Water-containing fluid pressure-feed pipe

Abstract

To provide a water-containing fluid pressure-feed pipe made of resin that is difficult for its joint to detach when concrete is pressure-fed, even when connected by the joint.SOLUTION: A water-containing fluid pressure-feed pipe comprises a resin outer pipe, and a metal inner pipe disposed along an inner wall of an end portion of the resin outer pipe.SELECTED DRAWING: Figure 1A

Description

Technical Field

[0001] The present invention relates to a water-containing fluid pumping pipe.

Background Art

[0002] Fresh concrete before hardening (hereinafter, also simply referred to as "concrete") is a mixture of cement, water, fine aggregate, coarse aggregate, and admixtures added as necessary, and is a fluid having both liquid properties and solid properties. Such a fluid is called a "water-containing fluid". Examples of water-containing fluids include mortar in addition to concrete.

[0003] When pumping, a water-containing fluid such as fresh concrete forms a solid plug inside a steel pipe and is pumped while generating friction with the pipe inner wall. At this time, mainly the coarse aggregate is located at the center of the steel pipe, mainly water and cement paste are located on the inner wall side of the steel pipe, and water etc. located on the inner wall side buffers the frictional resistance generated during pumping while the pumping progresses. The pumpability of concrete varies depending on its type etc. For example, those with high viscosity such as low water content have large frictional resistance leading to blockage of the steel pipe, and those with high water content are likely to cause separation of solid and liquid, easily resulting in blockage of the steel pipe and deterioration of the quality of the pumped concrete.

[0004] Generally, steel pipes are used for pumping fresh concrete (see, for example, Patent Document 1). The steel pipes are connected with joints as necessary and pump fresh concrete to any placement location. The steel pipes that are straight pipes have a length of about 1, 2, or 3 m, and the thicker and heavier the pipe wall is, the higher the pressure resistance performance of the steel pipe is. For example, in the case of a 3 m steel pipe for high pressure, its weight is about 65 kg. Therefore, at the construction site, it is necessary for multiple people to handle one steel pipe.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

[0006] If it becomes possible to replace such a steel pipe with a resin pipe other than a metal pipe, the preparation of the facility of the water-containing fluid pressure pipe at the construction site will be facilitated, and it will be possible to expect an overall improvement in work efficiency. However, it has been considered difficult to realize a water-containing fluid pressure pipe that has a pressure resistance performance capable of pumping heavy fresh concrete, mortar, etc., and can withstand wear during the pumping of fresh concrete, mortar, etc. without a metal pipe.

[0007] Further, in the conventional pumping method using a steel pipe, it is necessary to check the position to which fresh concrete, mortar, etc. are pumped by hitting the steel pipe and checking the change in its sound. The longer the pumping distance, the more man-hours are required for this checking work. If the situation of the water-containing fluid pressure pipe can be checked more simply, it will be possible to deal with situations such as blockage at an early stage and to perform the placing work more safely.

[0008] In view of the above points, the inventors of the present case have been developing a water-containing fluid pressure pipe without a metal pipe, which has excellent pumping performance, is light, and has excellent safety (see, for example, Patent Document 2).

[0009] By the way, a plurality of water-containing fluid pressure pipes are connected by joints and used at the work site. When pumping concrete, the pressure inside the water-containing fluid pressure pipe is not constant, and pressure pulsations occur. Due to this pulsation, when the water-containing fluid pressure pipes connected by joints sway in the axial direction (pumping direction), the ends of each water-containing fluid pressure pipe are distorted inward. And it has been found that due to this distortion, the tightening of the joints of the water-containing fluid pressure pipes becomes loose, and concrete flows out from the connection parts of each water-containing fluid pressure pipe.

[0010] The present invention has been made in view of the above problems, and an object thereof is to provide a water-containing fluid pressure-feeding pipe made of resin, which is difficult to disconnect at joints when concrete is pressure-fed in a state connected by joints.

Means for Solving the Problems

[0011] The inventors of the present invention have intensively studied to solve the above problems. As a result, they have found that the above problems can be solved by using a water-containing fluid pressure-feeding pipe made of a cylindrical body of ultra-high molecular weight polyethylene having predetermined characteristics, and have completed the present invention.

[0012] That is, the present invention is as follows. 〔1〕 A resin outer pipe, and a metal inner pipe disposed along the inner wall of the end portion of the resin outer pipe, a water-containing fluid pressure-feeding pipe. 〔2〕 The metal inner pipe has a metal flange portion with one end face protruding outward in the radial direction, the water-containing fluid pressure-feeding pipe according to 〔1〕, wherein the metal flange portion of the metal inner pipe and the end face of the resin outer pipe are locked. 〔1〕The water-containing fluid pressure-feeding pipe according to 〔1〕. 〔3〕 The end face of the water-containing fluid pressure-feeding pipe is composed of the end face of the metal flange portion of the metal inner pipe, 〔2〕The water-containing fluid pressure-feeding pipe according to 〔2〕. 〔4〕 The end face of the water-containing fluid pressure-feeding pipe is composed of the end face of the resin outer pipe and the end face of the metal inner pipe, 〔1〕~〔3〕The water-containing fluid pressure-feeding pipe according to any one of 〔1〕~〔3〕. 〔5〕 The water-containing fluid pressure-feeding pipe according to any one of 〔1〕~〔4〕, which has a screwing portion in which the inner wall of the resin outer pipe and the outer wall of the metal inner pipe are at least partially screwed together. 〔1〕~〔4〕The water-containing fluid pressure-feeding pipe according to any one of 〔1〕~〔4〕. 〔6〕 It has a smooth portion where the smooth surface of the inner wall of the resin outer tube and the smooth surface of the outer wall of the metal inner tube are at least partially in contact. The water-containing fluid pressure transmission pipe according to [1] or [5]. 〔7〕 The screwing portion is located on the end face side of the resin outer tube with respect to the smooth portion. The water-containing fluid pressure transmission pipe according to [6]. 〔8〕 The ratio of the formation area S1 of the screwing portion to the formation area S2 of the smooth portion is 10:90 to 90:10. The water-containing fluid pressure transmission pipe according to [6]. 〔9〕 The metal inner tube is detachable with respect to the resin outer tube. The water-containing fluid pressure transmission pipe according to any one of [1] to [8]. 〔10〕 The resin outer tube has a thin-walled portion that is thinned inward in the radial direction at the end. The water-containing fluid pressure transmission pipe according to any one of [1] to [9]. 〔11〕 The axial length of the thin-walled portion is 5 to 30 mm. The water-containing fluid pressure transmission pipe according to

