Preparation method of high-durability concrete pipe pile
By modifying the surface of quartz fibers with a macromolecular material of alternating polybutadiene-piperazine sulfonate linkage structure, the porosity problem between concrete pipe pile components was solved, enabling the preparation of highly durable concrete pipe piles and improving crack resistance and mechanical strength.
Patent Information
- Application Number
- CN202511084794.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-04
- Publication Date
- 2025-11-11
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
The existing concrete pipe piles have large pores among their components, resulting in low compactness, average strength and crack resistance, and poor durability.
A macromolecular material with an alternating polybutadiene-piperazine sulfonate structure modified on the surface of quartz fiber is used as a fiber modifier. It fills the gaps between concrete components through capillary action and forms a mortise and tenon structure-like connection during the drying and curing process, thereby improving the compactness and mechanical strength of the concrete components.
It improves the crack resistance and mechanical strength of concrete pipe piles, enhances the bonding tightness between concrete components, reduces porosity, and significantly improves the durability of concrete pipe piles.
Smart Images
Figure BDA0005532063110000071
Abstract
Description
Technical Field
[0001] This invention relates to the field of concrete technology, and more specifically to a method for preparing high-durability concrete pipe piles. Background Technology
[0002] Concrete pipe piles are precast pile foundation components widely used in construction, bridges, ports, highways, and other engineering projects. They are mainly used for soft soil foundation reinforcement and bearing structural loads. Formed either in a factory or cast on-site, they feature high strength, good durability, and fast construction speed, and have become one of the important technologies in modern foundation engineering.
[0003] As the application scenarios of concrete pipe piles become increasingly diversified, the performance requirements for concrete pipe piles are also gradually increasing. Among them, the strength and crack resistance of concrete pipe piles are important standards for evaluating whether they can withstand the diverse environmental requirements. However, existing concrete pipe piles have large pores between their components and low concrete density, resulting in relatively poor overall performance in terms of strength and crack resistance, leading to poor durability. Based on this, the present invention provides a concrete pipe pile that can solve the problems existing in the prior art. Summary of the Invention
[0004] (a) Technical problems to be solved
[0005] To address the shortcomings of existing technologies, this invention provides a method for preparing highly durable concrete pipe piles.
[0006] (II) Technical Solution
[0007] A method for preparing high-durability concrete pipe piles includes the following steps:
[0008] Step 1: Prepare the concrete mixture
[0009] Cement, sand, crushed stone, fly ash, fiber modifier, water-reducing agent and water are added to a mixer, mechanically mixed evenly, and shaped to form a concrete mixture.
[0010] Step 2: Preparing concrete pipe piles
[0011] Clean the filling mold thoroughly, then spray talcum powder as a release agent to form a molding mold. Then pour the concrete mixture into the molding mold to obtain concrete pipe piles.
[0012] As a further embodiment of the present invention, the weight parts of each raw material in the concrete mixture are as follows: 35-45 parts cement, 100-120 parts sand, 150-200 parts crushed stone, 15-25 parts fly ash, 4-8 parts fiber modifier, 2-5 parts water-reducing agent, and 20-30 parts water.
[0013] As a further aspect of the present invention, the method for preparing the fiber-modified material includes the following steps:
[0014] Step 1: Surface functionalization modification of quartz fibers
[0015] Quartz fibers are dispersed in an aqueous ethanol solution with a volume fraction of 50-70%. Then, a silane coupling agent is added to the resulting dispersion. After the addition is complete, the mixture is stirred until homogeneous. The temperature is raised to 60-70°C and stirred continuously for 6-9 hours. The mixture is then cooled and discharged. The solid material is centrifuged to obtain functionalized modified quartz fibers.
[0016] Step 2: Preparation of fiber-modified material
[0017] Functionalized modified quartz fibers were added to toluene and dispersed evenly. Then, carboxyl-terminated liquid polybutadiene rubber and a phase transfer catalyst were added to the dispersion and stirred evenly. The temperature was raised to 70-80℃ and stirred for 4-6 hours. Then, piperazine sulfonate derivatives were added and the temperature was raised to 90-100℃. Stirring was continued for 16-24 hours. Heating was stopped, the material was cooled and discharged to obtain the modified fiber material.
[0018] As a further embodiment of the present invention, the silane coupling agent is 3-glycidyl etheroxypropyltrimethoxysilane or 3-glycidyl etheroxypropyltriethoxysilane.
[0019] As a further aspect of the present invention, the number-average molecular weight of the carboxyl-terminated liquid polybutadiene rubber is 1000.
