Separation fence stand column of multi-layer composite structure and preparation method of separation fence stand column

Abstract

The invention discloses a multi-layer composite structure separation fence stand column and a preparation method thereof, and belongs to the technical field of building materials. The multi-layer composite structure separation fence stand column is of a composite structure, the outer layer is a fiber toughening ultrahigh strength cement-based composite material protection layer, the middle layer is a basalt fiber net framework layer, the interior is a geopolymer concrete filling layer, and the three layers are tightly wrapped to form a stable and reliable stress system. The geopolymer concrete filling layer comprises the following components in parts by weight: 40-55 parts of municipal solid waste incineration ash, 45-60 parts of II type phosphogypsum, 10-15 parts of an alkaline activator solution, 100-120 parts of aggregate, 10-15 parts of water, 3-4 parts of a water reducing agent, 5-6 parts of a shrinkage reducing agent and 3-4 parts of nano silicon dioxide. Compared with an existing separation fence stand column commonly used on a road, the separation fence stand column of the multi-layer composite structure is ultrahigh in mechanical property and excellent in durability, the service life of the separation fence stand column can be effectively prolonged, and material consumption and maintenance frequency are remarkably reduced in the whole life cycle. The factory prefabricated stand column is subjected to form removal and maintenance, and the construction and installation efficiency can be remarkably improved.

Description

Technical Field

[0001] This invention belongs to the field of building materials technology, specifically relating to a multi-layer composite structure isolation fence column and its preparation method. Background Technology

[0002] As the core supporting component of the highway guardrail system, highway guardrail posts play an irreplaceable and fundamental role in highway traffic safety, order maintenance, and facility stability, and are an important part of ensuring the effective functioning of highways. Current Chinese standards generally use metal materials to manufacture these components, such as low-carbon steel pipes, steel profiles, and aluminum alloy posts. Although the technology is mature, the following defects have been exposed in long-term service environments: in humid and rainy environments, metal posts are often susceptible to corrosion; they are prone to brittle fracture upon impact, making it difficult to absorb impact force through plastic deformation, resulting in limited impact toughness. Highway guardrail posts are usually exposed to air, making them prone to electrochemical corrosion, and severe reductions in structural strength necessitate complete replacement. Secondly, some existing structures use precast ordinary concrete posts with built-in steel reinforcement frames. Due to the lower design strength of ordinary concrete, large cross-sectional dimensions are required to ensure its load-bearing capacity, resulting in heavy components. Furthermore, the components need to be cast in a centralized prefabrication plant and transported to the site, making transportation and installation difficult. In addition, existing fence posts have also been innovated by using composite materials such as glass fiber reinforced plastics. However, under long-term alternating loads, the fatigue life of such components is relatively short. In extreme low-temperature environments, the toughness of such components decreases significantly, and the impact resistance is reduced by about 20%-30%.

[0003] Multi-layer composite structure guardrail posts, with their ultra-high mechanical properties, extremely low permeability, and excellent freeze-thaw and corrosion resistance, provide an effective solution for extending the lifespan of traffic sign components. They not only significantly reduce component weight and improve construction and installation efficiency, but also greatly extend service life, significantly reducing material consumption and maintenance frequency throughout their entire lifespan, resulting in outstanding long-term economic benefits. Therefore, multi-layer composite structure guardrail posts are of great significance for improving the quality of highway construction and are an ideal material choice for such components. The thickness of these components is significantly reduced compared to ordinary concrete, resulting in a substantial reduction in structural weight. This characteristic achieves a leap in performance while effectively reducing transportation costs. Furthermore, using basalt fiber mesh as the load-bearing skeleton not only significantly improves the load-bearing capacity of the posts but also significantly enhances their impact resistance; simultaneously, the outer fiber-reinforced ultra-high-strength cement protective layer forms a tight protective barrier, effectively isolating external erosion and ensuring the long-term stability of the internal sleeve.

[0004] Patent (CN220266372U) discloses a composite fence post. The post has been improved and optimized in parts such as the post cap and the fence connecting groove. However, the metal material product has the defect of being easily corroded, and there is still room for improvement in its durability performance.

[0005] Patent (CN212925885U) discloses a composite isolation fence concrete column and foundation, but compared with UHPC, ordinary concrete has shortcomings such as lower strength, poorer durability, and greater self-weight.

[0006] Patent (CN221000773U) discloses a composite isolation fence post. The post body is a glass fiber reinforced concrete post that is wrapped with a UHPC layer and a fiberglass layer from the outside to the inside. However, its impact resistance and toughness need to be improved in extreme environments.