[10] . 〔12〕 In the axial direction, the formation position of the thin-walled portion and the arrangement position of the metal inner tube overlap. The water-containing fluid pressure transmission pipe according to

[10] or

[11] . 〔13〕 The resin outer tube has a resin protruding edge portion whose end face protrudes outward in the radial direction. The water-containing fluid pressure transmission pipe according to any one of [1] to

[12] . 〔14〕 The inner diameter of the metal inner tube is -5 mm to +5 mm with respect to the inner diameter of the resin outer tube. The water-containing fluid pressure transmission pipe according to any one of [1] to

[13] . 〔15〕 The synthetic resin constituting the resin outer tube contains polyolefin. The water-containing fluid pressure transmission pipe according to any one of [1] to

[14] . 〔16〕 The polyolefin is ultra-high molecular weight polyethylene with a viscosity average molecular weight of 1.0×10 6 or more, the water-containing fluid pumping pipe according to

[15] .

[17] When pumping concrete at 60°C and an internal pipe pressure of 4 Mpa, the maximum strain of the resin outer pipe is 50% or less, the water-containing fluid pumping pipe according to any one of [1] to

[16] .

[18] When pumping concrete at 35°C and an internal pipe pressure of 4 MPa, the maximum strain of the resin outer pipe is 35% or less, the water-containing fluid pumping pipe according to any one of [1] to

[17] .

[19] Using the water-containing fluid pumping pipe according to any one of [1] to

[18] , pumping concrete, Concrete pumping method.

[20] Connecting and using a plurality of the water-containing fluid pumping pipes by using resin joints, the concrete pumping method according to

[19] .

[21] Arranging rubber on the contact surface between the resin joint and the water-containing fluid pumping pipe to connect a plurality of the water-containing fluid pumping pipes, the concrete pumping method according to

[20] .

Effect of the Invention

[0013] According to the present invention, there is provided a water-containing fluid pumping pipe made of resin, which is difficult to be disconnected at the joint when pumping concrete in a state connected by the joint.

Brief Description of the Drawings

[0014]

Fig. 1A

Fig. 1B

Fig. 2

Fig. 3

Fig. 4

Mode for Carrying Out the Invention

[0015] Hereinafter, embodiments of the present invention (hereinafter referred to as "the present embodiment") will be described in detail. However, the present invention is not limited to this, and various modifications are possible without departing from the gist thereof.

[0016] In this specification and / or these drawings, unless otherwise specified, the following interpretation shall apply. Terms and / or numerical values meaning shape and / or geometric conditions need not be bound by a strict meaning, and may be interpreted to include a range to the extent that similar functions may be expected. For example, terms such as "parallel" and / or "orthogonal" fall under the above terms. Also, "length value" and / or "angle value" fall under the above numerical values.

[0017] When a certain configuration is described as being "above", "below", "on the upper side", "on the lower side", "above", or "below" another configuration, it may include a mode in which a certain configuration is in direct contact with another configuration and a mode in which another configuration is included between a certain configuration and another configuration. In other words, a mode in which another configuration is included between a certain configuration and another configuration may also be expressed as a certain configuration being in indirect contact with another configuration. Also, the expressions "above", "on the upper side", or "above" are interchangeable with the expressions "below", "on the lower side", or "below". In other words, the vertical direction may be reversed.

[0018] When attaching the same reference numerals or similar reference numerals to the same part and / or parts having similar functions, repetitive descriptions may be omitted. Also, the dimensional ratios in the drawings may differ from the actual ratios. Further, a part of the configuration of the embodiment may be omitted from the drawings.

[0019] 1. Water-containing fluid delivery pipe The water-containing fluid delivery pipe of this embodiment has a resin outer pipe and a metal inner pipe arranged along the inner wall of the end of the resin outer pipe. From the viewpoint of suppressing the inner distortion of the end of the water-containing fluid delivery pipe due to the pulsation during concrete pumping, the water-containing fluid delivery pipe of this embodiment has a metal inner pipe arranged along the inner wall of the end of the resin outer pipe. Thus, even if a force causing inner distortion at the end acts on the resin outer pipe due to the pulsation during concrete pumping, the metal inner pipe resists this from the inside of the pipe, so the occurrence of distortion is suppressed. Therefore, concrete can be pumped without the joint coming off.

[0020] The metal inner pipe is arranged along the inner wall of the end of the resin outer pipe from the above viewpoint, and the pipe body of the water-containing fluid delivery pipe of this embodiment is constituted by the resin outer pipe. Thereby, the lightweight property and the visibility of the contents that the water-containing fluid delivery pipe made of resin has can be ensured.

[0021] By not using a metal pipe such as a steel pipe as the pipe body, the water-containing fluid delivery pipe of this embodiment is different from a water-containing fluid delivery pipe that is heavy and has problems in handleability, and can realize a water-containing fluid delivery pipe that is lightweight and can be handled more safely at the work site.

[0022] In addition, the coefficient of kinetic friction between the resin-made pipe body of the flowing water-containing fluid conveying pipe of the present embodiment and concrete tends to be smaller than that between a metal pipe and concrete. Therefore, for the purpose of suppressing the pressure loss due to friction during the pumping of concrete, it is not necessary to use a primer. As a result, not only can the process of using the primer itself be reduced, but also the use and disposal costs of the primer can be significantly reduced. In addition, it is possible to suppress the separation of the components of the concrete during pumping, and the cost associated with the disposal of the concrete with a fluctuating composition can also be significantly reduced.

