A high-strength corrugated pipe for prestressed concrete

Abstract

The present invention relates to a high-strength corrugated pipe for prestressed concrete, which comprises a plastic inner pipe, a support belt spirally wound on the plastic inner pipe, and a steel-plastic composite belt wrapped on the support belt and the plastic inner pipe; the support belt comprises a top angle bar fixed to the inner wall of the steel-plastic composite belt and a pair of bottom angle bars wound on the plastic inner pipe, and a steel bar fixed on the top angle bar and the pair of bottom angle bars, and the steel bar is formed by bending multiple times between the bottom angle bar and the top angle bar. The present invention adopts a plastic inner pipe combined with a steel-plastic composite belt, and fills and supports it with a structurally optimized support belt, which can improve the bonding strength between the corrugated pipe and the concrete after installation while strengthening the corrugation hardness and contact area, and can enhance the rigidity of the corrugated pipe as a whole, which can meet the use requirements of concrete infrastructure fields such as bridges and large-span buildings.

Description

Technical Field

[0001] The invention relates to the technical field of corrugated pipes, in particular to a high-strength corrugated pipe for prestressed concrete. Background Art

[0002] Bridges such as large-span cast-in-place continuous beam bridges or continuous rigid frame bridges usually use post-cast joint sections to connect the main bridge structure. The joint section is a prestressed component, and the concrete must be poured before the prestressed steel bars are tensioned. Therefore, it is necessary to install a corrugated pipe before pouring the concrete to form a post-tensioned prestressed channel. Plastic corrugated pipes or metal corrugated pipes are usually used. When using corrugated pipes as prestressed channels, the theoretical process is: install corrugated pipes → pour concrete → insert prestressed steel bars → tension → corrugated pipe grouting. However, the current prestressed plastic corrugated pipes are made of a single high-density polyethylene, with a single performance, and are insufficient in stiffness, toughness, dimensional stability, tensile strength, etc., and the current plastic corrugated pipes are relatively light, and are prone to floating during the concrete pouring process.

[0003] A Chinese patent with authorization announcement number CN201473874U discloses a prestressed plastic steel corrugated pipe for a bridge, including a pipe body, on the pipe wall of which spiral or annular corrugations with inner concave and outer convex shapes are arranged at equal intervals. The pipe body includes an inner steel pipe, and a plastic layer is compositely arranged on the outer surface of the inner steel pipe.

[0004] The above-mentioned existing technical solutions have the following defects: the corrugations and wave spacing of the above-mentioned spiral thread structure corrugated pipe are small, and the contact area is small, which will affect the bonding strength between the outside of the corrugated pipe and the concrete, and then cause the corrugated pipe to be damaged by pulling the bridge components due to the tensile force. At the same time, although the above-mentioned corrugated pipe strengthens the corrugation hardness by adding threads on the inner wall, this will make the overall rigidity of the corrugated pipe insufficient, and then cause the corrugated pipe to crack due to the bending force acting on the bridge components. Therefore, it is now necessary to improve the plastic corrugated pipe so that it has the advantages of high strength and stable performance, which can meet the use requirements of concrete infrastructure fields such as bridges and large-span buildings. Summary of the invention

[0005] The problem to be solved by the present invention is to provide a high-strength corrugated pipe for prestressed concrete in view of the above-mentioned deficiencies in the prior art, which has the advantages of high strength and stable performance and avoids damage due to tensile and bending forces.

[0006] The above-mentioned object of the present invention is achieved through the following technical solutions:

[0007] A high-strength corrugated pipe for prestressed concrete, comprising a plastic inner tube, a support belt spirally wound on the plastic inner tube, and a steel-plastic composite belt wrapped around the support belt and the plastic inner tube; the support belt comprises a top angle bar fixed to the inner wall of the steel-plastic composite belt and a pair of bottom angle bars wound around the plastic inner tube, a steel bar fixed to the top angle bar and the pair of bottom angle bars, and the steel bar is formed by multiple bending between the bottom angle bar and the top angle bar.

