JP3641445B2 - Pressure-feed spraying method for wet materials - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is a method of spraying a wet material mainly composed of mortar or concrete using a pumping pump and air when constructing, repairing, or reinforcing a slope, a retaining wall, a tunnel, or an underground structure. The present invention relates to a wet-feeding and spraying method for a wet material, in which a low-slump wet material having a slump value of less than 1 to 8 cm, which has conventionally been impossible, can be pumped and sprayed using a pump.
[0002]
[Prior art]
Conventionally, as a method of transporting and spraying wet materials mainly composed of mortar or concrete to construction sites of various construction sites such as slopes, retaining walls, tunnels, underground structures, etc., repair, reinforcement, etc. In general, an all-air transport spraying method for transporting by air and a pump pressurization + air transport spraying method for using both pump pumping and air transport are generally employed. The all-air transport spraying method uses a sealed rotating pocket type or closed tank type spraying machine, and this sealed rotating pocket type spraying machine is used in a tunnel construction or other natom construction method. A material transfer hose with a length of ˜65 mm and a length of 10 to 30 m is connected, air is supplied to the sprayer, and air is transported to the construction site for spraying. A hose connection port for a quick setting agent for powder is provided a few meters before the spray nozzle so as to supply the quick setting agent. Concrete as a wet material has a weight ratio of cement: fine aggregate: coarse aggregate (15 mm or less) of 1: 2 to 3: 1 to 2 and a slump value of 8 to 16 cm. In such a soft material, there is a risk of peeling after spraying and an initial strength is required, so a powder quick-setting agent of 5 to 10% of the cement weight ratio is used, but a lot of dust is generated. There is a problem that the on-site environment deteriorates and the cost is high.
[0003]
The other closed tank type sprayer is used in the slope construction method. Connect a polyhose or rubber hose with an inner diameter of 38 to 50 mm and a length of 10 to 100 m to the material discharge port, and supply air from the hose connection port. It is a construction method in which air is conveyed to the construction site and sprayed. The mortar as a wet material has a cement: fine aggregate weight ratio of 1: 4, and the concrete has a cement: fine aggregate: coarse aggregate (15 mm or less) weight ratio of 1: 4: 1-2, and slump. The value is 0-2 cm. In this construction method, since the slump value of the material is extremely small, there is no sag at the time of spraying, and the initial strength is not emphasized, usually no quick setting agent is used. However, when the slump value is 0 cm, the material is not sufficiently filled in the back side of the reinforcing bars or in the narrow gaps, and cavities are generated and many rebounds occur, resulting in a large material loss and a decrease in strength. There's a problem. Note that the wet material having a slump value of 0 to 2 cm, which is poor in fluidity, can be transferred because it is transferred by air, so that the wet material does not become a consolidated state during transfer.
[0004]
The construction range of these all-air conveyance spraying methods is determined by the length and height of the material conveyance hose. If the entire extension becomes longer or the height is increased, it becomes difficult to transport the material, and the material may be separated to cause variation, resulting in a decrease in strength. The length is within 45m. If this range is exceeded, the quality of the material cannot be maintained by air transportation alone and the construction becomes difficult, so there is a problem that the spraying machine, the material, and other materials must be relocated.
[0005]
Therefore, when the transport length exceeds 100 m or the vertical height exceeds 45 m, it is necessary to use a pressure feed pipe to the point where the transfer by air is possible and use the pressure feed by the pressure feed pump together. An example of constructing, repairing, and reinforcing a slope, a retaining wall, etc. using this pressure pump and air will be described with reference to FIG. When constructing the slope and retaining wall, a piston type pressure pump 1 having a cylinder inner diameter of 100 to 160 mm is used, and the other end of the curved pipe 2 led out from the piston type pressure pump 1 through the discharge pipe 18 is throttled. A pipe 3 is attached, and a necessary number of pressure feed pipes 4 made of iron pipes or high-pressure hoses of 2.5 inches (inner diameter of about 70 mm) or 3 inches (inner diameter of about 80 mm) or high pressure hoses are connected to the throttle pipe 3, and several meters to several hundreds Construct a pressure-feeding pipeline with a predetermined length that spans a meter. The piston-type pressure pump 1 includes two plunger pumps P and M each having a piston and a cylinder. The wet material sucked from the suction pipes 17 and 17a can be continuously fed to the discharge pipe 18 by alternately driving the pistons. ing.
[0006]
The throttle pipe 3 is connected to the curved pipe 2 and has a diameter reduced toward the pressure feeding direction. For example, when the cylinder inner diameter of the piston type pressure feeding pump 1 is 100 mm, this is used within a length of 500 to 1500 mm. The inner diameter is reduced to 2.5 inches (the inner diameter is about 70 mm) which is the same diameter as the pressure feeding pipe 4 to be performed. This is because the laying of the pressure feed pipe is a harsh work that is mainly performed manually in a steep field, and therefore it is necessary to reduce the weight by reducing the inner diameter of the pressure feed pipe 4 to improve workability. An air / quick binding agent joining pipe 5 is attached to the tip of the pressure feed pipe 4 made of this iron pipe or high pressure hose, and the air / quick joining agent joining pipe 5 is provided with an air hose connection port 6 and a quick setting agent hose connection port 7. It is. Further, a rubber hose or polyhose 9 having an inner diameter of 38 to 50 mm is attached to the tip of the air / quickening agent merging pipe 5 in a length of about 5 to 40 meters, and a spray nozzle 10 is attached to the tip of the rubber hose or polyhose 9. It is attached. The air / quickening agent merging pipe 5 has a length of 300 to 1000 mm immediately after merging with air, and is narrowed from 2.5 inches (inner diameter: about 70 mm) or 3 inches (inner diameter: about 80 mm) to an inner diameter of 38 to 50 mm. The arrangement position of the quick setting agent hose connection port 7 is not limited to the air / quick setting agent merging pipe 5 but may be connected to the spray nozzle 10 or several meters before the spray nozzle 10.