[0023] Moreover, in the present embodiment, by using a cylindrical body made of resin, it is also possible to ensure the visibility of the contents inside the cylinder. As a result, even if the concrete is clogged in the middle of the flowing water-containing fluid conveying pipe, it is possible to quickly confirm the blockage, and a rupture accident can be suppressed. Moreover, when the internal pressure increases, the resin cylinder bulges outward to such an extent that it can be immediately visually recognized before it breaks. As a result, the on-site workers can immediately recognize the position where rupture may occur and can evacuate appropriately.

[0024] Hereinafter, the flowing water-containing fluid conveying pipe of the present embodiment will be described in detail.

[0025] 1.1. Outer shape FIG. 1A shows a perspective view of the flowing water-containing fluid conveying pipe of the present embodiment, and FIG. 1B shows a cross-sectional view of the end portion of the flowing water-containing fluid conveying pipe shown in FIG. 1A cut along the center line of the cylinder. As shown in FIGS. 1A and 1B, the flowing water-containing fluid conveying pipe 10 has a resin outer pipe 20 made of resin and a metal inner pipe 30 arranged along the inner wall 21 of the end portion 12 of the resin outer pipe.

[0026] The resin outer pipe 20 has a pipe body 11 and an end portion 12, and at the end portion 12, it may have a resin flange portion 23 and a thin-walled portion 24 for joining with other flowing water-containing fluid conveying pipes by a joint.

[0027] Here, the "pipe body" means the main part of the pipe sandwiched between both ends of the water-containing fluid conveying pipe, and refers to the part that receives the flow of concrete. Also, the "end part" refers to the end part of the water-containing fluid conveying pipe, and in particular, includes the part within the range clamped by the joint for connecting the water-containing fluid conveying pipes. Since the structure of the resin outer pipe 20 of the present embodiment is not defined by the boundary between the pipe body 11 and the end part 12, the boundary does not necessarily have to be clear. However, as an example, the range of 10 cm in the axial direction of the cylinder from the opening of the resin outer pipe 20 can be referred to as the end part 12.

[0028] The resin flange portion 23 is a portion where the end face 22 of the resin outer pipe 20 protrudes outward in the radial direction, and the thin-walled portion 24 is a portion that is thinned inward in the radial direction at the end part 12. For example, the claw of the joint fits into the thin-walled portion 24, and the resin flange portions 23 of the two water-containing fluid conveying pipes to be connected are clamped by the claw of the joint, thereby connecting the two water-containing fluid conveying pipes.

[0029] In the aspect shown in FIG. 1B, the axial length of the resin flange portion 23 is preferably 5 to 30 mm, 10 to 25 mm, and 15 to 20 mm. Also, the thickness of the resin flange portion 23 is 5 to 25 mm, 7.5 to 20 mm, and 10 to 15 mm. The outermost end of the resin flange portion may have a notch for locking the metal flange portion 33 described later, and the notch length is preferably 5 to 10 mm and the notch thickness is 1 to 3 mm.

[0030] The axial length of the thin-walled portion 24 is preferably 5 to 30 mm, 10 to 25 mm, and 10 to 20 mm. Also, the thickness of the thin-walled portion 24 is 5 to 20 mm, 7.5 to 15 mm.

[0031] As shown in FIG. 1B, the water-containing fluid pressure-feeding pipe 10 may have a smooth portion 14 where the smooth surface of the inner wall 21 of the resin outer pipe 20 and the smooth surface of the outer wall 31 of the metal inner pipe 30 are at least partially in contact with each other. Thereby, the water-containing fluid pressure-feeding pipe 10 can be easily configured by inserting the metal inner pipe 30 into the resin outer pipe 20. The thickness of the metal inner pipe in the smooth portion is preferably 1 to 5 mm.

[0032] At this time, since the thin-walled portion 24 is inferior in strength compared to the end portion, as shown in FIG. 1B, in the axial direction, the metal inner pipe 30 may be inserted beyond the back side of the thin-walled portion 24 to the pipe body 11 side so that the formation position of the thin-walled portion 24 and the arrangement position of the metal inner pipe 30 overlap.

[0033] Also, as shown in FIG. 1B, the metal inner pipe 30 may have a metal protruding edge portion 33 where one end face 32 protrudes outward in the radial direction. By locking the metal protruding edge portion 33 of the metal inner pipe 30 and the end face 22 of the resin outer pipe 20, it is possible to prevent the metal inner pipe 30 from shifting from the end portion 12 of the resin outer pipe 20 toward the pipe body 11 side during the pumping of concrete.

[0034] At this time, by locking the metal protruding edge portion 33 of the metal inner pipe 30 inserted into the resin outer pipe 20 and the end face 22 of the resin outer pipe 20, the end face 13 of the water-containing fluid pressure-feeding pipe 10 may be composed of the end face 22 of the resin outer pipe 20 and the end face 32 of the metal inner pipe 30.

[0035] Note that the metal inner pipe 30 is preferably detachable from the resin outer pipe 20. Thereby, when one of the resin outer pipe 20 or the metal inner pipe 30 deteriorates or is deformed, it can be easily replaced.

[0036] Also, although not shown in FIG. 1B, in the aspect shown in FIG. 1B, a locking portion 25 for locking the metal inner pipe 30 may be provided on the inner wall 21 of the resin outer pipe 20. The shape of the locking portion is the same as that in FIG. 2.

[0037] Next, regarding another aspect of the water-containing fluid pressure pipe of the present embodiment, it will be described with reference to FIGS. 2 and 3, which are cross-sectional views obtained by cutting the end of the water-containing fluid pressure pipe along the center line of the cylinder.

[0038] FIG. 2 shows an aspect in which all of the resin flange portion 23 shown in FIG. 1B is replaced by the metal flange portion 33 of the metal inner pipe 30. In this aspect, the metal inner pipe 30 has a metal flange portion 33 with one end face 32 protruding radially outward, and the metal flange portion 33 of the metal inner pipe 30 and the end face 22 of the resin outer pipe 20 are locked. Thereby, the end face 13 of the water-containing fluid pressure pipe 10 is constituted by the end face 32 of the metal flange portion 33 of the metal inner pipe 30.