[0007] Based on the above-mentioned problems, this invention proposes a multi-layer composite structure isolation fence post and its preparation method. The post, from the outside in, consists of: a fiber-reinforced ultra-high strength cement protective layer, a basalt fiber mesh skeleton, and a geopolymer concrete filling layer, exhibiting excellent mechanical properties, durability, and long-term economic benefits. Summary of the Invention

[0008] To address or partially address the problems existing in related technologies, this invention proposes a multi-layer composite structure isolation fence post and its manufacturing method. This multi-layer composite structure isolation fence post adopts a three-layer composite structure design, possessing multiple advantages: the component thickness is significantly reduced compared to ordinary concrete products, greatly reducing self-weight and improving construction and installation efficiency, while achieving a qualitative leap in mechanical and durability performance; it consumes less material and requires less maintenance throughout its entire life cycle, significantly extending its service life and resulting in particularly outstanding long-term economic benefits.

[0009] This invention provides a multi-layer composite structure isolation fence post, comprising: an outer layer of fiber-reinforced ultra-high strength cement-based composite material protective layer, a middle layer of basalt fiber mesh skeleton layer, and an inner layer of geopolymer concrete filling layer; the geopolymer concrete filling layer comprises the following components by weight: 40-55 parts of municipal solid waste incineration ash, 45-60 parts of type II phosphogypsum, 10-15 parts of alkaline activator solution, 100-120 parts of aggregate, 10-15 parts of water, 3-4 parts of water-reducing agent, 5-6 parts of shrinkage-reducing agent, and 3-4 parts of nano-silica.

[0010] Preferably, the municipal solid waste incineration ash is the incineration ash from municipal solid waste that has undergone two incinerations with a constant weight difference of less than 0.5 mg. Preferably, the type II phosphogypsum has a calcium sulfate content of greater than 80%.

[0011] Preferably, the alkaline activator solution is a mixed alkaline activator of sodium hydroxide and water glass, wherein the equivalent concentration of sodium hydroxide is 5~8 mol / L, the modulus of water glass is 1.0~1.5, and water is used as a solvent accounting for 30-50% of the total mass of the alkaline activator solution.

[0012] Preferably, the water-reducing agent is a polycarboxylate-based high-performance water-reducing agent with a water reduction rate of not less than 30%.

[0013] Preferably, the shrinkage-reducing agent is an organic powdered shrinkage-reducing agent, such as a polyether-based shrinkage-reducing agent like diethylene glycol monobutyl ether.

[0014] Preferably, the protective layer of the fiber-reinforced ultra-high strength cement-based composite material comprises the following components in parts by weight: 40-50 parts silicate cement, 10-20 parts silica fume, 10-15 parts metakaolin, 15-25 parts granulated blast furnace slag, 85-90 parts quartz sand, 10-15 parts recycled waste fine sand aggregate, 15-18 parts carbon fiber, 2-3 parts polyvinyl alcohol (PVA) fiber, 18-20 parts water, 3-3.5 parts water-reducing agent, and 8-10 parts nano-SiO2.

[0015] Preferably, the silicate cement is one of PO 42.5, PO 52.5, and PI 42.5 cement.

[0016] Preferably, the silica fume is silica fume with a silica content of not less than 92%.

[0017] Preferably, the metakaolin is highly reactive metakaolin with an impurity content of less than 5%.

[0018] Preferably, the granulated blast furnace slag is granulated blast furnace slag with an activity index of not less than S95.

[0019] Preferably, the nano-SiO2 is SiO2 nanoparticles with a purity of not less than 99.8%.

[0020] Preferably, the recycled waste fine sand aggregate is fine sand aggregate with a particle size of 26-40 mesh.

[0021] Preferably, the water-reducing agent is a polycarboxylate-based high-performance water-reducing agent with a water reduction rate of not less than 30%.

[0022] Preferably, the carbon fiber is a high-strength carbon fiber with an average length of 13 mm.

[0023] In the protective layer components of the fiber-toughened ultra-high strength cement-based composite material, the mass ratio of water to cementitious materials is not greater than 0.2, and the cementitious materials include silicate cement, silica fume, metakaolin, and granulated blast furnace slag.

[0024] Preferably, the quartz sand includes three gradations: 26-40, 40-70, and 70-120 mesh, with the three particle sizes accounting for 35-40%, 22%, and 28% of the total mass of the quartz sand and recycled fine sand aggregate, respectively.

