Solid waste-based asphalt pavement with water quality purification function and preparation method thereof

Abstract

This invention provides a solid waste-based asphalt pavement with water purification function and its preparation method. The pavement comprises, from top to bottom, a solid waste-based functionalized asphalt surface layer, a solid waste-based asphalt bottom layer, a base layer, and a subgrade. The solid waste-based functionalized asphalt surface layer comprises binder, coarse aggregate, filler, additives, and core functional aggregate. The core functional aggregate is obtained by dry mixing a carrier component, a piezoelectric catalytic phase, and a biomineralization phase at a mass ratio of 100:(2.0-5.0):(0.8-1.5). By constructing a multi-dimensional synergistic system of "piezoelectric catalysis-physical adsorption-biomineralization," this invention not only actively degrades non-point source organic pollutants and permanently immobilizes heavy metals, achieving deep purification of rainwater runoff, but also realizes the high-value synergistic utilization of multi-source solid waste, while ensuring the long-term mechanical performance and service stability of the pavement.

Description

Technical Field

[0001] This invention relates to the fields of asphalt pavement environmental engineering and solid waste resource utilization technology, and in particular to a solid waste-based asphalt pavement with water purification function and its preparation method. Background Technology

[0002] Currently, the traditional dense-graded asphalt concrete pavement mainly used on high-grade highways and urban arterial roads primarily functions to bear traffic loads and provide driving comfort. During rainfall, road runoff carries pollutants such as heavy metals, suspended particles, and petroleum hydrocarbons, forming typical non-point source pollution. Traditional pavement structures lack the ability to actively purify runoff in situ.

[0003] With the advancement of urban construction, permeable asphalt pavements with rainwater infiltration and runoff control functions are being applied. Existing technologies mainly include the following approaches: First, physical adsorption / retention, achieved by adding adsorbent materials such as activated carbon and zeolite powder; second, microbial modification, attempting to introduce microorganisms for biodegradation; third, solid waste substitution, using industrial solid wastes such as steel slag and fly ash to replace natural aggregates; fourth, geopolymer-based functional materials, exploring the formation of purifying phases through alkali activation; and fifth, passive degradation technologies such as photocatalysis, attempting to introduce catalytic materials to degrade organic matter, but the catalytic efficiency is severely limited by actual working conditions such as low pavement light transmittance and easy surface wear.

[0004] However, the aforementioned technologies still have the following objective limitations in achieving the synergistic goals of "long-term self-purification" and "high-value utilization of all solid waste":

[0005] (1) The purification mechanism is simple and the ability to treat organic matter is insufficient: traditional adsorption materials are easily saturated and difficult to regenerate, and their function is lost or lost due to scouring; at the same time, the existing system generally lacks long-term active degradation methods for typical organic pollutants such as petroleum hydrocarbons in road surface pollution.

[0006] (2) Microbial activity is difficult to maintain: The high temperature (over 160°C) during road construction and the high alkalinity, drought and stress environment during service make it difficult for microorganisms to survive and form a stable purification community.

[0007] (3) Traffic mechanical energy dissipation and unutilized: During the service period of roads, they are subjected to massive vehicle rolling loads and tire vibrations. Most of this mechanical energy is converted into heat energy dissipation and is not effectively collected and converted into environmental chemical energy to drive the active purification of the road surface.

[0008] (4) Insufficient depth of solid waste utilization and potential secondary pollution: Existing utilization is mostly low-value simple substitution, lacking a synergistic activation mechanism among various solid wastes; some alkaline activation technologies rely on highly polluting chemical raw materials, deviating from the green and low-carbon concept.

[0009] (5) Conflict between road performance and environmental function: Existing purification functions often come at the cost of material mechanical strength, durability or interlayer bonding, making it difficult to maintain structural stability under complex long-term heavy traffic loads.

[0010] Therefore, there is an urgent need to develop a new type of road material and technology that can efficiently and persistently purify rainwater runoff, realize the high-value utilization of solid waste, and ensure the long-term mechanical properties and service stability of the road surface. Summary of the Invention

[0011] To address the above technical problems, this invention discloses a solid waste-based asphalt pavement with water purification function and its preparation method. This pavement can not only efficiently and persistently purify rainwater runoff, but also realize the high-value utilization of solid waste, while ensuring the long-term mechanical properties and service stability of the pavement.

[0012] The technical solution adopted by this invention is as follows:

[0013] A solid waste-based asphalt pavement with water purification function comprises, from top to bottom, a solid waste-based functionalized asphalt surface layer, a solid waste-based asphalt bottom layer, a base layer, and a subgrade.

[0014] The components of the solid waste-based functionalized asphalt top layer include binder, coarse aggregate, filler, additives, and core functional aggregate;

[0015] The core functional aggregate is composed of a carrier component and a purification functional component, wherein the purification functional component includes a piezoelectric catalytic phase and a biomineralization phase. Specifically, the core functional aggregate is obtained by dry mixing the carrier component, the piezoelectric catalytic phase and the biomineralization phase at a mass ratio of 100:(2.0-5.0):(0.8-1.5). The carrier component is synthesized by hydrothermal reaction of a mixture of slag, carbide slag and desulfurized gypsum with water, and then obtained by crushing and screening.

[0016] In the above technical solution, the solid waste-based functionalized asphalt surface layer, through the physical interlocking design of epoxy modified asphalt and steel slag aggregate, not only imparts purification function but also improves the high and low temperature stability and interlayer shear resistance of the pavement, ensuring mechanical stability, anti-stripping and long-term service.

[0017] The core functional aggregate constructs a multi-dimensional synergistic purification and regeneration system of "piezoelectric catalysis-physical adsorption-biomineralization". The carrier component provides physical adsorption and serves as a protective loading substrate for the multi-dimensional materials; the piezoelectric catalytic phase actively degrades organic matter; and the biomineralization phase utilizes metabolic activities to convert adsorbed heavy metal ions into carbonate precipitates.

[0018] Specifically, the carrier component utilizes industrial strong alkali / acid solid wastes such as carbide slag and desulfurization gypsum to synergistically activate slag activity, synthesizing a highly efficient purification carrier in situ without the need for external chemical reagents, thereby improving the utilization rate of solid waste. The stepped composite process ensures both high-temperature anchoring of the piezoelectric phase and, through microencapsulation protection technology, ensures a high survival rate of functional microorganisms under the high temperatures and extreme service environments of asphalt mixing and paving.

