High-strength cement pole material and method for manufacturing the same

Abstract

The application belongs to the technical field of cement pole material, and particularly relates to a high-strength cement pole material and a preparation method thereof. The high-strength cement pole material comprises the following components in parts by weight: cement 450-500 parts, fly ash 60-80 parts, fine aggregate 500-550 parts, coarse aggregate 800-1000 parts, slag powder 80-120 parts, composite fiber 30-50 parts, redispersible latex powder 5-10 parts, water reducing agent 2-6 parts, and water 100-150 parts. The composite fiber comprises modified basalt fiber and polypropylene reticular fiber. The high-strength cement pole material provided by the application uses polypropylene reticular fiber and specific modified basalt fiber to jointly act, so that the cement pole material has high compressive strength and high flexural strength, and the cement pole prepared from the cement pole material has high bending bearing capacity.

Description

Technical Field

[0001] This invention belongs to the technical field of cement pole materials, specifically relating to a high-strength cement pole material and its preparation method. Background Technology

[0002] Cement poles are critical infrastructure in modern power and communication engineering, serving the core function of supporting power lines and cables. The quality and performance of cement poles directly affect the long-term safe and stable operation of the entire engineering system.

[0003] Currently, ordinary cement poles have the problem of low strength. When subjected to large loads, they are prone to cracking or even tower collapse, which can lead to power outages.

[0004] Chinese patent CN116409970B, published in the prior art, discloses a high-strength, impermeable concrete and cement pole, comprising, by weight: 500-600 parts of gel material, 1400-1600 parts of aggregate, 100-120 parts of epoxy resin emulsion, 20-30 parts of hydroxyl acrylate emulsion, 5-10 parts of aliphatic organic amine, 50-80 parts of epoxy-based basalt fiber, 5-10 parts of calcium sulfoaluminate, 1020 parts of ethanolamine-modified metakaolin, 1-5 parts of polycarboxylate superplasticizer, and 100-120 parts of mixing water. The hydroxyl group in this technical solution... The hydroxyl groups in acrylic emulsions can promote the curing of amines and form a cross-linked three-dimensional network after curing with epoxy resin emulsions. This spatial network structure connects cement hydration products and aggregates together, improving the structural morphology of concrete, enhancing its crack resistance and density, and providing sufficient mechanical support. However, the compressive strength can only reach about 78 MPa, and cement poles are prone to developing microcracks on their surface due to long-term asymmetrical tension in the vertical and horizontal directions. Therefore, the flexural strength of concrete is also crucial, but the above-mentioned technical solutions do not address this property.

[0005] Chinese Patent Publication No. CN116119994A discloses a high-strength ultrafine admixture concrete pole and its preparation method. The concrete pole includes a steel reinforcement skeleton and a concrete layer covering the steel reinforcement skeleton. The concrete layer includes the following raw materials in parts by weight: 80-140 parts water; 400-460 parts cement; 1000-1200 parts coarse aggregate; 600-650 parts fine aggregate; 40-160 parts slag powder; 40-100 parts fly ash; 1-10 parts admixture; 10-25 parts by weight of reinforcing fiber; and 2-6 parts of regulator. The reinforcing fibers in this technical solution have excellent tensile strength and elongation. Adding reinforcing fibers can effectively improve the tensile, flexural, and impact resistance of concrete, and enhance the impact toughness of concrete poles. The compressive strength of this technical solution can reach about 147 MPa, and the flexural strength can reach about 17 MPa. However, although the glass fiber used in this technical solution can improve the mechanical properties of concrete poles, the tensile strength and toughness of glass fiber will gradually decrease when exposed to the atmospheric environment for a long time, affecting the service life of cement poles. Summary of the Invention

[0006] This invention provides a high-strength cement pole material and its preparation method. The high-strength cement pole material provided by this invention utilizes the combined action of polypropylene mesh fibers and specific modified basalt fibers (prepared by modifying basalt fibers with terminal epoxy-based liquid nitrile rubber and then depositing pyrophyllite powder). This results in the cement pole material having both high compressive strength and high flexural strength, and the cement pole prepared using this cement pole material has high bending load capacity.

