Ultra high performance concrete pile
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- JIANHUA CONSTRUCTION MATERIALS (CHINA) CO LTD
- Filing Date
- 2025-08-07
- Publication Date
- 2026-07-24
Smart Images
Figure CN224549098U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of concrete pile technology, and in particular to an ultra-high performance concrete pile. Background Technology
[0002] China has a vast territory and a complex and diverse natural environment, resulting in diverse service environments for pile foundations. Chloride ion corrosion is very common in marine and nearshore environments. The degree of corrosion damage to concrete structures in marine environments is influenced by the combined effects of regional environment, material properties, and corrosive media, with the splash zone and tidal zone being the most severely affected. The core mechanism is the combined effect of chloride ion penetration, sulfate expansion, and physical damage. Chloride ions in seawater damage the passivation film of reinforcing steel, leading to steel corrosion, while sulfates may react with components in cement to generate expansive products, causing concrete cracking. In the splash zone, the wet-dry cycle accelerates chloride ion (Cl⁻) penetration, and the expansion of salt crystals (such as sulfate forming gypsum and ettringite) also leads to concrete cracking. Under these environmental conditions, the corrosive effects of corrosive ions will cause significant damage to the pile body, seriously affecting its quality, jeopardizing its load-bearing capacity and various performance characteristics. This damage intensifies over time, posing serious safety hazards and severely threatening the safety of the superstructure of marine engineering projects. With the increasing demands for load-bearing capacity and durability in marine engineering, there is an urgent need to design pile types that better meet the requirements of different application scenarios to serve the development of the marine infrastructure industry. For example, in offshore wind power projects, the original steel pipe piles have been gradually replaced by large-diameter PHC pipe piles due to factors such as the rapid corrosion rate of steel in high salt spray and high humidity environments and the difficulty of maintenance. However, the application and development of ordinary PHC pipe piles in the marine engineering field are restricted by factors such as low compressive strength and limited corrosion resistance.
[0003] Ultra-High Performance Concrete (UHPC) is one of the most innovative engineering materials of recent decades, breaking through the performance bottlenecks of traditional concrete and representing a new direction for the future development of concrete materials. UHPC possesses advantages such as ultra-high strength (compressive strength can reach over 120 MPa), ultra-high durability (stable performance and non-corrosive even after long-term immersion in sulfate solutions), ultra-high toughness (fiber-reinforced technology increases its fracture energy several times over, absorbs impact energy, and reduces crack propagation), and dense microstructure (porosity <2%, extremely low permeability), making it an environmentally friendly green building material. When ordinary UHPC is used in the production of pipe piles, its uneven distribution within the piles, limited by the characteristics of the metal fibers, significantly reduces its bending resistance.
[0004] In view of the above, this utility model is hereby proposed. Utility Model Content
[0005] The purpose of this invention is to provide an ultra-high performance concrete pile to solve the technical problem that the bending resistance of UHPC pipe piles is greatly reduced due to the uneven distribution of metal fibers in the pipe pile, which is limited by the characteristics of metal fibers.
[0006] In order to achieve the above-mentioned objectives of this utility model, the following technical solution is adopted: This utility model provides an ultra-high performance concrete pile, including a UHPC concrete pile body and metal fibers located inside the UHPC concrete pile body; The metal fiber content is 2.1%~4% v / v; At least 80% of the metal fibers are uniformly distributed along the axial direction of the UHPC concrete pile.
[0007] Furthermore, at least 95% of the metal fibers are uniformly distributed along the axial direction of the UHPC concrete pile.
[0008] Furthermore, the diameter of the metal fiber is 0.1~0.3mm; the aspect ratio of the metal fiber is 50~100; the tensile strength of the metal fiber is >1000MPa; and the unit weight of the UHPC concrete in the UHPC concrete pile body is >2600kg / m³. 3 UHPC concrete does not contain coarse aggregate.
