Force-feed system, and force-feeding method

Abstract

To efficiently force-feed a fiber-reinforced cement-based composition.SOLUTION: A force-feed system 10 for a fiber-reinforced cement-based composition, includes: a force-feed pipe 20 for supplying the fiber-reinforced cement-based composition discharged from a pump device 80 to a predetermined placing place 90; and temperature adjusting means 21, 23, 27, 28 capable of adjusting a temperature of the fiber-reinforced cement-based composition force-fed in the force-feed pipe 20 by the pump device 80 and / or a temperature of the fiber-reinforced cement-based composition placed in the placing place 90.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present disclosure relates to a pumping system and a pumping method, and particularly to a technique suitable for pumping a fiber-reinforced cement-based composition.

Background Art

[0002] For example, Patent Document 1 discloses a fiber dispersion device in which a dispersion means is provided at the tip of a pipe through which high-strength fiber-reinforced concrete is pumped from a concrete pump truck, and steel fibers in the high-strength fiber-reinforced concrete pumped into a formwork for a floor slab from the pipe are randomly oriented.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The fluidity of a fiber-reinforced cement-based composition such as high-strength fiber-reinforced concrete decreases with the passage of time after production, and furthermore, it is likely to change due to the influence of the ambient temperature during pumping (i.e., in pipes and formworks). When the fluidity of the fiber-reinforced cement-based composition decreases, there is a problem that the pumping load of the concrete pump increases, making it impossible to pump the fiber-reinforced cement-based composition. On the other hand, if the fluidity of the fiber-reinforced cement-based composition becomes too high, the fibers in the fiber-reinforced cement-based composition separate, and a lump of fibers (hereinafter, fiber ball) blocks the pipe flow path, also making it impossible to pump the fiber-reinforced cement-based composition. Therefore, in order to efficiently pump a fiber-reinforced cement-based composition by a concrete pump, it is desirable to maintain the fluidity of the fiber-reinforced cement-based composition within a range of values suitable for pumping.

[0005] The technology of the present disclosure has been made in view of the above circumstances, and an object thereof is to provide a technology capable of efficiently pumping a fiber-reinforced cement-based composition.

Means for Solving the Problems

[0006] The pumping system of the present disclosure is a pumping system (10) for a fiber-reinforced cement-based composition, a pumping pipe (20) for supplying the fiber-reinforced cement-based composition discharged from a pump device (80) to a predetermined placement location (90), and temperature adjusting means (21, 23, 27, 28) capable of adjusting the temperature of the fiber-reinforced cement-based composition pumped in the pumping pipe (20) by the pump device (80) and / or the temperature of the fiber-reinforced cement-based composition placed in the placement location (90). It is characterized by the above.

[0007] In the pumping system of the present disclosure, the temperature adjusting means may be means (21, 28) for adjusting the temperature by exchanging heat between the inside of the pumping pipe (20) and / or the placement location (90) with a high-temperature fluid or a low-temperature fluid before the fiber-reinforced cement-based composition is pumped into the pumping pipe (20) by the pump device (80).

[0008] In the pumping system of the present disclosure, the temperature adjusting means desirably further includes heat insulating materials (27A, 27B, 27C) covering the outer peripheral surface of the pumping pipe (20).

[0009] In the pumping system of the present disclosure, the temperature adjusting means may be heating means (23) provided on the outer peripheral surface of the pumping pipe (20) and capable of heating the fiber-reinforced cement-based composition in the pumping pipe (20) by generating heat.

[0010] In the pumping system of the present disclosure, the heating means (23) desirably includes a heating wire (23) wound around the outer peripheral surface of the pumping pipe (20).

[0011] The pumping system according to another aspect of the present disclosure is a pumping system (10) for a fiber-reinforced cementitious composition, a pumping pipe (20) for supplying the fiber-reinforced cementitious composition discharged from a pump device (80) to a predetermined placement location (90), and vibration applying means (29) for applying vibration to the pumping pipe (20) and / or the placement location (90). It is characterized by this.

[0012] The pumping method of the present disclosure is a pumping method for a fiber-reinforced cementitious composition in which the fiber-reinforced cementitious composition produced by a mixer device (70) is discharged into a pumping pipe (20) by a pump device (80) and supplied to a predetermined placement location (90), wherein the flow value (JIS R5201 0-slump flow value) of the fiber-reinforced cementitious composition produced by the mixer (70) is adjusted to 250 to 290 mm. It is characterized by this.

[0013] In the pumping method of the present disclosure, it is desirable to adjust the kneading temperature of the fiber-reinforced cementitious composition produced by the mixer (70) to 15 to 45°C.

[0014] In the above description, in order to assist the understanding of the present disclosure, reference numerals used in the embodiments are attached to the constituent elements corresponding to the embodiments in parentheses, but each constituent element is not limited to the embodiments defined by the above reference numerals.

Advantages of the Invention

[0015] According to the technology of the present disclosure, a fiber-reinforced cementitious composition can be efficiently pumped.