[0007] The technical solution for achieving the objective of this invention is as follows:

[0008] In a first aspect, the present invention provides a high-strength cement pole material, comprising the following components in parts by weight: 450-500 parts cement, 60-80 parts fly ash, 500-550 parts fine aggregate, 800-1000 parts coarse aggregate, 80-120 parts slag powder, 30-50 parts composite fiber, 5-10 parts redispersible latex powder, 2-6 parts water-reducing agent, and 100-150 parts water;

[0009] The composite fiber includes modified basalt fiber and polypropylene mesh fiber;

[0010] The modified basalt fiber is prepared by modifying basalt fiber with terminal epoxy-based liquid nitrile rubber and then depositing pyrophyllite powder.

[0011] Preferably, the cement is silicate cement.

[0012] Preferably, the fly ash is secondary fly ash.

[0013] Preferably, the fine aggregate is sand and gravel with a fineness modulus of 2.6-2.8.

[0014] Preferably, the coarse aggregate is basalt crushed stone with a particle size of 5-15 mm.

[0015] Preferably, the mass ratio of the modified basalt fiber to the polypropylene mesh fiber is 7-8:2-3.

[0016] Preferably, the modified basalt fiber is prepared by dispersing aminated basalt fiber in DMF (N,N-dimethylformamide), adding terminal epoxy-terminated liquid nitrile rubber and triethylamine, heating to react, filtering, washing and drying after the reaction to obtain terminal epoxy-terminated liquid nitrile rubber modified basalt fiber.

[0017] Pyrophyllite powder, polyvinylpyrrolidone, and water were mixed and stirred evenly. Then, terminal epoxy-terminated liquid nitrile rubber modified basalt fiber was added, stirred, and deposited. After deposition, the mixture was filtered, washed, and dried to obtain modified basalt fiber.

[0018] Preferably, the mass ratio of the aminated basalt fiber, DMF, terminal epoxy liquid nitrile rubber, and triethylamine is 1:20-30:3-5:0.05-0.15.

[0019] Preferably, the epoxy equivalent of the terminal epoxy group liquid nitrile rubber is 2000-3000 g / eg.

[0020] Preferably, the mass ratio of pyrophyllite powder, polyvinylpyrrolidone, water, and terminal epoxy-terminated liquid nitrile rubber modified basalt fiber is 5-15:1-2:83-94:1-2.

[0021] Preferably, the pyrophyllite powder has a mesh size of 300-600 mesh.

[0022] Preferably, the modified basalt fiber is prepared by dispersing aminated basalt fiber in DMF, adding terminal epoxy-terminated liquid nitrile rubber and triethylamine, heating to 120-130℃ for 2-3 hours, filtering, washing and drying after the reaction to obtain terminal epoxy-terminated liquid nitrile rubber modified basalt fiber.

[0023] Pyrophyllite powder, polyvinylpyrrolidone, and water were mixed and stirred evenly. Then, terminal epoxy-terminated liquid nitrile rubber modified basalt fiber was added and deposited at 40-60℃ and 100-300 rpm for 3-4 hours. After deposition, the mixture was filtered, washed, and dried to obtain modified basalt fiber.

[0024] Preferably, the preparation method of the aminated basalt fiber is as follows: basalt fiber is ultrasonically dispersed in an ethanol aqueous solution, γ-aminopropyltriethoxysilane is added, the mixture is stirred and reacted, and after the reaction is completed, the mixture is filtered, washed, and dried to obtain the aminated basalt fiber.

[0025] Preferably, the ethanol-water solution is prepared by mixing ethanol and water in a volume ratio of 80-90:10-20.

[0026] Preferably, the mass ratio of the basalt fiber, the aqueous ethanol solution, and γ-aminopropyltriethoxysilane is 1:10-20:0.2-0.5.

[0027] Preferably, the basalt fiber has a diameter of 6-20µm and a length of 6-15mm.

