 6, the internal structure that cannot be observed from the outside is depicted by dashed lines.

[0048] The shutter valve 60 illustrated in Fig. 6 comprises a main body 61 having a substantially rectangular parallelepiped shape, a shutter 62 which is a substantially flat member, and a joint part 63 which is a member for connecting the piping 41 of the concrete pump 40 and / or the pipe 51 filled with filler material to the shutter valve 60. The shutter 62 is provided with a through-hole 62h having a shape similar to the cross section of the pouring port 25, and is slidably inserted into an insertion hole provided in the main body 61, as indicated by the double-headed arrow drawn with a thick dashed line in Fig. 6. The joint part 63 comprises a tubular part 63c having a substantially cylindrical shape, and a flange part 63f which extends in a flange-like shape at the base end of the tubular part 63c and is used to fix the joint part 63 to the main body 61.

[0049] Fig. 7 is a schematic side view (a) and a cross-sectional view (b) of the shutter valve 60 shown in Fig. 6 when observed from the direction of the arrow drawn by the thick solid line in Fig. 6. Also, Fig. 8 is a schematic exploded perspective view of the shutter valve 60 shown in Fig. 6 and Fig. 7 when observed from the outside to the inside of the joint 30, that is, from the cylindrical portion 63c side (top 61t side) to the main body 61 side (bottom 61b side).

[0050] 7 and 8, the main body 61 has a three-layer structure consisting of a top 61t, a pair of guide portions 61g, and a bottom 61b. The pair of guide portions 61g are sandwiched between the top 61t and the bottom 61b to define an insertion hole, which is a space surrounded by the pair of guide portions 61g, the top 61t, and the bottom 61b. As described above, the shutter 62 is slidably inserted into the insertion hole. The cross sections of the three through holes provided in the top 61t and bottom 61b of the main body 61 and the flange portion 63f of the joint portion 63, and the internal space of the tubular portion 63c of the joint portion 63, have the same shape as the cross section of the pouring hole 25 and are arranged coaxially with each other.

[0051] The shutter valve 60 having the above-described configuration is attached to the formwork that defines the joint 30 so that the three through holes and the internal space of the cylindrical portion 63c face the pouring port 25. In this state, when the shutter 62 is slid so that the pouring port 25 provided in the formwork overlaps with the through hole 62h, the internal space of the cylindrical portion 63c communicates with the pouring port 25. In other words, the shutter valve 60 as a shutoff mechanism is in the "open" state, and filler can be poured into the joint 30 via the shutter valve 60 and the pouring port 25.

[0052] On the other hand, when the shutter 62 is slid in the above state so that the pouring port 25 provided in the formwork does not overlap with the through-hole 62h, the internal space of the cylindrical portion 63c is not in communication with the pouring port 25. In other words, the shutter valve 60 as a shutoff mechanism is in the "closed" state, making it impossible to pour filler material into the joint 30 via the shutter valve 60 and the pouring port 25, and maintaining the pressure of the pressurized filler material poured inside the joint 30.

[0053] 9 is a photograph showing an example of the top surface of joint 30 filled with ultra-high strength fiber reinforced concrete (UFC) by the method of filling filler into joints connecting structural members according to the present disclosure (the method of the present disclosure) described above. As shown in FIG. 9, the method of the present disclosure can reduce the occurrence of pitting on the top surface of joint 30, even when UFC, which has high fluidity, is filled into joint 30 as a filler and a frame 21 is placed over the top surface of the filler poured into joint 30.

[0054] As described above, in the disclosed method, after the casting step and mold closing step are performed, a pressurizing step is performed in which the filler poured into the joint 30 is pressurized by further pumping the filler into the joint 30 through a pouring port provided in the formwork. As a result, the disclosed method can reduce residual air bubbles on the top surface and inside of the filler poured into the joint 30 connecting structural members, thereby improving filling properties. Furthermore, in the disclosed method, the filler hardens while remaining in a pressurized state, so pressure remains inside the hardened filler. This residual pressure acts in a direction that causes the inside of the joint (joint) 30 to expand, thereby achieving the effect of reducing the likelihood of cracks occurring on the surface of the joint after construction.

[0055] FIG. 10 is a schematic diagram illustrating a wedge-shaped protrusion 13 as an example of a structure formed at the end of the precast PC deck 10 to increase the contact area between the precast PC deck 10 and the filler by complicating the structure of the end face of the precast PC deck 10, as described above, for the purpose of increasing the connection strength between the precast PC deck 10 and the filler. In FIG. 10, the wedge-shaped protrusion 13 is formed in the area with diagonal grid hatching. In addition to the wedge-shaped protrusion 13, for similar purposes, the end face of the precast PC deck 10 may be roughened by, for example, applying a set retarder to the surface of the formwork. Both of these methods increase the connection strength between the precast PC deck 10 and the filler by complicating the structure of the end face of the precast PC deck 10 and increasing the contact area between the precast PC deck 10 and the filler. However, the more complex the structure of the end face of the precast PC deck 10, the more difficult it becomes for the filler to penetrate deep into the structure.

