Self-stress concrete steel pipe

Abstract

The utility model relates to a self-stress concrete steel pipe, which is applied to the technical field of water delivery pipelines, and comprises a steel pipe and a concrete lining, and the concrete lining is arranged on the inner side of the steel pipe. The annular concrete lining is poured in the steel pipe, the concrete lining is formed by mixing the cement with the self-expansion performance, in the curing process of the concrete lining, the self-stress cement is hydrated to generate an expansion component, the size of the concrete lining is increased, therefore, tensile stress is generated in the steel pipe, and pressure stress is generated in the concrete lining; the pipeline manufactured in this way has the capacity of bearing internal water pressure and external load at the same time, and the use amount of steel is reduced.

Description

Technical Field

[0001] This application relates to the technical field of water pipelines, and in particular to a self-stressing concrete steel pipe. Background Art

[0002] For traditional steel pipes, their pipe walls have high tensile strength and excellent internal water pressure resistance. However, due to their relatively thin wall thickness, they have poor rigidity and poor external load resistance. Especially when their diameter reaches 4 meters, a large amount of steel is used to improve the pipe's rigidity. Generally, the wall thickness of the steel pipe is designed to be 0.8% - 1% of the pipe's inner diameter, resulting in a large consumption of steel.

[0003] For current self-stressing concrete pipes, the diameter range is DN100 - DN800, and the working pressure is 0.2MPa - 0.8MPa. In the early standards (GB4084 - 83, GB / T4084 - 1999), the working pressure was up to 1.2MPa. Later practice found that the self-stressing concrete pipes were prone to bursting when the working pressure was too high during water conveyance. Therefore, the current maximum working pressure of self-stressing concrete pipes is 0.8MPa. For traditional self-stressing concrete pipes, the reinforcement ratio has certain limitations (the pitch of the steel bar cage cannot be too dense, otherwise the stones cannot pass through the steel bar cage during concrete pouring, which will cause defects in the steel bar protection layer and affect the service life of the pipe). Usually, the steel bar cage is welded with cold-drawn low-carbon steel wires, and the elongation is not good. It is difficult to control the expansion stabilization period of self-stressing cement, making the diameter of this traditional pipe small, the maximum working pressure low, and the quality unstable. Moreover, the traditional self-stressing concrete pipe has a socket end protruding from the pipe body surface, making it impossible to carry out jacking construction.

[0004] In view of this, there is an urgent need for a self-stressing concrete steel pipe that saves steel and has high compressive capacity to solve the above problems. Summary of the Invention

[0005] In order to help solve the problems existing in the prior art, a self-stressing concrete steel pipe provided by this application adopts the following technical solutions: It includes: a steel pipe and a concrete lining, and the concrete lining is arranged inside the steel pipe.

[0006] It is further characterized in that

[0007] Socket rings and spigot rings are respectively arranged at both ends of the steel pipe, and the outer diameter of the end of the spigot ring is adapted to the inner diameter of the socket ring.

[0008] One end of the socket ring extends to the inside of the steel pipe and is connected to the inside of the steel pipe.

[0009] One end of the socket ring is connected to the end of the steel pipe.

[0010] One end of the spigot ring extends to the inside of the steel pipe and is connected to the inside of the steel pipe.

[0011] One end of the socket ring is connected to the end of the steel pipe.

[0012] At least one annular sealing groove is provided on the outer circumferential surface of the socket ring, and an annular sealing ring is provided in the annular sealing groove.

[0013] An anti-corrosion layer is provided on the outer wall of the steel pipe.

[0014] The concrete lining is made of self-stressing cement.

[0015] Both the socket ring and the spigot ring are made of steel.

[0016] In summary, by pouring a ring-shaped concrete lining inside the steel pipe, the concrete lining is prepared by mixing with cement having self-expansion performance. During the curing process of the concrete lining, the hydration of the self-stressing cement generates expansion components, causing the volume of the concrete lining to increase, thereby generating tensile stress inside the steel pipe and compressive stress inside the concrete lining. The pipeline thus made has the ability to withstand both internal water pressure and external loads, and reduces the amount of steel used. Brief Description of the Drawings

[0017] Figure 1 is a schematic structural view of the present application;

[0018] Figure 2 is a cross-sectional structural view of the present application;

[0019] Figure 3 is a cross-sectional structural view of the present application from another perspective;

[0020] Figure 4 is a schematic structural view of the socket ring, spigot ring and steel pipe of the present application;

[0021] Figure 5 is a schematic structural view of the present application in the use state.