[0025] Preferably, the particle size of the recycled fine sand aggregate is 26-40 mesh, and the mass percentage of the recycled fine sand aggregate in the total mass of quartz sand and recycled fine sand aggregate is 10-15%.

[0026] Preferably, the basalt fiber mesh in the basalt fiber mesh skeleton layer is a square mesh coated with a silane coupling agent.

[0027] Preferably, the silane coupling agent can be KH-550 or KH-560.

[0028] Preferably, the cross-section of the multi-layer composite structure isolation fence column is square; the thickness of the fiber-toughened ultra-high strength cement-based composite material protective layer is 20mm; the thickness of the basalt fiber mesh skeleton layer is 10mm; and the bottom edge length of the geopolymer concrete filling layer is 40mm.

[0029] This invention also claims protection for a method for preparing the multi-layer composite structure isolation fence post, the steps of which include the following: Step S1: Thoroughly clean the mold and evenly apply release oil to the surface of the mold; Step S2: Place the basalt fiber mesh in the inner skeleton layer of the mold and fix it in place; Step S3: Prepare the raw materials of the fiber-toughened ultra-high strength cement-based composite material protective layer according to the corresponding weight parts, pour nano-SiO2 into water for ultrasonic dispersion, and then add water-reducing agent for uniform dispersion to obtain a mixed solution. Step S4: After mixing silicate cement, silica fume, metakaolin, granulated blast furnace slag, quartz sand and waste recycled fine sand aggregate evenly, add the mixed solution, carbon fiber and polyvinyl alcohol fiber and continue mixing to obtain ultra-high performance mortar mixture. Step S5: Pour the ultra-high performance mortar material obtained in S4 between the mold and the skeleton, and compact it by vibration to form a fiber-toughened ultra-high strength cement-based composite material protective layer and a basalt fiber mesh skeleton layer. Step S6: Prepare the raw materials for the geopolymer concrete filling layer according to the corresponding weight proportions, and premix the alkali activator solution and water to obtain the mixture; Step S7: Add municipal solid waste incineration ash, type II phosphogypsum, aggregate, shrinkage reducer and nano silica to the mixture after stirring evenly, and then add the mixture liquid. After stirring evenly, freshly mixed polymer concrete is obtained. Step S8: The obtained freshly mixed polymer concrete is poured into the skeleton layer and vibrated to form a specimen with a three-layer structure of protective layer-skeleton layer-filling layer. Step S9: Cover the surface of the specimen in contact with air in S8 with a thin film, place it at room temperature for 20-24 hours, and then perform standard curing to obtain a multi-layer composite structure isolation fence column.

[0030] The mold in this invention can be adjusted in shape and specifications according to actual needs to obtain the required multi-layer composite structure isolation fence column.

[0031] The technical solution of the present invention has the following beneficial effects: (1) The weight of the multi-layer composite structure isolation fence column product provided by the present invention is reduced by about 40% compared with ordinary concrete column products, which significantly improves the efficiency of transportation and installation.

[0032] (2) The multi-layer composite structure guardrail post provided by this invention exhibits significantly higher toughness and durability than existing highway guardrail posts, ordinary concrete posts, and metal post products. Tests have shown that the compressive strength and flexural strength of the material are approximately 3-4 times that of ordinary concrete, and its resistance to chloride ion penetration is < This indicates that multi-layer composite structure fence posts can significantly improve durability while ensuring mechanical performance, thereby significantly reducing maintenance frequency and costs.

[0033] (3) This product effectively reduces carbon emissions by using silica fume, metakaolin and slag powder to partially replace cement; at the same time, it further highlights the green and environmentally friendly concept by using waste fine sand aggregate to replace part of the quartz sand while ensuring that the mechanical properties are not affected. Attached Figure Description

[0034] Figure 1 This is a front cross-sectional view of the multi-layer composite structure isolation fence column prepared in Example 1.

[0035] Figure 2 This is a left view of the multi-layer composite structure isolation fence column prepared in Example 1.

[0036] Figure 3 This is a top view of the multi-layer composite structure isolation fence column prepared in Example 1. Detailed Implementation

[0037] Example 1 like Figure 1-3 As shown, a multi-layer composite structure isolation fence post includes: an outer layer of fiber-reinforced ultra-high strength cement-based composite material protective layer, a middle layer of basalt fiber mesh skeleton layer, and an inner layer of geopolymer concrete filling layer.