[0028] Preferably, the preparation method of the aminated basalt fiber is as follows: basalt fiber is ultrasonically dispersed in an ethanol aqueous solution, γ-aminopropyltriethoxysilane is added, and the mixture is stirred at 60-70°C for 4-7 hours. After the reaction is completed, the mixture is filtered, washed, and dried to obtain the aminated basalt fiber.

[0029] Preferably, the redispersible latex powder is obtained by spray drying of vinyl acetate-ethylene copolymer emulsion.

[0030] Preferably, the water-reducing agent is a polycarboxylate-based water-reducing agent.

[0031] Secondly, the present invention provides a method for preparing high-strength cement pole material, comprising the following steps: after mixing fine aggregate, coarse aggregate and composite fiber evenly, cement, fly ash and slag powder are added and mixed evenly; finally, redispersible latex powder, water-reducing agent and water are added and mixed evenly to obtain high-strength cement pole material.

[0032] Compared with the prior art, the advantages and beneficial effects of the present invention are as follows:

[0033] The modified basalt fibers prepared in this invention are first modified with terminal epoxy-based liquid nitrile rubber. The epoxy-based liquid nitrile rubber and the aminated basalt fibers undergo chemical bonding to form a flexible soft rubber layer. This flexible soft rubber not only improves the dispersibility of basalt fibers in cement pole materials, preventing fiber agglomeration and allowing for more uniform load bearing, but more importantly, it forms a stress buffer layer between the basalt fibers and the cement pole material matrix, thereby simultaneously improving the compressive and flexural strength of the cement pole material. Subsequently, pyrophyllite powder is deposited. The plate-like and radially arranged pyrophyllite powder is deposited on the flexible rubber layer, further increasing the surface roughness of the basalt fibers, improving the mechanical interlocking between the basalt fibers and the cement pole material matrix, and reducing the probability of interfacial breakdown and debonding of the basalt fibers. During pull-out damage, the basalt fibers can absorb more energy, effectively bearing and dispersing stress, thus significantly improving the compressive and flexural strength of the cement pole material.

[0034] In particular, this invention also incorporates polypropylene mesh fibers. The modified basalt fibers and polypropylene mesh fibers can form a three-dimensional reinforcing network that is intertwined and randomly supported. The combined effect of the two results in a high-strength cement pole material with a compressive strength greater than 140 MPa, a flexural strength greater than 22 MPa, and a flexural-compression ratio greater than 0.16. The cement poles prepared using the high-strength cement pole material of this invention have a bending bearing capacity greater than 230 KN·m. Attached Figure Description

[0035] Figure 1 This is a photograph of a cement pole made using the high-strength cement pole material of Example 3. Detailed Implementation

[0036] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0037] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0038] Unless otherwise specified, the raw materials, reagents or apparatus used in the following examples and comparative examples are available from conventional commercial sources or can be obtained by existing known methods.

[0039] The basic raw materials used in this invention are as follows:

[0040] (1) The cement is silicate cement with a strength grade of PO 42.5;

[0041] (2) The fly ash is grade II fly ash;

[0042] (3) The slag powder is S95 grade blast furnace slag micro powder;

[0043] (4) The fine aggregate is sand and gravel with a fineness modulus of 2.6;

[0044] (5) The coarse aggregate is basalt crushed stone with a particle size of 5-15mm;

[0045] (6) The diameter of the basalt fiber is 13µm and the length is 6mm;

[0046] (7) The mesh size of the pyrophyllite powder is 600 mesh;

[0047] (8) The mesh size of metakaolin is 600 mesh;

[0048] (9) The water-reducing agent is a polycarboxylate water-reducing agent, Sichuan Yingbang Chemical Co., Ltd., YB-501-40;

[0049] (10) Polypropylene mesh fiber, Changzhou Tianyi Engineering Fiber Co., Ltd.;

[0050] (11) The redispersible latex powder is made by spray drying of vinyl acetate-ethylene copolymer emulsion, Shandong Xindadi Industrial Group Co., Ltd., XDD-502 adhesive powder;

[0051] (12) High-strength, high-modulus polyethylene fiber, Changzhou Tianyi Engineering Fiber Co., Ltd.;

[0052] (13) Polypropylene monofilament fiber, Changzhou Tianyi Engineering Fiber Co., Ltd.