[0022] Reference numerals: 1, steel pipe; 2, concrete lining; 3, socket ring; 4, spigot ring; 5, annular sealing groove; 6, annular sealing ring. Detailed Description of the Embodiments

[0023] In order to enable those skilled in the art to better understand the solution of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0024] It should be noted that the terms "including" and "having" and any variations thereof in the description, claims and the above-mentioned drawings of this application are intended to cover non-exclusive inclusion. For example, a process, method, device, product or equipment that includes a series of steps or units does not necessarily have to be limited to those clearly listed steps or units, but may include other steps or units that are not clearly listed or are inherent to these processes, methods, products or equipment.

[0025] The following will further elaborate on this application in conjunction with the attached Figures 1-5 drawings.

[0026] Referring to Figures 1-3 , a self-stressing concrete steel pipe includes: a steel pipe 1 and a concrete lining 2. The concrete lining 2 is arranged inside the steel pipe 1. Thus, a ring-shaped concrete lining 2 is poured inside the steel pipe 1 (the concrete lining 2 can be formed by vertical vibration, core mold vibration or radial extrusion process). The concrete lining 2 is prepared with cement having self-expansion performance (the best choice is to use self-stressing cement). During the curing process of the concrete lining 2, the self-stressing cement hydrates to generate expansion components, causing the volume of the concrete lining 2 to increase, thereby generating tensile stress inside the steel pipe 1 and compressive stress inside the concrete lining 2. The pipeline made in this way has the ability to withstand internal water pressure and external loads at the same time, and reduces the consumption of steel.

[0027] Referring to Figure 4 and 5 , for the convenience of butt joint between steel pipes, a socket ring 3 and a spigot ring 4 are respectively arranged at both ends of the steel pipe 1. The outer diameter of the end of the spigot ring 4 is adapted to the inner diameter of the socket ring 3. Thus, during construction, the spigot ring 4 of one steel pipe is inserted into the socket ring 3 of another steel pipe, and thus the butt joint of the two steel pipes is completed. Further optimized, in order to ensure the sealing performance at the joint of the steel pipes, at least one annular sealing groove 5 is arranged on the outer circumferential surface of the spigot ring 4, and an annular sealing ring 6 is arranged in the annular sealing groove 5. Thus, by arranging the annular sealing ring 6 on the circumferential surface of the spigot ring 4, the sealing performance after the spigot ring 4 of one steel pipe is inserted into the socket ring 3 of another steel pipe is improved. And in order to further improve the matching degree between the spigot ring 4 and the socket ring 3 (as Figure 5 shown), a rounding machine is used to process and size the spigot ring 4 and the socket ring 3. (The rounding machine is a general equipment in the manufacturing industry of prestressed concrete cylinder pipes. Its working principle is to pull down the vertical wedge block through the oil cylinder, push the horizontal wedge block and expand the diameter of the rounding module, forcing the butt joint socket ring and spigot ring to be circumferentially tensioned and exceed the yield limit, thereby accurately sizing, and causing the annular sealing ring 6 pre-set in the annular sealing groove 5 to undergo plastic deformation). And in order to improve the strength of the socket ring 3 and the spigot ring 4, the socket ring 3 and the spigot ring 4 are preferably made of steel.

[0028] Reference Figure 4 One end of the socket ring 3 extends to the inner side of the steel pipe 1 and is connected to the inner side of the steel pipe 1, or one end of the socket ring 3 is connected to the end of the steel pipe 1. In this way, the socket ring 3 and the steel pipe 1 can be welded by butt-jointing or plug-jointing to ensure the sealing of the connection between the socket ring 3 and the steel pipe 1.

[0029] Reference Figure 4 One end of the spigot ring 4 extends to the inner side of the steel pipe 1 and is connected to the inner side of the steel pipe 1, or one end of the spigot ring 4 is connected to the end of the steel pipe 1. In this way, the spigot ring 4 and the steel pipe 1 can be welded by butt-jointing or plug-in welding to ensure the sealing of the connection between the spigot ring 4 and the steel pipe 1.