[0019] The multi-dimensional collaborative purification process of this road surface during actual use can be divided into three stages:

[0020] 1) Piezoelectric catalytic degradation stage: Under the mechanical action of vehicle cyclic load, tire vibration and other factors, the piezoelectric catalytic phase is polarized to generate surface charge, which induces water and dissolved oxygen in the runoff to generate reactive oxygen species (ROS), actively and efficiently degrading organic pollutants such as petroleum hydrocarbons (TPH) in the runoff.

[0021] 2) Physical adsorption stage: The zeolite-like phase in the support component utilizes the charge imbalance within the crystal lattice to rapidly capture heavy metal cations (M...) in the runoff through ion exchange. 2+ ) and NH4⁺.

[0022] 3) Biomineralization stage: The dormant biomineralized phase is awakened by rainwater, secreting ammonia-producing enzymes to increase the local pH value. The generated CO2 is converted into CO3 in the alkaline environment. 2- .

[0023] The reaction equation is: M 2+ (Adsorbed state) + CO3 2- → MCO3↓ (solid minerals).

[0024] The functional effect of this reaction is that the mineralized products fill the large pores of the carrier in a solid state, which not only achieves the permanent preservation of heavy metals, but also frees up highly active adsorption sites on the zeolite surface, thus realizing the long-term cyclic regeneration of the carrier performance.

[0025] As a further improvement of the present invention, the core functional aggregate is prepared using a stepped multidimensional composite process, including the following steps:

[0026] Step S11 involves immersing the pre-prepared support component in a solution containing the piezoelectric catalytic precursor, drying it, and then calcining and solidifying it at 400℃-600℃. This allows the piezoelectric crystal phase to grow in situ and anchor onto the support component, forming a primary composite. This step achieves high-temperature robust loading of the piezoelectric catalytic material.

[0027] Step S12 involves preparing a biomineralized phase using immobilization and encapsulation technology: First, mineralizing functional bacteria are cultured in a liquid culture medium with shaking at 30-35℃ for 24-48 hours to obtain a highly active bacterial solution. Then, 2%-5% sodium alginate and 1%-3% skim milk powder (by mass) are added to the highly active bacterial solution. The solution is then spray-dried at an air inlet temperature of 60-80℃ to obtain microcapsule bacterial powder, ensuring the bacteria are in a highly stable dormant spore state. Finally, the microcapsule bacterial powder is mixed evenly with 0.5%-2.0% calcium lactate powder. Calcium lactate not only acts as a carbon and calcium source to induce biomineralization but also rapidly regulates the microenvironment within the pores and activates spore reactivation in the early stages of rainwater intrusion.

[0028] Step S13: After the primary composite is cooled to room temperature, it is dry-mixed with the biomineralized phase, and the biomineralized phase is physically locked in by the micropores inside the carrier to obtain the core functional aggregate.

[0029] As a further improvement of the present invention, the precursor of the piezoelectric catalytic phase is BaTiO3, ZnO, PVDF or a precursor of at least two of the aforementioned composite materials.

[0030] As a further improvement of the present invention, the effective viable bacteria count of the biomineralized phase is ≥1.0×10⁻⁶. 9 CFU / g.

[0031] As a further improvement of the present invention, in step S12, the mineralizing functional bacteria include Bacillus mucilaginosus.

[0032] As a further improvement of the present invention, in step S12, the particle size of the microcapsule bacterial powder is 50-200 μm.

[0033] As a further improvement of the present invention, the hydrothermal reaction is carried out under saturated steam at 80-120°C for 6-48 hours. During the hydrothermal synthesis process, the alkalinity of carbide slag and the sulfate of gypsum are used to activate the slag and promote the transformation of hydration products into the zeolite phase.

[0034] As a further improvement of the present invention, the carrier component is porous particles rich in zeolite-like phase with a particle size of 1-5 mm.

[0035] As a further improvement of the present invention, the mass percentages of the mixture of slag, carbide slag, and desulfurized gypsum are as follows: slag 65%-75%, carbide slag 15%-25%, and desulfurized gypsum 5%-10%. Further, the slag is granulated blast furnace slag. This formulation utilizes the strongly alkaline environment provided by the carbide slag to initiate the depolymerization of the aluminosilicate framework in the slag. Under the sulfate activation effect of the desulfurized gypsum, it is transformed in situ into microporous particles rich in zeolite-like phases (such as analcime and clinoptilolite) through a hydrothermal reaction.

[0036] As a further improvement of the present invention, the thickness of the solid waste-based functionalized asphalt top layer is 4–8 cm, and it adopts a dense skeleton or semi-open gradation structure.

[0037] As a further improvement of the present invention, the binder is epoxy-modified asphalt, which gives the surface layer extremely high Marshall stability and fatigue crack resistance.

[0038] As a further improvement of the present invention, the coarse aggregate includes steel slag coarse aggregate with a particle size of 4.75-13.2mm that has undergone aging and rust removal treatment. Its high angularity and wear resistance provide skeleton strength, and the amount added is 75%-85% of the total material mass of the solid waste-based functionalized asphalt surface layer.

[0039] As a further improvement of the present invention, the filler includes fly ash, and the amount added is 2%-5% of the total material mass of the solid waste-based functionalized asphalt surface layer.

[0040] As a further improvement of the present invention, the additive is an amine-based anti-stripping agent, and the amount added is 0.3%-0.5% of the total mass of the solid waste-based functionalized asphalt surface layer material.

[0041] As a further improvement of the present invention, the amount of the core functional aggregate added is 5wt%-15wt% of the total material mass of the solid waste-based functionalized asphalt surface layer.

[0042] As a further improvement of the present invention, the thickness of the solid waste-based bitumen lower layer is 8–15 cm.

[0043] As a further improvement of the present invention, the components of the solid waste-based asphalt lower layer are binder, coarse aggregate, filler and additives, and do not contain the core functional aggregate.

[0044] As a further improvement of the present invention, the binder in the solid waste-based asphalt lower layer is epoxy-modified asphalt, the coarse aggregate includes steel slag coarse aggregate that has been aged and derusted, the filler includes fly ash, and the additive is an amine anti-stripping agent.

[0045] As a further improvement of the present invention, the thickness of the base layer is 15–30 cm.

[0046] As a further improvement of the present invention, the base layer is a cement-stabilized crushed stone semi-rigid base layer or an asphalt-stabilized crushed stone flexible base layer.

