Prestressed high-strength concrete blow-off pipeline and manufacturing method thereof

Abstract

The invention discloses a prestressed high-strength concrete blow-off pipeline and a manufacturing method thereof. Belongs to the technical field of concrete pipelines, and can synchronously realize the fundamental improvement of the crack resistance of a pipe body structure and the long-term dynamic sealing of a connector under the micro deformation of a foundation through the combination of a pre-tensioning method pre-stressed high-strength concrete pipe body and a socket-and-spigot joint type double-channel flexible sealing connector system. Comprising the following steps that S1, a mold with a bell end steel mold and a spigot end steel mold is fixed to a long-line pedestal, and the spigot end steel mold is integrated with a flange piece; s2, the prestressed steel bars penetrate into the mold and are integrally tensioned according to the tensioning control stress; s3, concrete with the strength grade not lower than C80 is poured into the mold, and curing is carried out after vibrating and compacting; s4, after the concrete reaches the preset strength, the prestressed steel bars are released, the mold is dismantled, and a pipe body is obtained; and S5, an elastic sealing ring is installed in a groove in the outer wall of the spigot end of the pipe body, and the prestressed high-strength concrete blow-off pipeline is obtained.

Description

Technical Field

[0001] This invention relates to the field of concrete pipe technology, specifically a prestressed high-strength concrete sewage pipe and its manufacturing method. Background Technology

[0002] Municipal sewage pipes are a critical component of the city's underground lifeline, and their performance directly affects public health, environmental safety, and urban resilience. Currently, my country's massive existing municipal sewage pipe network generally faces two major challenges: First, insufficient structural durability. Traditional concrete pipes, due to their low tensile strength, are prone to cracking and deformation under the combined effects of external soil pressure, traffic dynamic loads, and internal corrosion, leading to potential leakage. Second, poor system sealing efficiency. Pipe cracks and misalignment at rigid interfaces allow large amounts of groundwater to infiltrate, severely diluting the influent concentration at sewage treatment plants, resulting in huge wastes of energy and chemicals and a decline in treatment efficiency.

[0003] To address these issues, the industry has attempted improvements such as thickening pipe walls and using reinforced plastic pipes. However, these measures are insufficient to fundamentally solve the problems of pipe crack resistance and dynamic sealing at joints under complex and demanding conditions, including trenchless pipe jacking, deep burial (e.g., exceeding 5 meters), and soft soil foundations. Under the combined effects of construction jacking forces and long-term earth pressure, structural cracking and joint leakage remain prominent problems in existing pipelines.

[0004] Therefore, there is an urgent need to develop a prestressed high-strength concrete sewage pipe and its manufacturing method to solve the problems in the existing technology. Summary of the Invention

[0005] The purpose of this invention is to provide a prestressed high-strength concrete sewage pipe and its manufacturing method. By combining the pre-tensioned prestressed high-strength concrete pipe body with a socket-type double-channel flexible sealing interface system, the fundamental improvement of the pipe body structure's crack resistance and the long-term dynamic sealing of the interface under micro-deformation of the foundation can be achieved simultaneously. Moreover, the structure is simple and easy to use, thus solving the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A method for manufacturing a prestressed high-strength concrete sewage pipe includes the following steps: S1: A mold with a socket end steel mold and a spigot end steel mold is fixed on a long line pedestal, wherein the spigot end steel mold is integrated with a flange plate; S2: Insert the prestressed steel bars into the mold and tension them as a whole according to the tensioning control stress; S3: Pour concrete with a strength grade of not less than C80 into the mold, compact it, and then cure it. S4: After the concrete reaches the predetermined strength, the prestressed steel bars are released and the mold is removed to obtain the pipe body; S5: Install an elastic sealing ring in the groove on the outer wall of the pipe spigot end to obtain the prestressed high-strength concrete sewage pipe.

[0007] By adopting the above technical solution, the manufacturing process of the pipeline of the present invention is defined. The pre-stress of concrete is established by pre-tensioning, and high-strength concrete is combined to make the pipe body have high crack resistance. The installation of sealing rings prepares for the formation of dynamic sealing interfaces.

[0008] As a further aspect of the present invention: in S2, the prestressed steel bar is a spiral ribbed steel wire, and the tension control stress is 0.70-0.75 times the standard value of the prestressed steel bar strength.