[0008] By adopting the above technical scheme, the original outer steel pipe combined with the inner steel-plastic composite pipe is transformed into a plastic inner pipe combined with a steel-plastic composite belt, and the support belt is used to fill and support it. While strengthening the corrugation hardness and contact area, the ring stiffness of the corrugated pipe can be improved, thereby ensuring the bonding strength between the corrugated pipe and the concrete after installation; in addition, by optimizing the structure of the support belt, the top angle bar and the pair of bottom angle bars are abutted and fixed on the steel-plastic composite belt, so that the top angle bar and the pair of bottom angle bars, and the two adjacent sections of the steel bar and the top angle bar and / or the bottom angle bar can be connected to form a triangular support structure. When tensile and bending forces act on the corrugated pipe, this structure can The force is evenly transferred and dispersed, and it has a better force effect. Therefore, after the installation is completed, under the premise of ensuring that the support belt stably supports the plastic inner tube and the steel-plastic composite belt, the connection structure between the three is made more solid, and the weight of the corrugated pipe can be increased to avoid the floating of the corrugated pipe, thereby enhancing the rigidity of the corrugated pipe as a whole; in summary, the plastic inner tube is combined with the steel-plastic composite belt, and the structurally optimized support belt is used to fill and support it. While strengthening the hardness and contact area of ​​the corrugation, the bonding strength between the corrugated pipe and the concrete after installation can be improved, and the rigidity of the corrugated pipe can be enhanced as a whole, which can meet the use requirements in concrete infrastructure fields such as bridges and large-span buildings.

[0009] Furthermore, the steel bar is bent back and forth between one of the bottom angle bars, the top angle bar and the other bottom angle bar in sequence. The steel bar as a whole is extended and bent along the spiral direction of the support belt, and its bending points are arranged on one of the bottom angle bars, the top angle bar, the other bottom angle bar, the top angle bar and one of the bottom angle bars in sequence, which facilitates the installation and fixation of the steel bar between the top angle bar and the pair of bottom angle bars while ensuring the strength of the support belt, which is conducive to improving the installation efficiency.

[0010] Furthermore, one end of the steel-plastic composite belt spirally extends to the outside of the plastic inner tube, and the extended section of the steel-plastic composite belt forms a sleeve, and the inner wall of the sleeve is provided with a connecting pipe for sleeve-connecting with the other end of the steel-plastic composite belt. When two corrugated pipes are connected, the connecting pipe of one corrugated pipe can be sleeved on the end of the other corrugated pipe away from the sleeve, which is simple and quick to operate.

[0011] Preferably, one end of the connecting pipe extends into the steel-plastic composite belt and is tightly sleeved on the plastic inner tube, and the end of the connecting pipe close to the plastic inner tube is provided with a guide surface that contacts the steel-plastic composite belt. When the steel-plastic composite belt is wrapped, the guide surface can guide the steel-plastic composite belt to smoothly transition between the plastic inner tube and the connecting pipe, which can ensure the structural strength of the transition point while facilitating installation.

[0012] Preferably, a heating wire is inserted into the bottom angle strip, and one end of the heating wire is inserted into the outside of the bottom angle strip and fixed on the connecting pipe. After the two sections of the corrugated pipe are installed, the bottom angle strip, the sleeve and the plastic inner pipe can be connected by hot melting by energizing the heating wire. The layer-by-layer fusion and mutually wrapped support structure can make the plastic inner pipe and the steel-plastic composite belt, and the corrugated pipes and the corrugated pipes tightly connected, thereby ensuring the structural strength of the corrugated pipe.

[0013] Furthermore, the steel-plastic composite belt includes an adhesive resin layer, a steel belt layer, a plastic coating layer and a wear-resistant coating layer connected in sequence from the inside to the outside. The adhesive resin layer facilitates the bonding and fixing of the top and bottom angle strips on the steel-plastic composite belt, and the bonding and fixing of the steel-plastic composite belt on the casing and the plastic inner tube, and then the steel belt layer, the plastic coating layer and the wear-resistant coating layer respectively enhance the strength and corrosion resistance of the corrugation, so as to avoid the collapse or cracking of the outer part of the corrugated pipe due to the impact of concrete during pouring.