[0053] The preparation method of aminated basalt fiber is as follows: basalt fiber, ethanol aqueous solution and γ-aminopropyltriethoxysilane are prepared in a mass ratio of 1:15:0.3. The basalt fiber is ultrasonically dispersed in ethanol aqueous solution (ethanol and water in a volume ratio of 90:10). γ-aminopropyltriethoxysilane is added and the mixture is stirred at 60°C for 6 hours. After the reaction is completed, the mixture is filtered, washed and dried to obtain aminated basalt fiber.

[0054] Modified basalt fiber 1

[0055] The aminated basalt fiber, DMF, terminal epoxy liquid nitrile rubber and triethylamine were prepared in a mass ratio of 1:25:4:0.1. The aminated basalt fiber was dispersed in DMF, and the terminal epoxy liquid nitrile rubber and triethylamine were added. The mixture was heated to 120°C and reacted for 3 hours. After the reaction was completed, the mixture was filtered, washed and dried to obtain terminal epoxy liquid nitrile rubber modified basalt fiber.

[0056] The basalt fiber modified with pyrophyllite powder, polyvinylpyrrolidone, water, and terminal epoxy-terminated liquid nitrile rubber was prepared in a mass ratio of 10:1.5:87:1.5. The pyrophyllite powder, polyvinylpyrrolidone, and water were mixed and stirred evenly. Then, the terminal epoxy-terminated liquid nitrile rubber modified basalt fiber was added. The mixture was stirred at 200 rpm at 50°C for 3 hours for deposition. After deposition, the mixture was filtered, washed, and dried to obtain modified basalt fiber 1.

[0057] The epoxy equivalent of the terminal epoxy group liquid nitrile rubber is 2300-2800 g / eg, model: HYPRO®1300X68 ETBN.

[0058] Modified basalt fiber 2

[0059] The aminated basalt fiber, DMF, terminal epoxy-terminated liquid nitrile rubber, and triethylamine were prepared according to a mass ratio of 1:25:4:0.1. The aminated basalt fiber was dispersed in DMF, and the terminal epoxy-terminated liquid nitrile rubber and triethylamine were added. The mixture was heated to 120°C and reacted for 3 hours. After the reaction was completed, the mixture was filtered, washed, and dried to obtain modified basalt fiber 2.

[0060] Modified basalt fiber 3

[0061] The pyrophyllite powder, polyvinylpyrrolidone, water, and aminated basalt fiber were prepared in a mass ratio of 10:1.5:87:1.5. The pyrophyllite powder, polyvinylpyrrolidone, and water were mixed and stirred evenly. Then, the aminated basalt fiber was added, and the mixture was deposited at 50°C and 200 rpm for 3 hours. After deposition, the mixture was filtered, washed, and dried to obtain modified basalt fiber 3.

[0062] Modified basalt fiber 4

[0063] The aminated basalt fiber, DMF, terminal epoxy liquid nitrile rubber and triethylamine were prepared in a mass ratio of 1:25:4:0.1. The aminated basalt fiber was dispersed in DMF, and the terminal epoxy liquid nitrile rubber and triethylamine were added. The mixture was heated to 120°C and reacted for 3 hours. After the reaction was completed, the mixture was filtered, washed and dried to obtain terminal epoxy liquid nitrile rubber modified basalt fiber.

[0064] The modified basalt fiber was prepared by mixing metakaolin, polyvinylpyrrolidone, water, and terminal epoxy-terminated liquid nitrile rubber in a mass ratio of 10:1.5:87:1.5. The metakaolin, polyvinylpyrrolidone, and water were mixed and stirred evenly. Then, the terminal epoxy-terminated liquid nitrile rubber modified basalt fiber was added. The mixture was stirred at 200 rpm at 50°C for 3 hours for deposition. After deposition, the mixture was filtered, washed, and dried to obtain modified basalt fiber 4.

[0065] The epoxy equivalent of the terminal epoxy group liquid nitrile rubber is 2300-2800 g / eg, model: HYPRO®1300X68 ETBN.