[0039] In the aspect shown in FIG. 2, when two water-containing fluid pressure pipes are connected, the claws of the joint are fitted into the thin portion 24, and the metal flange portions 33 of the two water-containing fluid pressure pipes to be connected are clamped by the claws of the joint. At this time, when a force is applied in the axial direction by the pumping of concrete, the metal inner pipe 30 may come out of the resin outer pipe 20. Therefore, in FIG. 2, the inner wall 21 of the resin outer pipe 20 and the outer wall 31 of the metal inner pipe 30 may have a screwed portion 15 that is at least partially screwed together. Thereby, even when a force is applied in the axial direction, the metal inner pipe 30 can be fixed so as not to come out of the resin outer pipe 20.

[0040] In the aspect shown in FIG. 2, the axial length of the metal flange portion 33 is preferably 5 to 30 mm, 10 to 25 mm, and 15 to 20 mm. Further, the thickness of the metal flange portion 33 is 5 to 25 mm, 7.5 to 20 mm, and 10 to 15 mm.

[0041] Also, in the embodiment shown in FIG. 2, it may partially have a smooth portion 14 where the smooth surface of the inner wall 21 of the resin outer tube 20 and the smooth surface of the outer wall 31 of the metal inner tube 30 are at least partially in contact. At this time, the screwing portion 15 may be located on the end face 22 side of the resin outer tube 20 rather than the smooth portion 14. Thereby, on the end face 22 side of the resin outer tube 20 where distortion tends to be large, the resin outer tube 20 and the metal inner tube 30 are firmly fixed by screwing by the screwing portion 15. On the other hand, on the tube body 11 side of the resin outer tube 20, even when concrete infiltrates into the gap between the resin outer tube 20 and the metal inner tube 30 that may be caused by distortion due to the smooth portion 14, since there are no irregularities for screwing, the concrete easily escapes. Also, if there is a screwing portion 15 on the tube body 11 side, there is a concern that the resin that has swelled outward may not return to the original irregularities and the adhesion between the resin and the metal may be impaired. However, since the smooth portion 14 is on the tube body 11 side, such a situation can be prevented.

[0042] The ratio of the formation area S1 of the screwing portion 15 to the formation area S2 of the smooth portion 14 is preferably 10:90 to 90:10, 20:80 to 80:20, and 30:70 to 70:30.

[0043] Also, in the embodiment shown in FIG. 2, a locking portion 25 for locking the metal inner tube 30 may be provided on the inner wall 21 of the resin outer tube 20. Regarding the preferable ranges of the dimensions of the other parts, it is the same as in the case of the embodiment described in FIG. 1B.

[0044] FIG. 3 shows an embodiment in which a part of the resin flange portion 23 shown in FIG. 1B is replaced by the metal flange portion 33 of the metal inner tube 30. In this embodiment, the metal inner tube 30 has a metal flange portion 33 with one end face 32 protruding outward in the radial direction, and the resin outer tube 20 has a resin flange portion 23 with the end face 22 protruding outward in the radial direction. Then, the resin flange portion 23 of the resin outer tube 20 and the metal flange portion 33 of the metal inner tube 30 are locked. Thereby, the end face 13 of the water-containing fluid conveying pipe 10 is constituted by the end face 32 of the metal flange portion 33 of the metal inner tube 30.

[0045] In the embodiment shown in FIG. 3, the axial length of the protruding edge portion 16 (resin protruding edge portion 23 and metal protruding edge portion 33) is preferably 5 to 30 mm, 10 to 25 mm, or 15 to 20 mm. Among them, the axial length of the resin protruding edge portion 23 is preferably 2.5 to 12 mm, 3 to 10 mm, or 4 to 7.5 mm. Further, the thickness of the protruding edge portion 16 (resin protruding edge portion 23 and metal protruding edge portion 33) is 5 to 25 mm, 7.5 to 20 mm, or 10 to 15 mm. Regarding the preferred ranges of the dimensions of the other parts than the above, it is the same as the case of the embodiments described in FIGS. 1B and 2.

[0046] FIG. 4 shows a cross-sectional view of the case where the water-containing fluid pressure-feeding pipe shown in FIG. 3 is connected by a joint 40. In the embodiments shown in FIGS. 1B and 2, the connection structure with the joint is the same as that in FIG. 4. However, as shown in FIG. 4, in the water-containing fluid pressure-feeding pipe shown in FIG. 3, the protruding edge portion 16 is composed of a resin protruding edge portion 23 and a metal protruding edge portion 33. Therefore, when two water-containing fluid pressure-feeding pipes are connected, the claw of the joint 40 fits into the thin-walled portion 24, and the protruding edge portions 16 (resin protruding edge portion 23 and metal protruding edge portion 33) of the two connected water-containing fluid pressure-feeding pipes are clamped by the claw of the joint 40. Thereby, even if a force is applied in the axial direction, the metal inner pipe 30 can be fixed so as not to come off from the resin outer pipe 20.

[0047] 1.2. Resin outer pipe The resin outer pipe 20 is made of a resin pipe, and examples include a multilayer pipe composed of multiple resin layers, a multilayer pipe with an arbitrary inner layer provided on a pipe composed of a single resin layer, and a single-layer pipe composed of a single resin layer. Among these, a single-layer pipe is preferred. Note that there may be a mode in which a metal band is wound around a part of the outer periphery of the resin outer pipe made of a resin pipe for the purpose of suppressing rupture or as a handle during movement. Even in such a mode, it corresponds to the resin-made water-containing fluid pressure-feeding pipe without a metal pipe in the present invention.

[0048] The outer diameter, inner diameter, and thickness of the resin outer pipe are not particularly limited as long as they are the sizes used for conventional water-containing fluid pumping pipes. For example, the maximum outer diameter R is preferably 100 to 250 mm, 110 to 240 mm, or 120 to 230 mm. The inner diameter r of the resin outer pipe is preferably 70 to 170 mm, 80 to 160 mm, or 90 to 150 mm. By using such a resin outer pipe, it is possible to efficiently pump a relatively large amount of concrete containing various solid components, and the pumping performance tends to be further improved.