[0007]
The mortar as the wet material sucked from the suction pipes 17 and 17a has a cement: fine aggregate weight ratio of 1: 1 to 4, and the concrete has a cement: fine aggregate: coarse aggregate (15 mm or less) weight ratio of 1. : 1-4: 1 to 2 is basically used, and the slump value is 8 to 27 cm. Since the spraying work is performed with the worker holding the spray nozzle 10, the spray amount is 1 to 5 m per hour. ³ , Air volume is 2-7Nm ³ Generally about / min. The slump value is set to 8 to 27 cm. Unlike the air conveyance, when the pressure pump 1 is used for pressure feeding, the wet material is compressed in the pressure feeding pipe, so that the slump value is less than 8 cm. This is because stable pumping cannot be performed and there are many cases where blockage occurs, so that only a slump value having a fluidity of 8 to 27 cm can be pumped.
[0008]
In this construction method, there are a solid blowing method in which a wet material is sprayed over the entire construction surface forming the slope, and a method frame method in which a wet material is sprayed into the method frame. For wet materials with a slump value of 8 to 27 cm, a wet material is used. There is a large amount of material loss due to a large amount of sag and outflow from the frame. In addition, there is a problem that the sprayed material moves due to the spraying air pressure and uniform spraying cannot be performed, so the liquid quick setting agent is supplied from 3 to 8% of the cement weight ratio from the quick setting agent hose connection port 7. And the slump at the time of spraying is slumped down to about 1-6 cm and spraying is performed. That is, the slump value is increased for pumping to increase the fluidity, and a quick setting agent is added to return to a property suitable for construction at the end of the pumping to lower the slump value. Therefore, it is ideal if a wet material having a slump value of less than 8 cm, more preferably 1 to 6 cm can be pumped as it is. However, conventionally, the problem of clogging cannot be solved, and wet materials having a slump value of less than 8 cm have been considered impossible to pump.
[0009]
On the other hand, as a spraying method when constructing, repairing, or reinforcing a tunnel and an underground structure, a method in which an operator sprays while holding the spray nozzle 10 and a method in which a spray robot is used. There is. In the case of a method in which an operator performs spraying while holding the spray nozzle 10, the method is almost the same as in the case of the slope and retaining wall shown in FIG. 5 described above.
[0010]
On the other hand, an example of using a spraying robot will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the component same as the structure shown in FIG. Piston type pumping pump 1 with a cylinder inner diameter of 120 to 180 mm is used, and a section of several meters from the piston type pumping pump 1 to the air merging pipe 5a is piped with a pressure feeding pipe 4 made of an iron pipe or a high pressure hose, and the tip of the pressure feeding pipe is reached. The throttle pipe 3 is used to throttle to 3 to 4 inches (inner diameter of about 80 to 100 mm), an air merging pipe 5a is attached to the tip of the pressure feeding pipe, and a rubber hose 9 having an inner diameter of 65 to 80 mm is attached to the tip of the air merging pipe. The spray nozzle 10 is attached to the tip of the attachment. The air merging pipe 5a has a length of 300 to 1000 mm immediately after the air and the merging pipe, and is narrowed from 3 to 4 inches (an inner diameter of about 80 mm to about 100 mm) to an inner diameter of 65 to 80 mm. The air hose is connected to the air merging pipe 5 a via the air hose connection port 6, and the quick setting agent hose connection port 7 is provided several meters before the spray nozzle 10. The wet material concrete has a weight ratio of cement: fine aggregate: coarse aggregate (15 mm or less) of 1: 2 to 3: 1 to 2 and a slump value of 8 to 18 cm. The amount of material sprayed is 5-25m per hour ³ Air quantity is 10-20Nm ³ / Min is common. In such soft materials, there is a risk of peeling after spraying and an initial strength is required, so a powder quick-setting agent of 5 to 10% of the cement weight ratio is used, but a lot of dust is generated. There is a problem that the on-site environment deteriorates and the cost is high.
[0011]
Even in this case, the slump value is increased for pump pumping to increase fluidity, and a quick setting agent is added to return to a suitable property for construction at the end of pumping, so the slump value is lowered. is there. Therefore, if the wet material close to the slump value suitable for various constructions can be pumped as it is, the amount of the quick setting agent can be reduced, the cost can be reduced, and the working environment is improved, which is ideal. However, the pumping process cannot conventionally solve the problem of clogging, and a wet material having a slump value of less than 8 cm has been considered impossible to pump.
[0012]
The slump is an index indicating the degree of softness of the fresh concrete, and is a value represented by a length (cm) of a drop from the top measured immediately after pulling up the slump cone. It can be seen that the smaller the slump value, the harder the fresh concrete, and the larger the slump value, the softer the concrete.
[0013]
[Problems to be solved by the invention]
If a wet material with a slump value of 8 cm or more is sprayed as it is, dripping at the time of spraying, rebound loss, and outflow from the inside of the frame will often occur, resulting in a lot of material loss, poor workability and high cost. Because there is a problem that the sprayed material moves due to the air pressure at the time of application and uniform spraying is not possible, generally a quick setting agent is used as a solution, and the slump value at the time of spraying is 1 to By slumping down to about 6 cm and reducing dripping, rebound loss, and outflow from the frame, material loss can be reduced and uniform spraying can be performed. However, the use of the quick setting agent causes a problem that not only the dust is generated and the on-site environment is deteriorated, but also the cost is increased.
[0014]
In addition, as a means of reducing the amount of wet material sag and outflow from the frame, the admixture or fly ash, fine powder of blast furnace slag, silica fume, fine powder of limestone, etc. are mixed in the wet material. Means for increasing the viscosity and decreasing the aperture ratio of the frame material of the method frame are known. However, in any case, there is a problem that the cost is high, and when the viscosity is increased, the air conveyance distance is shortened and the workability is lowered.