Brief Description of the Drawings

[0016]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Modes for Carrying Out the Invention

[0017] Hereinafter, based on the accompanying drawings, the pumping system and the pumping method according to this embodiment will be described.

[0018] [Overall Configuration] FIG. 1 is a schematic diagram for explaining an example of a site where fiber-reinforced concrete is placed using the pumping system 10 according to the present embodiment. The site shown in FIG. 1 is a site for a floor slab renewal work in which an existing floor slab of a bridge 1 is replaced with a new floor slab 2. Note that the pumping system 10 of the present disclosure is not limited to the floor slab renewal work shown in the example, and can be widely applied to construction sites of concrete structures where fiber-reinforced concrete is placed, such as new construction work of bridges, new construction work or renewal work of tunnels, new construction work or renewal work of dams, and construction work of reinforced concrete buildings. Hereinafter, the floor slab renewal work will be described as an example.

[0019] The bridge 1 is, for example, a road bridge such as an exclusive automobile road, and includes a traffic lane L for vehicles to travel and a road shoulder S where vehicles can evacuate in case of emergency. Note that the bridge 1 may not include the road shoulder S. In the floor slab renewal work, if traffic control is implemented during a time period when the traffic volume is large, such as during the day, the impact on the surrounding traffic environment will be large. Therefore, in the example shown in FIG. 1, a temporary protective fence 8 is installed between the traffic lane L and the road shoulder S, and the area on the road shoulder S side of the temporary protective fence 8 is set as a work zone W for performing work, and the traffic lane L is open to traffic.

[0020] Within the work zone W, operations such as removal of the existing floor slab, installation of the new floor slab 2, driving of joint concrete into the joint portion 6 between the newly installed new floor slabs 2, 2, and installation of a new wall railing 5 on the covering portion 4 of the new floor slab 2 are performed. When the existing floor slab in a predetermined section on the road shoulder S side is replaced with the new floor slab 2, the work zone W is set in the area on the traffic lane L side. The work zone W is set as a narrow space with a short road width so as not to affect the passage of vehicles regardless of whether it is set on the road shoulder S side or the traffic lane L side.

[0021] In the floor slab renewal work shown in FIG. 1, high-strength and highly durable fiber-reinforced concrete is driven into the joint portion 6. Examples of such fiber-reinforced concrete include ultra-high strength fiber-reinforced concrete (hereinafter referred to as UFC) containing steel fibers or the like.

[0022] The pumping system 10 of this embodiment is a system that continuously pumps UFC to a placement location such as the joint portion 6 while manufacturing UFC at a construction site, and is arranged within the work zone W. Specifically, the pumping system 10 includes a mixer device 70 for manufacturing UFC, a pump device 80 for pumping the UFC manufactured by the mixer device 70, and a pumping pipe 20 for supplying the UFC pumped from the pump device 80 to a desired placement location (within the formwork 90 of the joint portion 6 in the illustrated example).

[0023] The mixer device 70 includes a manufacturing hopper 71 (see FIG. 11) into which various materials of UFC (such as concrete, steel fibers, etc.) are charged. The manufacturing hopper 71 is provided with stirring blades 72 (see FIG. 11), and UFC is manufactured by rotating the stirring blades 72 to knead various materials of UFC. Powders, aggregates, etc., which are materials of UFC, are preferably placed in a temperature-controlled container 76 installed on-site and kept at an appropriate temperature. Also, the water used in the manufacture of UFC is preferably stored in a temperature-controlled tank 78 installed on-site and kept at an appropriate temperature. The UFC manufactured by the mixer device 70 is charged into the pump hopper 85 provided in the pump device 80.

[0024] In addition, when the total quantity of UFC to be placed in one day is more than the quantity of UFC in one batch that can be manufactured by the mixer device 70, an interim receiving hopper (not shown) for temporarily storing the UFC manufactured by the mixer device 70 may be arranged between the mixer device 70 and the pump device 80. It is desirable that the capacity of the interim receiving hopper is larger than the capacity of the pump hopper 85 and also larger than the capacity of the manufacturing hopper 71. If the interim receiving hopper is arranged, the mixer device 70 can start manufacturing the next batch of UFC by discharging the entire quantity of the manufactured batch of UFC into the interim receiving hopper, and the pump device 80 can receive the supply of the next UFC from the interim receiving hopper before all the UFC in the pump hopper 85 is exhausted. That is, it becomes possible to realize continuous pumping of UFC by the pump device 80.

[0025] The pump device 80 is a so-called piston type (parallel sliding type) concrete pump and is arranged adjacent to the mixer device 70. The pump device 80 discharges the UFC charged into the pump hopper 85. The pressure conveying pipe 20 is connected to the discharge pipe 88 of the pump device 80. When the UFC is manufactured at a location other than the construction site, the pump device 80 may be a concrete pump truck.