[0066] The material formulations for high-strength cement poles in Examples 1-3 are shown in Table 1 below (unit: kg).

[0067] Table 1:

[0068]

[0069] The preparation method of high-strength cement pole material in Examples 1-3 includes the following steps: fine aggregate, coarse aggregate, modified basalt fiber 1, and polypropylene mesh fiber are mixed evenly, and then cement, fly ash, and slag powder are added and mixed evenly; finally, redispersible latex powder, water-reducing agent, and water are added and mixed evenly to obtain high-strength cement pole material.

[0070] Comparative Example 1

[0071] The difference from Example 3 is that modified basalt fiber 1 is replaced with modified basalt fiber 2 of the same mass, while the rest are the same as in Example 3.

[0072] Comparative Example 2

[0073] The difference from Example 3 is that the modified basalt fiber 1 is replaced with the same mass of modified basalt fiber 3, while the rest are the same as in Example 3.

[0074] Comparative Example 3

[0075] The difference from Example 3 is that the modified basalt fiber 1 is replaced with the same mass of modified basalt fiber 4, while the rest are the same as in Example 3.

[0076] Comparative Example 4

[0077] The difference from Example 3 is that the modified basalt fiber 1 is replaced with basalt fiber of the same mass, while the rest is the same as in Example 3.

[0078] Comparative Example 5

[0079] The difference from Example 3 is that no polypropylene mesh fiber is added, while all other aspects are the same as in Example 31.

[0080] Comparative Example 6

[0081] The difference from Example 3 is that the polypropylene mesh fibers are replaced with high-strength, high-modulus polyethylene fibers of equal mass, while all other aspects remain the same as in Example 3.

[0082] Comparative Example 7

[0083] The difference from Example 3 is that the polypropylene mesh fibers are replaced with polypropylene monofilament fibers of equal mass, while the rest are the same as in Example 3.

[0084] Performance testing: The compressive strength and flexural strength of the high-strength cement pole materials of Examples 1-3 and Comparative Examples 1-7 were tested after 28 days of curing in accordance with GB / T 50081-2019. The results are shown in Table 2 below.

[0085] Table 2:

[0086]

[0087] As can be seen from Table 2, the high-strength cement pole material prepared using the specific composite fiber of this invention not only has high compressive strength and flexural strength, but also a high flexural-compression ratio (the ratio of concrete flexural strength to compressive strength).

[0088] The modified basalt fiber used in Comparative Example 1 was not loaded with pyrophyllite powder. The flexural-compression ratio of the high-strength cement pole material prepared was reduced by a small margin, but the compressive strength and flexural strength were significantly reduced.

[0089] The modified basalt fiber used in Comparative Example 2 was not coated with terminal epoxy-based liquid nitrile rubber; the flexural strength and flexural-compression ratio of the prepared high-strength cement pole material were significantly reduced.

[0090] In Comparative Example 3, the modified basalt fiber used replaced pyrophyllite powder with metakaolin; the flexural strength and flexural-compression ratio of the prepared high-strength cement pole material both decreased significantly.

[0091] The basalt fiber used in Comparative Example 4 was not modified; the compressive strength, flexural strength, and flexural-compression ratio of the prepared high-strength cement pole material all decreased significantly.

[0092] In Comparative Example 5, no polypropylene mesh fiber was added; the flexural strength and flexural-compression ratio of the prepared high-strength cement pole material were significantly reduced.

[0093] Comparative Example 6 replaced the polypropylene mesh fibers with the same mass of high-strength, high-modulus polyethylene fibers; although the compressive strength of the prepared high-strength cement pole material was improved, the flexural strength and flexural-compression ratio were significantly reduced.

[0094] In Comparative Example 7, when the polypropylene mesh fibers were replaced with the same mass of polypropylene monofilament fibers, the flexural strength and flexural-compression ratio of the prepared high-strength cement pole material both decreased significantly.