[0014] Preferably, the bonding resin of the bonding resin layer is made of the following raw materials in parts by weight: 10-25 parts of metallocene linear low-density polyethylene; 15-25 parts of maleic anhydride grafted high-density polyethylene; 10-15 parts of polypropylene; 30-35 parts of polyurethane; 5-15 parts of terpene resin; 5-10 parts of nanofiller; 0.1-0.5 parts of antioxidant. The bonding resin layer is a key structure to ensure the bonding force between the layers of the corrugated pipe. First, metallocene linear low-density polyethylene has very obvious advantages in improving and enhancing product performance due to its excellent heat sealing performance, good low-temperature toughness and optical properties, and excellent drop hammer impact strength. Then, the metallocene linear low-density polyethylene, terpene resin, polypropylene and polyurethane blending system are toughened and modified by maleic anhydride grafted high-density polyethylene, which can better adhere to the steel belt layer, and can shrink and tightly bond with the above structure when it is higher than the shrinkage temperature of the support belt and the plastic inner tube, and has good bonding force to polyethylene materials and steel materials, thereby achieving the purpose of sealing and barrier.

[0015] Specifically, the nano filler is one or a combination of nano calcium carbonate, nano zinc oxide and nano silicon dioxide treated with a silane coupling agent; the antioxidant is antioxidant 168, antioxidant 245 or antioxidant 300. By optimizing the nano filler and antioxidant, the influence of light and oxygen on the bonding resin can be strongly blocked, thereby ensuring the sealing and barrier effects.

[0016] Preferably, the coating of the wear-resistant coating is mixed with the following raw materials in parts by weight: 20-80 parts of polyurethane hexaacrylate; 5-15 parts of epoxy modified acrylate; 5-50 parts of phenoxyethyl acrylate; 5-50 parts of β-carboxyethyl acrylate; 2-50 parts of pentaerythritol tetraacrylate; 0.5-2.0 parts of butyl titanate; 3-10 parts of cleavage photoinitiator. The plastic coating layer on the outside of the steel belt layer is mainly to prevent the steel belt layer from being affected by chemical corrosion. Therefore, the composite wear-resistant coating on the outside of the plastic coating layer can further avoid corrosion of the steel-plastic composite belt while avoiding wear of the plastic coating layer. Therefore, polyurethane hexaacrylate is used in conjunction with epoxy modified acrylate to improve the hardness of the wear-resistant coating, phenoxyethyl acrylate is used in conjunction with β-carboxyethyl acrylate and pentaerythritol tetraacrylate to adjust the viscosity and leveling of the wear-resistant coating, and finally butyl titanate is used in conjunction with a cleavage photoinitiator to promote the modification and bonding of the above components, which can effectively enhance the wear resistance and scratch resistance of the wear-resistant coating.

[0017] Specifically, the cleavage-type photoinitiator is photoinitiator 184, photoinitiator 1173 or photoinitiator 8700. The compounding effect of these cleavage-type photoinitiators is the best.

[0018] To sum up, the beneficial technical effects of the present invention are: using a plastic inner tube combined with a steel-plastic composite belt, and filling and supporting it with a structurally optimized support belt, while strengthening the corrugation hardness and contact area, it can improve the bonding strength between the corrugated pipe and the concrete after installation, and can enhance the rigidity of the corrugated pipe as a whole, which can meet the use requirements in concrete infrastructure fields such as bridges and large-span buildings. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic structural diagram of a high-strength corrugated pipe for prestressed concrete according to Example 1 of the present invention.

[0020] Figure 2 It is a schematic diagram of the connection relationship between the sleeve, the connecting pipe and the plastic inner pipe in Example 1 of the present invention.

[0021] Figure 3 It is a schematic diagram of the connection relationship between the support belt and the plastic inner tube of Example 1 of the present invention.