[0047] As a further improvement of the present invention, an interlayer functional bonding layer is provided between the base layer and the solid waste-based asphalt lower layer; further, the interlayer functional bonding layer is prepared by spraying at a rate of 0.4-0.6 kg / m³. 2The pavement consists of high-viscosity modified emulsified asphalt and single-particle steel slag particles with a diameter of 3-5 mm spread on it, with the steel slag particles covering 15%-25% of the surface. The steel slag particles serve as interlocking aggregate. This interlayer functional bonding layer enhances the shear strength between the two layers, preventing interlayer displacement or delamination under complex loads such as vehicle start-stop and steering, thus ensuring the long-term service life of the integrated structure-function pavement.

[0048] This invention discloses a method for preparing solid waste-based asphalt pavement with water purification function as described above, comprising the following steps:

[0049] Step S1: Spread the base course on the compacted roadbed surface and compact it.

[0050] Step S2: Lay the solid waste-based asphalt base course and compact it to a dense state using a heavy roller.

[0051] Step S3: The coarse aggregate, filler and binder at 160℃-180℃ are wet-mixed, and then the pre-treated core functional aggregate is added and mixed to obtain the upper layer mixture.

[0052] Step S4: Continuously spread the top layer mixture, using double steel wheel static pressure for initial compaction and rubber wheel kneading for secondary compaction. Strong vibration rolling is strictly prohibited. After molding, allow it to cool and cross-link naturally. The paving temperature of the top layer is controlled at 155℃-160℃.

[0053] As a further improvement of the present invention, step S1 further includes spraying the interlayer functional adhesive layer onto the base layer.

[0054] As a further improvement of the present invention, in step S3, before adding the core functional aggregate, it is subjected to a micro-atomized water spray treatment to reduce its moisture content to 3%-5%; and it is added in the last 15 seconds before the wet-mixed aggregate is discharged from the boiler, using a delayed admixture method for short-time mixing. When asphalt mixture at a temperature above 160°C is added, the moisture in the core functional aggregate vaporizes upon heating, absorbing a large amount of latent heat, thus reducing the instantaneous temperature of the internal microbial core area to a safe range. This method, in conjunction with the thermal barrier effect of the inorganic porous carrier, effectively resolves the contradiction between the high temperature of road construction and the heat resistance of biological materials, ensuring a high initial survival rate of the microbial community.

[0055] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0056] The technical solution of this invention achieves the goal of deep purification of rainwater runoff while realizing the high-value resource utilization of solid waste and ensuring the long-term safety and stability of the road structure. Its overall performance is significantly superior to existing technologies. Specifically, this is manifested in:

[0057] First, it achieves the synergistic utilization of all solid waste in a low-carbon manner: through systematic design, it synergistically utilizes a variety of bulk industrial solid wastes, including steel slag, fly ash, slag, carbide slag, and desulfurization gypsum, in different structural layers of the road surface, constructing a green material closed loop of waste-to-waste treatment, which significantly reduces resource consumption and environmental burden.

[0058] Secondly, a long-term and efficient purification mechanism has been established: through the synergistic effect of "piezoelectric degradation of organic matter" and "biomineralization to fix heavy metals," pollutants are decomposed or transformed into stable minerals. This effectively overcomes the bottleneck of traditional single physical adsorption being prone to saturation and failure, and significantly extends the effective service life of the road surface purification function.

[0059] Third, it expands the active catalytic purification function of the road surface: By introducing piezoelectric catalytic technology into asphalt pavement, it can actively collect the mechanical energy of vehicle rolling and tire vibration and convert it into chemical energy, directly catalytically degrading organic pollutants such as petroleum hydrocarbons in rainwater runoff, effectively improving the weakness of traditional environmental protection roads in treating surface-source organic pollutants.

[0060] Fourth, it ensures the high survival rate and long-term activity of microorganisms: The "step-by-step composite process" not only achieves effective anchoring of piezoelectric materials, but also utilizes the porous carrier combined with the "vaporization heat shielding" effect to provide good physical protection for microcapsule bacterial powder, enabling it to better resist the instantaneous high temperature and strong alkaline environment of hot-mix asphalt, thus ensuring a high biological survival rate.

[0061] Fifth, it takes into account both excellent road mechanical properties and durability: the surface layer uses epoxy modified asphalt and steel slag aggregate, which significantly improves the crack resistance, fatigue resistance and skid resistance of asphalt pavement, and solves the shortcoming of low strength of traditional asphalt pavement. Attached Figure Description

[0062] Figure 1 This is a schematic diagram of the structure of a solid waste-based asphalt pavement with water purification function according to an embodiment of the present invention.

[0063] The reference numerals in the figures include:

[0064] 1-Solid waste-based functionalized asphalt top layer, 2-Solid waste-based asphalt bottom layer, 3-Base layer, 4-Subgrade, 11-Carrier component, 12-Purification functional component. Detailed Implementation

[0065] The preferred embodiments of the present invention will be described in further detail below.

[0066] A solid waste-based asphalt pavement with water purification function adopts a layered functional design, such as... Figure 1As shown, from top to bottom, it includes: a solid waste-based functionalized asphalt top layer 1, a solid waste-based asphalt bottom layer 2, a base course 3, and a subgrade 4. The solid waste-based functionalized asphalt top layer 1 is a load-bearing and in-situ purification layer, containing core functional aggregates, and is composed of a carrier component 11 and a purification functional component 12. The solid waste-based asphalt bottom layer 2 is a compressive and fatigue-resistant layer, the base course 3 is a load-bearing layer, and the subgrade 4 is the soil base course.

[0067] The structural layer design and material composition are described in detail below.

[0068] The first layer: solid waste-based functionalized asphalt top layer 1 (hereinafter referred to as "top layer"), which bears the role of in-situ purification.

[0069] Thickness: 4–8cm.

[0070] Gradation design: Adopt a dense or semi-open gradation structure (such as modified SMA) with a designed porosity of 18%-25%.

[0071] Cementitious material: Epoxy-modified asphalt. Its addition amount is 4wt%-6wt% of the total mass of the solid waste-based functionalized asphalt surface layer. This cementitious material imparts extremely high Marshall stability, fatigue crack resistance, and heat resistance to the surface layer.

[0072] Coarse aggregate: aged rust-removed steel slag with a particle size of 4.75–13.2 mm is used. Its addition amount is 75wt%-85wt% of the total material mass of the top layer. Its high angularity and wear resistance provide skeleton strength.

