Road material and method for preparing road material from solid waste-based geopolymer

Abstract

The invention relates to the technical field of geopolymer materials, in particular to a road material and a method for preparing the road material from a solid waste-based geopolymer. The pavement material is prepared from the following raw materials in parts by weight: 40 to 50 parts of fly ash, 25 to 35 parts of slag, 10 to 25 parts of construction waste micro powder, 5 to 15 parts of red mud, 8 to 10 parts of composite exciting agent, 0.5 to 1.5 parts of nano silicon dioxide, 0.1 to 0.5 part of water reducing agent, 0.4 to 0.5 part of fiber, 2.0 to 5.0 parts of self-repairing microcapsule and 30 to 40 parts of mixing water. The risk that the material generates microcracks can be reduced, meanwhile, the internal compactness of the product is improved, the strength of the product is improved, and the composite material is suitable for high-grade highway full-structure layer (base layer and surface layer) or cold region roadbed engineering.

Description

Technical Field

[0001] The present invention relates to the technical field of geopolymer materials, and in particular to a road material and a method for preparing the road material from solid waste-based geopolymers. Background Art

[0002] Geopolymers are a class of inorganic polymer materials formed through geopolymerization. They are composed of aluminosilicates chemically reorganized under alkaline conditions to form a three-dimensional network structure. Their name stems from the fact that their synthesis process resembles the geological formation mechanism of natural rocks, such as volcanic ash. Geopolymers break with the traditional calcium-dominated model of Portland cement, creating a new "silicon-aluminum-based" cementitious material system and are considered a disruptive technology in the building materials industry.

[0003] Solid waste-based geopolymer (SWBG) is an inorganic polymer material formed through geopolymerization using industrial solid waste (such as fly ash, slag, and construction waste) as its primary raw materials. SWBG can be made from a wide range of raw materials, including: industrial solid waste such as fly ash (a byproduct of coal-fired power plants), blast furnace slag (from the steel industry), and red mud (aluminum smelting waste); and construction waste such as discarded concrete, bricks, tiles, and ceramic fragments. The low cost and widespread availability of raw materials align with the concepts of "zero-waste cities" and the circular economy.

[0004] For example, patent CN 119504163 A discloses a medical solid waste-based polymer material, its preparation method, and application. The medical solid waste-based polymer material includes: an interface-modified bandage, an ultraviolet radiation-modified infusion set, iron tailings slag, ceramic slag, an alkali-activated solution, and a strengthening agent. The bandage is immersed in a hypochlorous acid solution for disinfection. Hypochlorous acid can kill pathogenic microorganisms, and the generated chloride ions can also change the osmotic pressure of bacteria and viruses, inactivating their cells; the sterilized bandage is subjected to interface adjustment to improve the adhesion between the bandage fiber and the matrix; the infusion set is subjected to ultraviolet radiation, which can increase the roughness of the infusion set surface while disinfecting and sterilizing, improve the adhesion between the infusion set surface and the matrix interface, and enable the infusion set to be better integrated into the matrix. The present invention realizes the recycling of medical solid waste, and the medical solid waste-based polymer material has excellent mechanical properties. Its use in prefabricated building materials has certain environmental benefits and use value.

[0005] For example, patent CN 119490343 A discloses an iron tailings-based polymer grouting material and a preparation method thereof. The iron tailings-based polymer grouting material includes the following components in parts by weight: 30-60 parts of iron tailings powder, 15-45 parts of slag, 10-20 parts of fly ash, 5-8 parts of desulfurized gypsum, 17-33 parts of water glass, 2-4 parts of NaOH, 70-80 parts of water, and 0.8-1 part of a water reducer. The iron tailings-based polymer grouting material described in the present invention can apply iron tailings as a cementitious admixture to the geopolymer system, broadening the application range of iron tailings and reducing the large-scale storage of iron tailings; at the same time, the present invention uses iron tailings powder, slag, fly ash and desulfurization gypsum as main raw materials, and mechanical ball milling and alkali excitation as activation methods, while absorbing solid waste and avoiding carbon emissions caused by high-temperature calcination activation. The prepared grouting material has a 28d strength of up to 6.94MPa, which meets the requirements for filling goaf areas, and has good fluidity, and can effectively replace cement-based materials for filling goaf areas.