[0026] The pressure conveying pipe 20 is a pipe for supplying the UFC discharged from the pump device 80 to a desired placing location (in the illustrated example, inside the formwork 90 of the joint part 6). The pressure conveying pipe 20 is, for example, a steel pipe and is constituted by connecting a plurality of straight pipes and elbow pipes with pipe fittings 50. In the illustrated example, the pressure conveying pipe 20 is connected to the injection pipe 95 provided at the lower part of the formwork 90 so as to drive the UFC into the formwork 90 from below, but it may be connected so as to drive the UFC into the formwork 90 from above. The pipe diameter of the pressure conveying pipe 20 is not particularly limited, but it is desirable to use a 2 - 3 inch pipe and set the discharge amount of the pump device 80 to about 0.5 - 1.5 m 3 / h. By adopting such a combination, it becomes possible to realize stable pressure conveyance of the UFC. Also, the pressure conveying pipe 20 may be made of something other than a steel pipe, such as rubber.

[0027] In the configuration shown in FIG. 1, only one pump device 80 is shown, but it is also possible to realize pressure conveyance of the UFC over a longer distance by connecting a plurality of pump devices 80 in series with the pressure conveying pipe 20. By connecting the pump devices 80 in series, it becomes possible to supply the UFC to a more distant placing location without moving the mixer device 70 from its initial installation position.

[0028] Incidentally, when the fluidity of UFC decreases, there is a problem that when the UFC is pumped by the pump device 80, the pumping load of the pump device 80 increases, making it impossible to pump the UFC. On the other hand, if the fluidity of UFC becomes too high, the steel fibers and mortar in the UFC separate, and the fiber balls block the pipe flow path, also making it impossible to pump the UFC. Therefore, to efficiently pump the UFC by the pump device 80, it is desirable to maintain the fluidity of the UFC within a range of values suitable for the pumping of the pump device 80.

[0029] The fluidity of UFC decreases with the passage of time after production, and furthermore, it is likely to change significantly due to the influence of the ambient temperature during pumping (i.e., the pumping pipe 20 and the formwork 90). Therefore, to maintain the fluidity of UFC within the optimal value range during construction, it is important to control the kneading temperature and flow value of the UFC produced by the mixer device 70, the temperature control of the pumping pipe 20 for pumping the UFC, and the temperature control within the formwork 90 where the UFC is placed. In this embodiment, by controlling the kneading temperature and flow value during the production of UFC, and the temperature control of the pumped UFC, inside the pumping pipe 20, and inside the formwork 90, efficient pumping of the UFC, whose fluidity is likely to change, by the pump device 80 is realized.

[0030] Hereinafter, specific examples will be described. Note that any one or a combination of two or more of the plurality of examples described below can be implemented. Which example to implement may be appropriately selected according to various conditions at the construction site (air temperature, length of the pumping pipe 20, size of the formwork 90, performance of the mixer device 70 and the pump device 80, etc.).

[0031] [Example 1] FIG. 2 is a schematic diagram for explaining Example 1. In Example 1, before pumping the UFC, the piping 20 for pumping is preheated with a high-temperature fluid in advance, so as to effectively prevent the temperature of the UFC from dropping during pumping in an environment where the outside air temperature is low, such as in winter. In the example shown in FIG. 2, the piping 20 for pumping is preheated in a state before being connected by a pipe joint, but it is also possible to perform preheating after connecting a plurality of pipes 20 for pumping by a pipe joint. The timing for preheating the piping 20 for pumping may be during the period when the UFC is being manufactured by the mixer device 70 (see FIG. 1). The high-temperature fluid for preheating the piping 20 for pumping may be either high-temperature water or high-temperature air.

[0032] FIG. 2(A) is an example when high-temperature water is used as the high-temperature fluid. For the high-temperature water, for example, the high-temperature water scooped up by an operator into a container such as a bucket may be manually circulated inside the piping 20 for pumping. Alternatively, the high-temperature water stored in the container may be pumped up by a water pump and discharged inside the piping 20 for pumping. Alternatively, the piping 20 for pumping may be left in a water storage tank storing high-temperature water for a predetermined time. The water temperature of the high-temperature water is desirably a water temperature that can adjust the internal temperature of the piping 20 for pumping to 15 to 45°C (preferably 35°C or lower) by preheating. For this reason, it is desirable to use high-temperature water that has been pre-adjusted to a desired high water temperature by heating means such as a heater in advance. The specific water temperature of the high-temperature water is not particularly limited, but the lower the outside air temperature, the higher the water temperature is desirably set.

[0033] Whether the temperature of the piping 20 for pumping has risen to the desired temperature by the high-temperature water may be recognized based on the measured value of a thermometer capable of measuring the internal temperature of the piping 20 for pumping, or may be recognized by an operator touching the inside of the piping 20 for pumping by hand, etc.

[0034] FIG. 2(B) is an example when hot air is used as the high-temperature fluid. For the hot air, for example, a warm air blower 21 incorporating a heater may be used, and the hot air blown from the nozzle 21A of the warm air blower 21 may be circulated inside the pressure feed pipe 20. The temperature of the hot air is desirably a temperature that can adjust the internal temperature of the pressure feed pipe 20 to 15 to 45°C (preferably 35°C or lower) by preheating. For this reason, it is desirable to use a warm air blower 21 having a temperature adjustment function. The specific temperature of the hot air is not particularly limited, but it is desirable to set a higher temperature as the outside air temperature is lower.