[0022] Figure 4 It is a schematic diagram of the cross-sectional structure of the high-strength corrugated pipe for prestressed concrete according to Example 1 of the present invention.

[0023] In the figure, 1. plastic inner tube; 2. support belt; 21. top angle strip; 22. bottom angle strip; 23. steel strip; 3. steel-plastic composite strip; 31. adhesive resin layer; 32. steel belt layer; 33. plastic coating layer; 34. wear-resistant coating; 4. connecting pipe; 41. guide surface; 5. sleeve; 6. heating wire. DETAILED DESCRIPTION

[0024] In order to make the technical means, creative features, objectives and functions achieved by the present invention clearer and easier to understand, the present invention is further explained below in conjunction with the accompanying drawings and specific implementation methods. Example

[0025] Example 1: Reference Figure 1 and Figure 2 , a high-strength corrugated pipe for prestressed concrete disclosed in the present invention, includes a plastic inner pipe 1, a support belt 2 spirally wound on the plastic inner pipe 1, and a steel-plastic composite belt 3 wrapped around the support belt 2 and the plastic inner pipe 1, so that the corrugated pipe has a structure with threads on the outside and a smooth inside.

[0026] Reference Figure 2 In order to facilitate the connection and fixation between the corrugated pipes, one end of the plastic inner pipe 1 is tightly sleeved with a connecting pipe 4, and the connecting pipe 4 is provided with a guide surface 41 at one end close to the plastic inner pipe 1, and the other end is extended and used to be sleeved with the other end of the steel-plastic composite belt 3. One end of the steel-plastic composite belt 3 is tightly wrapped around the connecting pipe 4 along the guide surface 41 to form a sleeve 5. When the steel-plastic composite belt 3 is wrapped, the guide surface 41 can guide the steel-plastic composite belt 3 to smoothly transition between the plastic inner pipe 1 and the connecting pipe 4, which can ensure the structural strength of the transition point while facilitating installation. Then, when the two corrugated pipes are connected, the connecting pipe 4 of one corrugated pipe can be sleeved on the end of the other corrugated pipe away from the sleeve 5, which is simple and quick to operate.

[0027] Reference Figure 3 The support belt 2 is the main structure for enhancing the rigidity of the corrugated pipe, and includes a top angle bar 21 fixed to the inner wall of the steel-plastic composite belt 3, a pair of bottom angle bars 22 wound around the plastic inner tube 1, and a steel bar 23 fixed to the top angle bar 21 and the pair of bottom angle bars 22. The steel bar 23 is formed by bending multiple times between the bottom angle bar 22 and the top angle bar 21, and the bending order of the steel bar 23 is one of the bottom angle bars 22, the top angle bar 21, the other bottom angle bar 22, and the top angle bar 21, one of the bottom angle bars 22, so that the cross-section of the support belt 2 is V-shaped in the tangential direction. In actual installation, the steel bar 23 is first bent according to a predetermined shape, and then the bottom angle bar 22 and the top angle bar 21 of the plastic material are fixed on the steel bar 23, and then the support belt 2 is fixed to the steel-plastic composite belt 3 by bonding, and then the steel-plastic composite belt 3 is installed on the plastic inner tube 1.

[0028] By optimizing the structure of the support belt 2, the top angle bar 21 and the pair of bottom angle bars 22 are fixed against the steel-plastic composite belt 3, so that the top angle bar 21 and the pair of bottom angle bars 22, and the two adjacent sections of the steel bar 23 and the top angle bar 21 and / or the bottom angle bar 22 can be connected to form a triangular support structure. When tensile and bending forces act on the corrugated pipe, this structure can evenly transfer and disperse the forces exerted on the corrugated pipe and have a better force-bearing effect. Therefore, after the installation is completed, under the premise of ensuring that the support belt 2 stably supports the plastic inner tube 1 and the steel-plastic composite belt 3, the connection structure between the three is made more secure, and the weight of the corrugated pipe can be increased to prevent the corrugated pipe from floating, thereby enhancing the rigidity of the corrugated pipe as a whole.