[0006] For example, patent CN 119461959 A discloses a high-strength fly ash-based polymer slurry and its preparation method. The slurry comprises 62-70 parts by weight of an activated geopolymer precursor, 7-11 parts by weight of an alkali activator, 80-95 parts by weight of aggregate, 0.4-2 parts by weight of silica-grafted polyester fibers, and 18-22 parts by weight of water. The activated geopolymer precursor is obtained by ball-milling the fly ash and slag with triethanolamine. Nanosilica is grafted onto the surface of the polyester fibers, creating a good interfacial compatibility with the silica and silicate phases in the fly ash and slag, improving the compatibility between the polyester fibers and the geopolymer precursor. Furthermore, hydrophilic groups such as carboxyl and imino groups are introduced onto the fiber surface, enhancing dispersibility in the aqueous slurry. This synergistic effect improves the compressive and flexural strengths of the geopolymer slurry specimens.

[0007] In summary, the core principle of using solid waste to prepare geopolymers is that under the action of alkaline activators (such as sodium hydroxide and sodium silicate), the aluminosilicate components in solid waste dissolve and repolymerize to form a three-dimensional network structure of cementitious materials. By utilizing solid waste resources, it reduces dependence on natural resources (such as cement) and reduces carbon emissions.

[0008] The technical defects of the solid waste-based polymer prepared above are as follows: (1) Geopolymer materials are prone to microcracks under fatigue loads, which leads to a surge in permeability, accelerates the invasion of erosive media, and affects material properties.

[0009] (2) The solid waste raw materials have an uneven gel structure due to the difference in dissolution-condensation rate. At the same time, the degree of polymerization reaction after molding is insufficient, resulting in a large porosity of the product, which reduces the density of the material and makes it difficult for the strength to meet the freeze-thaw / fatigue requirements. Summary of the Invention

[0010] In response to the technical problems in the existing preparation of solid waste-based polymers, such as the proneness of microcracks in products and the difficulty in meeting freeze-thaw / fatigue requirements in terms of strength, the present invention provides a road material and a method for preparing road materials from solid waste-based polymers, which can reduce the risk of microcracks in the material, while improving the internal density of the product and increasing the product strength. It is suitable for the entire structural layer (base layer, surface layer) of high-grade highways or roadbed projects in cold regions.

[0011] The technical solutions of the present invention are as follows: In a first aspect, the present invention provides a road material comprising the following raw materials in parts by weight: 40 to 50 parts fly ash, 25 to 35 parts slag, 10 to 25 parts construction waste powder, 5 to 15 parts red mud, 8 to 10 parts composite activator, 0.5 to 1.5 parts nano-silica, 0.1 to 0.5 parts water reducer, 0.4 to 0.5 parts fiber, 2.0 to 5.0 parts self-repairing microcapsules, and 30 to 40 parts mixing water.

[0012] It should be further explained that the specific surface area of fly ash, slag and construction waste powder is ≥400 m 2 / kg.

[0013] It should be further noted that the red mud was pre-treated by drying to a water content of ≤1% and then passed through a 200-mesh sieve. It should be further noted that the composite activator is prepared by mixing water glass with a modulus of 1.5 and a sodium hydroxide solution with a concentration of 8 mol / L in a mass ratio of 1:1.2.

[0014] It should be further explained that the water reducer is one of a polycarboxylate water reducer, a lignin sulfonate water reducer or a calcium lignin sulfonate water reducer.

[0015] It should be further noted that the fiber is at least one of cellulose fiber or steel fiber.