[0030] Further optimization is that in order to improve the corrosion resistance of the steel pipe and further increase the service life of the steel pipe, an anti-corrosion layer is provided on the outer wall of the steel pipe 1, and according to the anti-corrosion requirements, the anti-corrosion layer can be composed of PE, three oils and two cloths, epoxy coal tar, epoxy powder spraying, polyurethane coating, wire mesh cement mortar protective layer, etc. for anti-corrosion.

[0031] Further optimization is that the steel pipe 1 can be made of steel of different materials and grades according to design conditions and economic conditions, such as Q235, Q355, etc., or the steel pipe 1 can be made directly of stainless steel without an anti-corrosion layer.

[0032] In summary: an annular concrete lining 2 is poured inside the steel pipe 1. The concrete lining 2 is mixed with cement having self-expansion properties. During the curing process of the concrete lining 2, the self-stress cement is hydrated to produce expansion components, which increases the volume of the concrete lining 2, thereby generating tensile stress inside the steel pipe 1 and compressive stress inside the concrete lining 2. The pipe made in this way has the ability to withstand both internal water pressure and external loads.

[0033] Compared with steel pipes, this product has strong corrosion resistance, strong resistance to internal water pressure, high rigidity, and the same diameter pipe uses about 50% less steel than steel pipes, with low energy consumption and high cost performance;

[0034] The self-stressed concrete steel pipe manufactured by the present invention has a much higher reinforcement ratio than the traditional self-stressed concrete pipe, breaking through the reinforcement ratio limit of the original cold-drawn low-carbon steel wire welded skeleton, and can use higher-grade self-stressed cement. Even the current self-stressed cement with a maximum self-stress value of 5.5MPa can no longer meet the needs of self-stressed concrete steel pipes, which can drive the further development of the special cement industry. Water pipelines with larger diameters and higher pressure resistance can be designed and manufactured. Targeted external anti-corrosion of steel pipes can be adopted according to different use environments. The use of deformed Carnegie interfaces allows the pipeline to be jacked in for construction, breaking through the limitation that traditional self-stressed concrete pipes can only be constructed by slotting and burying.

[0035] This application can be used for conveying water or other liquids. It combines the respective advantages of steel pipes and self-stressing concrete pipes, and abandons their respective disadvantages. It can be applied to technical fields such as water conservancy and municipal water service projects, inter-basin water transfer projects, urban and rural water supply source projects, rural drinking water safety projects, comprehensive utilization water conservancy pivot projects, irrigation area renovation and supporting facility construction, efficient water transmission and distribution, popularization and application of water-saving irrigation technologies, and farmland water conservancy facility construction projects, etc.

[0036] This specific embodiment is only an interpretation of the present invention and is not a limitation thereto. After reading this specification, those skilled in the art can make modifications to this embodiment that do not contribute creatively as needed, but as long as it is within the scope of the claims of the present invention, it is protected by the patent law.

Claims

1. A self-stressing concrete steel pipe, characterized in that, Comprising: A steel pipe (1) and a concrete lining (2), the concrete lining (2) being arranged inside the steel pipe (1); Both ends of the steel pipe (1) are respectively provided with a socket ring (3) and a spigot ring (4), the outer diameter of the end of the spigot ring (4) being adapted to the inner diameter of the socket ring (3); One end of the socket ring (3) extends to the inside of the steel pipe (1) and is connected to the inside of the steel pipe (1); One end of the spigot ring (4) extends to the inside of the steel pipe (1) and is connected to the inside of the steel pipe (1).

2. A self-stressing concrete steel pipe according to claim 1, wherein: At least one annular sealing groove (5) is arranged on the outer circumferential surface of the spigot ring (4), and an annular sealing ring (6) is arranged in the annular sealing groove (5).

3. A self-stressing concrete steel pipe according to claim 1, characterized in that: An anti-corrosion layer is arranged on the outer wall of the steel pipe (1).

4. A self-stressing concrete steel pipe according to claim 1, characterized in that: The concrete lining (2) is made of self-stressing cement.

5. A self-stressing concrete steel pipe according to claim 1, wherein: Both the socket ring (3) and the spigot ring (4) are made of steel.

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