[0038] The geopolymer concrete filler layer comprises the following components by weight: 50 parts municipal solid waste incineration ash, 50 parts type II phosphogypsum, 12 parts alkaline activator solution, 110 parts aggregate, 13 parts water, 3 parts water-reducing agent, 6 parts shrinkage-reducing agent, and 3 parts nano silica.

[0039] The municipal solid waste incineration ash is the ash with a constant weight difference of less than 0.5 mg between two burning cycles. The alkaline activator solution is a mixed alkaline activator composed of sodium hydroxide and water glass, wherein the equivalent concentration of sodium hydroxide is 6 mol / L, the modulus of water glass is 1.3, and water, as the solvent, accounts for 40% of the total solution mass. The water-reducing agent is a high-performance polycarboxylate-based water-reducing agent with a water reduction rate of not less than 30%. The shrinkage-reducing agent is diethylene glycol monobutyl ether.

[0040] The fiber-reinforced ultra-high strength cement-based composite protective layer comprises the following components by weight: 40 parts silicate cement, 15 parts silica fume, 15 parts metakaolin, 20 parts granulated blast furnace slag, 9 parts nano-SiO2, 85 parts quartz sand, 15 parts recycled waste fine sand aggregate, 15 parts carbon fiber, 3 parts PVA fiber, 18 parts water, and 3 parts water-reducing agent.

[0041] The silicate cement is PO 42.5 cement. The silica fume is silica fume with a silica content of not less than 92%. The metakaolin is highly active metakaolin with an impurity content of less than 5%. The granulated blast furnace slag is granulated blast furnace slag with an activity index of not less than S95. The nano-SiO2 is SiO2 nanoparticles with a purity of not less than 99.8%. The recycled waste fine sand aggregate is fine sand aggregate with a particle size of 26-40 mesh. The water-reducing agent is a polycarboxylate-based high-performance water-reducing agent with a water reduction rate of not less than 30%. The carbon fiber is high-strength carbon fiber with an average length of 13 mm. The PVA fiber is high-strength, high-modulus polyvinyl alcohol fiber.

[0042] The basalt fiber mesh skeleton layer is a square mesh coated with a silane coupling agent.

[0043] The preparation method of the above-mentioned multi-layer composite structure isolation fence post includes the following steps: Step S1: Thoroughly clean the mold and evenly apply release oil to the surface of the mold; Step S2: Place the basalt fiber mesh in the inner skeleton layer of the mold and fix it in place; Step S3: Prepare the raw materials of the fiber-toughened ultra-high strength cement-based composite material protective layer according to the corresponding weight parts, pour nano-SiO2 into water for ultrasonic dispersion, and then add water-reducing agent for uniform dispersion to obtain a mixed solution. Step S4: After mixing silicate cement, silica fume, metakaolin, granulated blast furnace slag, quartz sand and waste recycled fine sand aggregate evenly, add the mixed solution, carbon fiber and polyvinyl alcohol fiber and continue mixing to obtain ultra-high performance mortar mixture. Step S5: Pour the ultra-high performance mortar material obtained in S4 between the mold and the skeleton, and compact it by vibration to form a fiber-toughened ultra-high strength cement-based composite material protective layer and a basalt fiber mesh skeleton layer. Step S6: Prepare the raw materials for the geopolymer concrete filling layer according to the corresponding weight proportions, and premix the alkali activator solution and water to obtain the mixture; Step S7: Add municipal solid waste incineration ash, type II phosphogypsum, aggregate, shrinkage reducer and nano silica to the mixture after stirring evenly, and then add the mixture liquid. After stirring evenly, freshly mixed polymer concrete is obtained. Step S8: The obtained freshly mixed polymer concrete is poured into the skeleton layer and vibrated to form a specimen with a three-layer structure of protective layer-skeleton layer-filling layer. Step S9: Cover the surface of the specimen in contact with air in S8 with a thin film, place it at room temperature for 20-24 hours, and then perform standard curing to obtain a multi-layer composite structure isolation fence column.

[0044] The resulting multi-layer composite structure fence post is a composite structure: the outer layer is a fiber-reinforced ultra-high strength cement-based composite material protective layer 1.1, the middle layer is a basalt fiber mesh skeleton layer 1.2, and the inner layer is a geopolymer concrete filling layer 1.3. The three layers are tightly wrapped to form a stable and reliable load-bearing system. The cross-section of the resulting multi-layer composite structure fence post is square; the thickness of the fiber-reinforced ultra-high strength cement-based composite material protective layer is 20 mm; the thickness of the basalt fiber mesh skeleton layer is 10 mm; and the bottom edge length of the geopolymer concrete filling layer is 40 mm.