[0016] It should be further explained that the self-healing microcapsules are core-shell structure microcapsules, the wall material is a polyurethane / epoxy resin copolymer, and the core material is a mixture of sodium silicate solution and nano-metakaolin. Furthermore, the preparation method of the composite activator includes the following steps: (1) Core material pretreatment: Sodium silicate solution and nano-metakaolin are mixed in a mass ratio (e.g., 1:0.5-1:2), and ultrasonic treatment is performed for 10-30 minutes to ensure that the nanoparticles are evenly dispersed in the solution to form a stable suspension system. A small amount of surfactant (e.g., sodium lauryl sulfate) can be added to the system to reduce the interfacial tension and improve the stability of the core material. (2) Wall material copolymer preparation: (21) Polyurethane prepolymer synthesis: Toluene diisocyanate (TDI) or isophorone diisocyanate (IPDI) is used as a monomer and reacted with a polyol (e.g., polyether polyol) at 60-80°C for 2-4 hours to generate a polyurethane prepolymer with terminal isocyanate groups. (21) Epoxy resin modification: pre-mix epoxy resin (such as E-51) and curing agent (such as amine curing agent) in proportion, adjust reaction conditions (such as temperature, catalyst) to form a low-viscosity liquid system, which is convenient for subsequent copolymerization with polyurethane. (23) Preparation of copolymer solution: mix polyurethane prepolymer and epoxy resin solution in proportion (such as 1:1-1:3), add diluent (such as cyclohexanone or chlorobenzene) to reduce viscosity, and form a uniform copolymer solution. (3) Microcapsule formation process: (31) Emulsification and dispersion: slowly add core material suspension to wall material copolymer solution, form water / oil (W / O) or oil / water (O / W) emulsion under high shear (8000-12000 rpm), and control the droplet size to 50-200 μm. (32) Interfacial polymerization: Add a chain extender (e.g., 1,4-butanediol) or a crosslinker (e.g., triethylamine) to gradually solidify the wall material on the surface of the core material droplet through interfacial polymerization. The reaction temperature is controlled at 50-70°C for 2-6 hours. (33) In-situ curing: By increasing the temperature or adjusting the pH (e.g., alkaline conditions are required for epoxy resin), the copolymerization reaction of polyurethane and epoxy resin is promoted to form a dense composite shell layer. The finished product of the core-shell structure is obtained.

[0017] In a second aspect, the present invention provides a method for preparing road materials from solid waste-based polymers, comprising the following steps: (1) Grind and mix fly ash, slag, and construction waste powders to obtain solid powders, dry and sieve the red mud, and set aside; (2) Mixing water glass and sodium hydroxide solution under an inert gas environment and allowing to stand to obtain a composite activator; (3) The solid micropowder and the sieved red mud from step (1) are put into a stirring kettle, mixing water and part of the composite activator are added and stirred for the first time, and then the remaining composite activator, nano-silica, water reducing agent, fiber and self-repairing microcapsules are added and stirred for the second time to obtain a mixed slurry; (4) The mixed slurry obtained in step (3) is placed in a mold and cured at room temperature to obtain a finished product.

[0018] It should be further explained that in step (3), the temperature of the mixed slurry is controlled to be ≤40°C during the first stirring and the second stirring.

[0019] It should be further explained that in step (4), the method of curing at room temperature includes first sealing and curing at room temperature for 40 hours, and then naturally curing for 7 days.

[0020] In the road material provided by the present invention, the action mechanisms of the various raw material components are: Fly ash: provides SiO2 and Al2O3, which dominate the formation of geopolymerization gel phase.

[0021] ‌Slag: Rich in CaO, it accelerates the reaction process and improves early strength.

[0022] Construction waste powder: The micro-aggregate effect fills pores and reduces shrinkage.

[0023] ‌Red mud: Alkaline components assist in activation and solidify its heavy metals (such as Cr 6+ wait).

[0024] Composite activator: dissolves and repolymerizes the aluminosilicate components in solid waste to form a gelling material with a three-dimensional network structure.

[0025] Nano-silicon dioxide: It is a nano-particle with good compatibility with oligomeric materials. It can fill the nano-pores inside the product, improve the density of the product, and then improve the strength of the geopolymer material.

[0026] Water reducer: It can reduce the water-binder ratio in geopolymer materials and improve the fluidity of the slurry.

[0027] Fiber: Fibers of a certain length can be evenly distributed in the three-dimensional network structure of the cementitious material under stirring conditions. After curing, they enhance the strength of the material and prevent cracking. At the same time, the fibers can fill larger pores, improve density, and synergistically improve the strength of the material with nano-silica.

[0028] Self-repairing microcapsules: The microcapsules have a core-shell structure (diameter 50-200 μm), the wall material is polyurethane / epoxy resin copolymer (thickness 20 μm), the core material is sodium silicate solution (concentration 25wt%) and nano-metakaolin (d 50 =500nm) mixture, when the crack propagation of the material leads to local stress concentration (σ≥5MPa), the microcapsules inside the material are triggered to rupture, and the released sodium silicate undergoes condensation reaction with the unreacted precursor of the geopolymer (≡Si-O⁻) to form hydrated calcium silicate gel to fill the cracks, reducing the risk of microcracks in the material.