[0020] As a further aspect of the present invention, the phase transfer catalyst is any one of tetrabutylammonium bromide, tetramethylammonium bromide, tetrabutylammonium bisulfate, tetramethylammonium chloride, or tetramethylammonium bromide.
[0021] As a further aspect of the present invention, the method for preparing the piperazine sulfonate derivative is as follows:
[0022] Piperazine-N,N'-bis(2-ethanesulfonic acid) and epichlorohydrin are added to acetonitrile and stirred until homogeneous. The temperature is then raised to 70-80℃ and stirred for 3-5 hours. Heating is then stopped, the solvent is evaporated and removed, and the product is collected and purified.
[0023] As a further embodiment of the present invention, the molar ratio of piperazine-N,N'-bis(2-ethanesulfonic acid) to epichlorohydrin is 1:2.
[0024] As a further aspect of the present invention, the mass ratio of the functionalized modified quartz fiber, the carboxyl-terminated liquid polybutadiene rubber, and the piperazine sulfonate derivative is 1:1.5-2.5:0.8-1.2.
[0025] In the above technical solution, firstly, silane coupling agents are used to functionalize the surface of quartz fibers to obtain quartz fibers with epoxy substituents on the surface, i.e., functionalized modified quartz fibers. Then, using carboxyl-terminated liquid polybutadiene rubber as a binder and sulfonate piperazine derivative as a chain extender, under the action of a phase transfer catalyst, the epoxy groups of the functionalized modified quartz fibers are used as active initiation sites to initiate in-situ ring-opening esterification polymerization of carboxyl-terminated liquid polybutadiene rubber and sulfonate piperazine derivative on the surface of quartz fibers. This modifies the surface of quartz fibers with a polybutadiene-sulfonate piperazine alternating linkage structure, thus obtaining a modified fiber material.
[0026] Among them, the piperazine sulfonate derivative is prepared by quaternization reaction of the tertiary amines in the structures of piperazine-N,N'-bis(2-ethanesulfonic acid) and epichlorohydrin with halogen substituents.
[0027] As a further aspect of the present invention, the water-reducing agent is any one of polycarboxylate water-reducing agent or naphthalene-based water-reducing agent.
[0028] (III) Beneficial Technical Effects
[0029] This invention modifies quartz fibers by modifying the surface of quartz fibers with a macromolecular material having an alternating polybutadiene-piperazine sulfonate linkage structure, thus producing a fiber-modified material that can be used as an additive in concrete. Due to the strong fluidity of polybutadiene, the macromolecular material can flow capillarily to all areas of the concrete during mixing, filling the gaps between the concrete components. During the subsequent drying and curing process, the quartz fibers can form a "mortise and tenon"-like connection with the concrete components, effectively utilizing the tensile strength of the quartz fibers to improve the crack resistance of the concrete pipe piles. Furthermore, the quaternary ammonium cations and sulfonic acid groups in the macromolecular structure can interact with calcium ions in the cement, accelerating the hydration rate of tricalcium silicate and inhibiting the loose structure of the concrete in the early stages of hydration. This results in a tighter connection between the concrete components and the quartz fibers, reducing the porosity between the components and effectively improving the mechanical strength of the concrete pipe piles. Detailed Implementation
[0030] To facilitate understanding of the present invention, a more complete description will be provided below. Preferred embodiments of the invention are given below. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.
[0031] Preparation Example
[0032] Preparation of fiber-modified materials:
[0033] Step S1: Surface functionalization modification of quartz fibers
[0034] 1.8g of quartz fiber was dispersed in a 60% (v / v) aqueous ethanol solution. Then, 2.5g of 3-glycidyl etheroxypropyltriethoxysilane was added to the resulting dispersion. After the addition was complete, the mixture was stirred until homogeneous. The temperature was raised to 70°C and stirred continuously for 8 hours. The mixture was then cooled and discharged. The solid material was centrifuged to obtain functionalized modified quartz fiber.
[0035] Step S2: Preparation of piperazine sulfonate derivatives
[0036] Add 0.5g piperazine-N,N'-bis(2-ethanesulfonic acid) and 0.3g epichlorohydrin to acetonitrile, stir and mix evenly, then raise the temperature to 75℃, keep it at this temperature and stir for 4 hours, then stop heating, evaporate and remove the solvent, collect the product, and purify it to obtain the final product.
[0037] Step S3: Preparation of fiber-modified material
[0038] 1.5g of functionalized modified quartz fiber was added to toluene and dispersed evenly. Then, 3.5g of carboxyl-terminated liquid polybutadiene rubber with a number average molecular weight of 1000 and 0.2g of tetrabutylammonium bromide were added to the formed dispersion. After stirring evenly, the temperature was raised to 75℃ and stirred for 6 hours. Then, 1.5g of piperazine sulfonate derivative was added and the temperature was raised to 95℃. Stirring was continued for 18 hours. Heating was stopped, the material was cooled and discharged to obtain the fiber-modified material.