[0035] Whether the temperature of the pressure feed pipe 20 has risen to the desired temperature by the hot air may be recognized based on the measured value of a thermometer capable of measuring the internal temperature of the pressure feed pipe 20, or may be recognized, for example, by an operator touching the inside of the pressure feed pipe 20 by hand. Alternatively, in advance, by experiments or the like, the blowing time of the hot air (the time from the start to the end of blowing) required to raise the internal temperature of the pressure feed pipe 20 to the desired temperature may be obtained, and the warm air blower 21 may be stopped at the timing when the blowing time has elapsed.

[0036] In this way, by preheating the inside of the pressure feed pipe 20 with high-temperature water or hot air in advance, it becomes possible to effectively suppress the temperature of the UFC from decreasing during pressure feeding (in other words, decreasing inside the pressure feed pipe 20). That is, the decrease in fluidity accompanying the temperature decrease of the UFC inside the pressure feed pipe 20 can be suppressed, and it becomes possible to effectively suppress the increase in the pressure feeding load of the pump device 80. By suppressing the increase in the pressure feeding load of the pump device 80, it becomes possible to realize continuous pressure feeding of the UFC by the pump device 80.

[0037] Incidentally, the hot air blower 21 shown in FIG. 2(B) may be used not only for preheating the pressure feed pipe 20 but also for keeping the UFC being pressure-fed warm by blowing hot air toward the outer peripheral surface of the pressure feed pipe 20 during the pressure feeding of the UFC. In this case, the heating of the pressure feed pipe 20 by the hot air blower 21 may be performed manually by an operator, or may be performed by fixing the hot air blower 21 to a support tool such as a tripod.

[0038] [Example 2] FIG. 3 is a schematic diagram for explaining Example 2. In Example 2, before pumping the UFC, the pressure feed pipe 20 is pre-cooled with low-temperature water in advance, so as to effectively suppress the rise in the temperature of the UFC during pumping in an environment where the outside air temperature is high, such as in summer. In the example shown in FIG. 3, the pre-cooling of the pressure feed pipe 20 is performed in a state before it is connected by a pipe joint, but it is also possible to perform the pre-cooling after connecting a plurality of pressure feed pipes 20 by pipe joints. The timing for pre-cooling the pressure feed pipe 20 may be during the period when the UFC is being manufactured by the mixer device 70.

[0039] For the low-temperature water, for example, the low-temperature water scooped up by an operator into a container such as a bucket may be manually circulated inside the pressure feed pipe 20. Alternatively, the low-temperature water stored in the container may be pumped up by a water pump and discharged inside the pressure feed pipe 20. Alternatively, the pressure feed pipe 20 may be left in a water storage tank storing the low-temperature water for a predetermined time. The water temperature of the low-temperature water is desirably a water temperature that can adjust the internal temperature of the pressure feed pipe 20 to 15 to 45°C (preferably 35°C or lower) by pre-cooling. For this reason, it is desirable to use low-temperature water that has been pre-adjusted to a desired low water temperature by a cooling means such as a cooler. The specific water temperature of the low-temperature water is not particularly limited, but it is desirable to lower the water temperature as the outside air temperature is higher. Whether the temperature of the pressure feed pipe 20 has dropped to the desired temperature by the low-temperature water may be recognized based on the measured value of a thermometer capable of measuring the internal temperature of the pressure feed pipe 20, or may be recognized by an operator touching the inside of the pressure feed pipe 20 by hand, etc.

[0040] In this way, by pre-cooling the inside of the pressure-feeding pipe 20 with low-temperature water in advance, it becomes possible to effectively suppress the temperature of the UFC from rising during pressure-feeding (in other words, rising within the pressure-feeding pipe 20). That is, as the temperature of the UFC rises within the pressure-feeding pipe 20, it becomes possible to suppress the deterioration of fluidity due to the fluidity becoming too high, and it becomes possible to effectively suppress the generation of fiber balls due to the separation of steel fibers. By suppressing the generation of fiber balls, it is possible to prevent the blockage of the pipe flow path and the like due to the fiber balls, and it becomes possible to realize the continuous pressure-feeding of the UFC by the pump device 80.

[0041] [Example 3] FIG. 4 is a schematic diagram for explaining Example 3. Example 3 effectively suppresses the temperature of the UFC from decreasing during pressure-feeding in an environment where the outside air temperature is low, such as in winter, by heating the pressure-feeding pipe 20 with the heating wire 23. Note that the heating of the pressure-feeding pipe 20 by the heating wire 23 can also be performed as preheating before pressure-feeding the UFC, similar to Example 1.