[0029] The beneficial effects of the present invention are: (1) The road material provided by the present invention adds self-repairing microcapsules to the geopolymer reaction raw materials. When cracking occurs under load fatigue conditions, the crack expansion of the material causes local stress concentration, triggering the rupture of the microcapsules inside the material. The released sodium silicate undergoes a condensation reaction with the unreacted precursor of the geopolymer to generate hydrated calcium silicate gel to fill the cracks, thereby reducing the risk of microcracks in the material.

[0030] (2) The road material provided by the present invention adds nano-silica to the geopolymer reaction raw materials, which can fill the nano-pores inside the product and improve the density of the product. At the same time, by adding fibers of a certain length to the raw material components, the fibers can be evenly distributed in the three-dimensional network structure of the cementitious material under stirring conditions. After curing and solidification, the strength of the material is enhanced to prevent cracking. At the same time, the fibers can fill larger pores and improve the density. They can synergistically improve the strength of the material with the nano-silica and meet the requirements of the material under freeze-thaw / fatigue conditions.

[0031] (3) In the method of preparing road materials from solid waste-based polymers of the present invention, the composite activator is added twice to produce two activations. When the activator is first added, the highly alkaline environment of the activator preferentially dissolves the amorphous silicon-aluminum phase in the raw materials (such as fly ash and slag), releasing active SiO4 4- and AlO4 5- The dissolved active monomers form oligomers through condensation reactions to generate an initial gel network (Si-O-Al bonds), forming nanoscale precursor particles that provide nucleation sites for subsequent reactions. The alkaline environment or supplementary activator introduced by the second excitation further promotes the transformation of the oligomers into a high-polymerization three-dimensional network, enhancing the crosslinking density of Si-O-Si and Si-O-Al bonds, improving the strength of the geopolymer material, and reducing defects. DETAILED DESCRIPTION

[0032] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions in the embodiments of the present invention are clearly and completely described below. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work should fall within the scope of protection of the present invention.

[0033] The present invention provides a road material, comprising the following raw materials in parts by weight: 40 to 50 parts of fly ash, 25 to 35 parts of slag, 10 to 25 parts of construction waste fine powder, 5 to 15 parts of red mud, 8 to 10 parts of composite activator, 0.5 to 1.5 parts of nano-silicon dioxide, 0.1 to 0.5 parts of water reducer, 0.4 to 0.5 parts of fiber, 2.0 to 5.0 parts of self-repairing microcapsules, and 30 to 40 parts of mixing water.

[0034] As a preferred embodiment of the present invention, the specific surface area of fly ash, slag and construction waste powder is ≥400 m 2 / kg. Under this specific surface area, the geopolymer can fully react and have a physical-chemical synergistic effect.

[0035] As a preferred embodiment of the present invention, the red mud is dried to a water content of ≤1% and then passed through a 200-mesh sieve. The red mud is dried to remove moisture, thereby reducing the impact of moisture on the reaction system. Furthermore, the metal substances in the red mud are magnetically separated and removed.

[0036] As a preferred embodiment of the present invention, a composite activator is prepared by mixing water glass with a modulus of 1.5 and sodium hydroxide solution with a concentration of 8 mol / L in a mass ratio of 1:1.2. This composite activator system has a pH of 12.5-13.5, which balances reaction rate and product stability.

[0037] As a preferred embodiment of the present invention, the water reducer is a polycarboxylate water reducer, a lignin sulfonate water reducer, or a calcium lignin sulfonate water reducer. The above water reducers are suitable for the geopolymerization reaction of the present invention.

[0038] In a preferred embodiment of the present invention, the fibers are at least one of cellulose fibers and steel fibers. Cellulose fibers are soft and suitable for flexible existence within the gelling material, while steel fibers are rigid and can be distributed on the surface of the material to enhance the strength of the geopolymer material.