[0015]
Therefore, if a wet material having a slump value of less than 8 cm, more preferably 1 to 6 cm or less suitable for various constructions is pumped and sprayed as it is, the above means are not necessary, and the quick setting agent is unnecessary or reduced. In addition, the working environment is improved and the cost is reduced. However, pumping wet materials with a slump value of less than 8 cm has poor fluidity when using a discharge pipe of a pump or a throttle pipe or a curved pipe of a pumping pipe whose cross-sectional shape changes. The increase in deformation resistance of the pipe increases the pressure loss in the pipe, the frequency of clogging in the pumping pump and the piping is increased, and not only stable pumping is not possible, but also due to slump down due to separation of wet material There is a problem that properties change and stable quality cannot be maintained. Therefore, it has been impossible to pump and spray a low slump wet material having a slump value of less than 8 cm using a pump.
[0016]
In recent years, both fine aggregates (sand) and coarse aggregates (gravel), which are mortar and concrete materials, are less naturally produced, and many crushed sand and crushed stones are artificially produced by crushing rocks with crushers. It has come to be. The artificially made crushed sand and crushed stone are square and cannot be stably pumped compared to natural sand and gravel. Since clogging is likely to occur, the slump value is increased by adding water, cement fine powder, admixture, etc., and it is not suitable for pumping unless the fluidity is increased. Low slump materials are becoming increasingly difficult to pump. In particular, in the case of construction using pump pumping together, it is important to perform stable pumping and to prevent the occurrence of blockage in the pump or pipe.
[0017]
In the case of flowing in a normal straight pipe, the flow in a deformed pipe such as a throttle pipe and a curved pipe constituting a discharge pipe of a pressure feed pump and a pressure feed pipe in which a wet material mainly composed of mortar or concrete is pumped in a compacted state In contrast to this, it is necessary to consider deformation resistance such as in-tube blockage that occurs accidentally when the shape of the pumping material changes. Examination of the risk of blockage in the pipe is most reliable by carrying out test pumping under piping conditions close to the actual construction conditions and confirming the presence or absence of blockage in the pipe. However, these field experiments are not always feasible due to constraints such as cost, duration, and field conditions, and the present situation is that a technique for accurately predicting the risk of intravascular blockage has not been established.
[0018]
When a blockage occurs in a pressure pump or piping, the location of the blockage, removal work, recovery work, investigation of the cause, etc. must usually be performed within 1 hour. This is because, since the quality of the material cannot be maintained if the restoration work takes a long time, it is necessary to discharge all the material in the pressure feeding pipe and the pressure feeding pump and then re-pressure feed. In addition, if the restoration work takes a long time, the materials in the pumping pipe and pumping pump will be hardened, so the pumping pipe must be discarded or the pumping pipe must be reworked. And time is required. In curved pipes and throttle pipes with large deformation resistance, the curved pipe can be reduced in deformation resistance by increasing the radius of curvature, but if the length of the throttle pipe is increased, the frequency of blockage in the pipe is increased. Deformation resistance may decrease somewhat, but it is not a fundamental measure.
[0019]
Originally, the slump value must be determined with emphasis on material strength, durability, workability, cost, and the like. In particular, if pumping can be performed with a slump value suitable for construction, it is effective in terms of material strength, workability, and cost, and a durable structure can be constructed. In addition, it is not preferable to increase the unit water amount in order to increase the fluidity at the time of pumping, and if the water-cement ratio is increased, there arises a problem that the strength of the concrete decreases. Even when the unit water volume is increased with the water-cement ratio kept constant, the increase in the cement volume increases the cost and also leads to an increase in cracks, which adversely affects durability.
[0020]
When the unit water volume is reduced, the slump value is lowered and the pumpability is inferior, but the strength is increased and a durable structure can be obtained. In addition, high-performance water reducing agents and AE water reducing agents are sometimes used as a means of reducing the unit water volume and increasing the fluidity to improve the pumpability. There is a problem that the amount of the agent or the hardener used is increased, the cost is further increased, the viscosity is increased, the air conveyance distance is shortened, and the workability is lowered. It is ideal that the wet material can be pumped and sprayed as it is without adding any wet material having a slump value of less than 8 cm, more preferably 1 to 6 cm, suitable for construction. However, in the past, in order to pump the pump stably, the admixture or fine powder is added to the wet material to increase the slump value and viscosity, and the material with reduced deformation resistance when passing through the throttle tube is pumped. The fact is that a quick setting agent or a hardener is used in order to reduce the slump value to 1 to 6 cm when pumped and sprayed onto the construction surface.
[0021]
Therefore, the present invention solves the above problems and is suitable for various constructions such as construction, repair and reinforcement of slopes, retaining walls, tunnels, underground structures, etc., which have been impossible to pump by conventional pumps. Pumping of wet material that enables smooth pumping and spraying of low-slump wet material with a slump of less than 8 cm, more preferably 1 to 6 cm or less, without causing clogging in the pump or piping. The purpose is to provide a spraying method.
[0022]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a wet material mainly composed of mortar or concrete. To the point where transportation by air is possible A pressure feed pump is used to pump the inside of the specified length of the pressure feed pipe and to the tip of the pressure feed pipe. Via connected junction Combine the air At the same time, a hose with an inner diameter suitable for spraying work was connected to the tip of the merging pipe and attached to the tip of the hose. Pressure-feed spraying method for wet materials sprayed from spray nozzles Because A discharge pump and a pressure feed pump that use a piston pressure feed pump as the pressure feed pump and that have an inner diameter that is substantially equal to or larger than the cylinder inner diameter of the piston pressure feed pump and that do not substantially shrink in the pressure feed direction. By using piping, the wet spraying method of wet material which makes it possible to pump wet materials mainly composed of mortar or concrete having a slump value of less than 1 to 8 cm or a slump value of 1 to 6 cm or less is provided.
