Warm mix asphalt mixture based on construction waste recycled micro powder as functional filler

Abstract

The invention discloses a warm mix asphalt mixture based on construction waste recycled micropowder as a functional filler in the field of road engineering materials. The mixture comprises the following main raw materials: matrix asphalt, a dynamic imine crosslinking type warm mixing modifier, a siloxane-asphaltene amphiphilic coupling agent, alkali activation-esterification activity regenerated micro powder, waste plastic particles and waste tire rubber powder, as well as limestone gravel, steel slag sand and limestone mineral powder in a specific proportion. Wherein the three functional compounds respectively play key roles in reducing viscosity by warm mixing, self-repairing, strengthening interface adhesion and activating filler, and have a synergistic interaction with the waste plastic and the waste tire rubber powder. The preparation method comprises the following steps: preparing composite modified asphalt from three modifiers and asphalt, and mixing the composite modified asphalt with aggregate, filler and the like at a temperature obviously lower than that of hot-mix asphalt to finally obtain the high-performance warm-mix asphalt mixture. According to the invention, high value-added resource utilization of the construction waste, the waste plastics and the waste tires is realized.

Description

Technical Field

[0001] This invention belongs to the field of road engineering materials technology, specifically relating to a warm-mix asphalt mixture based on recycled construction waste micropowder as a functional filler. Background Technology

[0002] With the continuous acceleration of urbanization and infrastructure construction in my country, the amount of construction waste generated has reached an astonishing scale, making its resource utilization a major issue concerning sustainable economic and social development. Recycled micropowder, produced after crushing and sorting construction waste, is the most challenging link in the current resource utilization chain due to its small particle size, complex composition, and low activity. Traditional disposal methods mainly involve landfilling or using it as a raw material for low-end building materials, resulting in extremely low added value and environmental risks. In recent years, some studies have attempted to use it as a mineral filler in asphalt mixtures to replace some stone powder, but the results have been unsatisfactory. Unmodified recycled micropowder has an inert surface, weak interfacial adhesion with asphalt, and may contain harmful impurities. Direct incorporation often leads to decreased adhesion of asphalt mastic, and damage to the water stability and long-term durability of the mixture. Therefore, how to activate the potential value of recycled micropowder from construction waste through effective technical means, transforming it from a "burden" into a "functional resource," is one of the core bottlenecks that urgently need to be overcome in the field of solid waste resource utilization and green building materials.

[0003] In the field of road engineering, warm-mix asphalt technology, which reduces energy consumption in asphalt mixture production and construction, has received widespread attention. This technology, by mixing and compacting at temperatures lower than traditional hot-mix asphalt, can significantly reduce fuel consumption and emissions of greenhouse gases and asphalt fumes, demonstrating significant environmental advantages. However, existing warm-mix technologies still face common challenges: many physical or chemical warm-mix agents, while effectively reducing the high-temperature viscosity of asphalt, may negatively impact key road performance characteristics such as the low-temperature performance and elastic recovery of the asphalt colloidal system, exhibiting a "one-sided" deficiency. The problem is even more complex when warm-mix technology is combined with solid waste modification. Lower mixing temperatures are not conducive to the melting and dispersion of waste plastic particles and the full swelling of waste tire rubber powder, significantly reducing the modification effect of solid waste and even affecting the uniformity of the mixture. Therefore, developing a synergistic technology that can both guarantee significant warm-mix effects and be compatible with or even enhance the efficiency of solid waste modification is crucial for promoting the development of green, low-carbon, high-performance asphalt pavements.

[0004] Currently, research has been conducted on the comprehensive utilization of various solid wastes (such as waste plastics and waste tire rubber powder) to modify asphalt, aiming to achieve "waste treatment with waste" and improve the overall performance of asphalt mixtures. However, existing technologies mostly remain at the level of simple physical blending of several wastes, lacking in-depth design considering the interaction mechanisms between the characteristics of different wastes and asphalt. Poor interfacial compatibility between components makes it difficult to form a stable and synergistic reinforcing system. The process often requires extremely high temperatures or long-term high-pressure shearing, which is not only energy-intensive but also prone to polymer degradation. More importantly, when low-activity recycled construction waste powder is compounded with the aforementioned polymer wastes, the system becomes more complex, the interfacial problems become more prominent, and performance shortcomings are easily encountered. In summary, there is an urgent need for an innovative systematic solution that can build a bridge connecting asphalt, various solid waste fillers, and polymer modification from the molecular design level. This solution should ensure that the final composite material has excellent and balanced high and low temperature performance, durability, and volume stability while achieving low-temperature friendly construction, thereby truly opening up a technical path for the high-value-added resource utilization of various solid wastes such as construction waste in asphalt pavements. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a warm-mix asphalt mixture based on recycled construction waste micropowder as a functional filler.