[0042] The heating wire 23 generates heat when a voltage is applied from the power source 24. The heating wire 23 is preferably wound spirally around the outer peripheral surface of the pressure-feeding pipe 20. A switching element 25 is provided between the heating wire 23 and the power source 24. The switching element 25 is connected to a temperature setter 26 as a control unit. The temperature setter 26 controls the energization (application of voltage) to the heating wire 23 by switching the on / off of the switching element 25. The temperature setter 26 is provided with an operation unit 26A for setting the heat generation temperature of the heating wire 23.

[0043] The temperature setter 26 controls the energization to the heating wire 23 so that the heat generation temperature of the heating wire 23 becomes the temperature set by the operation of the operation unit 26A. The set temperature of the temperature setter 26 is desirably set to 15 to 45°C (preferably 35°C or lower) that can suppress the decrease in the fluidity of the UFC.

[0044] In this way, by heating the pressure - feeding pipe 20 with the heating wire 23, it becomes possible to effectively suppress the decrease in the temperature of the UFC during pressure - feeding (in other words, the decrease within the pressure - feeding pipe 20). That is, the decrease in fluidity accompanying the decrease in the temperature of the UFC within the pressure - feeding pipe 20 is suppressed, and it becomes possible to effectively suppress the increase in the pressure - feeding load of the pump device 80. By suppressing the increase in the pressure - feeding load of the pump device 80, it becomes possible to realize the continuous pressure - feeding of the UFC by the pump device 80.

[0045] Example 3 is more effective when combined with Example 1. Specifically, before the pressure - feeding of the UFC, the pressure - feeding pipe 20 is pre - heated with a high - temperature fluid, and during the pressure - feeding of the UFC, the pre - heated pressure - feeding pipe 20 is kept warm by heating it with the heating wire 23. By keeping the pressure - feeding pipe 20 warm after pre - heating in this way, it becomes possible to suppress the power consumption of the heating wire 23.

[0046] [Example 4] FIG. 5 is a schematic diagram for explaining Example 4. Example 4 effectively suppresses the decrease in the temperature of the UFC during pressure - feeding in an environment where the outside air temperature is low, such as in winter, by covering the outer peripheral surface of the pressure - feeding pipe 20 with a heat - insulating material 27.

[0047] The type of the heat - insulating material 27 is not particularly limited as long as it can cover the outer peripheral surface of the pressure - feeding pipe 20. Specifically, as shown in FIG. 5(A), the heat - insulating material 27 may be an air - filled bubble curing sheet 27A having a large number of convex portions formed on one surface, or as shown in FIG. 5(B), it may be composed of a pair of foamed polystyrene bodies 27B, 27B having a semi - circular arc - shaped cross - section that sandwich the pressure - feeding pipe 20, or as shown in FIG. 5(C), a sheet - shaped heat - insulating curing material 27C can also be used.

[0048] In this way, by covering the outer peripheral surface of the pressure-feeding pipe 20 with the heat insulating material 27, it becomes possible to effectively suppress the temperature of the UFC from decreasing during pressure-feeding (in other words, decreasing within the pressure-feeding pipe 20). That is, the decrease in fluidity accompanying the decrease in the temperature of the UFC within the pressure-feeding pipe 20 is suppressed, and it becomes possible to effectively suppress an increase in the pressure-feeding load of the pump device 80. By suppressing an increase in the pressure-feeding load of the pump device 80, it becomes possible to realize continuous pressure-feeding of the UFC by the pump device 80.

[0049] Example 4 is more effective when combined with Example 1 or Example 2. Specifically, before pressure-feeding the UFC, the pressure-feeding pipe 20 is preheated with a high-temperature fluid, and during pressure-feeding of the UFC, the preheated pressure-feeding pipe 20 is heat-insulated with the heat insulating material 27. Alternatively, before pressure-feeding the UFC, the pressure-feeding pipe 20 is precooled with a low-temperature fluid, and during pressure-feeding of the UFC, the precooled pressure-feeding pipe 20 is heat-insulated with the heat insulating material 27. If the pressure-feeding pipe 20 after preheating or the pressure-feeding pipe 20 after precooling is heat-insulated with the heat insulating material 27 in this way, it becomes possible to maintain the UFC at the lowest temperature for a long time during pressure-feeding of the UFC.

[0050] Also, Example 4 can be combined with Example 3. Specifically, it is configured such that the outer peripheral surface of the pressure-feeding pipe 20 around which the heating wire 23 is wound is covered with the heat insulating material 27. If the heating wire 23 and the heat insulating material 27 are used in combination in this way, it becomes possible to effectively suppress the power consumption of the heating wire 23.

[0051] [Example 5] FIG. 6 is a schematic diagram for explaining Example 5. Example 5 effectively suppresses the temperature of the UFC from decreasing during placement in an environment where the outside air temperature is low, such as in winter, by preheating the inside of the formwork 90, which is the placement location of the UFC, with hot air.