[0009] By adopting the above technical solution, using spiral ribbed steel wire and controlling the tensile stress within this range, sufficient effective pre-stress can be safely and efficiently established in concrete, ensuring that the pipe body obtains high ring stiffness and crack resistance.

[0010] As a further aspect of the present invention: in S3, the concrete mix proportion contains silica fume and / or mineral powder, and the curing is steam curing.

[0011] By adopting the above technical solutions, the addition of active admixtures can improve the density and strength of concrete, and steam curing can accelerate the early strength development, shorten the production cycle, and ensure that the strength index of C80 and above is achieved.

[0012] As a further aspect of the present invention: in S5, the elastic sealing ring is an EPDM rubber sealing ring with a Shore hardness of 70±5.

[0013] By adopting the above technical solutions, EPDM rubber is resistant to aging and corrosion. Controlling the hardness to 70±5 allows the sealing ring to have both elasticity and resistance to compression deformation, forming a stable and effective compression sealing band at the interface, adapting to minute displacements, and achieving dynamic sealing.

[0014] As a further aspect of the present invention: before pouring concrete in S3 or after obtaining the pipe body in S4, the method further includes a step of pre-embedding a sensor in the pipe body, the sensor being used to monitor the stress, strain or leakage status of the pipe.

[0015] By adopting the above technical solutions, pre-embedded sensors can realize real-time monitoring and early warning of pipeline stress, strain and leakage status, providing support for intelligent operation and maintenance and precise maintenance of pipeline networks.

[0016] As a further aspect of the present invention: a prestressed high-strength concrete sewage pipe, comprising: The pipe body is made of prestressed concrete using the pre-tensioning method; The socket prefabricated at one end of the pipe body has at least one annular sealing groove on its inner wall; The insertion port prefabricated at the other end of the pipe body has a flange and at least one groove for installing an elastic sealing ring on its outer side; The socket is fixed to the prestressed steel bars inside the pipe by welding the flange.

[0017] By adopting the above technical solution, the basic structure of the pipeline was defined. The spigot flange is welded to the prestressed steel bars, ensuring the connection and integrity of the interface and the pipe body, enabling the interface to transmit huge jacking forces, and making it suitable for harsh working conditions such as trenchless pipe jacking.

[0018] As a further aspect of the present invention: the concrete strength grade of the pipe body is not lower than C80, and the inner wall of the bearing and the outer wall of the spigot are respectively provided with two annular sealing grooves and two grooves for installing elastic sealing rings.

[0019] By adopting the above technical solution, C80 high-strength concrete serves as the load-bearing foundation. The double-sealing structure forms a redundant sealing defense line, significantly improving the reliability and safety of the interface sealing system and reducing the risk of leakage.

[0020] As a further aspect of the present invention: the socket and spigot are connected by a socket-insertion type, allowing adjacent pipe sections to have a relative angular displacement of ±1° to ±2° at the interface after installation.

[0021] By adopting the above technical solution, controllable micro-angular displacement of the interface is allowed, which can absorb stress and deformation caused by foundation settlement, construction errors, etc., prevent damage caused by stress concentration at the interface, and improve adaptability to complex foundations.

[0022] As a further aspect of the present invention, the pipeline also includes a sensor pre-embedded in the pipe body for real-time monitoring of the pipeline's mechanical state or leakage information.

[0023] By adopting the above technical solutions, the integrated pre-embedded sensors enable pipelines to have the function of monitoring structural health and sealing status, support predictive maintenance, and improve the long-term operational safety of the pipeline network.

[0024] As a further aspect of the present invention: the external pressure cracking load of the pipeline is not less than 450kN / m, the failure load is not less than 550kN / m, and it remains without leakage for 5 minutes under a relative angle of ±2° at the interface and a water pressure of 0.15MPa.

[0025] By adopting the above technical solutions, the specified load indexes proved the high structural bearing capacity of the pipe body, and the corner seal test results proved the reliable sealing performance of the interface under dynamic deformation.

[0026] Compared with the prior art, the beneficial effects of the present invention are: by combining the pre-tensioned high-strength concrete pipe body with the socket-type double flexible sealing interface system, the fundamental improvement of the crack resistance of the pipe body structure and the long-term dynamic sealing of the interface under the micro deformation of the foundation are achieved simultaneously.

[0027] Other features and advantages of the present invention will be disclosed in detail in the following detailed description and accompanying drawings. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of an overall structure in an embodiment of the present invention.