[0023]
And the means for adding the quick setting agent after the front end of the pressure feed pipe or the air is merged, and joining the wet material with the air and the quick set agent, and the valve structure of the piston type pressure feed pump, A parallel sliding means is provided.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, specific embodiments of the wet material pressure blowing method according to the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram for explaining a case in which the present invention is applied to a slope or a retaining wall, wherein 1 is a piston type pressure feed pump having a cylinder inner diameter of 70 mm, and P and M are pistons constituting the piston type pressure feed pump 1. And two plunger pumps having cylinders. The piston-type pump 1 can continuously feed a wet material mainly composed of mortar or concrete sucked from the suction pipes 17 and 17a to the discharge pipe 18 by alternately driving the pistons. The discharge pipe 18 is connected to a pressure feed pipe 11 having a predetermined length. The pressure-feeding pipe 11 has a bent pipe portion 11a and a bent pipe portion 11b having a bending radius of 500R and a length of 2.5 inches (inner diameter: about 70 mm) or 3 inches (inner diameter: about 80 mm). In the present invention, as the discharge pipe 18 and the pressure feed pipe 11, a pipe having an inner diameter substantially equal to or larger than the cylinder inner diameter of the piston type pressure feed pump 1 and having a diameter which is not substantially reduced in the pressure feed direction is used. It is the feature that a throttle pipe is not used in a pressure-feeding pipeline.
[0025]
As mentioned above, in the construction method that uses air to spray wet materials mainly composed of mortar or concrete to the construction sites of various construction sites such as construction, repair, reinforcement, etc. of slopes, retaining walls, tunnels, underground structures, etc. Needs to be pumped through a predetermined length of pressure-feed piping using a pressure-feed pump to a point at which conveyance by air is possible. Lay this pressure feed pipe There are many steep places where slopes and retaining walls are built, and one pipe is connected to one by one by manually transporting a pressure feed pipe 11 consisting of an iron pipe or a high-pressure hose with a length of 3 to 6 m. Since this is a very harsh and dangerous operation that must be performed, it is desirable that the pressure feeding pipe 11 be as light and small as possible. Therefore, as described above, conventionally, in order to increase the discharge efficiency, a pumping pump having a large inner diameter is used, and a throttle pipe is interposed in the pumping pipe line to use a pumping pipe having a small diameter, that is, a light weight. It was like that. By the way, the 2.5-inch pipe that is usually used is a straight pipe with a wall thickness of 2.8 mm and a length of 3 m, and the weight is 16 kg per pipe, and the weight is 6 kg and is 31 kg. The 3-inch pipe is a straight pipe with a wall thickness of 3.2 mm and a length of 3 m, and the weight is 21 kg per pipe and the length of 6 m is 41 kg. The 4-inch pipe is a straight pipe with a wall thickness of 3.2 mm and a length of 3 m. The weight is 24 kg per pipe, and the weight is 6 m and the weight is 47 kg. The joints connecting the pipes are 3.4 kg for 2.5 inches and 3 inches, and 6.7 kg for 4 inches.
[0026]
The minimum pipe diameter of the pressure feed pipe 11 to be used is determined by the maximum coarse aggregate diameter and the pressure feed load. Coarse aggregates are natural and artificially crushed stones, and natural ones are round and have good pumpability, so the pipe diameter is three times larger than the maximum coarse aggregate diameter. Since crushed stones are angular and poor in pumpability, a pipe diameter that is at least four times the maximum coarse aggregate diameter is required.
[0027]
Since the maximum coarse aggregate diameter of 10 to 15 mm is often used when using concrete as the wet material, the minimum pipe diameter selected from the maximum coarse aggregate diameter is 60 mm or more. Often 2.5 inch (70.7 mm or 69.9 mm ID) tubing is used. In the case of long-distance pumping and high-pressure pumping, a 3-inch pipe (inner diameter: 82.7 mm or 80.7 mm) may be unavoidably used to reduce the pumping load. Even if the pipes to be used have the same outer dimensions, a slight difference is caused in the inner diameter depending on the wall thickness, so that the inner diameter is different as described above.
[0028]
Therefore, in the present invention, the pressure feed pipe 11 connected to the discharge pipe 18 of the piston type pressure feed pump 1 is mainly composed of a 2.5 inch straight pipe (inner diameter 70.7 mm) having a minimum pipe diameter, and similarly 2.5 inches. In the case where a pressure-feed pipe line having a predetermined length is configured using the bent pipe portion 11a and the bent pipe portion 11b having a bending radius of 500R, the cylinder inner diameter of the piston-type pressure feed pump 1 is also a discharge pipe. 18 and the pressure-feeding pipe 11, and the inner diameter of the cylinder having the same diameter as that of the curved pipe portions 11a and 11b is 70 mm. Therefore, the pipe line from the pressure feed pump 1 to the tip of the pressure feed pipe where the air is merged is approximately equal to or larger than the diameter, and the diameter is not generally reduced in the pressure feed direction. Note that “substantially” indicates that a displacement of several millimeters at the time of connection between the pressure feeding pipes 11 and joining with the curved pipe portions 11a and 11b is allowed. In general, commercially available pipes have different inner diameters depending on the thickness of the steel pipe even if they have the same outer diameter. Further, since the bent pipe portions 11a and 11b are manufactured by bending a straight pipe, the outer wall thickness is reduced and the inner wall thickness is increased. Taking a 2.5 inch tube as an example, the outer diameter is 76.3 mm, the wall thickness is 3.2 mm, the bending radius is 500 R, and the outer wall thickness is 2.97 mm, which is about 93% of the original wall thickness. . If the bending radius is constant and the pipe size is increased, the amount of change in wall thickness is also increased. Therefore, in consideration of pressure resistance and wear, the curved pipe is thicker than the straight pipe. The allowable step between the straight pipe and the curved pipe or the discharge pipe is usually within 3% of the inner diameter of the cylinder of the pump. However, it is desirable to make the step smaller as the slump material becomes lower.