[0052] In Example 5, similar to Example 1, a hot air blower 21 with a built-in heater is used. The hot air blower 21 inserts a nozzle 21A into an injection pipe 95 provided at the lower part of the formwork 90, and preheats the inside of the formwork 90 by blowing high-temperature air from the tip of the nozzle 21A. The temperature of the high-temperature air is desirably a temperature that can adjust the temperature inside the formwork 90 to 15 - 45°C (preferably 35°C or lower) by preheating. The specific temperature of the high-temperature air is not particularly limited, but it is desirable to set a higher temperature as the outside air temperature is lower. The timing for preheating the inside of the formwork 90 may be implemented during the period when the UFC is being manufactured by the mixer device 70.

[0053] The high-temperature air blown from the hot air blower 21 may be stopped when the temperature inside the formwork 90 reaches the desired temperature (when it has risen to 15 - 45°C). The temperature inside the formwork 90 may be recognized based on the measured value of a thermometer capable of measuring the temperature inside the formwork 90. Alternatively, in advance through experiments or the like, the blowing time of the high-temperature air required to raise the temperature inside the formwork 90 to the desired temperature (the time from the start to the end of blowing) may be obtained, and the hot air blower 21 may be stopped at the timing when the blowing time has elapsed.

[0054] In this way, by preheating the inside of the formwork 90 with high-temperature air in advance, it becomes possible to effectively suppress the decrease in the temperature of the UFC during casting into the formwork 90 (in other words, the decrease inside the formwork 90). That is, the decrease in fluidity accompanying the temperature decrease of the UFC inside the formwork 90 can be suppressed, and it becomes possible to uniformly and efficiently cast the UFC into the formwork 90.

[0055] Example 5 is more effective when combined with Examples 1, 3, and 4. That is, according to Examples 1, 3, and 4, the decrease in the fluidity of the UFC during pressure feeding is effectively suppressed, and according to Example 5, the decrease in the fluidity of the UFC during casting is effectively suppressed. As a result, it becomes possible to realize the continuous pressure feeding of the UFC by the pump device 80 while realizing the uniform and efficient casting of the UFC into the formwork 90.

[0056] [Example 6] FIG. 7 is a schematic diagram for explaining Example 6. In Example 6, by preheating the inside of the formwork 90, which is the placement location of UFC, with warm water mist, it effectively suppresses the temperature of UFC from dropping during placement in an environment with a low outside air temperature such as in winter.

[0057] In Example 6, a mist device 28 capable of spraying warm water mist is used. The mist device 28 inserts a nozzle 28A into an injection pipe 95 provided at the lower part of the formwork 90, and preheats the inside of the formwork 90 by spraying warm water mist from the tip of the nozzle 28A. The temperature of the warm water mist is desirably a temperature that can adjust the temperature inside the formwork 90 to 15 - 45°C (preferably 35°C or lower) by preheating. For this reason, it is desirable to use warm water supplied to the mist device 28 that has been pre - adjusted to a desired high water temperature by heating means such as a heater in advance. The specific water temperature of the high - temperature water is not particularly limited, but the lower the outside air temperature, the higher the water temperature is desirably set. The timing for preheating the inside of the formwork 90 may be during the period when UFC is being manufactured by the mixer device 70.

[0058] The warm water mist sprayed from the mist device 28 may stop when the temperature inside the formwork 90 reaches the desired temperature (when it rises to 15 - 45°C). The temperature inside the formwork 90 may be recognized based on the measured value of a thermometer capable of measuring the temperature inside the formwork 90. Or, in advance through experiments or the like, obtain the total spray amount of warm water mist required to raise the temperature inside the formwork 90 to the desired temperature, and stop the mist device 28 at the timing when the spraying of the total spray amount of warm water mist is completed.

[0059] In this way, by preheating the inside of the formwork 90 with warm water mist in advance, it becomes possible to effectively suppress the temperature of UFC from dropping during placement into the formwork 90 (in other words, dropping inside the formwork 90). That is, the decrease in fluidity accompanying the temperature drop of UFC inside the formwork 90 can be suppressed, and it becomes possible to place UFC uniformly and efficiently inside the formwork 90.

[0060] Example 6 is more effective when combined with Examples 1, 3, 4, and 5. That is, with Examples 1, 3, 4, and 5, the decrease in the fluidity of UFC during pumping is effectively suppressed, and with Example 6, the decrease in the fluidity of UFC during placement is effectively suppressed. As a result, it becomes possible to realize continuous pumping of UFC by the pump device 80 and uniform and efficient placement of UFC into the formwork 90. Note that preheating with warm water mist can also be applied to the preheating in the pumping pipe 20.

[0061] [Example 7] FIG. 8 is a schematic diagram for explaining Example 7. In Example 7, by pre-cooling the inside of the formwork 90, which is the placement location of UFC, with cold water mist, it effectively prevents the temperature of UFC from rising during placement in an environment where the outside air temperature is high, such as in summer.