[0039] As a preferred embodiment of the present invention, the self-healing microcapsule is a core-shell structure microcapsule, the wall material is a polyurethane / epoxy resin copolymer, and the core material is a mixture of sodium silicate solution and nano-metakaolin. Furthermore, the preparation method of the composite activator includes the following steps: (1) core material pretreatment: sodium silicate solution and nano-metakaolin are mixed in a mass ratio (such as 1:0.5-1:2), and ultrasonic treatment is performed for 10-30 minutes to ensure that the nanoparticles are uniformly dispersed in the solution to form a stable suspension system. A small amount of surfactant (such as sodium lauryl sulfate) can be added to the system to reduce the interfacial tension and improve the stability of the core material. (2) wall material copolymer preparation: (21) polyurethane prepolymer synthesis, using toluene diisocyanate (TDI) or isophorone diisocyanate (IPDI) as a monomer, and reacting with a polyol (such as polyether polyol) at 60-80°C for 2-4 hours to generate a polyurethane prepolymer with a terminal isocyanate group. (21) Epoxy resin modification: pre-mix epoxy resin (such as E-51) and curing agent (such as amine curing agent) in proportion, adjust reaction conditions (such as temperature, catalyst) to form a low-viscosity liquid system, which is convenient for subsequent copolymerization with polyurethane. (23) Preparation of copolymer solution: mix polyurethane prepolymer and epoxy resin solution in proportion (such as 1:1-1:3), add diluent (such as cyclohexanone or chlorobenzene) to reduce viscosity, and form a uniform copolymer solution. (3) Microcapsule formation process: (31) Emulsification and dispersion: slowly add core material suspension to wall material copolymer solution, form water / oil (W / O) or oil / water (O / W) emulsion under high shear (8000-12000rpm), and control droplet size to 50-200 μm. (32) Interfacial polymerization: Add a chain extender (e.g., 1,4-butanediol) or a crosslinker (e.g., triethylamine) to gradually solidify the wall material on the surface of the core material droplet through interfacial polymerization. The reaction temperature is controlled at 50-70°C for 2-6 hours. (33) In-situ curing: By increasing the temperature or adjusting the pH (e.g., alkaline conditions are required for epoxy resin), the copolymerization reaction of polyurethane and epoxy resin is promoted to form a dense composite shell layer. The finished product of the core-shell structure is obtained.

[0040] The present invention also provides a method for preparing road materials from solid waste-based polymers, comprising the following steps: (1) Grind and mix fly ash, slag, and construction waste powders to obtain solid powders, dry and sieve the red mud, and set aside; (2) Mixing water glass and sodium hydroxide solution under an inert gas environment and allowing to stand to obtain a composite activator; (3) The solid micropowder and the sieved red mud from step (1) are put into a stirring kettle, mixing water and part of the composite activator are added and stirred for the first time, and then the remaining composite activator, nano-silica, water reducing agent, fiber and self-repairing microcapsules are added and stirred for the second time to obtain a mixed slurry; (4) The mixed slurry obtained in step (3) is placed in a mold and cured at room temperature to obtain a finished product.

[0041] As a preferred embodiment of the present invention, in step (3), the temperature of the mixed slurry is controlled to be ≤40°C during the first and second stirring. The temperature can be controlled by a jacket device outside the stirred tank. When the temperature is too low, hot water is used for heating. Cooling water is introduced for cooling the reaction heat.

[0042] As a preferred embodiment of the present invention, in step (4), the method of curing at room temperature includes first sealing and curing at room temperature for 40 hours, and then naturally curing for 7 days. Curing at room temperature avoids the technical problem of construction inconvenience caused by high-temperature steam curing in the prior art.

[0043] The self-repairing microcapsules in the following examples were prepared by the following method: (1) Core material pretreatment Mix the sodium silicate solution and nano-metakaolin in a mass ratio of 1:1.5 and ultrasonicate for 20 minutes to ensure that the nanoparticles are evenly dispersed in the solution to form a stable core material suspension system. A small amount of sodium lauryl sulfate can be added to the system to reduce interfacial tension and improve core material stability.

[0044] (2) Preparation of wall material copolymers (21) Synthesis of polyurethane prepolymer: Toluene diisocyanate (TDI) is used as a monomer and reacted with polyether polyol at 70°C for 3 hours to produce a polyurethane prepolymer with terminal isocyanate groups.

[0045] (22) Epoxy resin modification: pre-mix the epoxy resin and amine curing agent in proportion, and adjust the reaction conditions to form a low-viscosity liquid system to facilitate subsequent copolymerization with polyurethane.