[0029]
Also, the pressure feed pipe 11 Ahead At the end As a junction The air / quickening agent joining pipe 12 is connected, and the air / quickening agent joining pipe 12 is connected. The inner diameter is suitable for spraying Air hose connection 6 And providing Quick setting agent hose connection port 7 The It is provided. A rubber hose or polyhose 9 having an inner diameter of 44 mm with a low coefficient of friction and a low transport resistance is connected to the length of 20 to 80 meters from the air / quickening agent merging pipe 12 to the vicinity of the construction site. A spray nozzle 10 having an inner diameter of 42 mm × 38 mm × 250 mm is attached to the tip of the polyhose 9. In some cases, the spray nozzle 10 may be attached after a rubber hose having an inner diameter of 42 mm capable of reducing the bending radius is connected to the polyhose 9 for 5 to 20 meters. The air / quick-setting agent joining pipe 12 has a length of 300 to 1000 mm from 2.5 inches (inner diameter of about 70 mm) or 3 inches (inner diameter of about 80 mm) to an inner diameter of 38 to 50 mm immediately after joining the air and the quick-setting agent. It is narrowed down to. In addition, after the air for spraying is merged, since it does not become a compacted state by air, the inner diameter of the rubber hose or the polyhose 9 is reduced to an inner diameter suitable for the spraying operation.
[0030]
Explaining the material composition example of the wet material sucked from the suction pipes 17 and 17a, when the wet material is mortar, the cement amount is 400 to 460 kg / m. ³ The water-cement ratio was 50-60% and the slump value was less than 1-8 cm. When the wet material is concrete, the cement amount is 360 to 400 kg / m. ³ , Water-cement ratio is 50-60%, coarse aggregate (15mm or less) is 360-750kg / m ³ The slump value is less than 1-8 cm, more preferably 1-6 cm or less.
[0031]
I will add some slump values suitable for construction, repair, and reinforcement of slopes, retaining walls, tunnels, and underground structures. A slump suitable for construction is a slump value on the slope and retaining wall that prevents dripping and outflow from the frame, and the slump value is such that the sprayed material does not move due to the air pressure at the time of spraying. 6 cm is preferred. On the other hand, in the case of tunnels and underground structures, spraying is applied to the side and ceiling surfaces, and the sprayed material may peel off and fall, which is very dangerous. Use a binder. When a powder quick setting agent is used, if the slump is too low, rebound loss and dust may increase, and usually a slump value of about 3 to 8 cm is preferable. When a liquid quick setting agent is used, since the dust is also reduced, a slump value of about 1 to 5 cm is preferable. Therefore, the present invention provides a novel wet-pumping method for wet materials that enables the pumping of low-slump mortar or concrete-based wet materials having a slump value of less than 1-8 cm, more preferably 1-6 cm or less. is there.
[0032]
The valve structure of the piston-type pump 1 uses a parallel sliding pump. As for the specific configuration of the piston-type pressure feed pump 1, as described in Japanese Utility Model Publication No. 6-17003 proposed by the applicant of the present application, a suction pipe to which a hopper for charging ready-mixed concrete is connected, and A fixed plate in which a discharge pipe is connected in parallel; a sliding plate that is slidably mounted on the fixed plate and in which a plunger pump composed of a cylinder and a piston is connected orthogonally; the sliding plate and the above Two plunger pumps, each having a hydraulic cylinder integrated with a plunger pump and capable of reciprocating in a direction parallel to the fixed plate, and a guide table fixed on a mounting base and guiding the sliding plate Is connected in parallel to the sliding plate and the sliding plate is reciprocated in the horizontal direction on the fixed plate in synchronism with the plunger pump, so that either one of the cylinders and the suction pipe communicate with each other. While the ready-mixed concrete is sucked into the cylinder, the other cylinder communicates the discharge pipe to push the ready-mixed concrete sucked into the cylinder, and the ready-mixed concrete is continuously produced by alternately performing the suction and the pushing operation. Pump.
[0033]
Specifically, as shown in FIGS. 3 and 4, the pressure pump 1 includes cylinders 14 and 14 a for sucking and discharging fresh concrete, pistons 19 and 19 a engaged with the cylinders 14 and 14 a, and pistons thereof. An opening in which two plunger pumps P and M, each consisting of a hydraulic cylinder 27 and 27a engaging with pistons 20 and 20a provided at the other ends of the rods 21 and 21a, are formed in a sliding plate (two-hole face plate) 15. The discharge pipe connection hole of the fixed plate (three-hole face plate) 30 is connected to the ready-mixed concrete discharge pipe 18 and the suction pipe connection hole is connected to the suction pipes 17 and 17a in parallel. The sliding plate 15 is configured to slidably face 15 and to slide in the horizontal direction in sliding contact with the fixed plate 30 in synchronism with the plunger pumps P and M by a hydraulic cylinder 23. The discharge pipe 18 connected to the central opening of the fixed plate 30 is connected to a raw concrete pumping pipe (not shown), and the suction pipes 17 and 17a are connected to a hopper.
[0034]
Therefore, as shown in FIG. 3, while the cylinder 14 and the ready-mixed concrete suction pipe 17 are connected to each other and the ready-mixed concrete is sucked into the cylinder 14, the other cylinder 14a is connected to the discharge pipe 18. The fresh concrete sucked into the cylinder 14a is pushed out. Further, as shown in FIG. 4, while the cylinder 14a and the ready-mixed concrete suction pipe 17a are connected to each other and the ready-mixed concrete is sucked into the cylinder 14a, the other cylinder 14 is connected to the discharge pipe 18. The fresh concrete sucked into the cylinder 14 is pushed out. By repeating the above operation, a discharge pipe in which the ready-mixed concrete put into the hopper is connected to the fixed plate 30 without requiring a complicated configuration such as a switching valve or the like and without increasing the flow resistance in the switching portion. 18 can be continuously pumped. This parallel-sliding piston-type pressure pump 1 does not require a complicated valve configuration such as a switching valve, and has a simple configuration and can smoothly and continuously feed wet materials such as ready-mixed concrete.