[0073] Filler: Fly ash is used to replace traditional mineral powder, with an addition amount of 2wt%-5wt% of the total material mass of the upper layer, utilizing the microsphere effect to improve construction workability.

[0074] Additives: Amine-based anti-stripping agents are used, with an addition amount of 0.3wt%-0.5wt% of the total mass of the top layer material, to enhance the interfacial adhesion between steel slag and asphalt.

[0075] Core functional aggregate: The addition amount is 5wt%-15wt% of the total material mass of the upper layer. It is composed of "carrier component" and "purification functional component", realizing the unity of structural embedding and multi-dimensional synergistic purification.

[0076] Carrier component (solid waste-based porous ceramsite carrier): a high-strength porous particle carrier used to provide particle strength, pore structure and interfacial embedding conditions.

[0077] Optional raw materials: granulated blast furnace slag, carbide slag, desulfurized gypsum, and other industrial solid waste.

[0078] Function: In-situ synthesis of microporous particles rich in zeolite-like phase provides physical adsorption function, while also serving as a physical shelter and support substrate for purification functional components.

[0079] Purification functional component (piezoelectric catalysis and biomineralization composite component): It contains two core materials, a piezoelectric catalytic phase and a biological phase, which are loaded together on the surface and in the internal pores of the carrier component.

[0080] Piezoelectric catalytic materials: preferably piezoelectric catalytic active phases (such as BaTiO3, ZnO, PVDF, or composites of at least two of the aforementioned). These materials are used to generate charge separation and trigger catalytic reactions under mechanical action such as vehicle loads, vibrations, or raindrop impacts, primarily targeting the degradation of organic pollutants.

[0081] Compound microbial powder: mineralizing functional microbial powder (such as Bacillus subtilis) encapsulated in microcapsules. Activated under suitable humidity, it primarily targets the mineralization and fixation of heavy metal ions.

[0082] Synergistic effect: The carrier component provides physical adsorption and a high-strength structural framework, and serves as a physical shelter and load substrate for the purification component; in the purification component, the piezoelectric catalytic phase utilizes mechanical energy such as vehicle load and vibration to generate charge separation, inducing the generation of ROS (reactive oxygen species) to catalyze the degradation of organic pollutants in the runoff; the biomineralization phase utilizes metabolic activities to convert the heavy metal ions adsorbed by the carrier component into carbonate precipitation (biomineralization), achieving long-term fixation.

[0083] The core functional aggregate in the asphalt surface layer is composed of a carrier component, a piezoelectric catalytic component, and a biomineralization component in a mass ratio of 100:(2.0-5.0):(0.8-1.5).

[0084] The raw material ratio of the carrier component is as follows: 65%-75% granulated blast furnace slag, 15%-25% calcium carbide slag, and 5%-10% desulfurized gypsum. This ratio utilizes the strongly alkaline environment provided by the calcium carbide slag to initiate the depolymerization of the aluminosilicate skeleton in the slag. Under the sulfate activation effect of the desulfurized gypsum, it is transformed in situ into microporous particles rich in zeolite-like phases (such as analcime and clinoptilolite) through a hydrothermal reaction at 80-120℃.

[0085] The piezoelectric catalytic material is uniformly loaded and anchored on the surface and within the large pores of the support component.

[0086] The composite microbial powder is physically embedded in the deep micropores of the carrier components, with an effective viable count ≥1.0×10⁻⁶. 9 CFU / g.

[0087] Functional Effects: This specific formulation not only achieves a self-excited effect of "treating waste with waste" (without the need for external alkaline chemical reagents), but also produces a carrier with a well-developed pore structure and extremely high specific surface area. This multi-level pore structure provides ample catalytic reaction contact surface for the piezoelectric phase of the piezoelectric catalytic material, while its deep micropore size is highly matched with the microorganisms in the biomineralization phase, forming a perfect physical thermal shield. Ultimately, it achieves multi-dimensional synergy and self-regeneration of "physical adsorption-piezoelectric catalytic degradation-biomineralization fixation".

[0088] The second layer: the solid waste-based asphalt base layer, which is a compressive and fatigue-resistant layer.

[0089] Thickness: 8–15cm.

[0090] Material description: The gradation design and the binder, coarse aggregate, filler and additives used are the same as those of the surface layer, but it does not contain core functional aggregates and is specifically designed for the load-bearing structure of the pavement.

[0091] Third level: Basic level

[0092] Thickness: 15–30cm.

[0093] Materials: Cement-stabilized crushed stone semi-rigid base course or asphalt-stabilized crushed stone flexible base course.

[0094] Furthermore, an interlayer functional bonding layer is set between the solid waste-based asphalt base layer and the base layer. High-viscosity modified emulsified asphalt is used, with a application rate of 0.4-0.6 kg / m³. 2 Immediately after application, a small amount of single-diameter steel slag particles (3-5mm in diameter, with a coverage rate of 15%-25%) are spread as "interlocking aggregate." This interlayer functional bonding layer enhances the shear strength between the functional layer and the surface layer, preventing interlayer displacement or delamination under complex loads such as vehicle start-stop and steering, thus ensuring the long-term service life of the integrated "structure-function" pavement.

[0095] The core of this invention lies in the preparation of high-temperature resistant, long-lasting, self-regenerating multi-dimensional synergistic functional aggregates and their survival mechanism in hot-mix asphalt. A "stepped multi-dimensional composite process" is employed, with the specific steps as follows:

[0096] 1) Preparation of the carrier component:

[0097] Mixing: Dry mix slag, carbide slag, and desulfurized gypsum according to the designed proportions.

[0098] Hydrothermal synthesis: After adding water to form a slurry, it is cured under saturated steam at 80-120℃ for 6-48 hours. This process utilizes the alkalinity of carbide slag and the sulfate of gypsum to activate the slag and promote the transformation of hydration products into the zeolite phase.

[0099] Granulation: Crush and screen to obtain porous carrier particles of 1-5mm.

[0100] 2) High-temperature loading of piezoelectric catalytic phase:

[0101] Impregnation: The pre-prepared support components are impregnated in a solution containing piezoelectric catalytic precursors (such as BaTiO3, ZnO, etc.), and vacuum treatment is used to ensure that they fully penetrate the support surface and large pores.