[0039] Example 1
[0040] A method for preparing high-durability concrete pipe piles includes the following steps:
[0041] Step 1: Prepare the concrete mixture
[0042] Weigh out 35 parts cement, 100 parts sand, 150 parts crushed stone, 15 parts fly ash, 4 parts fiber modifier, 2 parts water-reducing agent and 20 parts water according to the following weight proportions, add them to the mixer and mechanically mix them evenly to form a concrete mixture.
[0043] Step 2: Preparing concrete pipe piles
[0044] Clean the filling mold thoroughly, then spray talcum powder as a release agent to form a molding mold. Then pour the concrete mixture into the molding mold to form the concrete pipe pile.
[0045] The cement used is 42.5R type ordinary Portland cement; the sand used is river sand with a particle size ≤5mm; the crushed stone used is fine stone with a particle size ≤10mm; the fly ash used is Grade I fly ash; the preparation method of the fiber modified material is shown in the preparation example; the water-reducing agent used is SPC-100 type polycarboxylate water-reducing agent, and the following are all the same.
[0046] Example 2
[0047] A method for preparing high-durability concrete pipe piles includes the following steps:
[0048] Step 1: Prepare the concrete mixture
[0049] Weigh out 38 parts cement, 110 parts sand, 160 parts crushed stone, 20 parts fly ash, 6.5 parts fiber modifier, 4.5 parts water-reducing agent and 25 parts water according to the weight ratio, add them to the mixer and mechanically mix them evenly to form a concrete mixture.
[0050] Step 2: Preparing concrete pipe piles
[0051] Clean the filling mold thoroughly, then spray talcum powder as a release agent to form a molding mold. Then pour the concrete mixture into the molding mold to form the concrete pipe pile.
[0052] Example 3
[0053] A method for preparing high-durability concrete pipe piles includes the following steps:
[0054] Step 1: Prepare the concrete mixture
[0055] Weigh out 45 parts cement, 120 parts sand, 200 parts crushed stone, 25 parts fly ash, 8 parts fiber modifier, 5 parts water-reducing agent and 30 parts water according to the following weight proportions, add them to the mixer and mechanically mix them evenly to form a concrete mixture.
[0056] Step 2: Preparing concrete pipe piles
[0057] Clean the filling mold thoroughly, then spray talcum powder as a release agent to form a molding mold. Then pour the concrete mixture into the molding mold to form the concrete pipe pile.
[0058] Comparative Example 1
[0059] A method for preparing high-durability concrete pipe piles includes the following steps:
[0060] Step 1: Prepare the concrete mixture
[0061] Weigh out 38 parts cement, 110 parts sand, 160 parts crushed stone, 20 parts fly ash, 6.5 parts quartz fiber, 4.5 parts water-reducing agent and 25 parts water according to the weight ratio, add them to the mixer, and mechanically mix them evenly to form a concrete mixture.
[0062] Step 2: Preparing concrete pipe piles
[0063] Clean the filling mold thoroughly, then spray talcum powder as a release agent to form a molding mold. Then pour the concrete mixture into the molding mold to form the concrete pipe pile.
[0064] Comparative Example 2
[0065] A method for preparing high-durability concrete pipe piles includes the following steps:
[0066] Step 1: Prepare the concrete mixture
[0067] Weigh out 38 parts cement, 110 parts sand, 160 parts crushed stone, 20 parts fly ash, 4.5 parts water-reducing agent and 25 parts water according to the weight ratio, add them to the mixer, and mechanically mix them evenly to form a concrete mixture.
[0068] Step 2: Preparing concrete pipe piles
[0069] Clean the filling mold thoroughly, then spray talcum powder as a release agent to form a molding mold. Then pour the concrete mixture into the molding mold to form the concrete pipe pile.
[0070] Performance testing
[0071] Various performance tests were conducted on the concrete pipe piles in the examples and comparative examples, and the results are shown in the table below:
[0072] Table 1 - Test Results
[0073]
[0074] The compressive strength was tested according to the standards GB / T 13476-2023 and GB / T 50081-2002; the cracking index was tested according to the standard JGJ / T 70-2009.
[0075] Analysis and test results show that concrete pipe piles prepared using fiber-modified materials as additives have advantages such as high strength, good crack resistance, and excellent durability. Replacing the fiber-modified materials with unmodified quartz fibers significantly reduces both strength and crack resistance. This is because the loss of macromolecular substances increases the porosity between the quartz fibers and the other raw materials in the concrete, making it impossible to form a good interlocking structure and thus hindering their efficient performance.