[0009] Furthermore, the metal fiber is copper-plated steel fiber or stainless steel fiber.
[0010] Furthermore, it also includes a second concrete pile body, which is located inside the UHPC concrete pile body.
[0011] Furthermore, it also includes a steel reinforcement cage located inside the UHPC concrete pile body or the second concrete pile body.
[0012] Furthermore, the thickness of the UHPC concrete pile body is 2.0~7.0cm.
[0013] Furthermore, when the thickness of the UHPC concrete pile body is 3.5~7.0 cm, the reinforcing steel cage is located inside the UHPC concrete pile body; When the thickness of the UHPC concrete pile body is less than 3.5cm, the steel reinforcement cage is located inside the second concrete pile body.
[0014] Furthermore, the steel reinforcement cage includes main bars and stirrups.
[0015] Furthermore, the outer contour of the cross-section of the ultra-high performance concrete pile is circular, square, or polygonal; the inner contour of the cross-section of the ultra-high performance concrete pile is circular.
[0016] This invention provides an ultra-high performance concrete pile. The ultra-high performance concrete pile has a dense structure and low permeability, preventing seawater or groundwater intrusion and erosion of the pile's inner wall, thus meeting the durability requirements of the pile body in corrosive environments. The pile body is made of UHPC (Ultra-High Performance Concrete), which has high compressive strength, and the metal fibers in the pile body are uniformly distributed along the pile's axial direction, improving the pile's bending resistance. Through high fiber content, the axial tensile strength of UHPC concrete can reach more than twice that of ordinary C80 concrete. Compared with ordinary PHCC80 pipe piles, UHPC pipe piles have a crack resistance bending moment increased by more than 90% and an ultimate bending moment increased by more than 38%. This solves the technical problem in existing UHPC pipe pile applications where the bending resistance is significantly reduced due to the uneven distribution of metal fibers within the pipe pile, which is limited by the characteristics of the metal fibers. Attached Figure Description To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0017] Figure 1 This is a schematic diagram of the overall structure of the ultra-high performance concrete pile provided in Embodiment 1 of this utility model; Figure 2 This is a schematic diagram of the cross-sectional structure of an ultra-high performance concrete pile provided in Embodiment 1 of this utility model; Figure 3 for Figure 2 Enlarged structural diagram at point A in the middle; Figure 4 A cross-sectional photograph of the ultra-high performance concrete pile product provided in Embodiment 1 of this utility model; Figure 5 This is a schematic diagram of the cross-sectional structure of the ultra-high performance concrete pile provided in Embodiment 5 of this utility model; Figure 6 for Figure 5 Enlarged structural diagram at point B; Figure 7 This is a schematic diagram of the cross-sectional structure of the ultra-high performance concrete pile provided in Embodiment 6 of this utility model; Figure 8 for Figure 7 Enlarged structural diagram at point C.
[0018] Icons: 1-UHPC concrete pile body; 2-metal fiber; 3-second concrete pile; 4-main reinforcement; 5-stirrups. Detailed Implementation
[0019] Unless otherwise defined herein, the scientific and technical terms used in connection with this utility model shall have the meanings commonly understood by one of ordinary skill in the art. The meaning and scope of terms shall be clear; however, in any case of potential ambiguity, the definitions provided herein shall prevail over any dictionary or foreign definitions. In this application, unless otherwise stated, the use of "or" means "and / or". Furthermore, the use of the term "comprising" and other forms is non-limiting.
[0020] The technical solution of this utility model will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.
[0021] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.
[0022] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.
[0023] In the description of this utility model, it should be noted that the terms "proximal end," "distal end," "front end," "rear end," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the utility model product is in use. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first," "second," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.
[0024] The terms "horizontal" and "vertical" do not imply that a component must be absolutely horizontal or suspended, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.
[0025] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," and "connect" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.