[0045] Based on the requirements of commonly used highway guardrail posts, this invention, in manufacturing multi-layer composite structure guardrail posts, uses a mold with two sets of symmetrical groove holes 1.4 on the left and right sides of the post, and the surface of the post is provided with anti-climb texture, such as... Figure 1-3 .

[0046] Example 2 A multi-layer composite structure isolation fence post includes: an outer layer of fiber-reinforced ultra-high strength cement-based composite material protective layer, a middle layer of basalt fiber mesh skeleton layer, and an inner layer of geopolymer concrete filling layer.

[0047] The geopolymer concrete filler layer comprises the following components by weight: 40 parts municipal solid waste incineration fly ash, 60 parts type II phosphogypsum, 15 parts alkaline activator solution, 100 parts aggregate, 10 parts water, 3 parts water-reducing agent, 5 parts shrinkage-reducing agent, and 4 parts nano silica.

[0048] The municipal solid waste incineration ash is defined as ash with a constant weight difference of less than 0.5 mg between two burning cycles. The alkaline activator solution is a mixed alkaline activator composed of sodium hydroxide and water glass, wherein the equivalent concentration of sodium hydroxide is 5 mol / L, the modulus of water glass is 1.0, and water, as the solvent, accounts for 30% of the total solution mass. The water-reducing agent is a high-performance powdered polycarboxylate-based water-reducing agent with a water reduction rate of not less than 30%. The shrinkage-reducing agent is diethylene glycol monobutyl ether.

[0049] The fiber-reinforced ultra-high strength cement-based composite protective layer comprises the following components by weight: 45 parts silicate cement, 15 parts silica fume, 12 parts metakaolin, 25 parts granulated blast furnace slag, 8 parts nano-SiO2, 87 parts quartz sand, 13 parts recycled waste fine sand aggregate, 17 parts carbon fiber, 3 parts PVA fiber, 19 parts water, and 3.5 parts water-reducing agent.

[0050] The silicate cement is PI 42.5 cement. The silica fume is silica fume with a silica content of not less than 92%. The metakaolin is highly active metakaolin with an impurity content of less than 5%. The granulated blast furnace slag is granulated blast furnace slag with an activity index of not less than S95. The nano-SiO2 is SiO2 nanoparticles with a purity of not less than 99.8%. The recycled waste fine sand aggregate is fine sand aggregate with a particle size of 26-40 mesh. The water-reducing agent is a polycarboxylate-based high-performance water-reducing agent with a water reduction rate of not less than 30%. The carbon fiber is high-strength carbon fiber with an average length of 13 mm. The PVA fiber is high-strength, high-modulus polyvinyl alcohol fiber. The basalt fiber mesh skeleton layer is a square mesh coated with a silane coupling agent.

[0051] The preparation method of the above-mentioned multi-layer composite structure isolation fence post includes the following steps: Step S1: Thoroughly clean the mold and evenly apply release oil to the surface of the mold; Step S2: Place the basalt fiber mesh in the inner skeleton layer of the mold and fix it in place; Step S3: Prepare the raw materials of the fiber-toughened ultra-high strength cement-based composite material protective layer according to the corresponding weight parts, pour nano-SiO2 into water for ultrasonic dispersion, and then add water-reducing agent for uniform dispersion to obtain a mixed solution. Step S4: After mixing silicate cement, silica fume, metakaolin, granulated blast furnace slag, quartz sand and waste recycled fine sand aggregate evenly, add the mixed solution, carbon fiber and polyvinyl alcohol fiber and continue mixing to obtain ultra-high performance mortar mixture. Step S5: Pour the ultra-high performance mortar material obtained in S4 between the mold and the skeleton, and compact it by vibration to form a fiber-toughened ultra-high strength cement-based composite material protective layer and a basalt fiber mesh skeleton layer. Step S6: Prepare the raw materials for the geopolymer concrete filling layer according to the corresponding weight proportions, and premix the alkali activator solution and water to obtain the mixture; Step S7: Add municipal solid waste incineration ash, type II phosphogypsum, aggregate, shrinkage reducer and nano silica to the mixture after stirring evenly, and then add the mixture liquid. After stirring evenly, freshly mixed polymer concrete is obtained. Step S8: The obtained freshly mixed polymer concrete is poured into the skeleton layer and vibrated to form a specimen with a three-layer structure of protective layer-skeleton layer-filling layer. Step S9: Cover the surface of the specimen in contact with air in S8 with a thin film, place it at room temperature for 20-24 hours, and then perform standard curing to obtain a multi-layer composite structure isolation fence column.