[0056] However, in the disclosed method, as described above, after the casting step and the mold closing step are performed, a pressurizing step is performed in which pressure is applied to the filler material poured into the joint. Therefore, even if the structure of the end face of the precast PC deck 10 is complex as described above, the filler material can be sufficiently inserted deep into the structure. As a result, according to the disclosed method, the effect of increasing the connection strength between the precast PC deck 10 and the filler material by forming the wedge-shaped protrusions 13 and / or roughening can be more reliably achieved.

[0057] Figure 11 is a photograph of the top surface of a joint 30 formed between two precast PC decks 10 with wedge-shaped protrusions 13 at their ends. The joint is formed by pouring ultra-high-strength fiber-reinforced concrete (UFC) between the two decks and then curing the concrete while the upper surface is closed by a facing frame 21. Figure 11(a) shows the top surface of the wedge-shaped protrusion 13 immediately after the formwork is removed after hardening. The top surface (feather edge) of the wedge-shaped protrusion 13 is lightly covered with UFC that seeped through a small gap between the precast PC deck 10 and the facing frame 21. Figure 11(b) shows the state after the feather edge has been cut to expose the boundary between the wedge-shaped protrusion 13 and the filler material, and water has been poured over the boundary to make it easier to see. The boundary should exist at the location indicated by the thick white dashed line in Figure 11(b), but it is not visible, at least visually.

[0058] As described above, according to the disclosed method, even if the structure of the end face of the precast PC deck 10 is complex, the filler material can be sufficiently penetrated deep into the structure, so that the effect of increasing the connection strength between the precast PC deck 10 and the filler material by forming the wedge-shaped protrusion 13 and / or roughening can be more reliably achieved.

[0059] As described above, in the disclosed method, after the casting step and mold closing step are performed, a pressurizing step is performed in which the filler material cast in the joint 30 is pressurized by further pumping the filler material into the joint 30 through a casting port provided in the formwork. As a result, the disclosed method can reduce residual air bubbles on the top surface and inside of the filler material cast in the joint 30 connecting structural members, thereby improving filling properties. Furthermore, in the disclosed method, the filler material hardens while remaining in a pressurized state, so pressure remains inside the hardened filler material. This residual pressure acts in a direction that expands the inside of the joint (joint) 30, thereby achieving the effect of reducing the likelihood of cracks occurring on the surface of the joint after construction.

[0060] However, depending on the application of the structural member to which the method of the present disclosure is applied, there may be a need to further improve the filling performance by further reducing residual air bubbles on the upper surface and inside of the filler cast at the joint 30 connecting the structural members. Alternatively, depending on various factors such as the volume and structure of the joint 30 and the fluidity of the cast filler, the method of the present disclosure described above may not be sufficiently effective in reducing residual air bubbles on the upper surface and inside of the filler.

[0061] In the above case, it is preferable to place at least a breathable sheet between the filler and the formwork (facework) 21 that closes the opening above the joint 30. In other words, it is preferable to use a formwork that has at least a breathable sheet on the surface facing the filler as the formwork (facework) 21 that closes the opening above the joint 30.

[0062] The sheet is not particularly limited as long as it does not adversely affect the properties of the joint 30 and is at least breathable, thereby reducing the amount of air bubbles remaining on the top surface and inside the filler. Preferably, the sheet is not only breathable but also water-permeable. Specific examples of such sheets include "Abanon" (registered trademark), which is commercially available from Maeda Kosen Co., Ltd. as a water-permeable formwork sheet.

[0063] Fig. 12 is a schematic diagram illustrating a state in which the joint 30 is closed using a frame with a water-permeable sheet 70 disposed on the surface facing the filler in the method of the present disclosure according to a preferred embodiment. Fig. 12(a) is a schematic cross-sectional view of the vicinity of the joint 30 in a plane parallel to the bridge axis of a steel girder bridge constructed with precast PC deck slabs 10. Fig. 12(b) is a schematic cross-sectional view of the vicinity of the joint 30 in a plane perpendicular to the bridge axis, represented by line AA in Fig. 12(a). Note that Figs. 12(a) and 12(b) omit the formwork 22 below the joint 30 and the members for fastening the formwork 21 and 22 to the upper and lower surfaces of the joint 30.