[0029] Reference Figure 2 and Figure 4 In order to match the structure of the sleeve 5, the connecting pipe 4, etc., a heating wire 6 is inserted into the bottom angle strip 22, and one end of the heating wire 6 is inserted into the outside of the bottom angle strip 22 and fixed on the connecting pipe 4. After the two sections of the corrugated pipe are installed, the bottom angle strip 22, the sleeve 5 and the plastic inner pipe 1 can be connected by hot melting by energizing the electric heating wire. Such a layer-by-layer fusion and mutually wrapped support structure can make the plastic inner pipe 1 and the steel-plastic composite belt 3, and the corrugated pipes can be tightly structured, thereby ensuring the structural strength of the corrugated pipe.

[0030] Reference Figure 4 On the outside of the corrugated pipe, the steel-plastic composite belt 3 includes an adhesive resin layer 31, a steel belt layer 32, a plastic coating layer 33 and a wear-resistant coating 34 connected in sequence from the inside to the outside. The adhesive resin layer 31 facilitates the bonding and fixing of the top angle strip 21 and the bottom angle strip 22 on the steel-plastic composite belt 3, and the bonding and fixing of the steel-plastic composite belt 3 on the sleeve 5 and the plastic inner tube 1. The steel belt layer 32, the plastic coating layer 33 and the wear-resistant coating 34 respectively enhance the strength and corrosion resistance of the corrugation to avoid the collapse or cracking of the corrugated pipe due to the impact of concrete during pouring. The original method of combining the outer steel pipe with the inner steel-plastic composite pipe is transformed into a method of combining the plastic inner tube 1 with the steel-plastic composite belt 3, and the support belt 2 is used to fill and support it. While strengthening the hardness and contact area of ​​the corrugation, the ring stiffness of the corrugated pipe can be improved, thereby ensuring the bonding strength between the corrugated pipe and the concrete after installation.

[0031] Among them, the bonding resin of the bonding resin layer 31 is made of raw materials including the following parts by weight: 10 parts of metallocene linear low-density polyethylene; 22 parts of maleic anhydride grafted high-density polyethylene; 15 parts of polypropylene; 33 parts of polyurethane; 5 parts of terpene resin; 5 parts of nanofiller; 0.1 part of antioxidant; the nanofiller is nano calcium carbonate treated with a silane coupling agent; and the antioxidant is antioxidant 168. The bonding resin layer 31 is a key structure to ensure the bonding strength between the various layers of the corrugated pipe. First, the metallocene linear low-density polyethylene has very obvious advantages in improving and enhancing product performance due to its excellent heat sealing performance, good low-temperature toughness and optical properties, and excellent drop hammer impact strength. The metallocene linear low-density polyethylene, terpene resin, polypropylene and polyurethane blending system are toughened and modified by grafting high-density polyethylene with maleic anhydride, which can better adhere to the steel belt layer 32, and can shrink and tightly bond with the above structure when it is higher than the shrinking temperature of the support belt 2 and the plastic inner tube 1, and has good bonding strength to polyethylene materials and steel, thereby achieving the purpose of sealing and barrier. In addition, by optimizing nanofillers and antioxidants, the effects of light and oxygen on the bonding resin can be strongly blocked, thereby ensuring the sealing and barrier effects.

[0032] In addition, the coating of the wear-resistant coating 34 is mixed with the following raw materials in parts by weight: 20 parts of polyurethane hexaacrylate; 10 parts of epoxy-modified acrylate; 35 parts of phenoxyethyl acrylate; 15 parts of β-carboxyethyl acrylate; 2 parts of pentaerythritol tetraacrylate; 0.5 parts of butyl titanate; and 3 parts of a cleavage-type photoinitiator; the cleavage-type photoinitiator is photoinitiator 184. The plastic coating layer 33 on the outside of the steel belt layer 32 is mainly used to prevent the steel belt layer 32 from being affected by chemical corrosion. Therefore, the composite wear-resistant coating 34 on the outside of the plastic coating layer 33 can further prevent the steel-plastic composite belt 3 from being corroded while avoiding the wear of the plastic coating layer 33. Therefore, polyurethane hexaacrylate is used in conjunction with epoxy modified acrylate to improve the hardness of the wear-resistant coating 34, and phenoxyethyl acrylate is used in conjunction with β-carboxyethyl acrylate and pentaerythritol tetraacrylate to adjust the viscosity and leveling properties of the wear-resistant coating 34. Finally, titanate butyl ester is used in conjunction with a cleavage-type photoinitiator to promote the modification and bonding of the above components, which can effectively enhance the wear resistance and scratch resistance of the wear-resistant coating 34.