[0052] The resulting multi-layer composite structure fence post is a composite structure: the outer layer is a fiber-reinforced ultra-high strength cement-based composite material protective layer 1.1, the middle layer is a basalt fiber mesh skeleton layer 1.2, and the inner layer is a geopolymer concrete filling layer 1.3. The three layers are tightly wrapped to form a stable and reliable load-bearing system. The cross-section of the resulting multi-layer composite structure fence post is square; the thickness of the fiber-reinforced ultra-high strength cement-based composite material protective layer is 20 mm; the thickness of the basalt fiber mesh skeleton layer is 10 mm; and the bottom edge length of the geopolymer concrete filling layer is 40 mm.

[0053] Example 3 A multi-layer composite structure isolation fence post includes: an outer layer of fiber-reinforced ultra-high strength cement-based composite material protective layer, a middle layer of basalt fiber mesh skeleton layer, and an inner layer of geopolymer concrete filling layer.

[0054] The geopolymer concrete filler layer comprises the following components by weight: 55 parts municipal solid waste incineration fly ash, 45 parts type II phosphogypsum, 10 parts alkaline activator solution, 120 parts aggregate, 15 parts water, 4 parts water-reducing agent, 6 parts shrinkage-reducing agent, and 3 parts nano silica.

[0055] The incineration ash is the incineration ash with a constant weight difference of less than 0.5 mg between two burning cycles. The alkaline activator solution is a mixed alkaline activator composed of sodium hydroxide and water glass, with an alkali equivalent concentration of 8 mol / L, a water glass modulus of 1.5, and water as a solvent accounting for 50% of the total solution mass. The water-reducing agent is a high-performance polycarboxylate-based water-reducing agent with a water reduction rate of not less than 30%. The shrinkage-reducing agent is diethylene glycol monobutyl ether shrinkage-reducing agent.

[0056] The fiber-reinforced ultra-high strength cement-based composite protective layer comprises the following components by weight: 50 parts silicate cement, 20 parts silica fume, 10 parts metakaolin, 15 parts granulated blast furnace slag, 10 parts nano-SiO2, 90 parts quartz sand, 10 parts recycled waste fine sand aggregate, 18 parts carbon fiber, 2 parts PVA fiber, 18 parts water, and 3 parts water-reducing agent.

[0057] The silicate cement is PO 52.5 cement. The silica fume is silica fume with a silica content of not less than 92%. The metakaolin is highly active metakaolin with an impurity content of less than 5%. The granulated blast furnace slag is granulated blast furnace slag with an activity index of not less than S95. The nano-SiO2 is SiO2 nanoparticles with a purity of not less than 99.8%. The recycled waste fine sand aggregate is fine sand aggregate with a particle size of 26-40 mesh. The water-reducing agent is a polycarboxylate-based high-performance water-reducing agent with a water reduction rate of not less than 30%. The carbon fiber is high-strength carbon fiber with an average length of 13 mm. The PVA fiber is high-strength, high-modulus polyvinyl alcohol fiber.

[0058] The basalt fiber mesh skeleton layer is a square mesh coated with a silane coupling agent.

[0059] The preparation method of the above-mentioned multi-layer composite structure isolation fence post includes the following steps: Step S1: Thoroughly clean the mold and evenly apply release oil to the surface of the mold; Step S2: Place the basalt fiber mesh in the inner skeleton layer of the mold and fix it in place; Step S3: Prepare the raw materials of the fiber-toughened ultra-high strength cement-based composite material protective layer according to the corresponding weight parts, pour nano-SiO2 into water for ultrasonic dispersion, and then add water-reducing agent for uniform dispersion to obtain a mixed solution. Step S4: After mixing silicate cement, silica fume, metakaolin, granulated blast furnace slag, quartz sand and waste recycled fine sand aggregate evenly, add the mixed solution, carbon fiber and polyvinyl alcohol fiber and continue mixing to obtain ultra-high performance mortar mixture. Step S5: Pour the ultra-high performance mortar material obtained in S4 between the mold and the skeleton, and compact it by vibration to form a fiber-toughened ultra-high strength cement-based composite material protective layer and a basalt fiber mesh skeleton layer. Step S6: Prepare the raw materials for the geopolymer concrete filling layer according to the corresponding weight proportions, and premix the alkali activator solution and water to obtain the mixture; Step S7: Add municipal solid waste incineration ash, type II phosphogypsum, aggregate, shrinkage reducer and nano silica to the mixture after stirring evenly, and then add the mixture liquid. After stirring evenly, freshly mixed polymer concrete is obtained. Step S8: The obtained freshly mixed polymer concrete is poured into the skeleton layer and vibrated to form a specimen with a three-layer structure of protective layer-skeleton layer-filling layer. Step S9: Cover the surface of the specimen in contact with air in S8 with a thin film, place it at room temperature for 20-24 hours, and then perform standard curing to obtain a multi-layer composite structure isolation fence column.