[0046] (23) Preparation of copolymer solution: polyurethane prepolymer and epoxy resin solution are mixed in a ratio of 1:1, and diluent cyclohexanone is added to reduce the viscosity to form a uniform wall material copolymer solution.

[0047] (3) Microcapsule formation process (31) Emulsification and dispersion: slowly add the core material suspension into the wall material copolymer solution to form a water / oil (W / O) emulsion under high shear (10,000 rpm), and control the droplet size to 50-200 μm.

[0048] (32) Interfacial polymerization: add triethylamine as a crosslinking agent, and the wall material is gradually solidified on the surface of the core material droplet through interfacial polymerization. The reaction temperature is controlled at 50-70°C and the reaction time is 5 hours.

[0049] (33) In situ curing: by adjusting the pH to alkaline conditions, the copolymerization reaction of polyurethane and epoxy resin is promoted to form a dense composite shell layer, and the self-healing microcapsule product with a core-shell structure is obtained.

[0050] The composite activator used in the following examples is prepared by mixing water glass with a modulus of 1.5 and a sodium hydroxide solution with a concentration of 8 mol / L in a mass ratio of 1:1.2.

[0051] The specifications of some raw materials used in the following examples are shown in Table 1 below: Table 1 Specifications of raw materials

[0052] Example 1 A road material comprises the following raw materials in parts by weight: 45 parts of fly ash, 30 parts of slag, 20 parts of construction waste powder, 10 parts of red mud, 9 parts of a composite activator, 1.0 part of nano-silica, 0.3 parts of a polycarboxylate water reducer, 0.4 parts of cellulose fiber, 3 parts of self-repairing microcapsules, and 35 parts of mixing water.

[0053] According to the above raw material component ratios, Example 1 also provides a method for preparing road materials from solid waste-based polymers, comprising the following steps: (1) Grind and mix fly ash, slag, and construction waste powders to obtain solid powders, dry and sieve the red mud, and set aside; (2) Mixing water glass and sodium hydroxide solution under an inert gas environment and allowing to stand to obtain a composite activator; (3) The solid micropowder and the sieved red mud from step (1) are put into a stirring kettle, mixing water and part of the composite activator are added and stirred for the first time, and then the remaining composite activator, nano-silica, water reducer, fiber and self-repairing microcapsules are added and stirred for the second time. During the first and second stirring, the temperature of the mixed slurry is controlled to be ≤40°C to obtain a mixed slurry; (4) The mixed slurry obtained in step (3) is placed in a mold, first sealed and cured at room temperature for 40 hours, and then naturally cured for 7 days to obtain a finished product.

[0054] Example 2 A road material comprises the following raw materials in parts by weight: 40 parts of fly ash, 25 parts of slag, 10 parts of construction waste powder, 5 parts of red mud, 8 parts of a composite activator, 0.5 parts of nano-silica, 0.1 parts of a polycarboxylate water reducer, 0.45 parts of cellulose fiber, 2.0 parts of self-repairing microcapsules, and 30 parts of mixing water.

[0055] According to the above raw material component ratios, Example 2 also provides a method for preparing road materials from solid waste-based polymers, comprising the following steps: (1) Grind and mix fly ash, slag, and construction waste powders to obtain solid powders, dry and sieve the red mud, and set aside; (2) Mixing water glass and sodium hydroxide solution under an inert gas environment and allowing to stand to obtain a composite activator; (3) The solid micropowder and the sieved red mud from step (1) are put into a stirring kettle, mixing water and part of the composite activator are added and stirred for the first time, and then the remaining composite activator, nano-silica, water reducer, fiber and self-repairing microcapsules are added and stirred for the second time. During the first and second stirring, the temperature of the mixed slurry is controlled to be ≤40°C to obtain a mixed slurry; (4) The mixed slurry obtained in step (3) is placed in a mold, first sealed and cured at room temperature for 40 hours, and then naturally cured for 7 days to obtain a finished product.

[0056] Example 3 A road material comprises the following raw materials in parts by weight: 50 parts of fly ash, 35 parts of slag, 25 parts of construction waste powder, 15 parts of red mud, 10 parts of a composite activator, 1.5 parts of nano-silicon dioxide, 0.5 parts of a lignin sulfonate water reducer, 0.5 parts of cellulose fiber and steel fiber, 5.0 parts of self-repairing microcapsules, and 40 parts of mixing water.