[0033] Example 2: A high-strength corrugated pipe for prestressed concrete disclosed in the present invention is different from Example 1 in that the weight fractions of the components in the raw materials of the bonding resin of the bonding resin layer 31 and the coating of the wear-resistant coating 34 are shown in Table 1. In addition, the nano filler is nano zinc oxide treated with a silane coupling agent; the antioxidant is antioxidant 245; and the cleavage type photoinitiator is photoinitiator 1173.

[0034] Example 3: A high-strength corrugated pipe for prestressed concrete disclosed in the present invention is different from Example 1 in that the weight fractions of the components in the raw materials of the bonding resin of the bonding resin layer 31 and the coating of the wear-resistant coating 34 are shown in Table 1. The nanofiller is nano calcium carbonate treated with a silane coupling agent; the antioxidant is antioxidant 300; and the cleavage-type photoinitiator is photoinitiator 8700.

[0035] Example 4: A high-strength corrugated pipe for prestressed concrete disclosed in the present invention is different from Example 1 in that the weight fractions of the components in the raw materials of the bonding resin of the bonding resin layer 31 and the coating of the wear-resistant coating 34 are as shown in Table 1. The nanofiller is nanosilicon dioxide treated with a silane coupling agent; the antioxidant is antioxidant 168; and the cleavage-type photoinitiator is photoinitiator 1173.

[0036] Example 5: A high-strength corrugated pipe for prestressed concrete disclosed in the present invention is different from Example 1 in that the weight fractions of the components in the raw materials of the bonding resin of the bonding resin layer 31 and the coating of the wear-resistant coating 34 are shown in Table 1. The nanofiller is nanosilicon dioxide treated with a silane coupling agent; the antioxidant is antioxidant 245; and the cleavage-type photoinitiator is photoinitiator 8700.

[0037] Table 1

[0038] Components Example 1 Example 2 Example 3 Example 4 Example 5 Metallocene linear low density polyethylene 10 15 20 25 17 Maleic anhydride grafted high density polyethylene 22 20 25 15 18 Polypropylene 15 13 12 11 10 Polyurethane 33 35 32 30 33 Terpene resin 5 10 15 13 10 Nanofillers 5 10 6 8 8 Antioxidants 0.1 0.3 0.3 0.5 0.5 Polyurethane hexaacrylate 20 30 50 60 80 Epoxy modified acrylate 10 15 5 13 10 Phenoxyethyl acrylate 35 25 10 5 50 β-Carboxyethyl acrylate 15 30 50 50 5 Pentaerythritol tetraacrylate 2 9 15 30 50 Butyl Titanate 0.5 1.5 1.0 2.0 1.5 Cleavage photoinitiator 3 10 5 9 8

[0039] Performance testing

[0040] The bellows of Examples 1-5 were used as test pieces to measure tensile yield strength, elongation at break, bending strength, ring stiffness, etc. Among them, the tensile yield strength and elongation at break were tested according to the methods of GB / T 1040.1 and GB / T 1040.2, the bending strength was tested according to the method of GB / T 9341, and the ring stiffness was tested according to the method of GB / T 9647. The test results are shown in Table 2.