[0060] The resulting multi-layer composite structure fence post is a composite structure: the outer layer is a fiber-reinforced ultra-high strength cement-based composite material protective layer 1.1, the middle layer is a basalt fiber mesh skeleton layer 1.2, and the inner layer is a geopolymer concrete filling layer 1.3. The three layers are tightly wrapped to form a stable and reliable load-bearing system. The cross-section of the resulting multi-layer composite structure fence post is square; the thickness of the fiber-reinforced ultra-high strength cement-based composite material protective layer is 20 mm; the thickness of the basalt fiber mesh skeleton layer is 10 mm; and the bottom edge length of the geopolymer concrete filling layer is 40 mm.

[0061] Comparative Example 1 A method for manufacturing an isolation fence post includes the following steps: Step S1: Mix the following raw materials according to the following weight proportions: 70-80 parts cement, 15-20 parts slag powder, 1-2 parts polycarboxylate superplasticizer, 18-25 parts water and 1400-1600 parts coarse aggregate.

[0062] Step S2: Add the weighed solid raw materials cement, slag powder and coarse aggregate into the mixing pot in sequence, and mix for 3 to 5 minutes.

[0063] Step S3: Then add water mixed with high-efficiency water-reducing agent, stir evenly to form fresh concrete.

[0064] Step S4: Pour the freshly mixed concrete into a mold with fixed steel bars, vibrate to shape, and remove the mold after 1 day.

[0065] Step S5: Curing for 28 days under standard curing conditions of 20℃ and RH not less than 95% to form a concrete column product of the same size as in Example 1.

[0066] Example of effect The performance data of compressive strength, flexural strength, chloride ion penetration resistance, and abrasion coefficient of the concrete column products prepared in Examples 1-3 and Comparative Example 1 are shown in Table 1. Among them, the chloride ion penetration resistance test was carried out according to GB / T 50082-2024 standard: after vacuum saturation of φ100mm×50mm specimen, a 60V DC current was applied between the cathode cell and the anode cell for 6 hours, and the permeability was characterized by the total charge of the specimen (coulomb value). The lower the value, the better the permeability resistance.

[0067] The wear coefficient test follows the ASTM C418 standard: a 150mm×150mm×30mm specimen is dried and weighed, and quartz sand abrasive is vertically sprayed at a pressure of 0.14MPa for 60 seconds. After removing the dust, it is weighed again, and the wear coefficient is calculated according to the formula based on the mass of the abrasive. The smaller the value, the stronger the wear resistance.

[0068] Table 1 The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or improvement of the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A multi-layer composite structure isolation fence post, characterized in that: include: The outer layer is a fiber-reinforced ultra-high strength cement-based composite material protective layer, the middle layer is a basalt fiber mesh skeleton layer, and the inner layer is a geopolymer concrete filling layer. The geopolymer concrete filling layer includes the following components by weight: 40-55 parts municipal solid waste incineration ash, 45-60 parts type II phosphogypsum, 10-15 parts alkaline activator solution, 100-120 parts aggregate, 10-15 parts water, 3-4 parts water-reducing agent, 5-6 parts shrinkage-reducing agent, and 3-4 parts nano silica.

2. The multi-layer composite structure isolation fence post as described in claim 1, characterized in that: The municipal solid waste incineration ash is the incineration ash of municipal solid waste that has undergone two incinerations with a constant weight difference of less than 0.5 mg; the type II phosphogypsum is phosphogypsum with a calcium sulfate content greater than 80%; the alkaline activator solution is a mixed alkaline activator of sodium hydroxide and water glass, wherein the equivalent concentration of sodium hydroxide is 5~8 mol / L, the modulus of water glass is 1.0~1.5, and water is used as a solvent accounting for 30-50% of the total mass of the alkaline activator solution; the water-reducing agent is a polycarboxylate-based high-performance water-reducing agent with a water reduction rate of not less than 30%; the shrinkage-reducing agent is an organic powdered shrinkage-reducing agent.