[0057] According to the above raw material component ratios, Example 3 also provides a method for preparing road materials from solid waste-based polymers, comprising the following steps: (1) Grind and mix fly ash, slag, and construction waste powders to obtain solid powders, dry and sieve the red mud, and set aside; (2) Mixing water glass and sodium hydroxide solution under an inert gas environment and allowing to stand to obtain a composite activator; (3) The solid micropowder and the sieved red mud from step (1) are put into a stirring kettle, mixing water and part of the composite activator are added and stirred for the first time, and then the remaining composite activator, nano-silica, water reducer, fiber and self-repairing microcapsules are added and stirred for the second time. During the first and second stirring, the temperature of the mixed slurry is controlled to be ≤40°C to obtain a mixed slurry; (4) The mixed slurry obtained in step (3) is placed in a mold, first sealed and cured at room temperature for 40 hours, and then naturally cured for 7 days to obtain a finished product.

[0058] Example 4 A road material comprises the following raw materials in parts by weight: 43 parts of fly ash, 26 parts of slag, 13 parts of construction waste powder, 10 parts of red mud, 9 parts of a composite activator, 1.2 parts of nano-silicon dioxide, 0.4 parts of a lignin sulfonate water reducer, 0.5 parts of steel fiber, 4.9 parts of self-repairing microcapsules, and 39 parts of mixing water.

[0059] According to the above raw material component ratios, Example 4 also provides a method for preparing road materials from solid waste-based polymers, comprising the following steps: (1) Grind and mix fly ash, slag, and construction waste powders to obtain solid powders, dry and sieve the red mud, and set aside; (2) Mixing water glass and sodium hydroxide solution under an inert gas environment and allowing to stand to obtain a composite activator; (3) The solid micropowder and the sieved red mud from step (1) are put into a stirring kettle, mixing water and part of the composite activator are added and stirred for the first time, and then the remaining composite activator, nano-silica, water reducer, fiber and self-repairing microcapsules are added and stirred for the second time. During the first and second stirring, the temperature of the mixed slurry is controlled to be ≤40°C to obtain a mixed slurry; (4) The mixed slurry obtained in step (3) is placed in a mold, first sealed and cured at room temperature for 40 hours, and then naturally cured for 7 days to obtain a finished product.

[0060] Example 5 A road material comprises the following raw materials in parts by weight: 42 parts of fly ash, 35 parts of slag, 13 parts of construction waste powder, 9 parts of red mud, 10 parts of a composite activator, 0.8 parts of nano-silicon dioxide, 0.5 parts of a lignin sulfonate water reducer, 0.5 parts of cellulose fiber and steel fiber, 5.0 parts of self-repairing microcapsules, and 35 parts of mixing water.

[0061] According to the above raw material component ratios, Example 5 also provides a method for preparing road materials from solid waste-based polymers, comprising the following steps: (1) Grind and mix fly ash, slag, and construction waste powders to obtain solid powders, dry and sieve the red mud, and set aside; (2) Mixing water glass and sodium hydroxide solution under an inert gas environment and allowing to stand to obtain a composite activator; (3) The solid micropowder and the sieved red mud from step (1) are put into a stirring kettle, mixing water and part of the composite activator are added and stirred for the first time, and then the remaining composite activator, nano-silica, water reducer, fiber and self-repairing microcapsules are added and stirred for the second time. During the first and second stirring, the temperature of the mixed slurry is controlled to be ≤40°C to obtain a mixed slurry; (4) The mixed slurry obtained in step (3) is placed in a mold, first sealed and cured at room temperature for 40 hours, and then naturally cured for 7 days to obtain a finished product.

[0062] Example 6 A road material comprises the following raw materials in parts by weight: 50 parts of fly ash, 30 parts of slag, 19 parts of construction waste powder, 15 parts of red mud, 10 parts of a composite activator, 0.8 parts of nano-silicon dioxide, 0.5 parts of a lignin sulfonate water reducer, 0.5 parts of cellulose fiber and steel fiber, 5.0 parts of self-repairing microcapsules, and 40 parts of mixing water.