[0006] In a first aspect, the present invention provides a warm-mix asphalt mixture based on recycled construction waste powder as a functional filler, comprising the following raw materials in parts by weight:

[0007] Base asphalt: 80-120 parts by weight;

[0008] Dynamic imine crosslinking type warm stir modifier: 1.5-3.0 parts by weight;

[0009] Siloxane-asphaltic amphiphilic coupling agent: 0.5-2.0 parts by weight;

[0010] Alkali-activated esterified active regenerated micro powder: 20-50 parts by weight;

[0011] Waste plastic pellets: 2-8 parts by weight;

[0012] Waste tire rubber powder: 4-12 parts by weight;

[0013] Limestone crushed stone: 40-50 parts by weight;

[0014] Steel slag sand: 30-55 parts by weight;

[0015] Limestone powder: 10-30 parts by weight.

[0016] As a preferred technical solution of the present invention, the preparation method of the dynamic imine crosslinking warm-stir modifier includes: A1, adding polyether diamine and anhydrous xylene to a reactor under an argon atmosphere, heating to 78-82°C to dissolve; adding a xylene solution containing 1,3,5-benzenetriformaldehyde dropwise; heating to 110-120°C and refluxing to obtain a reaction solution; A2, cooling the reaction solution to 35-40°C, precipitating it in petroleum ether, filtering to obtain a solid product, washing the solid product with petroleum ether, and vacuum drying at 38-42°C.

[0017] In this invention, the preparation of a dynamic imine crosslinking warm-stir modifier is based on a nucleophilic addition-dehydration condensation reaction between an amine and an aldehyde, constructing a dynamic and reversible imine crosslinking network. Using polyether diamine and 1,3,5-benzenetriformaldehyde containing three aldehyde groups as the main raw materials, the amino groups at both ends of the polyether diamine molecular chain react with the aldehyde groups of the aromatic aldehyde under heating and an inert atmosphere. During the reaction, the nitrogen atom in the amino group nucleophilically attacks the carbon atom of the aldehyde group, forming an unstable intermediate, which then rapidly loses a water molecule to generate a stable carbon-nitrogen double bond, i.e., an imine bond. Since the aromatic aldehyde used has three aldehyde groups, and the polyether diamine is bifunctional, the reaction can form a crosslinked polymer with a three-dimensional network structure. The key to this reaction is the continuous removal of the generated water to drive the reaction equilibrium towards the formation of imine bonds, ensuring a product with an ideal crosslinking density. The unique feature of this dynamic imine bond is its reversibility; that is, under certain thermal excitation, this chemical bond can undergo reversible breaking and recombination. When the prepared solid product is added to hot asphalt, some imine bonds reversibly break at the mixing temperature of the mixture, significantly reducing the entanglement and interaction forces between the modifier molecular chains, thereby greatly reducing the apparent viscosity of the asphalt mastic and achieving a warm-mix effect. At the ambient temperature of the road surface during service, these broken imine bonds can recombine, restoring and strengthening the elastic network structure of the asphalt mastic. This not only improves the material's high-temperature deformation resistance but also endows it with potential self-healing properties, which are extremely beneficial for the healing of microcracks.

[0018] As a preferred embodiment of the present invention, in step A1, the mass ratio of polyether diamine to 1,3,5-benzenetriformaldehyde is 100:(8-12).

[0019] As a preferred embodiment of the present invention, in step A2, the vacuum drying time at 38-42°C is 24-30 hours.