[0049] Furthermore, the thickness (R - r) / 2 of the resin outer pipe is preferably 5 to 30 mm, 7.5 to 25 mm, or 10 to 20 mm. By using such a resin outer pipe, the life of the water-containing fluid pumping pipe tends to be longer.

[0050] Also, the length of the resin outer pipe is not particularly limited as long as it is the size used for conventional water-containing fluid pumping pipes. For example, the total length Lw of the water-containing fluid pumping pipe is preferably 0.3 to 4 m, 1.5 to 3.7 m, or 2.0 to 3.5 m.

[0051] The water-containing fluid pumping pipe 10 of the present embodiment does not have a metal pipe except at the ends, and by using a resin outer pipe in which at least the innermost layer and the outermost layer are made of resin, it is possible to ensure the visibility of the contents (concrete) inside the water-containing fluid pumping pipe during use.

[0052] The resin outer pipe made of resin can be manufactured by known methods such as injection molding and extrusion molding. After molding into a solid cylindrical shape, it may be hollowed out, or it can also be molded into a hollow cylindrical shape. However, a resin outer pipe made of ultra-high molecular weight polyethylene containing an ultraviolet absorber and having a viscosity average molecular weight of 1.0×10 6 or more is preferably extruded into a hollow shape, and in particular, a method by screw extrusion is preferred. With this method, it is possible to obtain a resin outer pipe made of ultra-high molecular weight polyethylene resin, which is difficult to be molded into a cylindrical shape compared to general resins, with a long length and high smoothness of the inner peripheral surface.

[0053] 1.2.1. Composition Examples of the resin constituting the resin outer tube include thermoplastic resins and thermosetting resins. Further, additives such as ultraviolet absorbers may be added to the resin.

[0054] The thermoplastic resin is not particularly limited, and examples thereof include polyolefin resins, polyester resins, polyarylate, liquid crystal polyester, polyvinyl chloride, polyvinyl alcohol, ethylene vinyl acetate, polystyrene, acrylonitrile-butadiene-styrene copolymer resin, acrylonitrile-styrene copolymer resin, polymethyl methacrylate, polyamide resins, polyacetal, polycarbonate, fluorine-based resins, polyether ether ketone, polyether sulfone, polyphenylene sulfide, and the like.

[0055] Examples of the thermosetting resin are not particularly limited, and include, for example, phenol resins, urea resins, melamine resins, allyl resins, epoxy resins, and the like.

[0056] Among these, thermoplastic resins are preferred from the viewpoints of formability, secondary processability, etc. Further, among thermoplastic resins, polyolefin resins typified by polyethylene and polypropylene are preferred because they are inexpensive, have excellent chemical resistance, excellent processability, and low hygroscopicity and water absorbency of the material.

[0057] The polyolefin resin is not particularly limited, and examples thereof include homopolymers of ethylene; copolymers of ethylene and one or more α-olefins such as propylene, butene-1, hexene-1, and octene-1; copolymers of ethylene and vinyl acetate, acrylic acid, methacrylic acid, acrylic acid esters, methacrylic acid esters, etc.; homopolymers of propylene; copolymers of propylene and one or more α-olefins such as ethylene and butene-1, and the like.

[0058] Among polyolefin resins, polyethylene is most preferred for reasons such as being inexpensive, having a low coefficient of friction, excellent workability after molding, excellent chemical resistance, and low moisture absorption and water absorption of the material itself.

[0059] The density of polyethylene is preferably 890 - 970 kg / m 3 and is 900 - 960 kg / m 3 and is 910 - 950 kg / m 3 That is. When the density is 890 kg / m 3 or more, the rigidity of the resin outer tube tends to be further improved. Also, when the density is 970 kg / m 3 or less, the handleability tends to be further improved. Here, the density of polyethylene can be measured in accordance with JIS K 7112:1999 by the density gradient tube method (23°C).

[0060] Also, the viscosity average molecular weight of the polyolefin resin is preferably 1.0×10 6 or more and is 2.5×10 6 - 5.0×10 8 and is 3.0×10 6 - 5.0×10 7 That is. When the viscosity average molecular weight of polyethylene is within the above range, the wear resistance is further improved, and a sufficient strength to withstand a high pumping pressure tends to be obtained. In this embodiment, polyethylene having the above viscosity average molecular weight is referred to as "ultra-high molecular weight polyethylene".

[0061] The viscosity average molecular weight can be determined, for example, by the method shown below. First, the polyolefin resin is dissolved in decalin (decalin) to prepare a plurality of solutions with different concentrations. These solutions are placed in a constant temperature bath at 135°C, and the reduced viscosity (ηsp / C) of each solution is determined using an Ubbelohde type viscometer. A linear equation of the concentration (C) and the reduced viscosity (ηsp / C) of the polymer is derived, and the limiting viscosity ([η]) extrapolated to a concentration of 0 is determined. The viscosity average molecular weight (Mv) can be determined from this limiting viscosity ([η]) according to the following equation. Mv = 5.34×10 4 ×[η] 1.49

[0062] The water-containing fluid delivery pipe may be made of a mixed raw material of polyethylene with different densities and / or viscosity average molecular weights, etc., or may be a mixed raw material of polyethylene and a raw material resin other than polyethylene.

[0063] In addition, various additives such as heat stabilizers, ultraviolet absorbers, coloring pigments, and flame retardants may be added to the resin in the water-containing fluid delivery pipe of the present embodiment as long as the effects of the present embodiment are not impaired.

[0064] (Ultraviolet absorber) The resin outer pipe of the present embodiment may further contain an ultraviolet absorber as an additive as needed. The ultraviolet absorber is not particularly limited as long as it is a substance that absorbs ultraviolet rays in a wavelength region harmful to the resin. For example, it includes benzophenone-based ultraviolet absorbers, benzotriazole-based ultraviolet absorbers, cyanoacrylate-based ultraviolet absorbers, etc.