[0076] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of these embodiments are merely to aid in understanding the method and core ideas of the present invention, including the best mode, and to enable any person skilled in the art to practice the present invention, including manufacturing and using any device or system, and implementing any combined method. It should be noted that those skilled in the art can make various improvements and modifications to the present invention without departing from its principles, and these improvements and modifications also fall within the scope of protection of the claims. The scope of protection of this patent is defined by the claims and may include other embodiments that can be conceived by those skilled in the art. If these other embodiments have structural elements similar to those expressed in the claims, or if they include equivalent structural elements that are not substantially different from those expressed in the claims, then these other embodiments should also be included within the scope of the claims.
[0077] Based on the preferred embodiments of the present invention, and through the above description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.
Claims
1. A method for preparing high-durability concrete pipe piles, characterized in that, Includes the following steps: Step 1: Prepare the concrete mixture Cement, sand, crushed stone, fly ash, fiber modifier, water-reducing agent and water are added to a mixer and mechanically mixed evenly to form a concrete mixture. Step 2: Preparing concrete pipe piles Clean the filling mold thoroughly, then spray talcum powder as a release agent to form a molding mold. Then pour the concrete mixture into the molding mold to form the concrete pipe pile.
2. The method for preparing a high-durability concrete pipe pile according to claim 1, characterized in that, The concrete mixture contains the following components by weight: 35-45 parts cement, 100-120 parts sand, 150-200 parts crushed stone, 15-25 parts fly ash, 4-8 parts fiber modifier, 2-5 parts water-reducing agent, and 20-30 parts water.
3. The method for preparing a high-durability concrete pipe pile according to claim 1, characterized in that, The preparation method of the fiber-modified material includes the following steps: Step 1: Surface functionalization modification of quartz fibers Quartz fibers are dispersed in an aqueous ethanol solution with a volume fraction of 50-70%. Then, a silane coupling agent is added to the resulting dispersion. After the addition is complete, the mixture is stirred until homogeneous. The temperature is raised to 60-70°C and stirred continuously for 6-9 hours. The mixture is then cooled and discharged. The solid material is centrifuged to obtain functionalized modified quartz fibers. Step 2: Preparation of fiber-modified material Functionalized modified quartz fibers were added to toluene and dispersed evenly. Then, carboxyl-terminated liquid polybutadiene rubber and a phase transfer catalyst were added to the dispersion and stirred evenly. The temperature was raised to 70-80℃ and stirred for 4-6 hours. Then, piperazine sulfonate derivatives were added and the temperature was raised to 90-100℃. Stirring was continued for 16-24 hours. Heating was stopped, the material was cooled and discharged to obtain the modified fiber material.
4. The method for preparing a high-durability concrete pipe pile according to claim 3, characterized in that, The silane coupling agent is 3-glycidyl etheroxypropyltrimethoxysilane or 3-glycidyl etheroxypropyltriethoxysilane.
5. The method for preparing a high-durability concrete pipe pile according to claim 3, characterized in that, The number-average molecular weight of the carboxyl-terminated liquid polybutadiene rubber is 1000.
6. The method for preparing a high-durability concrete pipe pile according to claim 3, characterized in that, The phase transfer catalyst is any one of tetrabutylammonium bromide, tetramethylammonium bromide, tetrabutylammonium bisulfate, tetramethylammonium chloride, or tetramethylammonium bromide.
7. The method for preparing a high-durability concrete pipe pile according to claim 3, characterized in that, The preparation method of the piperazine sulfonate derivative is as follows: Piperazine-N,N'-bis(2-ethanesulfonic acid) and epichlorohydrin are added to acetonitrile and stirred until homogeneous. The temperature is then raised to 70-80℃ and stirred for 3-5 hours. Heating is then stopped, the solvent is evaporated and removed, and the product is collected and purified.
8. The method for preparing a high-durability concrete pipe pile according to claim 7, characterized in that, The molar ratio of piperazine-N,N'-bis(2-ethanesulfonic acid) to epichlorohydrin is 1:
2.
9. The method for preparing a high-durability concrete pipe pile according to claim 3, characterized in that, The mass ratio of the functionalized modified quartz fiber, carboxyl-terminated liquid polybutadiene rubber, and piperazine sulfonate derivative is 1:1.5-2.5:0.8-1.
2.
10. The method for preparing a high-durability concrete pipe pile according to claim 1, characterized in that, The water-reducing agent is either a polycarboxylate water-reducing agent or a naphthalene-based water-reducing agent.