[0102] Calcination: After drying, the piezoelectric crystal phase is calcined and solidified at 400℃-600℃ for a short time, so that the piezoelectric crystal phase grows in situ and is firmly anchored on the support component framework, forming a primary composite of "support component + piezoelectric catalytic phase".

[0103] 3) Microcapsule preparation of biomineralized phases (low-temperature dormancy stage):

[0104] The biomineralized phase (composite microbial agent) described in this invention is prepared using immobilization and embedding technology, and the specific steps are as follows:

[0105] Strain propagation: Bacillus mucilaginosus is cultured in liquid culture medium with shaking at 30-35℃ for 24-48 hours to obtain a highly active bacterial solution.

[0106] Microencapsulation: 2%-5% sodium alginate and 1%-3% skim milk powder by mass are added to the bacterial solution as a protective matrix. Active bacterial powder with a particle size of 50-200μm is obtained by centrifugal spray drying technology at an air inlet temperature of 60-80℃, ensuring that the bacteria are in a highly stable dormant spore state.

[0107] Activator formulation: Dry mix the above-mentioned bacterial powder with calcium lactate powder at a mass fraction of 0.5%-2.0% until homogeneous. Calcium lactate not only acts as a carbon and calcium source to induce biomineralization, but also rapidly regulates the microenvironment within the pores and activates spore regeneration in the early stages of rainwater intrusion.

[0108] Functional effects: Through microencapsulation, microorganisms can withstand the instantaneous high temperature during road construction and the dry and highly alkaline environment during service, ensuring long-term biological activity.

[0109] 4) Multi-dimensional composite of all components and pre-wetting treatment (functional aggregate molding):

[0110] Dry compounding: After the primary composite of "carrier component + piezoelectric catalytic phase" has completely cooled to room temperature, it is dry-mixed with the biomineralized phase in a certain proportion. The remaining deep micropores of the carrier physically "lock" in the bacterial powder of the biomineralized phase, forming a complete core functional aggregate of "carrier component + piezoelectric catalytic phase + biomineralized phase".

[0111] Vaporization pre-humidification: The composite aggregate is treated with micro-atomized water spray to control its moisture content at 3%-5%, with the moisture mainly stored in the pores of the carrier for later use.

[0112] 5) Layered mixing and controlled paving of the mixture:

[0113] Base course and sub-base course laying: The base course is laid and compacted, and after the bonding layer is applied, the sub-base course is conventionally hot-mixed and spread, and then compacted using a heavy roller.

[0114] Top layer thermal barrier mixing (post-mixing method): First, coarse aggregate, filler and epoxy modified asphalt at 160℃-180℃ are wet-mixed at high temperature; in the last 15 seconds before the mixture is about to be discharged from the pot, the pre-wetted core functional aggregate is quickly added and mixed for a short time before being discharged from the pot.

[0115] Protection mechanism: When high-temperature asphalt comes into contact with functional aggregates, the moisture in the pores rapidly vaporizes and absorbs a large amount of latent heat, forming a microscopic instantaneous cooling zone. Combined with the low thermal conductivity of the inorganic skeleton, the instantaneous temperature of the core area of ​​the biomineralized phase is reduced to a safe range, ensuring a high survival rate of microorganisms.

[0116] Top layer paving: Control the paving temperature between 155℃ and 160℃. Use double steel wheel static pressure for initial compaction and rubber wheel kneading for secondary compaction. Strong vibration rolling is strictly prohibited to avoid crushing the porous carrier structure. After molding, allow it to cool naturally and cross-link.

[0117] The water purification function of this invention exhibits a three-dimensional synergistic mechanism of "piezoelectric catalysis-adsorption exchange-biomineralization" in actual service:

[0118] 1) Piezoelectric catalytic degradation stage: Under the mechanical action of vehicle cyclic load, tire vibration and other factors, the piezoelectric catalytic phase is polarized to generate surface charge, which induces water and dissolved oxygen in the runoff to generate reactive oxygen species (ROS), actively and efficiently degrading organic pollutants such as petroleum hydrocarbons (TPH) in the runoff.

[0119] 2) Physical adsorption stage: The zeolite-like phase in the support component utilizes the charge imbalance within the crystal lattice to rapidly capture heavy metal cations (M...) in the runoff through ion exchange. 2+ ) and NH4⁺.

[0120] 3) Biomineralization stage: The dormant biomineralized phase is awakened by rainwater, secreting ammonia-producing enzymes to increase the local pH value. The generated CO2 is converted into CO3 in the alkaline environment. 2- .

[0121] The reaction equation is: M 2+ (Adsorbed state) + CO3 2- → MCO3↓ (solid minerals).

[0122] This reaction permanently solidifies heavy metals into carbonate precipitates, which fill the large pores, thereby continuously freeing up highly active adsorption sites on the zeolite surface and realizing the long-term recycling of the road surface purification system.

[0123] The following description uses specific examples and comparative models for illustration.

[0124] Example 1

[0125] A solid waste-based asphalt pavement with water purification function, the specific preparation and construction process includes:

[0126] 1. Core Function: Aggregate Prefabrication

[0127] Component A (zeolite carrier): Dry mix slag, carbide slag, and desulfurized gypsum in a ratio of 70:20:10 (by mass), add water to form a mold, and then hydrothermally cure in an autoclave at 100℃ for 24 hours. Finally, crush and sieve to 2-5mm.

[0128] Component B1 (piezoelectric catalytic phase) loading: The above-mentioned component A particles were impregnated in a barium titanate (BaTiO3) precursor solution, and vacuum was applied to ensure full penetration. After drying, the mixture was calcined and solidified at 500℃ for a short time to allow the piezoelectric crystal phase to grow in situ and be firmly anchored. It was then naturally cooled to room temperature for later use (the mass ratio of A:B1 was controlled at 100:3).

[0129] Component B2 (biomineralized phase): 3 wt% sodium alginate and 2 wt% skim milk powder were added to Bacillus mucilage solution and spray-dried at 70°C to prepare dormant microcapsules, which were then mixed with 1 wt% calcium lactate.

[0130] Composite and pre-wetting: The cooled "A+B1" primary composite and component B2 are dry-mixed at a mass ratio of 103:1 (i.e., A is 100, B1 is 3, and B2 is 1) to lock the bacterial powder into the deep micropores through physical embedding; then, water is sprayed by atomization to adjust the moisture content of the core functional aggregate to 4% for later use.