[0065] The benzophenone-based ultraviolet absorber is not particularly limited, but examples include 2-hydroxy-4-octoxybenzophenone, etc. The benzotriazole-based ultraviolet absorber is not particularly limited, but examples include 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, etc. The cyanoacrylate-based ultraviolet absorber is not particularly limited, but examples include 2-ethylhexyl-2-cyano-3,3'-diphenyl acrylate, etc. Among these, benzophenone-based ultraviolet absorbers are more preferable. By using such an ultraviolet absorber, the weather resistance tends to be further improved. In the present embodiment, the weather resistance refers to the resistance to the deterioration of physical properties when the above-mentioned accelerated exposure test is performed.

[0066] The content of the ultraviolet absorber is preferably 0.01 to 10% by mass, more preferably 0.01 to 10% by mass, and even more preferably 0.01 to 10% by mass with respect to the total amount of the resin outer tube. When the content of the ultraviolet absorber is within the above range, the weather resistance tends to be further improved.

[0067] 1.2.2. Physical properties

[0068] The resin outer tube does not rupture or leak in the 25 MPa water pressure test. When the water pressure resistance performance is within the above range, it is not necessary to use a metal tube even when pumping heavy concrete at high pressure. In this embodiment, "not rupturing or leaking in the 25 MPa water pressure test" means that neither rupture nor leakage occurs. Also, the "25 MPa water pressure test" refers to a test in which tap water at room temperature is introduced from a pressurized pipe into the resin outer tube, pressurized up to 25 MPa, and the occurrence state of leakage and rupture after 2 minutes is confirmed.

[0069] The dynamic friction coefficient of the inner surface of the resin outer tube is preferably 0.07 to 0.30, 0.07 to 0.20, and 0.07 to 0.15. When the dynamic friction coefficient of the inner surface is within the above range, it is not necessary to use a pre-feed material, blockage is less likely to occur, and fluctuations in the discharged concrete components can be more suppressed. In particular, in order to make the dynamic friction coefficient of the inner surface of the resin outer tube made of ultra-high molecular weight polyethylene described later a value of 0.15 or less, which is extremely lower than the conventional value, it is preferable to perform molding by screw extrusion described later.

[0070] The total light transmittance per 2 mm thick test piece of the resin outer tube is preferably 10% or more, 20 to 90%, 30 to 80%, and 40 to 70%. When the total light transmittance per 2 mm thick test piece of the resin outer tube is 10% or more, the visibility of the content tends to be further improved. When the total light transmittance per 2 mm thick test piece of the resin outer tube is 90% or less, the mechanical strength of the resin outer tube tends to be further improved.

[0071] When pumping concrete at 60°C and an internal pipe pressure of 4 Mpa, the maximum strain of the resin outer pipe is preferably 50% or less, 40% or less, and 35% or less. When the maximum strain of the resin outer pipe is 50% or less when pumping concrete at 60°C and an internal pipe pressure of 4 Mpa, the joints tend to be less likely to come off. The lower limit of the maximum strain of the resin outer pipe when pumping concrete at 60°C and an internal pipe pressure of 4 Mpa is not particularly limited, but it is 0% or more.

[0072] When pumping concrete at 35°C and an internal pipe pressure of 4 Mpa, the maximum strain of the resin outer pipe is preferably 35% or less, 25% or less, and 15% or less. When the maximum strain of the resin outer pipe is 35% or less when pumping concrete at 35°C and an internal pipe pressure of 4 Mpa, the joints tend to be less likely to come off. The lower limit of the maximum strain of the resin outer pipe when pumping concrete at 35°C and an internal pipe pressure of 4 Mpa is not particularly limited, but it is 0% or more.

[0073] Note that the maximum strain of the resin outer pipe when pumping concrete at 60°C and an internal pipe pressure of 4 Mpa is assumed under the concrete pumping conditions at noon in summer, and the maximum strain of the resin outer pipe when pumping concrete at 35°C and an internal pipe pressure of 4 Mpa is assumed under the concrete pumping conditions at noon in winter.

[0074] The contact angle of the inner surface of the resin outer pipe is preferably 55° or more, 60° to 90°, and 65° to 85°. When the contact angle of the inner surface of the resin outer pipe is 55° or more, it becomes easier to repel the water component contained in the concrete. In a metal pipe, the water component adheres to the inner surface of the metal pipe, and the pumping speed is likely to be different between the center and the outside of the pipe, resulting in fluctuations in the composition of the discharged concrete. However, in the resin outer pipe of this embodiment, such fluctuations can be suppressed, so the use of a pre-feed material is unnecessary, blockage is less likely to occur, and fluctuations in the discharged concrete components tend to be more suppressed.

[0075] The wear amount of the inner surface of the resin outer tube by the sand slurry wear method is preferably 10 mg or less, 8.0 mg or less, 5.0 mg or less, and 2.0 mg or less. When the wear amount of the inner surface of the resin outer tube is 10 mg or less, the wear resistance tends to be further improved. The lower limit of the wear amount of the inner surface of the resin outer tube is not particularly limited, but it is 0 mg or more.

[0076] The tensile breaking strength of the resin outer tube after a 1200-hour accelerated exposure test at a black panel temperature of 63 °C ± 3 °C is preferably 50% or more, 75 - 150%, and 80 - 120% with respect to the tensile breaking strength before the accelerated exposure test. When the tensile breaking strength of the resin outer tube after the accelerated exposure test is 50% or more, the weather resistance of the water-containing fluid pressure conveying pipe exposed to direct sunlight and high temperatures tends to be more excellent.

[0077] Also, from the same perspective, the tensile breaking elongation of the resin outer tube after the above accelerated exposure test is preferably 50% or more, 50% or more, 75 - 150%, and 80 - 120% with respect to the tensile breaking elongation before the accelerated exposure test. When the tensile breaking elongation of the resin outer tube after the accelerated exposure test is 50% or more, the weather resistance of the water-containing fluid pressure conveying pipe exposed to direct sunlight and high temperatures tends to be more excellent.