[0035]
Specific examples and conventional examples of the wet feeding method for spraying wet materials according to the present invention will be described below.
[Example 1 and Conventional Example 1]
Two types of the cylinder inner diameter of the piston-type pump 1 were prepared, 80 mm as Example 1 and 100 mm as Conventional Example 1. Both stroke lengths are 550 mm, the valve structure is a parallel sliding type, and the mortar composition is cement amount 420 kg / m ³ , 824kg / m of sea sand ³ , River sand 828kg / m ³ , FM (rough particle ratio of sand) is 2.7, water 234kg / m ³ Thus, the slump value was 1.7 cm. For the cylinder having an inner diameter of 80 mm according to the first embodiment, a 3 inch curved pipe portion 11a (inner diameter 80.7 mm × 500 R × 90 °) having the same diameter as the cylinder inner diameter is connected to the discharge port 18 of the piston-type pump 1. Similarly, five 3-inch pressure-feeding pipes 11 (inner diameter 82.7 mm × 6 m) having the same diameter as the cylinder inner diameter were similarly connected, and the pipe length was set to 30 m. In the conventional example 1 having an inner diameter of 100 mm, a 4-inch curved pipe (inner diameter 105.7 mm × 500 R × 90 °) is connected to the discharge port of the piston type pump 1, and a throttle tube (inner diameter 105.7 mm × 82) is connected to the tip. 7 mm × 1 m) and five 3 inch straight pipes (inner diameter 82.7 mm × 6 m) were connected to the tip of the pipe, and the two piston-type pumps 1 were driven simultaneously with a pipe length of 31 m.
[0036]
The theoretical discharge of the piston pump 1 is 6m per hour ³ As a result of measuring the difference in discharge efficiency, it was 93% when the cylinder inner diameter according to Example 1 was 80 mm, and 91% when the cylinder inner diameter according to Conventional Example 1 was 100 mm. When the cylinder inner diameter was 100 mm, the pumping pressure became unstable due to blockage of the throttle pipe during pumping, so the reverse feed operation had to be repeated, and stable pumping could not be performed. On the other hand, when the cylinder inner diameter was 80 mm, it was never unstable and stable pumping was possible.
[0037]
[Example 2 and Conventional Example 2]
Two types of piston type pumping pump 1 having an inner diameter of 80 mm as Example 2 and 100 mm as Conventional Example 2 were prepared, and both stroke lengths were 550 mm. The valve structure is a parallel sliding type, and the mortar composition is cement amount 420kg / m ³ , 488kg / m of sea sand ³ , Crushed sand 1166kg / m ³ , FM (rough particle ratio of sand) is 2.59, water 241kg / m ³ Thus, the slump value was 7.3 cm. The mortar was left in the mixer truck and the progress of the slump was observed. After about 30 minutes, the slump value became 4 cm, and after about 25 minutes, it slumped down to 1.2 cm. The slump-down mortar was used for pressure feeding. The pressure feed piping was the same as in Example 1, and two piston type pressure feed pumps 1 were driven simultaneously.
[0038]
The theoretical discharge of the piston pump 1 is 6m per hour ³ As a result of measuring the difference in discharge efficiency, it was 71% when the cylinder inner diameter according to Example 2 was 80 mm and 80% when the cylinder inner diameter according to Conventional Example 2 was 100 mm. When the cylinder inner diameter according to Conventional Example 2 is 100 mm, when the pressure feeding is temporarily interrupted and then re-pressure feeding, the pressure feeding pressure becomes unstable due to clogging with the throttle tube, and further pressure feeding becomes impossible. The blockage could not be released. On the other hand, when the cylinder inner diameter according to Example 2 was 80 mm, it was never unstable and stable pumping could be performed.
[0039]
[Example 3 and Conventional Example 3]
Two types of piston type pressure feed pump 1 with a cylinder inner diameter of 70 mm as Example 3 and 100 mm as Conventional Example 3 were prepared, and both stroke lengths were 550 mm. The valve structure is a parallel sliding type, and the mortar composition is cement amount 420kg / m ³ 673kg / m of sea sand ³ , River sand 1032kg / m ³ , FM (roughness ratio of sand) is 2.6, water is 210kg / m ³ Thus, the slump value was 1.7 cm. When the cylinder inner diameter according to the third embodiment is 70 mm, the 2.5-inch curved pipe portion 11 a (inner diameter 69.9 mm × 500 R × 90 ° and 30 mm) having the same diameter as the inner diameter of the pressure pump cylinder is provided at the discharge port of the piston type pump 1. °) was connected, and 17 2.5 inch pressure feed pipes 11 (70.7 mm × 6 m) having the same diameter as the inside diameter of the pressure feed pump cylinder were connected to the tip, and the pipe length was set to 102 m. In the cylinder having an inner diameter of 100 mm according to the conventional example 3, the discharge port of the piston type pump 1 is throttled from an inner diameter of 100 mm to 80.7 mm with a length of 450 mm, followed by a 3 inch curved pipe (80.7 mm × 500R × 90 30 °) and a throttle tube (inner diameter 80.7 mm × 69.9 mm × 1 m) connected to the tip, and 17 2.5 inch straight tubes (inner diameter 69.9 mm × 6 m) connected to the tip. The two piston-type pumps 1 were simultaneously driven with the pipe length of 103 m.
[0040]
The theoretical discharge of the piston pump 1 is 6m per hour ³ As a result of measuring the difference in discharge efficiency, it was 77% when the cylinder inner diameter according to Example 3 was 70 mm, and 78% when the cylinder inner diameter according to Conventional Example 3 was 100 mm. When the cylinder inner diameter according to Conventional Example 3 was 100 mm, the pumping pressure when the pumping was temporarily interrupted and then pumped again was unstable, but the pumping was possible without reaching the blockage. When the inner diameter of the cylinder according to Example 3 was 70 mm, it was never unstable and stable pumping could be performed.