[0131] 2. Layered mixing of the mixture

[0132] Base materials: Both the upper and lower layers use the same dense gradation. The aggregate is 100% aged steel slag, the filler is 3% fly ash, and the binder is epoxy-modified asphalt.

[0133] Asphalt base course mixing: Dry mix steel slag heated to 170℃ with fly ash, spray in epoxy modified asphalt at 170℃ and wet mix for 60 seconds, then remove directly from the pot.

[0134] Asphalt surface layer mixing: Prepare 5 wt% epoxy modified asphalt, 81.5 wt% steel slag coarse aggregate, 3 wt% fly ash filler, 0.5 wt% amine anti-stripping agent, and 10 wt% pre-wetted core functional aggregate. During mixing, first, the coarse aggregate, filler, anti-stripping agent, and asphalt are conventionally wet-mixed at 170℃ for 40 seconds; in the last 15 seconds before the mixture is removed from the pot, the pre-wetted core functional aggregate is quickly added, utilizing the heat absorption of water vaporization to form a thermal barrier, and the mixture is immediately removed from the pot after a short mixing time.

[0135] 3. Spreading and shaping

[0136] Base course: On the compacted subgrade, lay a semi-rigid base course (cement-stabilized crushed stone) or a flexible base course (asphalt-stabilized crushed stone), compact it, and make it 20cm thick.

[0137] Undercoat: Sprinkle 0.5 kg / m² of high-viscosity modified emulsified asphalt on the base layer, and immediately spread 4 mm single-particle-size steel slag.

[0138] Asphalt base course paving: Pave the base course mixture to a thickness of 10cm and compact it to a dense state using a heavy roller.

[0139] Asphalt surface layer paving: Continuously pave the surface layer mixture to a thickness of 6cm at a paving temperature of 155℃-160℃. Initial compaction is achieved using double steel wheel static pressure, followed by secondary compaction using rubber-tired rollers (strong vibration is strictly prohibited), and then natural cooling for cross-linking and curing.

[0140] Comparative Example 1

[0141] This comparative example breaks the "self-excitation" equilibrium of component A—low-alkali excitation—based on Example 1. Specifically, the difference from Example 1 is as follows:

[0142] Component A raw materials: 90wt% slag + 10wt% desulfurized gypsum (to remove carbide slag and simulate an environment without strong alkali activation).

[0143] All other conditions and the proportions of each component are the same as in Example 1.

[0144] Comparative Example 2

[0145] This comparative example breaks the "self-excitation" equilibrium of component A—chemical strong base excitation—based on Example 1. The specific difference from Example 1 is as follows:

[0146] Component A raw materials: 100wt% slag + sodium hydroxide (NaOH) activator (using strong chemical alkali to replace solid waste carbide slag).

[0147] All other conditions and the proportions of each component are the same as in Example 1.

[0148] Comparative Example 3

[0149] This comparative example breaks away from the limitations of Example 1, which had an insufficient amount of biomineralized phase in the composite ratio of each component. Specifically, it differs from Example 1 in that:

[0150] Core functional aggregate composite ratio: Carrier A: Piezoelectric phase B1: Biological phase B2 = 100:3:0.1 (mass ratio). Other conditions are the same as in Example 1.

[0151] Comparative Example 4

[0152] This comparative example breaks away from the excessive proportions of components and biomineralized phases in Example 1. Specifically, it differs from Example 1 in that:

[0153] Core functional aggregate composite ratio: Carrier A: Piezoelectric phase B1: Biological phase B2 = 100:3:5 (mass ratio). Other conditions are the same as in Example 1.

[0154] Comparative Example 5

[0155] This comparative example uses a conventional mixing method based on existing technology. Specifically, it differs from Example 1 in that:

[0156] The microencapsulation process for component B2 was eliminated, as were the "atomized water spray pre-wetting" and "delayed post-mixing method". Equal amounts of pure Bacillus coumarin powder were directly added to the mixing drum along with 170°C steel slag aggregate and epoxy asphalt during the initial stage of hot mixing for conventional hot mixing (mixing time approximately 60 seconds).

[0157] Other conditions are the same as in Example 1.

[0158] Comparative Example 6

[0159] This comparative example, designed to verify the multidimensional purification synergistic mechanism, removes the piezoelectric catalytic phase. Specifically, it differs from Example 1 in that:

[0160] The high-temperature impregnation and calcination loading steps of component B1 are eliminated. The pre-prepared component A and component B2 (at a ratio of 100:1) are directly pre-wetted and compounded.

[0161] Other conditions are the same as in Example 1.

[0162] The performance of the "purification-functional composite aggregates" prepared in Example 1 and the comparative examples, as well as the resulting pavement mixtures, was tested. The test indicators focused on evaluating their survival rate under high-temperature hot-mix conditions, their mechanical and chemical compatibility as aggregates for asphalt surface layers, and their piezoelectric catalytic degradation ability under simulated traffic dynamic loads. Specifically, these included:

[0163] 1) Crushing value of composite aggregate particles.

[0164] 2) Survival rate of microorganisms after hot-mix paving.

[0165] 3) Heavy metal removal rate (in Zn) 2+ (For example).

[0166] 4) Ambient pH value.

[0167] 5) Degradation rate of organic pollutants (taking total petroleum hydrocarbons (TPH) as an example, with a simulated dynamic load of 10Hz applied).

[0168] Table 1 Performance Test Comparison

[0169]

[0170] A comparison of the data in Table 1 shows that:

[0171] (1) Effectively solves the problem of microbial inactivation under high temperature hot mixing conditions (Example 1 and Comparative Example 5)

[0172] In existing technologies, directly applying biomaterials to hot-mix asphalt processes results in near-complete inactivation of microorganisms (e.g., survival rate <0.1% in Comparative Example 5). This invention utilizes the synergistic effect of "porous carrier physical encapsulation + pre-wetting moisture vaporization endothermic + delayed admixture method" to create localized cooling micro-zones when the composite aggregate comes into contact with 170°C high-temperature asphalt. This mechanism effectively isolates the instantaneous high temperature, maintaining the survival rate of B2 microorganisms at 92.0% after hot-mix paving, overcoming the technical deficiency of conventional biomaterials' inability to withstand hot-mix construction.