[0078] 1.3. Metal inner tube The metal constituting the metal inner tube is not particularly limited, and examples include carbon steels such as rolled steel, alloy steels such as stainless steel, and cast iron.

[0079] The inner diameter of the metal inner tube is preferably -5 mm to +5 mm, and 0 mm to +5 mm with respect to the inner diameter of the resin outer tube.

[0080] 2. Concrete pumping method The concrete pumping method of this embodiment is a method of pumping concrete using the above-mentioned water-containing fluid pumping pipe, and it is preferable to connect and use a plurality of water-containing fluid pumping pipes by using resin joints. In this case, rubber may be disposed on the contact surface between the resin joint and the water-containing fluid pumping pipe, and a plurality of water-containing fluid pumping pipes may be connected.

[0081] Note that the joint is not limited to a resin joint, and a metal joint used when connecting conventional replacements may be used instead.

Example

[0082] Hereinafter, the present invention will be described more specifically using examples and comparative examples. The present invention is not limited by the following examples.

[0083] <Hydrostatic pressure test> The water pressure resistance of the resin part of the water-containing fluid pumping pipe was confirmed in accordance with the high-pressure test of the steel pipe. Specifically, a portion consisting only of the resin outer pipe without the metal inner pipe was cut out with a length of 1000 mm, and both ends were fastened with a sealing plug incorporating a pressurizing pipe and fixed to a sealing jig. Tap water at room temperature was introduced from the pressurizing pipe into the water-containing fluid pumping pipe, pressurized until the pressure from the device reached 25 MPa, and the occurrence state of leakage and rupture after 5 minutes was confirmed by visual inspection and pressure measurement.

[0084] Regarding the water-containing fluid pumping pipe, the device pressure was further increased to 180 MPa, and the occurrence state of leakage, swelling, and rupture after 2 minutes was confirmed by visual inspection and pressure measurement.

[0085] <Coefficient of dynamic friction> The resin part of the water-containing fluid pumping pipe was cut, and a test piece with an outer diameter of 25.6 × inner diameter of 20 mm × length of 15 mm was produced. The coefficient of dynamic friction of the obtained test piece was confirmed in accordance with JIS7218. Specifically, it was measured by rubbing against steel (S45C) under the conditions of a surface pressure of 0.83 kg / cm2 and a linear velocity of 6.2 cm / sec by the thrust wear method.

[0086] <Evaluation method of contact angle> The resin part of the water-containing fluid delivery pipe was cut to create a flat plate with a size of 50×50 mm. The contact angle with respect to water was measured by the static droplet method. Specifically, the contact angle when 20 μl of water was dropped onto the flat plate was observed with a microscope, and the contact angle was measured.

[0087] <Method for Evaluating Total Light Transmittance> The resin part of the water-containing fluid delivery pipe was cut to produce a test piece with a thickness of 2 mm. Then, in accordance with JIS-K-7361 (Total Light Transmittance Measurement Standard) and JIS-K-7136 (Haze Measurement Standard), the total light transmittance of the test piece was evaluated. Specifically, using HAZEMATER HM-150 manufactured by Murakami Color Technology Research Institute, the external haze and internal haze (using pure water in addition to the quartz cell to prevent unevenness), and the total light transmittance (%) of both were measured.

[0088] <Method for Accelerated Exposure Test> The resin part of the water-containing fluid delivery pipe was cut to produce a test piece. For the obtained test piece, a sunshine carbon arc type accelerated test was conducted, and the tensile breaking strength and tensile breaking elongation before and after the test were measured. Specifically, using a sunshine weather meter manufactured by Suga Test Instruments Co., Ltd. (sometimes also called a weatherometer), in accordance with JIS-B-7753, a 1200-hour exposure test was conducted under the conditions of a black panel temperature of 63°C (±3°C), a humidity of 50% (±5%), and rainfall (120-minute cycle; 102 minutes dry + 18 minutes rainfall).

[0089] Using the test pieces before and after the above tests, in accordance with JIS K 7127:1999 (Test Method for Tensile Properties of Plastics) and JIS Z 2241:2011 (Test Method for Tensile Properties of Metallic Materials), the tensile breaking strength and tensile breaking elongation were measured.

[0090] <Maximum Strain> The maximum strain of the resin outer pipe when pumping concrete at 35°C and an internal pipe pressure of 4 Mpa and the maximum strain of the resin outer pipe when pumping concrete at 60°C and an internal pipe pressure of 4 Mpa were measured using a strain gauge.

[0091] <Pumping Test> Three pieces of the water-containing fluid pumping pipes of the examples or comparative examples were respectively connected to a concrete pump truck by joints, and a concrete pumping test was conducted under the conditions described in Table 2. The state of connection by joints conforms to Figure 4. Note that ordinary concrete was used as the pumped concrete. The concrete was supplied from the pump truck to the water-containing fluid pumping pipe. The pressure inside the pipe was repeatedly increased and decreased between 0 and 4.0 MPa, and the cycle was 8 seconds on average. The average speed was 15 m 3 / h for 20 m 3 The pumping state during pumping was observed. (Pumping state) Good: There was no particular change from the beginning to the end of the pumping test. Bad: Joint disconnection occurred at the pipe connection part during the pumping test.

[0092] <Liquid leakage> Under the conditions described in Table 2, until 5000 m 3 of pumping, it was confirmed whether there was liquid leakage of concrete from the joint, which is the connection part of the water-containing fluid pumping pipe, and it was evaluated whether there was liquid leakage.

[0093] 〔Example 1〕 A cylindrical body was molded by using ultra-high molecular weight polyethylene powder (manufactured by Asahi Kasei Corporation, Sunfine UH910) and molding. At this time, an ultraviolet absorber, 2-(2'-hydroxy-5'-methylphenyl) benzotriazole, was added to polyethylene at 3000 ppm (0.3% by mass). The obtained cylindrical body was used as the resin outer pipe. The density of this resin outer pipe was 940 kg / m 3 , and the viscosity average molecular weight was 3.3×10 6 was.