[0026] This utility model provides an ultra-high performance concrete pile, including a UHPC concrete pile body 1 and metal fibers 2 located inside the UHPC concrete pile body 1; The metal fiber 2 has a doping content of 2.1%~4.0% v / v; At least 80% of the metal fiber 2 is uniformly distributed along the axial direction of the UHPC concrete pile body 1.
[0027] Ultra-high performance concrete (UHPC) piles have a dense structure and low permeability, preventing seawater or groundwater intrusion and erosion of the pile's inner wall, thus meeting the durability requirements of piles in corrosive environments. The pile body is made of UHPC concrete, which has high compressive strength, and the metal fibers within the pile are uniformly distributed along the pile's axial direction, improving its bending resistance. Through high fiber content, the axial tensile strength of UHPC concrete can reach more than twice that of ordinary C80 concrete. Compared to ordinary C80 pipe piles, UHPC pipe piles exhibit a crack resistance moment increase of over 90% and an ultimate bending moment increase of over 38%. This solves the technical problem in existing UHPC pipe pile production where the uneven distribution of metal fibers significantly reduces bending resistance.
[0028] In some specific implementations, at least 95% of the metal fiber 2 is uniformly distributed along the axial direction of the UHPC concrete pile body 1.
[0029] In some specific embodiments, the diameter of the metal fiber 2 is 0.1~0.3mm; the aspect ratio of the metal fiber 2 is 50~100; the tensile strength of the metal fiber 2 is >1000MPa; and the unit weight of the UHPC concrete in the UHPC concrete pile body 1 is >2600kg / m³. 3 UHPC concrete does not contain coarse aggregate.
[0030] In some specific embodiments, the metal fiber 2 is copper-plated steel fiber or stainless steel fiber.
[0031] In some specific embodiments, a second concrete pile body 3 is also included, located inside the UHPC concrete pile body 1. UHPC concrete itself has high compressive strength. In addition to its isolation and protection function, the inner and outer walls of the UHPC protective layer also provide lateral restraint to the prestressed reinforced concrete pipe body, allowing the pipe body to better perform its mechanical properties under pressure. Tests have shown that the mechanical bearing capacity of this type of pipe pile is significantly higher than that of equivalent prestressed pipe piles. The pile body is made of a combination of UHPC concrete and ordinary concrete, which not only meets the requirements for corrosion resistance and improves corrosion resistance and bending resistance, but also maintains the same bearing capacity, resulting in high economic benefits.
[0032] In some specific embodiments, a steel reinforcement cage is also included, which is located inside the UHPC concrete pile body 1 or the second concrete pile body 3.
[0033] In some specific embodiments, the thickness of the UHPC concrete pile body 1 is 2.0~7.0cm.
[0034] In some specific implementations, when the thickness of the UHPC concrete pile body 1 is 3.5~7.0cm, the reinforcing steel cage is located inside the UHPC concrete pile body 1; when the thickness of the UHPC concrete pile body 1 is <3.5cm, the reinforcing steel cage is located inside the second concrete pile body 3.
[0035] In some specific embodiments, the steel reinforcement cage includes main bars 4 and stirrups 5.
[0036] In some specific embodiments, the outer contour of the cross-section of the ultra-high performance concrete pile is circular, square, or polygonal; the inner contour of the cross-section of the ultra-high performance concrete pile is circular.
[0037] In this invention, both the UHPC concrete pile body 1 and the second concrete pile body 3 are manufactured by centrifugal process.
[0038] The present invention will be further illustrated below through embodiments. Unless otherwise specified, the materials in the embodiments are prepared according to existing methods or purchased directly from the market.