[0063] According to the above raw material component ratios, Example 6 also provides a method for preparing road materials from solid waste-based polymers, comprising the following steps: (1) Grind and mix fly ash, slag, and construction waste powders to obtain solid powders, dry and sieve the red mud, and set aside; (2) Mixing water glass and sodium hydroxide solution under an inert gas environment and allowing to stand to obtain a composite activator; (3) The solid micropowder and the sieved red mud from step (1) are put into a stirring kettle, mixing water and part of the composite activator are added and stirred for the first time, and then the remaining composite activator, nano-silica, water reducer, fiber and self-repairing microcapsules are added and stirred for the second time. During the first and second stirring, the temperature of the mixed slurry is controlled to be ≤40°C to obtain a mixed slurry; (4) The mixed slurry obtained in step (3) is placed in a mold, first sealed and cured at room temperature for 40 hours, and then naturally cured for 7 days to obtain a finished product.

[0064] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that the raw materials in Comparative Example 1 do not contain nano-silicon dioxide.

[0065] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that the raw material in Comparative Example 2 does not contain cellulose fiber.

[0066] Comparative Example 3 Comparative Example 3 is different from Example 1 in that the raw materials in Comparative Example 3 do not contain self-repairing microcapsules.

[0067] The performance of the geopolymer products prepared in each embodiment and comparative example was tested, and the relevant test data are shown in Table 2.

[0068] Table 2 Performance test data of geopolymer products prepared in various embodiments and comparative examples

[0069] Although the present invention has been described in detail by way of preferred embodiments, the present invention is not limited thereto. Without departing from the spirit and substance of the present invention, persons of ordinary skill in the art may make various equivalent modifications or substitutions to the embodiments of the present invention, and such modifications or substitutions shall be within the scope of the present invention. Any changes or substitutions that can be readily conceived by persons skilled in the art within the technical scope disclosed in the present invention shall be within the scope of protection of the present invention.

Claims

1. A road material, characterized in that: The invention comprises the following raw materials in parts by weight: 40 to 50 parts of fly ash, 25 to 35 parts of slag, 10 to 25 parts of construction waste powder, 5 to 15 parts of red mud, 8 to 10 parts of composite activator, 0.5 to 1.5 parts of nano-silicon dioxide, 0.1 to 0.5 parts of water reducer, 0.4 to 0.5 parts of fiber, 2.0 to 5.0 parts of self-repairing microcapsules, and 30 to 40 parts of mixing water.

2. The road material according to claim 1, wherein: The specific surface area of fly ash, slag and construction waste powder is ≥400 m 2 / kg.

3. The road material according to claim 1, characterized in that: The red mud is pre-treated by drying and dried to a water content of ≤1% before passing through a 200-mesh sieve.

4. The road material according to claim 1, wherein: The composite activator is prepared by mixing water glass with a modulus of 1.5 and a sodium hydroxide solution with a concentration of 8 mol / L in a mass ratio of 1:1.

2.

5. The road material according to claim 1, wherein: The water reducer is one of a polycarboxylate water reducer, a lignin sulfonate water reducer or a calcium lignin sulfonate water reducer.

6. The road material according to claim 1, wherein: The fibers are at least one of cellulose fibers or steel fibers.

7. The road material according to claim 1, wherein: The self-repairing microcapsules are core-shell structure microcapsules, the wall material is a polyurethane / epoxy resin copolymer, and the core material is a mixture of sodium silicate solution and nano-metakaolin.

8. A method for preparing the road material as claimed in claim 1 from solid waste-based polymers, characterized in that: The steps include: (1) Grind and mix fly ash, slag, and construction waste powders to obtain solid powders, dry and sieve the red mud, and set aside; (2) Mixing water glass and sodium hydroxide solution under an inert gas environment and allowing to stand to obtain a composite activator; (3) The solid micropowder and the sieved red mud from step (1) are put into a stirring kettle, mixing water and part of the composite activator are added and stirred for the first time, and then the remaining composite activator, nano-silica, water reducing agent, fiber and self-repairing microcapsules are added and stirred for the second time to obtain a mixed slurry; (4) The mixed slurry obtained in step (3) is placed in a mold and cured at room temperature to obtain a finished product.

9. The method according to claim 8, wherein In step (3), the temperature of the mixed slurry is controlled to be ≤40°C during the first stirring and the second stirring.

10. The method according to claim 8, wherein In step (4), the method of curing at room temperature includes first sealing and curing at room temperature for 40 hours, and then naturally curing for 7 days.

Images