[0029] The labels in the attached figures are: 1. Concrete; 2. Flange; 3. Socket; 4. Prestressed steel reinforcement; 5. Spigot. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] according to Figure 1 As shown in the figure, this embodiment provides a method for manufacturing a prestressed high-strength concrete sewage pipe, the specific steps of which are as follows: 1. Material Preparation and Mold Fixing: The prestressed steel reinforcement 4 is selected from Φ12mm spiral ribbed steel wire with a standard strength value fptk=1570MPa. The design strength of concrete 1 is C80, and the mix ratio is: cement:sand:stone:water = 1:1.2:2.5:0.32, with 15% silica fume added to the total cementitious material. On the long-line pedestal, a mold with a socket end 3 and a spigot end 5 is fixed. The spigot end 5 mold integrates a 20mm thick ductile iron flange 2.

[0032] 2. Prestressing tensioning: Insert the prestressed steel bars 4 into the fixed mold, tension them as a whole according to the tensioning control stress of 0.75fptk (i.e. 1177.5MPa), and anchor them firmly.

[0033] 3. Concrete 1 Pouring and Curing: Pour the mixed C80 concrete 1 into the formwork and compact it using a high-frequency attached vibrator to ensure it is dense and free of air bubbles. Immediately after pouring, steam curing is carried out: the temperature is raised to 60℃ and maintained for 4 hours, then kept at a constant temperature (60℃) for 8 hours, and then slowly cooled to room temperature. This curing regime aims to accelerate the early strength development of concrete 1.

[0034] 4. Prestressing release and demolding: When the compressive strength of concrete specimen 1, cured under the same conditions, reaches 50 MPa, the prestressed steel bars 4 are slowly and symmetrically released. After the release is completed, the side molds are removed to obtain the formed prestressed high-strength concrete pipe 1, which is then hoisted to the storage yard for subsequent natural curing.

[0035] 5. Sealing ring installation: Press EPDM rubber sealing rings with a Shore hardness of 70 into the two pre-made grooves on the outer wall of the five ends of the pipe body, ensuring that the installation is flat and without twisting.

[0036] 6. Performance Testing: An external pressure load test was conducted on the manufactured DN800 pipe. The cracking load was measured to be 460 kN / m, and the failure load was 560 kN / m. A joint sealing performance test was conducted, maintaining a water pressure of 0.15 MPa for 5 minutes at a relative angle of +2° between the joints. No leakage was observed at the joints.

[0037] Example 2: The difference between this embodiment and Embodiment 1 is that the concrete material and curing regime have been optimized, and a state sensing function has been integrated.

[0038] 1. Materials and molds: The prestressed steel bars 4 are the same as in Example 1. The design strength of concrete 1 is C90, and in addition to silica fume, 10% of the total cementitious material, mineral powder, is added to the mix proportion. The mold fixing method is the same.

[0039] 2. Sensor pre-embedding: Before pouring concrete 1, two sets of fiber optic grating sensors are pre-embedded in the middle of the pipe body and near the socket 3. The sensors are led out to the pipe end protection box through wires for future monitoring of pipe strain and stress concentration in the interface area.

[0040] 3. Tensioning and Casting: The tensioning process is the same as in Example 1. During casting, care should be taken to avoid the sensor location. When vibrating, a small vibrator should be used carefully around the sensor to avoid damage.

[0041] 4. Curing: High-temperature steam curing is adopted, with the temperature raised to 75℃ during the constant temperature stage and the curing time shortened to 6 hours, so as to achieve the release strength more quickly.

[0042] 5. Subsequent processes: The steps of releasing the sheet, demolding, and installing the sealing ring are the same as in Example 1. After installing the sealing ring, the sensor wires are sealed and waterproofed.

[0043] 6. Performance Testing: The performance test results of the pipe body were higher than those of Example 1: the cracking load reached 480 kN / m, and the failure load reached 580 kN / m. The sealing performance also met the requirements. The initial sensor readings were stable, and the signal transmission was good, verifying the feasibility of the pre-embedded process.

[0044] Example 3: This embodiment aims to demonstrate the adaptability of the pipe of the present invention to smaller diameters and the use of different sealing materials.