[0039] Example 1 Combination Figures 1-4 This paper describes an ultra-high performance concrete pile, comprising a UHPC concrete pile body 1 and metal fibers 2 located within the UHPC concrete pile body 1. Taking a pipe pile with a diameter of 500 mm as an example, the thickness of the UHPC concrete pile body 1 is 12.5 cm, and the reinforcing steel cage is located inside the UHPC concrete pile body 1, including main bars 4 and stirrups 5. The metal fiber 2 is added at a dosage of 2.1% v / v, wherein, for example... Figure 4As shown, the white dots, with the red circle as an example, represent axially distributed metal fibers 2, indicating that approximately 80% of the metal fibers 2 are uniformly distributed along the axial direction of the UHPC concrete pile body 1.
[0040] Metal fiber 2 is made of stainless steel, with a diameter of 0.1 mm, an aspect ratio of 100, and a tensile strength of 1200 MPa. The unit weight of UHPC concrete in the UHPC concrete pile body 1 is >2600 kg / m³. 3 UHPC concrete does not contain coarse aggregate.
[0041] Example 2 Unlike Example 1, the metal fiber 2 is copper-plated steel fiber with a content of 3% v / v; the diameter of the metal fiber 2 is 0.22 mm, the aspect ratio is 65, and the tensile strength is 1800 MPa. Example 3 Unlike Example 1, the metal fiber 2 has a content of 4% v / v; the diameter of the metal fiber 2 is 0.3 mm, the aspect ratio is 50, and the tensile strength is 2700 MPa. Example 4 Unlike Example 1, approximately 95% of the metal fibers are uniformly distributed along the axial direction of the UHPC concrete pile.
[0042] Example 5 Combination Figure 5 and Figure 6 To illustrate, unlike Embodiment 1, a second concrete pile body 3 is also provided. The second concrete pile body 3 is located inside the UHPC concrete pile body 1. The thickness of the UHPC concrete pile body 1 is 2.0 cm, and the steel reinforcement cage is located inside the second concrete pile body 3.
[0043] Example 6 Combination Figure 7 and Figure 8 To illustrate, unlike Embodiment 1, a second concrete pile body 3 is also provided. The second concrete pile body 3 is located inside the UHPC concrete pile body 1. The thickness of the UHPC concrete pile body 1 is 5.4 cm, and the steel reinforcement cage is located inside the UHPC concrete pile body 1.
[0044] Comparative Example 1 Unlike Example 1, approximately 75% of the metal fiber 2 is uniformly distributed along the axial direction of the UHPC concrete pile body 1.
[0045] Bending strength test The bending resistance of the concrete piles prepared in Examples 1-6 and Comparative Example 1 were tested according to the bending test method specified in GB13476 "Pre-tensioned Prestressed Concrete Pipe Piles". The results are shown in Table 1.
[0046] Table 1
[0047] It should be noted that Examples 1-4 above were prepared according to the following method: Step 1, Concrete preparation: Preparation of the first and second UHPC concrete: First, add aggregate and mix for 2 minutes. Add cementitious materials and mix for 3 minutes. Add admixtures and about 90% water and mix for 3 minutes. Add the remaining water according to the state of the concrete. When the concrete is in the form of a paste, sprinkle in the fiber and continue mixing for 2 minutes. The total time is about 10 minutes. When the fiber is evenly dispersed and the concrete state meets the requirements, it can be poured out of the machine.
[0048] The slump spread of the first UHPC concrete is 600 mm; the slump spread of the second UHPC concrete is 200 mm.
[0049] Step 2, concrete pouring: Place the steel cage (main reinforcement 3 and stirrups 4) inside the mold, and pour the first UHPC concrete and the second UHPC concrete in sequence. After pouring, manually clean the excess concrete from the edges of the pipe mold.
[0050] Step 3, Centrifugation for shaping: Centrifuge sequentially at low speed, low-medium speed, medium speed, medium-high speed, and high speed; low speed is 65 r / min, low-medium speed is 130 r / min, medium speed is 260 r / min, medium-high speed is 320 r / min, and high speed is 390 r / min. The centrifugation time is 5 min for low speed, 2 min for low-medium speed, 2 min for medium speed, 2 min for medium-high speed, and 5 min for high speed.