[0041]
[Example 4]
Under the same conditions as in the wet material blending performed in Example 3, using a pressure feed pump with a cylinder inner diameter of 70 mm, and connecting the air / quick agent merging pipe to the tip of the pressure feed pipe to join the air, Connect a polyhose with an inner diameter of 44 mm to the end of it, connect a rubber hose with an inner diameter of 42 mm to the end of 20 m, connect a spray nozzle to the end of the hose, set the air conveyance distance to 60 m, and the spray surface is inclined at about 80 ° An angle was set and a section of 1 m square was sprayed with a thickness of 10 cm. The theoretical discharge rate of the pressure pump is 6m per hour ³ The pumping speed is set to, no quick setting agent is used, and the air volume is 5 Nm per minute. ³ The original pressure of air is 0.3-0.35M P a. There was no sag of the spray material and no movement due to air pressure, resulting in a uniform finish, less pulsation, and stable pressure spraying.
[0042]
From Examples 1 to 4 and Conventional Examples 1 to 3 described above, the discharge efficiency (suction efficiency) of the piston-type pump 1 is the same as the theoretical discharge amount, cement amount, and slump value. It became clear that the discharge efficiency (suction efficiency) also differed depending on the type. Further, the discharge efficiency (suction efficiency) due to the difference in cylinder inner diameter was almost the same value when the slump value was 1.7 cm. However, in the state where the slump value is reduced to 1.2 cm, in the case of 80 mm according to the embodiment having a small cylinder inner diameter, it is 9% lower than that of the conventional example having an inner diameter of 100 mm. The variation in discharge efficiency (suction efficiency) even with the same slump value is considered to be due to the difference in material viscosity.
[0043]
In Example 1, FM (sand coarse particle ratio) of sea sand and river sand was 2.7, and the discharge efficiency (suction efficiency) was high because the material had a small amount of fine powder and low viscosity. Such a material tends to increase the air conveyance distance. The sand of Examples 2 and 3 is sea sand and crushed sand, and both FM (roughness ratio of sand) is about 2.6. Compared to that of Example 1, it is fine sand and contains a lot of fine powder. Since the ratio of the crushed sand was as high as 60 to 70% of the total sand, it became a material having higher viscosity than that of Example 1, and the discharge efficiency (suction efficiency) was lowered. Such materials tend to shorten the air transport distance. In addition, a pipe provided with a throttle pipe tends to be blocked or pumped unstable. When piping without a throttle pipe is used, stable pumping can be performed without a single blockage.
[0044]
If you use a piston-type pump to reduce the cylinder inner diameter and require the same amount of discharge per hour as before, the piston speed must be increased. In addition, using a material with an extremely low slump value of less than 8 cm, which was impossible to pump with a conventional piston-type pump, is that the suction efficiency of the material is greatly reduced and stable pumping cannot be performed. However, as a result of conducting the test in Examples and Conventional Examples 1 to 3, it was proved that almost no difference was observed. By the way, 6m per theoretical discharge volume time ³ When the piston speed is compared at a pumping speed of 100 mm, the cylinder having an inner diameter of 100 mm has a speed of 0.24 m / s and the cylinder having an inner diameter of 70 mm has a speed of 0.57 m / s. Therefore, the present invention can secure the amount of pumping required for construction in a state where the cylinder inner diameter of the pumping pump is matched with that of the minimum pipe diameter necessary for construction, The pumping spray with a slump value of less than 8 cm was made possible.
[0045]
Next, a case where the present invention is applied to a tunnel or an underground structure will be described with reference to FIG. When a worker performs spraying while holding the spray nozzle 10 during work, it is performed in the same manner as in the case of the slope and retaining wall shown in FIG. Discharge rate is 25m per maximum time ³ The cylinder diameter of the pressure pump must also be increased. Considering the suction efficiency, it is desirable that the piston speed of the piston type pump 1 is within 0.6 m / sec. At this piston speed, the cylinder inner diameter is 160 mm, and a 6-inch pipe (inner diameter 160.2 mm or 155.2 mm) is used as the pipe diameter. Since the pressure feeding pipe is fixed to the robot carriage by a pipe having a length of several meters, the workability does not change even if the pipe diameter is somewhat large.
[0046]
FIG. 2 is a schematic diagram showing the basic configuration. The basic configuration is substantially the same as the case shown in FIG. 1 applied to the slope or retaining wall, and the same components are indicated by the same reference numerals. is there. The cylinder inner diameter of the piston-type pressure feed pump 1 is 160 mm, the pressure feed pipe 11 is a 6-inch straight pipe and a curved pipe (bending radius 500R), an air junction pipe 5a is connected to the tip, and an air hose connection port is connected to the air junction pipe 5a. 6 is provided. 7 to 15 m of a rubber hose 9 having an inner diameter of 65 mm is connected to the tip of the air merging pipe 5a, a powder or liquid quick-connecting agent merging pipe 13 is connected to the tip of the rubber hose 9, and a rubber hose 9 having an inner diameter of 65 mm is connected to the tip. A spray nozzle 10 having an inner diameter of 65 mm × 50 mm × 1 m is attached to the tip of the rubber hose 9. The material composition example of the wet material sucked from the suction pipes 17 and 17a is the same as the composition example of the case where the present invention is applied to the slope or the retaining wall.
[0047]
[Example 5]
The cylinder inner diameter of the piston type pump 1 is 160 mm, the stroke length is 550 mm, the valve structure is a parallel sliding type, and the mortar composition is a cement amount of 420 kg / m. ³ , 824kg / m of sea sand ³ , River sand 828kg / m ³ , 234kg / m of water ³ Thus, the slump value was 3.3 cm. The pressure feed pipe is a 6-inch pipe (inner diameter 160.6 mm) straight pipe with a diameter of about 32 m connected to the inner diameter of the pressure-feed pump cylinder, and a 6-inch curved pipe (inner diameter 155.2 mm) with the same diameter as the pressure-feed pump cylinder inner diameter. 5 × 500R × 90 °) were connected. The theoretical discharge rate of the pressure pump is 20m per hour ³ Stable pumping was possible with a discharge efficiency of 76.4%.