[0173] (2) Active utilization of transportation mechanical energy and degradation of organic matter were realized (Example 1 and Comparative Example 6)

[0174] Comparative Example 6, lacking the B1 piezoelectric phase, achieved a total petroleum hydrocarbon (TPH) removal rate of only 12.4% (primarily relying on the limited physical retention of the carrier). In contrast, Example 1, under simulated dynamic load triggering, induced the generation of reactive oxygen species through polarization charges generated by the piezoelectric crystal phase, significantly increasing the TPH removal rate to 88.5%. This demonstrates that introducing piezoelectric catalytic materials can effectively utilize transportation mechanical energy to achieve the catalytic degradation of non-point source organic pollutants.

[0175] (3) Achieving bidirectional adaptation between "high intensity and micro-ecology" (Example 1 and Comparative Examples 1 and 2)

[0176] The preparation of conventional geopolymer carriers often faces a contradiction between "high strength" and "biocompatibility." Traditional chemical strong alkali activation (Comparative Example 2, pH > 12.5) destroys the microbial cell structure, leading to inactivation; while the lack of strong alkali activation (Comparative Example 1) prevents the formation of a high-strength zeolite phase, resulting in a crushing value as high as 35.2%, which is insufficient to meet the requirements for road surface aggregates. This invention utilizes the "solid-waste synergistic activation" of carbide slag and desulfurized gypsum to synthesize a high-strength framework in situ (reducing the crushing value to 18.5%) while controlling the carrier's pore microenvironment at around pH 8.5, effectively meeting the suitable environmental requirements for enzyme production by B2 mineralizing bacteria.

[0177] (4) Defining the critical threshold of “structure-function” (Example 1 and Comparative Examples 3 and 4)

[0178] Tests show that a reasonable component ratio represents the optimal balance between mechanical properties and multidimensional purification functions. When the proportion of B2 bacterial powder is too low (Comparative Example 3, 100:3:0.1), the biomineralization rate lags behind physical adsorption, with a heavy metal removal rate of only 38.6%. When the proportion of B2 bacterial powder is too high (Comparative Example 4, 100:3:5), the excessive organic microcapsule powder not only forms a "soft lubricating film" at the interface, leading to an excessive crushing value (28.6%), but also covers the surface of the B1 piezoelectric phase, hindering charge transfer and causing the TPH degradation rate to drop to 65.4%. Specific formulations ensure the effective synergy of structural load-bearing capacity, piezoelectric catalysis, and biomineralization functions.

[0179] To verify the technical effect of the present invention, we conducted a comparative test between the solid waste-based pavement prepared by the present invention (referred to as the "experimental group") and the traditional ordinary asphalt pavement (referred to as the "control group").

[0180] 1. Experimental group setup

[0181] Control group (ordinary open-graded pavement): OGFC-13 permeable surface layer using conventional SBS modified asphalt and natural basalt aggregate, without any functional materials.

[0182] Experimental group: Composite surface layer structure prepared in Example 1 (i.e., asphalt surface layer containing multidimensional composite functional aggregates)

[0183] 2. Comparison of road mechanical properties (Marshall test and water stability)

[0184] Table 2 Comparison of road mechanical performance parameters

[0185]

[0186] As can be seen from the data comparison in Table 2, the Marshall stability and dynamic stability of the experimental group were significantly improved compared with those of the control group. This is due to the irreversible high-strength cross-linked network formed after the epoxy resin asphalt is cured, which perfectly compensates for the strength loss caused by the semi-open gradation pores; at the same time, the extremely high crushing value and angularity of the steel slag coarse aggregate constitute a robust skeleton. This proves that the present invention is capable of being applied to heavy-load traffic sections of high-grade highways.

[0187] 3. Comparison of water purification efficiency (removal of heavy metals, nutrients, and organic matter)

[0188] Test method: Prepare simulated runoff rainwater containing high concentrations of pollutants (Pb). 2+ 2mg / L, Cu 2+ 2mg / L, Zn 2+ 5 mg / L, and NH4 + -N: 10 mg / L and total petroleum hydrocarbons (TPH) of organic pollutants: 15 mg / L. Under simulated traffic vibration load (frequency 10 Hz), the pollutants were leached through two sets of road structures at the same flow rate, and the pollutant concentrations in the effluent were measured. The results are shown in Table 3.

[0189] Table 3 Comparison of Water Purification Efficiency

[0190]

[0191] The following conclusions can be drawn from the comparison of the data in Table 3:

[0192] (1) Heavy metal removal: The control group mainly relied on physical interception, and the removal rate of dissolved heavy metals was extremely low (<20%). However, the experimental group of this invention utilized the ion exchange effect of geopolymer zeolite in the functional surface layer to increase the removal rate of Pb²⁺, Zn²⁺ and other metals to over 90%.

[0193] (2) Ammonia nitrogen removal: Zeolite carriers have a specific adsorption capacity for ammonium ions, which, combined with the local microecological metabolism of microbial communities, solves the problem that ordinary road surfaces cannot remove ammonia nitrogen.

[0194] (3) Degradation of organic pollutants: The control group showed limited effectiveness in removing petroleum hydrocarbon organic matter from runoff. In contrast, under simulated traffic dynamic loads, the piezoelectric catalytic phase inside the asphalt surface layer of the experimental group underwent a polarization reaction, and the generated reactive oxygen species (ROS) promoted the degradation of organic pollutants. This mechanism significantly increased the TPH removal rate to 88.5%, effectively improving the shortcomings of conventional environmentally friendly pavements in treating non-point source organic pollutants.

[0195] 4. Purification long-term effect test (synergistic effect of piezoelectric catalysis and biomineralization)

[0196] Test objective: To verify the synergistic effect of piezoelectric catalysis and biomineralization mechanisms on extending the life of pavement cleanliness.

[0197] Methods: Continuous water leaching was conducted under simulated traffic dynamic load (10Hz) to simulate the cumulative scouring equivalent to two years of rainfall. The removal rates of heavy metals and organic pollutants (in terms of Zn) were periodically tested. 2+ (Taking TPH as an example), the results are shown in Table 4.

[0198] Table 4 Comparison of Purification Long-Term Effectiveness Tests

[0199]

[0200] As can be seen from the data comparison in Table 4, after long-term operation, the control group's pavement showed a significant decline in its ability to remove heavy metals and organic matter due to the gradual saturation of physical adsorption and pore blockage, almost completely failing after two years of simulation. In contrast, the experimental group, after two years of simulated operation, showed a significant improvement in its ability to remove Zn. 2+ The removal rates of both TPH and piezoelectric agents remained above 86%. This indicates that, on the one hand, the microbial agents in the asphalt surface layer effectively promoted the mineralization reaction, converting adsorbed heavy metals into stable carbonate precipitates and alleviating the problem of carrier adsorption saturation; on the other hand, the piezoelectric catalytic phase exhibited relatively stable physical catalytic degradation characteristics under long-term loading, and was not easily washed away or significantly degraded. The synergistic effect of both maintained the long-term effectiveness of the pavement purification function.