[0045] 1. Materials and Molds: For manufacturing DN500 pipes. Prestressed steel reinforcement 4 uses Φ9mm spiral ribbed steel wire. Concrete 1 has a strength of C80, with the mix proportion adjusted accordingly. Molds are manufactured to DN500 specifications, and the flange thickness of spigot 5 is 15mm.

[0046] 2. Process: The tension control stress remains at 0.75fptk. The casting, curing (using the steam curing regime of Example 1), release, and demolding processes are the same as in Example 1, with parameters adjusted proportionally.

[0047] 3. Sealing ring installation: The elastic sealing rings installed in the two grooves at the five ends of the socket are made of neoprene rubber (CR) with a Shore hardness of 65±5 to adapt to possible oily environments.

[0048] 4. Performance Testing: An external pressure test was conducted on the DN500 pipe, with a cracking load of 320 kN / m and a failure load of 400 kN / m. A joint corner sealing test was performed, maintaining a leak-free connection for 5 minutes at a ±2° corner and 0.2 MPa water pressure. The results show that the proposed solution exhibits excellent mechanical and sealing performance across different pipe diameters.

[0049] Comparative example (traditional process) In comparison, pipes of the same size (DN800) as in Example 1 were manufactured using C50 ordinary reinforced concrete in accordance with the requirements of Class III pipes in the national standard GB / T 11836 "Concrete and Reinforced Concrete Drainage Pipes", and rigid flat joints were used.

[0050] The manufactured pipes were tested and found to have a cracking load of 180 kN / m and a failure load of 250 kN / m. Leakage occurred at the joints under a water pressure of 0.1 MPa with even slight simulated ground deformation.

[0051] This invention provides a prestressed high-strength concrete sewage pipe and its manufacturing method. By combining the pre-tensioned prestressed high-strength concrete pipe body with a socket-type double-channel flexible sealing interface system, the pipe body structure crack resistance performance can be fundamentally improved and the interface can be dynamically sealed under the micro-deformation of the foundation, resulting in high reliability.

[0052] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0053] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A prestressed high-strength concrete sewage pipe, characterized in that, include: The pipe body is made of prestressed concrete using the pre-tensioning method; The socket prefabricated at one end of the pipe body has at least one annular sealing groove on its inner wall; The insertion port prefabricated at the other end of the pipe body has a flange and at least one groove for installing an elastic sealing ring on its outer side; The socket is fixed to the prestressed steel bars inside the pipe by welding the flange.

2. The prestressed high-strength concrete sewage pipe according to claim 1, characterized in that, The concrete strength grade of the pipe body is not lower than C80, and the inner wall of the bearing and the outer wall of the spigot are respectively provided with two annular sealing grooves and two grooves for installing elastic sealing rings.

3. The prestressed high-strength concrete sewage pipe according to claim 1 or 2, characterized in that, The socket and spigot are connected by a socket-type connection, allowing for a relative angular displacement of ±1° to ±2° between adjacent pipe sections at the interface after installation.

4. A method for manufacturing a prestressed high-strength concrete sewage pipe, characterized in that, Includes the following steps: S1: A mold with a socket end steel mold and a spigot end steel mold is fixed on a long line pedestal, wherein the spigot end steel mold is integrated with a flange plate; S2: Insert the prestressed steel bars into the mold and tension them as a whole according to the tensioning control stress; S3: Pour concrete with a strength grade of not less than C80 into the mold, compact it, and then cure it. S4: After the concrete reaches the predetermined strength, the prestressed steel bars are released and the mold is removed to obtain the tube body; S5: Install an elastic sealing ring in the groove on the outer wall of the pipe spigot end to obtain the prestressed high-strength concrete sewage pipe.

5. The manufacturing method according to claim 4, characterized in that, In S2, the prestressed steel bar is a spiral ribbed steel wire, and the tension control stress is 0.70-0.75 times the standard value of the prestressed steel bar strength.

6. The manufacturing method according to claim 4, characterized in that, In S3, the concrete mix proportion contains silica fume and / or mineral powder, and the curing is steam curing.

7. The manufacturing method according to claim 4, characterized in that, In S5, the elastic sealing ring is an EPDM rubber sealing ring with a Shore hardness of 70±5.

8. The manufacturing method according to claim 4, characterized in that, Before pouring concrete in S3 or after obtaining the pipe body in S4, the process also includes the step of pre-embedding sensors in the pipe body, which are used to monitor the stress, strain, or leakage status of the pipe.

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