[0062] In Example 7, similar to Example 6, a mist device 28 capable of spraying cold water mist is used. The mist device 28 inserts a nozzle 28A into the injection pipe 95 provided at the lower part of the formwork 90 and pre-cools the inside of the formwork 90 by spraying cold water mist from the tip of the nozzle 28A. The temperature of the cold water mist is desirably a temperature that can adjust the temperature inside the formwork 90 to 15 - 45°C (preferably 35°C or lower) by pre-cooling. For this reason, it is desirable to use cold water supplied to the mist device 28 that has been pre-adjusted to the desired cold water temperature by a cooling means such as a cooler. The specific water temperature of the cold and warm water is not particularly limited, but it is desirable to lower the water temperature as the outside air temperature is higher. The timing for pre-cooling the inside of the formwork 90 may be during the period when the UFC is being manufactured by the mixer device 70.

[0063] The cold water mist sprayed from the mist device 28 may stop when the temperature inside the formwork 90 drops to the desired temperature (15 to 45 °C). The temperature inside the formwork 90 may be recognized based on the measured value of a thermometer capable of measuring the temperature inside the formwork 90. Alternatively, the total spray amount of the cold water mist required to lower the temperature inside the formwork 90 to the desired temperature may be obtained in advance through experiments or the like, and the mist device 28 may be stopped at the timing when the spraying of the cold water mist with the total spray amount is completed.

[0064] In this way, by pre-cooling the inside of the formwork 90 with cold water mist in advance, it becomes possible to effectively suppress the temperature of the UFC from rising during pouring into the formwork 90 (in other words, rising inside the formwork 90). That is, the separation of steel fibers (i.e., the generation of fiber balls) accompanying the temperature rise of the UFC inside the formwork 90 is suppressed, and it becomes possible to pour the UFC uniformly and efficiently into the formwork 90.

[0065] Example 7 is more effective when combined with Example 2. That is, due to the pre-cooling in Example 2, the increase in the fluidity of the UFC during pumping is effectively suppressed, and due to the pre-cooling in Example 7, the increase in the fluidity of the UFC during pouring is effectively suppressed. As a result, it becomes possible to realize the continuous pumping of the UFC by the pump device 80 while realizing the uniform and efficient pouring of the UFC into the formwork 90. In addition, the pre-cooling with cold water mist can also be applied to the pre-cooling inside the pumping pipe 20.

[0066] [Example 8] FIG. 9 is a schematic diagram for explaining Example 8. Example 8 maintains the fluidity of UFC suitable for pumping and placing by applying vibration to the pumping pipe 20 (see FIG. 9(A)) during the pumping of UFC and / or the formwork 90 (see FIG. 9(B)) during the placing of UFC. As a means for applying vibration, a vibration applying device 29 such as a trowel vibrator or an electric hammer can be used. The application of vibration by the vibration applying device 29 may be performed manually by an operator, or may be performed by directly installing it on the outer peripheral surface of the pumping pipe 20 or the outer peripheral surface of the formwork 90. For the formwork 90, it is desirable to apply vibration in the vicinity of the injection pipe 95 which is the placing port of UFC.

[0067] Thus, by applying vibration to the pumping pipe 20 and the formwork 90, it becomes possible to maintain the fluidity of UFC suitable for pumping and placing. That is, it becomes possible to uniformly and efficiently place UFC into the formwork 90 while suppressing an increase in the pumping load accompanying a decrease in the fluidity of UFC. Example 8 is more effective when combined with Examples 1 to 7.

[0068] [Example 9] FIG. 10 is a schematic diagram for explaining Example 9. Example 9 adjusts the flow value (0-beat flow value) of UFC within the range of 250 to 290 mm which is a value suitable for pumping, thereby preventing blockage of the pipe flow path due to separation of steel fibers and an increase in the pumping load accompanying a decrease in fluidity. The measurement of the flow value is performed based on the method of the flow test described in the physical test method of JIS R 5201 cement. That is, the diameter D of the UFC spread on the upper surface of the flat plate P after pulling up the flow cone is measured. The timing for measuring the flow value may be immediately after the UFC is kneaded by the mixer device 70, or may be performed every predetermined time (for example, 30 to 60 minutes) during the pumping of UFC by the pump device 80. When the measured flow value deviates from the range of the reference value (270 mm ± 20 mm), an admixture (high-performance water reducing agent) is appropriately mixed into the UFC in the production hopper of the mixer device 70 at a mass ratio of 0.005 to 0.100% to adjust the flow value to be within the range of the reference value.

[0069] In this way, by adjusting the flow value of the UFC manufactured by the mixer device 70 and / or the flow value of the UFC during pumping within the range of the reference value (270 mm ± 20 mm), it is possible to prevent a decrease in fluidity caused by the flow value falling below the lower limit value (250 mm), and further, fiber separation of steel fibers caused by the flow value exceeding the upper limit value (290 mm). That is, it is possible to effectively prevent an increase in pumping load and blockage of the pipe flow path due to fiber balls, and it becomes possible to realize continuous pumping of the UFC. Example 9 is more effective when combined with Examples 1 to 8.