[0201] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A solid waste-based asphalt pavement with water purification function, characterized in that: From top to bottom, it consists of a solid waste-based functionalized asphalt surface layer, a solid waste-based asphalt bottom layer, a base course, and a subgrade. The solid waste-based functionalized asphalt top layer comprises binder, coarse aggregate, filler, additives, and core functional aggregate; the solid waste-based asphalt bottom layer comprises binder, coarse aggregate, filler, and additives; wherein the binder is epoxy-modified asphalt, the coarse aggregate includes steel slag coarse aggregate treated with aging and rust removal, the filler includes fly ash, and the additive is an amine anti-stripping agent; the coarse aggregate includes steel slag coarse aggregate; The core functional aggregate is obtained by combining a carrier component, a piezoelectric catalytic phase and a biomineralization phase in a mass ratio of 100:(2.0-5.0):(0.8-1.5). The carrier component is synthesized by hydrothermal reaction of a mixture of slag, carbide slag and desulfurized gypsum with water, and then obtained by crushing and screening. The core functional aggregate is prepared using the following steps: Step S11: The pre-prepared support component is immersed in a solution containing a piezoelectric catalytic precursor, dried, and calcined at 400℃-600℃ to solidify, so that the piezoelectric crystal phase grows in situ and is anchored on the support component to form a primary composite; the piezoelectric catalytic precursor is BaTiO3, ZnO, PVDF, or a precursor of at least two of the aforementioned composite materials. Step S12: The mineralizing functional bacteria are cultured in a liquid culture medium with shaking at 30-35℃ for 24-48 hours to obtain a highly active bacterial solution; 2%-5% sodium alginate and 1%-3% skim milk powder are added to the highly active bacterial solution, and microcapsule bacterial powder is prepared by centrifugal spray drying at an air inlet temperature of 60-80℃; the microcapsule bacterial powder is then mixed evenly with 0.5%-2.0% calcium lactate powder to obtain a biomineralized phase; the mineralizing functional bacteria include Bacillus mucilaginosus; Step S13: After the primary composite is cooled to room temperature, the primary composite is dry-mixed with the biomineralized phase, and the biomineralized phase is physically locked in by the micropores inside the carrier to obtain the core functional aggregate.

2. The solid waste-based asphalt pavement with water purification function according to claim 1, characterized in that: The effective viable bacteria count of the biomineralized phase is ≥1.0×10⁻⁶. 9 CFU / g.

3. The solid waste-based asphalt pavement with water purification function according to claim 1, characterized in that: In step S12, the particle size of the microcapsule bacterial powder is 50-200 μm.

4. The solid waste-based asphalt pavement with water purification function according to claim 1, characterized in that: The hydrothermal reaction is carried out under saturated steam at 80-120℃ for 6-48 hours; the carrier component is porous particles rich in zeolite-like phase with a particle size of 1-5mm. The mass percentages of the mixture of slag, carbide slag, and desulfurized gypsum are as follows: slag 65%-75%, carbide slag 15%-25%, and desulfurized gypsum 5%-10%.

5. The solid waste-based asphalt pavement with water purification function according to claim 1, characterized in that: The thickness of the solid waste-based functionalized asphalt top layer is 4–8 cm; The coarse aggregate includes steel slag coarse aggregate with a particle size of 4.75-13.2mm. The steel slag coarse aggregate has undergone aging and rust removal treatment, and its addition amount is 75%-85% of the total material mass of the solid waste-based functionalized asphalt surface layer. The amount of filler added is 2%-5% of the total mass of the solid waste-based functionalized asphalt surface layer material; The amount of the additive added is 0.3%-0.5% of the total mass of the solid waste-based functionalized asphalt surface layer material; The amount of the core functional aggregate added is 5%-15% of the total material mass of the solid waste-based functionalized asphalt surface layer.

6. The solid waste-based asphalt pavement with water purification function according to claim 1, characterized in that: The thickness of the solid waste-based asphalt base layer is 8–15 cm; the thickness of the base layer is 15–30 cm; the base layer is a cement-stabilized crushed stone semi-rigid base layer or an asphalt-stabilized crushed stone flexible base layer.

7. The solid waste-based asphalt pavement with water purification function according to claim 1, characterized in that: An interlayer functional bonding layer is provided between the base layer and the solid waste-based asphalt lower layer; the interlayer functional bonding layer is composed of high-viscosity modified emulsified asphalt with a spraying rate of 0.4-0.6 kg / m² and single-particle-size steel slag particles with a particle size of 3-5 mm spread on it, and the coverage rate of the steel slag particles is 15%-25%.

8. The method for preparing solid waste-based asphalt pavement with water purification function according to any one of claims 1 to 7, characterized in that, Includes the following steps: Step S1: Spread the base course on the compacted roadbed surface and compact it. Step S2: Lay the solid waste-based asphalt base course and compact it to a dense state using a heavy roller. Step S3: The coarse aggregate, filler, additives and binder at 160℃-180℃ are wet-mixed, and then the pre-treated core functional aggregate is added and mixed to obtain the upper layer mixture. Step S4: The top layer mixture is continuously spread using a combination of static pressure from double steel wheels and kneading and pressing with rubber wheels. After molding, it is naturally cooled and cross-linked. The spreading temperature is 155℃-160℃.

9. The method for preparing solid waste-based asphalt pavement with water purification function according to claim 8, characterized in that: Step S1 further includes applying an interlayer functional adhesive layer to the base layer; the interlayer functional adhesive layer is applied at a rate of 0.4-0.6 kg / m³. 2 It consists of high-viscosity modified emulsified asphalt and single-particle steel slag particles with a particle size of 3-5 mm spread on it, wherein the coverage of the steel slag particles is 15%-25%; In step S3, the pre-treated core functional aggregate is in a pre-wetted state after being treated with micro-atomized water spraying, and the moisture content of the core functional aggregate is 3%-5%; and the core functional aggregate is added in the last 15 seconds before the wet-mixed mixture is discharged from the pot, and the mixture is mixed by post-mixing.

Images