[0064] As shown in Figure 12, a water-permeable sheet 70 is disposed on the surface of the face frame 21 that closes the opening above the joint 30, facing the filler, thereby interposing the water-permeable sheet 70 between the face frame 21 and the filler. Note that in Figure 12(b), it is depicted as if there is a slight gap between the water-permeable sheets 70 provided on adjacent face frames 21, but this is a gap intended to indicate the boundary between each water-permeable sheet 70, and in reality, there is substantially no gap between adjacent water-permeable sheets 70.

[0065] Figure 13 is a photograph showing the difference in the occurrence of pitting on the upper surface of the joint 30 after hardening depending on whether or not the water-permeable sheet 70 is used. Figure 13(a) is a photograph of the upper surface of the joint 30 when a side frame 21 without a water-permeable sheet 70 is used, and Figure 13(b) is a photograph of the upper surface of the joint 30 when a side frame 21 with a water-permeable sheet 70 is used. As is clear from Figure 13, by disposing the water-permeable sheet 70 on the surface of the side frame 21 that closes the upper opening of the joint 30, facing the filler, the occurrence of pitting on the upper surface of the joint 30 can be further reduced.

[0066] For the purpose of explaining the contents of the present disclosure, several embodiments having specific configurations have been described above, sometimes with reference to the accompanying drawings. However, the scope of the present disclosure should not be construed as being limited to these exemplary embodiments, and it goes without saying that appropriate modifications can be made within the scope of the claims and the matters described in the specification.

[0067] For example, the method of filling a filler material into a joint connecting structural members according to the present disclosure (the disclosed method) can be applied not only to the joining of a new deck slab to be installed in place of an existing deck slab in road or bridge deck replacement work, but also to the joining of new deck slabs in a newly constructed road or bridge. Furthermore, the disclosed method is not limited to deck slabs that make up roads or bridges, but can be widely applied to the joining of a wide variety of structural members that are joined by filling the joints with a filler material such as concrete or mortar. [Explanation of symbols]

[0068] 10...Precast PC deck slab, 11...Concrete, 12...Reinforcing bar, 13...Wedge-shaped protrusion (sawtooth shape), 14...Ultra-high-strength fiber-reinforced concrete (UFC), 15...Main girder, 21...Formwork (laying frame), 22...Formwork, 23...Square pipe, 24...Single pipe, 25...Pouring port, 30...Joint, 40...Concrete pump, 41...Piping, 51...Pipe, 52...Water supply jig, 60...Shutter valve (shutoff mechanism), 61...Main body, 61t...Top, 61g...Guide part, 61b...Bottom, 62...Shutter, 62h...Through hole, 63...Joint part, 63c...Cylindrical part, 63f...Flange part, 70...Water-permeable sheet

Claims

1. A method for pouring a filler material into a joint connecting structural members, comprising: a pouring step of pouring the filler material into the joint; a mold closing step, which is a step of closing a form that defines the joint; and a pressurizing step in which pressure is applied to the filler by further pumping the filler into the joint through a pouring port provided in the formwork; A method for pouring a filler material into a joint connecting structural members, comprising:

2. A method for pouring a filler material into a joint connecting structural members according to claim 1, The closing step is carried out after the casting step, In the pouring step, the filler is poured from above the joint, the lower side of which is closed by a formwork and the upper side of which is an opening, In the closing step, the opening of the joint is closed with a further form. A method of pouring filler material into joints connecting structural members.

3. A method for pouring a filler material into a joint connecting structural members according to claim 1, The closing step is carried out before the casting step, In the pouring step, the filler is poured into the joint through the pouring port. A method of pouring filler material into joints connecting structural members.

4. A method for pouring a filler into a joint connecting structural members according to any one of claims 1 to 3, In the pressurizing step, the filler material to be further pumped to the joint portion is pressed by the filler material itself from the upstream side. A method of pouring filler material into joints connecting structural members.

5. A method for pouring a filler into a joint connecting structural members according to any one of claims 1 to 3, In the pressurizing step, the filler material to be further pumped to the joint portion is pressed from the upstream side by a material other than the filler material. A method of pouring filler material into joints connecting structural members.

6. A method for pouring a filler into a joint connecting structural members according to any one of claims 1 to 3, A breathable sheet is disposed between the formwork that closes the opening above the joint and the filling material. A method of pouring filler material into joints connecting structural members.

7. A method for pouring a filler into a joint connecting structural members according to claim 4, A breathable sheet is disposed between the formwork that closes the opening above the joint and the filling material. A method of pouring filler material into joints connecting structural members.

8. A method for pouring a filler into a joint connecting structural members according to claim 5, A breathable sheet is disposed between the formwork that closes the opening above the joint and the filling material. A method of pouring filler material into joints connecting structural members.

Images