[0070] [Example 10] FIG. 11 is a schematic diagram for explaining Example 10. Example 10 prevents blockage of the pipe flow path due to fiber separation and an increase in pumping load associated with a decrease in fluidity by adjusting the kneading temperature of the UFC manufactured by the mixer device 70 within the range of 15 to 45°C (preferably 30°C), which is the reference temperature. In Example 10, powders, aggregates, etc., which are materials of the UFC, are stored in a container 76 with a temperature control function installed on-site to keep them at an appropriate temperature. Also, the water used for manufacturing the UFC is stored in a tank 78 with a temperature control function installed on-site to keep it at an appropriate temperature.

[0071] In this way, by keeping various materials of the UFC and water at an appropriate temperature and adjusting the kneading temperature of the UFC manufactured by the mixer device 70 to the reference temperature (15 to 45°C), it is possible to prevent a decrease in fluidity associated with a temperature drop and fiber separation of steel fibers associated with a temperature rise during pumping of the UFC. That is, it is possible to effectively prevent an increase in pumping load and blockage of the pipe flow path due to fiber balls, and it becomes possible to realize continuous pumping of the UFC. Example 10 is more effective when combined with Examples 1 to 9.

[0072] [Others] Note that the present disclosure is not limited to the above-described embodiments, and can be appropriately modified and implemented without departing from the spirit of the present disclosure.

[0073] For example, in Example 3 of the above embodiment, it was described that the heating wire 23 is used for heating the pressure feeding pipe 20. However, it is also possible to use a Peltier element instead of the heating wire 23. When using a Peltier element, a number of Peltier elements may be installed on the outer peripheral surface of the pressure feeding pipe 20. When using a Peltier element, not only the heating of the pressure feeding pipe 20 but also the cooling of the pressure feeding pipe 20 in summer or the like can be achieved by reversing the direction of the current. Further, as the means for heating the pressure feeding pipe 20, it is also possible to use other heating devices such as a PTC heater.

[0074] Also, in the above embodiment, the UFC is described as an example. However, the pressure feeding system and the pressure feeding method of the present disclosure can be widely applied to various fiber-reinforced cementitious compositions including reinforcing fibers such as steel fibers and synthetic fibers, such as fiber-reinforced mortar and fiber-reinforced grout.

Explanation of Reference Numerals

[0075] 10... Pressure feeding system, 20... Pressure feeding pipe, 21... Warm air blower, 21A... Nozzle, 23... Heating wire, 24... Power source, 25... Switching element, 26... Temperature setter, 26A... Operation unit, 27... Heat insulating material, 27A... Bubble curing sheet, 27B... Expanded polystyrene body, 27C... Heat insulating curing material, 28... Mist device, 28A... Nozzle, 29... Vibration applying device, 70... Mixing device, 72... Container with temperature control function, 74... Tank with temperature control function, 80... Pump device, 85... Hopper for pump, 88... Discharge pipe, 90... Formwork, 95... Injection pipe

Claims

1. A pumping system for a fiber-reinforced cementitious composition, comprising: A pumping pipe for supplying the fiber-reinforced cementitious composition discharged from a pump device to a predetermined placement location; Temperature adjusting means capable of adjusting the temperature of the fiber-reinforced cementitious composition pumped through the pumping pipe by the pump device and / or the temperature of the fiber-reinforced cementitious composition placed in the placement location. A pumping system characterized by the above.

2. The pumping system according to Claim 1, wherein: The temperature adjusting means is: Means for adjusting the temperature by heat-exchanging the pumping pipe and / or the placement location with a high-temperature fluid or a low-temperature fluid before the fiber-reinforced cementitious composition is pumped into the pumping pipe by the pump device. A pumping system characterized by the above.

3. The pumping system according to Claim 1 or 2, wherein: The temperature adjusting means further comprises: A heat insulating material covering the outer peripheral surface of the pumping pipe. A pumping system characterized by the above.

4. The pumping system according to Claim 1, wherein: The temperature adjusting means is: Heating means provided on the outer peripheral surface of the pumping pipe and capable of heating the fiber-reinforced cementitious composition in the pumping pipe by generating heat. A pumping system characterized by the above.

5. The pumping system according to Claim 4, wherein: The heating means comprises: A heating wire wound around the outer peripheral surface of the pumping pipe. A pumping system characterized by the above.

6. A pumping system for a fiber-reinforced cementitious composition, comprising: A pressure-feeding pipe for supplying the fiber-reinforced cementitious composition discharged from the pump device to a predetermined placing location, and vibration-imparting means for imparting vibration to the pressure-feeding pipe and / or the placing location, are provided. A pressure-feeding system characterized by the above.

7. A method for pressure-feeding a fiber-reinforced cementitious composition, in which the fiber-reinforced cementitious composition produced by a mixer device is discharged into a pressure-feeding pipe by a pump device and supplied to a predetermined placing location, wherein the flow value of the fiber-reinforced cementitious composition produced by the mixer is adjusted to 250 to 290 mm. A pressure-feeding method characterized by the above.

8. The pressure-feeding method according to Claim 7, wherein the kneading temperature of the fiber-reinforced cementitious composition produced by the mixer is adjusted to 15 to 45°C. A pressure-feeding method characterized by the above.

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