3. The multi-layer composite structure isolation fence post as described in claim 1, characterized in that: The protective layer of the fiber-reinforced ultra-high strength cement-based composite material comprises the following components in parts by weight: 40-50 parts silicate cement, 10-20 parts silica fume, 10-15 parts metakaolin, 15-25 parts granulated blast furnace slag, 85-90 parts quartz sand, 10-15 parts recycled waste fine sand aggregate, 15-18 parts carbon fiber, 2-3 parts polyvinyl alcohol fiber, 18-20 parts water, 3-3.5 parts water-reducing agent, and 8-10 parts nano-SiO2.

4. The multi-layer composite structure isolation fence post as described in claim 3, characterized in that: The silicate cement is one of P.O42.5, PO 52.5, and PI 42.5 cement; the silica fume is silica fume with a silica content of not less than 92%; the metakaolin is highly active metakaolin with an impurity content of less than 5%; the granulated blast furnace slag is granulated blast furnace slag with an activity index of not less than S95; the nano-SiO2 is SiO2 nanoparticles with a purity of not less than 99.8%; the waste recycled fine sand aggregate is fine sand aggregate with a particle size of 26-40 mesh; and the carbon fiber is high-strength carbon fiber with an average length of 13 mm.

5. The multi-layer composite structure isolation fence post as described in claim 3, characterized in that: The quartz sand includes three gradations: 26-40, 40-70, and 70-120 mesh. The mass of the three particle sizes accounts for 35-40%, 22%, and 28% of the total mass of the quartz sand and recycled fine sand aggregate, respectively.

6. The multi-layer composite structure isolation fence post as described in claim 3, characterized in that: The particle size of the recycled fine sand aggregate is 26-40 mesh, and the mass percentage of the recycled fine sand aggregate in the total mass of quartz sand and recycled fine sand aggregate is 10-15%.

7. The multi-layer composite structure isolation fence post as described in claim 1, characterized in that: The basalt fiber mesh in the basalt fiber mesh skeleton layer is a square mesh coated with a silane coupling agent.

8. The multi-layer composite structure isolation fence post as described in claim 1, characterized in that: The cross-section of the multi-layer composite structure isolation fence column is square; the thickness of the fiber-toughened ultra-high strength cement-based composite material protective layer is 20mm; the thickness of the basalt fiber mesh skeleton layer is 10mm; and the bottom edge length of the geopolymer concrete filling layer is 40mm.

9. A method for preparing the multi-layer composite structure isolation fence post according to any one of claims 1-8, characterized in that: The steps include the following: Step S1: Thoroughly clean the mold and evenly apply release oil to the surface of the mold; Step S2: Place the basalt fiber mesh in the inner skeleton layer of the mold and fix it in place; Step S3: Prepare the raw materials of the fiber-toughened ultra-high strength cement-based composite material protective layer according to the corresponding weight parts, pour nano-SiO2 into water for ultrasonic dispersion, and then add water-reducing agent for uniform dispersion to obtain a mixed solution. Step S4: After mixing silicate cement, silica fume, metakaolin, granulated blast furnace slag, quartz sand and waste recycled fine sand aggregate evenly, add the mixed solution, carbon fiber and polyvinyl alcohol fiber and continue mixing to obtain ultra-high performance mortar mixture. Step S5: Pour the ultra-high performance mortar material obtained in S4 between the mold and the skeleton, and compact it by vibration to form a fiber-toughened ultra-high strength cement-based composite material protective layer and a basalt fiber mesh skeleton layer. Step S6: Prepare the raw materials for the geopolymer concrete filling layer according to the corresponding weight proportions, and premix the alkali activator solution and water to obtain the mixture; Step S7: Add municipal solid waste incineration ash, type II phosphogypsum, aggregate, shrinkage reducer, water reducer and nano silica to the mixture after mixing evenly, and then add the mixture liquid. After mixing evenly, freshly mixed polymer concrete is obtained. Step S8: The obtained freshly mixed polymer concrete is poured into the skeleton layer and vibrated to form a specimen with a three-layer structure of protective layer-skeleton layer-filling layer. Step S9: Cover the surface of the specimen in contact with air in S8 with a thin film, place it at room temperature for 20-24 hours, and then perform standard curing to obtain a multi-layer composite structure isolation fence column.

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