[0048]
[Example 6]
Concrete pumping was performed under the same conditions as in Example 5. Concrete mix, cement amount 360kg / m ³ , 715kg / m of sea sand ³ , River sand 718kg / m ³ Coarse aggregate of 15 mm or less 360 kg / m ³ , 204kg / m of water ³ The slump value was 2.9 cm. The theoretical discharge rate of the pressure pump is 20m per hour ³ Stable pumping was possible with a discharge efficiency of 94%.
[0049]
【The invention's effect】
According to the present invention, a wet material having a slump value suitable for various constructions of less than 1 to 8 cm, more preferably 1 to 6 cm or less is pumped from a piston-type pump to approximately the same diameter as the cylinder inner diameter of the piston-type pump. By using pipes to pump and spray from the spray nozzle, the amount of spray per hour in the construction of slopes or retaining walls is 4-5m. ³ When the wet material is pumped at a speed that can be secured, even if the slump value is 1.2 to 1.7 cm, it is 71 to 93%, and if the slump value is 2 to 6 cm, the discharge efficiency is stable at 80% or more. Therefore, stable blasting can be performed with less pulsation during spraying.
[0050]
15-20m of sprayed concrete per hour in the construction of tunnels and underground structures ³ When the wet material is pumped at a speed that can be secured, even if the slump value is 3 cm, the discharge efficiency is 94%, and if the slump value is 2 to 6 cm, the discharge efficiency can be stably secured at 80% or more. It is possible to perform stable spraying with less pulsation of the wet material, to reduce the amount of the quick setting agent used, to improve the working environment, and to reduce the cost.
[0051]
As disclosed in the present invention, by performing pump pressure spraying using a wet material having a slump value of less than 1 to 8 cm and less viscosity and fluidity, it is possible to increase the air transport distance and to increase the stage of the pressure piping. It requires less replacement and can improve workability in various constructions.
[0052]
Further, the movement of the spray material due to the air pressure is reduced and finishing is easy, and the pulsation of the material is also small, and the spray operation by the worker is facilitated. A frame material such as a legal frame can be used even in a crimped wire mesh having a large aperture ratio, and the frame can be easily installed. In addition, the number of constructions that can be performed without using quick setting agents or hardeners will be greatly increased, and the amount of quick setting agents or hardeners used may be reduced even in steep or springy locations. it can.
[0053]
In the case of a legal frame or the like, the outflow and rebound loss from within the frame can be reduced, and further the use efficiency of the wet material can be increased by reducing the material loss. Further, conventionally, in order to secure the water cement ratio and increase fluidity and compressive strength, the amount of cement or water reducing agent has to be increased more than necessary, whereas in the present invention, the slump value is less than 1 to 8 cm. As a result, the amount of cement and the amount of water reducing agent used can be reduced, and the cost can be reduced. Conventionally, crushed sand made by crushing rocks, and crushed stones are significantly inferior in pumpability compared to natural sand and gravel. Although the fluidity is increased by increasing it, according to the present invention, even such a low slump material can be stably pumped, and blockage in the pump or pipe can be prevented.
[Brief description of the drawings]
BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a schematic diagram of a wet material pressure spraying method according to the present invention applied to a slope or a retaining wall.
FIG. 2 is a schematic diagram in which the wet material pressure blowing method according to the present invention is applied to a tunnel or an underground structure.
FIG. 3 is an explanatory view showing the structure of a pressure pump used in the present invention.
FIG. 4 is an explanatory view showing the structure of a pressure pump used in the present invention.
FIG. 5 is a schematic diagram in which a conventional pressure feeding method using a pressure pump and air is applied to a slope and a retaining wall.
FIG. 6 is a schematic diagram in which a conventional pressure pumping method using a pressure pump and air is applied to tunnels and underground structures.
[Explanation of symbols]
1 ... (Piston type) pump
6 ... Air hose connection port
7 ... Quick set hose connection port
9 ... Rubber hose or polyhose
10 ... Blowing nozzle
11 ... Pressure feeding piping
11a ... curved pipe part
12 ... Air / quick combination tube
13 ... Quick setting agent merge pipe
17, 17a ... suction pipe
18 ... discharge pipe
Reference number P3300

Claims (4)

Use a pressure pump to pump a wet material, mainly mortar or concrete, to the point where it can be conveyed by air , and pump the inside of the pressure feed pipe of a specified length, and then join the air through a junction pipe connected to the tip of the pressure feed pipe. is allowed Rutotomoni, connect the internal diameter of the hose that is suitable for spraying operations to the distal end of the merging pipe, a pumping spraying method of wet material as blown from the spray nozzle mounted to the distal end of the hose,
A discharge pipe and a pressure feed pipe that use a piston type pressure feed pump as the pressure feed pump, have an inner diameter that is approximately equal to or larger than the cylinder inner diameter of the piston type pressure feed pump, and that do not substantially shrink in the pressure feed direction. A wet spraying method for wet materials, characterized in that a wet material mainly composed of mortar or concrete having a slump value of less than 1 to 8 cm can be pumped.   The slump value is 1-6 cm or less, The pressure-feed spraying method of the wet material of Claim 1 characterized by the above-mentioned.   3. The wet spraying of the wet material according to claim 1 or 2, wherein a quick setting agent is added after the leading end of the pressure feeding pipe or air is joined, and the wet material is sprayed by joining the air and the quick setting agent. Construction method.   The wet-type material pressure spraying method according to claim 1, 2 or 3, wherein the valve structure of the piston pressure pump is a parallel sliding type.

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