[0095] Application Example: Reinforcing bars are cut, welded, and tied into a reinforcing cage (6 longitudinal reinforcing bars with a diameter of 9mm). The prefabricated reinforcing cage is placed inside a steel membrane, and high-strength cement pole materials from Examples 1-3 and Comparative Examples 1-7 are added respectively. Cement poles are then prepared using a centrifugal molding process, with a tip diameter of 190mm, a pole length of 12m, and a wall thickness of 50mm. The cement poles are cured at 25±5℃ for 14 days. The prepared cement poles are tested for bearing capacity bending moment according to GB / T4623-2014. The results are shown in Table 3 below. A physical image of the cement pole prepared using the high-strength cement pole material of Example 3 is shown below. Figure 1 As shown.

[0096] Table 3:

[0097]

[0098] As can be seen from Table 3, cement poles made with high-strength cement pole materials prepared using the specific composite fibers of this invention have high bending load capacity; while cement poles made with high-strength cement pole materials of Comparative Examples 1-7 have significantly reduced bending load capacity.

[0099] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A high-strength cement pole material, characterized in that, The product comprises the following components in parts by weight: 450-500 parts cement, 60-80 parts fly ash, 500-550 parts fine aggregate, 800-1000 parts coarse aggregate, 80-120 parts slag powder, 30-50 parts composite fiber, 5-10 parts redispersible latex powder, 2-6 parts water-reducing agent, and 100-150 parts water. The composite fiber includes modified basalt fiber and polypropylene mesh fiber; The modified basalt fiber is prepared by dispersing aminated basalt fiber in DMF, adding terminal epoxy-terminated liquid nitrile rubber and triethylamine, heating to react, filtering, washing and drying after the reaction to obtain terminal epoxy-terminated liquid nitrile rubber modified basalt fiber; and then redepositing pyrophyllite powder into the terminal epoxy-terminated liquid nitrile rubber modified basalt fiber.

2. The high-strength cement pole material according to claim 1, characterized in that, The mass ratio of the modified basalt fiber to the polypropylene mesh fiber is 7-8:2-3.

3. The high-strength cement pole material according to claim 1 or 2, characterized in that, The preparation method of the modified basalt fiber is as follows: aminated basalt fiber is dispersed in DMF, epoxy-terminated liquid nitrile rubber and triethylamine are added, the mixture is heated to react, and after the reaction is completed, it is filtered, washed and dried to obtain epoxy-terminated liquid nitrile rubber modified basalt fiber. Pyrophyllite powder, polyvinylpyrrolidone, and water were mixed and stirred evenly. Then, terminal epoxy-terminated liquid nitrile rubber modified basalt fiber was added, stirred, and deposited. After deposition, the mixture was filtered, washed, and dried to obtain modified basalt fiber.

4. The high-strength cement pole material according to claim 3, characterized in that, The mass ratio of the aminated basalt fiber, DMF, terminal epoxy liquid nitrile rubber, and triethylamine is 1:20-30:3-5:0.05-0.

15.

5. The high-strength cement pole material according to claim 4, characterized in that, The epoxy equivalent of the terminal epoxy group liquid nitrile rubber is 2000-3000 g / eg.

6. The high-strength cement pole material according to claim 5, characterized in that, The mass ratio of pyrophyllite powder, polyvinylpyrrolidone, water, and terminal epoxy-based liquid nitrile rubber modified basalt fiber is 5-15:1-2:83-94:1-2.

7. The high-strength cement pole material according to claim 6, characterized in that, The basalt fibers have a diameter of 6-20µm and a length of 6-15mm.

8. The high-strength cement pole material according to any one of claims 4-7, characterized in that, The redispersible latex powder is produced by spray drying of vinyl acetate-ethylene copolymer emulsion.

9. The high-strength cement pole material according to any one of claims 4-7, characterized in that, The water-reducing agent is a polycarboxylate-based water-reducing agent.

10. A method for preparing the high-strength cement pole material according to any one of claims 1-9, characterized in that, The process includes the following steps: after mixing fine aggregate, coarse aggregate and composite fiber evenly, cement, fly ash and slag powder are added and mixed evenly; finally, redispersible latex powder, water-reducing agent and water are added and mixed evenly to obtain high-strength cement pole material.

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