[0041] Table 2

[0042] Test items Example 1 Example 2 Example 3 Example 4 Example 5 Tensile yield strength (Mpa) 20.4 21.6 21.5 22.3 21.9 Elongation at break (%) 590 580 600 630 620 Bending strength (Mpa) 35.6 36.2 38.1 37.6 37.3 Ring stiffness (kN / m) 6.9 7.3 7.0 6.8 7.0

[0043] It can be seen from Table 2 that Examples 1-5 of the present invention use a plastic inner tube 1 combined with a steel-plastic composite belt 3, and fill and support it with a structurally optimized support belt 2. While strengthening the corrugation hardness and contact area, the overall stiffness of the corrugated pipe can be enhanced, which can meet the use requirements in concrete infrastructure fields such as bridges and large-span buildings.

[0044] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A high-strength corrugated pipe for prestressed concrete, characterized in that: It comprises a plastic inner tube (1), a support belt (2) spirally wound on the plastic inner tube (1), and a steel-plastic composite belt (3) wrapped around the support belt (2) and the plastic inner tube (1); the support belt (2) comprises a top angle bar (21) fixed to the inner wall of the steel-plastic composite belt (3) and a pair of bottom angle bars (22) wound around the plastic inner tube (1), and a steel bar (23) fixed to the top angle bar (21) and the pair of bottom angle bars (22), wherein the steel bar (23) is formed by bending multiple times between the bottom angle bar (22) and the top angle bar (21); One end of the steel-plastic composite belt (3) is spirally extended to the outside of the plastic inner tube (1), and the extended section of the steel-plastic composite belt (3) forms a sleeve (5), and the inner wall of the sleeve (5) is provided with a connecting pipe (4) for sleeve connection with the other end of the steel-plastic composite belt (3); One end of the connecting pipe (4) extends into the steel-plastic composite belt (3) and is tightly sleeved on the plastic inner tube (1); one end of the connecting pipe (4) close to the plastic inner tube (1) is provided with a guide surface (41) that contacts the steel-plastic composite belt (3); A heating wire (6) is inserted into the bottom angle bar (22), and one end of the heating wire (6) is inserted to the outside of the bottom angle bar (22) and is fixed to the connecting pipe (4).

2. The high-strength corrugated pipe for prestressed concrete according to claim 1, characterized in that: The steel bar (23) is bent back and forth in sequence between one of the bottom angle bars (22), the top angle bar (21) and the other bottom angle bar (22).

3. A high-strength corrugated pipe for prestressed concrete according to any one of claims 1-2, characterized in that: The steel-plastic composite belt (3) comprises an adhesive resin layer (31), a steel belt layer (32), a plastic coating layer (33) and a wear-resistant coating (34) which are connected in sequence from the inside to the outside.

4. The high-strength corrugated pipe for prestressed concrete according to claim 3, characterized in that: The adhesive resin of the adhesive resin layer (31) is made of the following raw materials in parts by weight: 10-25 parts of metallocene linear low density polyethylene; 15-25 parts of maleic anhydride grafted high density polyethylene; Polypropylene 10-15 parts; Polyurethane 30-35 parts; 5-15 parts of terpene resin; 5-10 parts of nano filler; Antioxidant 0.1-0.5 parts.

5. The high-strength corrugated pipe for prestressed concrete according to claim 4, characterized in that: The nano filler is one or a combination of nano calcium carbonate, nano zinc oxide and nano silicon dioxide treated with a silane coupling agent; the antioxidant is antioxidant 168, antioxidant 245 or antioxidant 300.

6. The high-strength corrugated pipe for prestressed concrete according to claim 3, characterized in that: The coating material of the wear-resistant coating (34) is prepared by mixing the following raw materials in parts by weight: Polyurethane hexaacrylate 20-80 parts; Epoxy modified acrylate 5-15 parts; Phenoxyethyl acrylate 5-50 parts; 5-50 parts of β-carboxyethyl acrylate; Pentaerythritol tetraacrylate 2-50 parts; 0.5-2.0 parts of butyl titanate; 3-10 parts of cleavage-type photoinitiator.

7. The high-strength corrugated pipe for prestressed concrete according to claim 6, characterized in that: The cleavage-type photoinitiator is photoinitiator 184, photoinitiator 1173 or photoinitiator 8700.

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