[0094] Also, both ends of the resin outer pipe obtained as described above were molded as shown in Figure 1B, and along the inner wall thereof, the metal inner pipe shown in Figure 1B was inserted therein to obtain the water-containing fluid pumping pipe of Example 1. Table 1 shows the specifications of the resin outer pipe, Table 2 shows the dimensions of each part of the water-containing fluid pumping pipe, Table 3 shows the pumping test conditions, and Table 4 shows the performance evaluation results of the water-containing fluid pumping pipe.

[0095]

Table 1

[0096] 〔Example 2〕 Both ends of the resin outer tube obtained in Example 1 were molded as shown in Fig. 2 (each part dimension is described in Table 2), and along its inner wall, the metal inner tube shown in Fig. 2 was inserted to obtain the water-containing fluid pumping tube of Example 2.

[0097] 〔Example 3〕 Both ends of the resin outer tube obtained in Example 1 were molded as shown in Fig. 3 (each part dimension is described in Table 2), and along its inner wall, the metal inner tube shown in Fig. 3 was inserted to obtain the water-containing fluid pumping tube of Example 3.

[0098] 〔Comparative Example 1〕 Both ends of the resin outer tube obtained in Example 1 were molded as shown in Fig. 1B (however, without the resin notch 26 at the outermost end and with the inner diameter of the resin tube unchanged), and the metal inner tube was not inserted to obtain the water-containing fluid pumping tube of Comparative Example 1. Here, the resin notch 26 is the part opposite to the metal flange 32. 〔Comparative Example 2〕 It was molded in the same manner as Comparative Example 1 except that resin tubes with different inner diameters were used, and the metal inner tube was not inserted to obtain the water-containing fluid pumping tube of Comparative Example 2.

[0099]

Table 2

[0100]

Table 3

[0101]

Table 4

Industrial Applicability

[0102] The water-containing fluid pumping pipe of the present invention has industrial applicability at the site where concrete is pumped.

Explanation of Signs

[0103] 10... Water-containing fluid pumping pipe, 11... Pipe body, 12... End portion, 13... End face, 14... Smooth portion, 15... Screwing portion, 16... Flange portion, 20... Resin outer pipe, 21... Inner wall, 22... End face, 23... Resin flange portion, 24... Thin-walled portion, 25... Locking portion, 26... Resin notch portion, 30... Metal inner pipe, 31... Outer wall, 32... End face, 33... Metal flange portion

Claims

1. A water-containing fluid delivery pipe having a resin outer pipe and a metal inner pipe arranged along the inner wall of the end portion of the resin outer pipe. A water-containing fluid delivery pipe.

2. The metal inner pipe has a metal flange portion with one end face protruding radially outward, and The water-containing fluid delivery pipe according to claim 1, wherein the metal flange portion of the metal inner pipe and the end face of the resin outer pipe are locked.

3. The water-containing fluid delivery pipe according to claim 2, wherein the end face of the water-containing fluid delivery pipe is constituted by the end face of the metal flange portion of the metal inner pipe.

4. The water-containing fluid delivery pipe according to claim 1, wherein the end face of the water-containing fluid delivery pipe is constituted by the end face of the resin outer pipe and the end face of the metal inner pipe.

5. The water-containing fluid delivery pipe according to claim 1, having a screwing portion in which the inner wall of the resin outer pipe and the outer wall of the metal inner pipe are at least partially screwed together.

6. The water-containing fluid delivery pipe according to claim 1 or 5, having a smooth portion in which the smooth surface of the inner wall of the resin outer pipe and the smooth surface of the outer wall of the metal inner pipe are at least partially in contact.

7. The water-containing fluid delivery pipe according to claim 6, wherein the screwing portion is located on the end face side of the resin outer pipe with respect to the smooth portion.

8. The water-containing fluid delivery pipe according to claim 6, wherein the ratio of the formation area S1 of the screwing portion to the formation area S2 of the smooth portion is 10:90 to 90:

10.

9. The water-containing fluid delivery pipe according to claim 1, wherein the metal inner pipe is detachable from the resin outer pipe.

10. The water-containing fluid delivery pipe according to claim 1, wherein the resin outer pipe has a thin-walled portion that is thinned radially inward at the end.

11. The water-containing fluid delivery pipe according to claim 10, wherein the axial length of the thin-walled portion is 5 to 30 mm.

12. The water-containing fluid delivery pipe according to claim 10, wherein in the axial direction, the formation position of the thin-walled portion and the arrangement position of the metal inner pipe overlap.

13. The water-containing fluid delivery pipe according to claim 1 or 10, wherein the resin outer pipe has a resin flange portion with an end face protruding radially outward.

14. The water-containing fluid delivery pipe according to claim 1, wherein the inner diameter of the metal inner pipe is -5 mm to +5 mm with respect to the inner diameter of the resin outer pipe.

15. The water-containing fluid delivery pipe according to claim 1, wherein the synthetic resin constituting the resin outer pipe contains polyolefin.

16. The polyolefin is ultra-high molecular weight polyethylene with a viscosity average molecular weight of 1.0 × 10 6 or higher. The water-containing fluid delivery pipe according to claim 15.

17. When pumping concrete at 60°C and an internal pipe pressure of 4 MPa, the maximum strain of the resin outer pipe is 50% or less. The water-containing fluid pumping pipe according to claim 1.

18. When pumping concrete at 35°C and an internal pipe pressure of 4 MPa, the maximum strain of the resin outer pipe is 35% or less. The water-containing fluid pumping pipe according to claim 1.

19. Concrete is pumped using the water-containing fluid pumping pipe according to any one of claims 1 to 18. Concrete pumping method.

20. The water-containing fluid pumping pipes are connected in multiple numbers and used by using resin joints. The concrete pumping method according to claim 19.

21. Rubber is arranged on the contact surface between the resin joint and the water-containing fluid pumping pipe, and multiple water-containing fluid pumping pipes are connected. The concrete pumping method according to claim 20.

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