[0051] Step 4, Steam curing: Gradually increase the temperature from 45℃ to 60℃ for 1.5 hours, with a heating rate of 10℃ / h, and then maintain the temperature at 60℃ for 15 hours to obtain ultra-high performance concrete pipe piles.
[0052] The preparation method of Example 5 also includes: placing a steel cage (main reinforcement 3 and stirrups 4) in the mold, filling it with UHPC concrete, cleaning the excess concrete around the mold by hand after filling, and performing the first centrifugation; after centrifugation, pumping ordinary concrete and then performing the second centrifugation; after the second centrifugation, curing is performed.
[0053] Comparative Example 1 adjusted the centrifugal molding process in step 3, specifically by sequentially centrifuging at low speed, low-medium speed, medium speed, medium-high speed, and high speed; the low speed was 50 r / min, the low-medium speed was 100 r / min, the medium speed was 200 r / min, the medium-high speed was 300 r / min, and the high speed was 400 r / min. The centrifugation time was 2 min for low speed, 1 min for low-medium speed, 1 min for medium speed, 2 min for medium-high speed, and 5 min for high speed. This reduced the proportion of metal fibers 2 evenly distributed along the axial direction of the UHPC concrete pile body 1.
[0054] In this embodiment, the concrete filling method is either open-mold placement or closed-mold pumping. Specifically, open-mold placement includes two placement processes, mold closing, prestressing tensioning, and centrifugal molding; closed-mold pumping includes mold closing, prestressing tensioning of the reinforcing cage, two placement processes, and centrifugal molding.
[0055] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.
Claims
1. A high-performance concrete pile, characterized in that, Includes UHPC concrete pile body (1) and metal fiber (2) located within UHPC concrete pile body (1); The metal fiber (2) is added at a concentration of 2.1% to 4% v / v; At least 80% of the metal fibers (2) are uniformly distributed along the axial direction of the UHPC concrete pile body (1).
2. The ultra-high performance concrete pile according to claim 1, characterized in that, At least 95% of the metal fibers (2) are uniformly distributed along the axial direction of the UHPC concrete pile body (1).
3. The ultra-high performance concrete pile according to claim 1, characterized in that, The diameter of the metal fiber (2) is 0.1~0.3 mm; The aspect ratio of the metal fiber (2) is 50~100; The tensile strength of the metal fiber (2) is >1000MPa; The unit weight of the UHPC concrete in the UHPC concrete pile body (1) is >2600 kg / m³. 3 UHPC concrete does not contain coarse aggregate.
4. The ultra-high performance concrete pile according to claim 1, characterized in that, The metal fiber (2) is copper-plated steel fiber or stainless steel fiber.
5. The ultra-high performance concrete pile according to any one of claims 1 to 4, characterized in that, It also includes a second concrete pile body (3), which is located inside the UHPC concrete pile body (1).
6. The ultra-high performance concrete pile according to claim 5, characterized in that, It also includes a steel reinforcement cage, which is located inside the UHPC concrete pile body (1) or the second concrete pile body (3).
7. The ultra-high performance concrete pile according to claim 6, characterized in that, The thickness of the UHPC concrete pile body (1) is 2.0~7.0cm.
8. The ultra-high performance concrete pile according to claim 7, characterized in that, When the thickness of the UHPC concrete pile body (1) is 3.5~7.0cm, the steel reinforcement cage is located inside the UHPC concrete pile body (1); When the thickness of the UHPC concrete pile body (1) is <3.5cm, the steel reinforcement cage is located inside the second concrete pile body (3).
9. The ultra-high performance concrete pile according to claim 8, characterized in that, The steel reinforcement cage includes main bars (4) and stirrups (5).
10. The ultra-high performance concrete pile according to claim 9, characterized in that, The cross-sectional outer contour of the ultra-high performance concrete pile is circular, square, or polygonal; The cross-sectional inner contour of the ultra-high performance concrete pile is circular.