[0020] As a preferred technical solution of the present invention, the preparation method of the siloxane-asphaltene amphiphilic coupling agent includes: B1, adding aminopropyltriethoxysilane and anhydrous tetrahydrofuran to a reaction flask and cooling to 0-5°C; adding dropwise a solution composed of stearoyl chloride and anhydrous tetrahydrofuran; after the addition is complete, heating to room temperature for reaction; B2, after the reaction is complete, rotary evaporating under reduced pressure at 38-42°C to obtain the product, dissolving the product in dichloromethane and then rotary evaporating again.

[0021] In this invention, the preparation of the siloxane-asphaltene amphiphilic coupling agent primarily involves the amidation reaction of an amine with an acyl chloride to construct an amphiphilic molecular structure possessing both inorganic and organic affinity. The reaction is carried out under low-temperature, anhydrous conditions, using a silane containing an amino group and three ethoxy groups as raw materials and an acyl chloride of a long-chain fatty acid. During the reaction, the terminal amino group of the silane molecule acts as a nucleophile, attacking the highly activated carbonyl carbon atom in the acyl chloride molecule, subsequently leading to the departure of the chloride ion and the formation of a stable amide bond, while simultaneously generating the byproduct hydrogen chloride. By controlling the low-temperature dropwise addition and subsequent purification steps, the reaction can be ensured to proceed smoothly and obtain a high-purity target product. Thus, a long-chain alkyl group is successfully covalently grafted onto a silane molecule via an amide bond. The resulting coupling agent molecule thus possesses a unique "bipolar affinity" structure: one end is a long alkyl chain derived from long-chain fatty acids, whose chemical structure is similar to the main asphaltenes in asphalt. According to the principle of "like dissolves like," it can generate strong physical adsorption and good compatibility with asphalt. The other end retains intact triethoxysilane groups. During the mixing process of asphalt mixtures, especially in the presence of trace amounts of moisture, these three ethoxy groups will gradually hydrolyze to generate highly reactive silanol groups. These silanol groups can undergo dehydration condensation reactions with inorganic fillers such as recycled construction waste powder and steel slag sand, as well as the hydroxyl groups on the surface of aggregates, to form strong siloxane covalent bonds. It is through this chemical bridging effect of "amide bond-long alkyl chain" and "siloxane bond" that the coupling agent greatly enhances the interfacial adhesion between the originally poorly compatible inorganic fillers and organic asphalt matrix, fundamentally improving the water stability and durability of the mixture.

[0022] As a preferred embodiment of the present invention, in step B1, the mass ratio of aminopropyltriethoxysilane to stearoyl chloride is 5:(2-3).

[0023] As a preferred embodiment of the present invention, in step B2, the time for rotary evaporation under reduced pressure at 38-42°C is 2-4 hours.

[0024] As a preferred technical solution of the present invention, the preparation method of the alkali-activated-esterified active regenerated micro powder includes: C1, calcining the construction waste regenerated micro powder at 740-760℃ and cooling to obtain an active matrix; adding the active matrix to a mixer, adding an alkali activator composed of sodium hydroxide, sodium silicate and deionized water, and wet mixing to obtain a wet mixture; C2, allowing the wet mixture to stand at 78-82℃ to obtain a standing material; drying the standing material at 104-106℃, putting it into a mixer at 58-62℃, adding an ethanol solution of isopropyl tris(dioctyl pyrophosphate oxy) titanate, and reacting at 80-90℃; finally, vacuum drying at 58-62℃, crushing and sieving.

[0025] As a preferred embodiment of the present invention, the mass ratio of isopropyltris(dioctylpyrophosphoryloxy)titanate to recycled construction waste powder is (0.05-0.07):1.

[0026] As a preferred technical solution of the present invention, the preparation steps of the recycled construction waste powder include: feeding approximately 1000.0 kg of construction waste (mainly composed of waste concrete blocks and waste clay bricks) into a jaw crusher for primary crushing, and separating mixed metal objects such as reinforcing bars through a magnetic separation device; then, screening the crushed material through a vibrating screen with a aperture of 40.0 mm to collect fragments with a particle size of less than 40.0 mm, and then conveying these fragments to a vertical impact crusher for secondary crushing; finally, using an air separation device to collect recycled construction waste powder with a particle size of less than 0.16 mm from the material after secondary crushing.

[0027] In this invention, the preparation of alkali-activated-esterified active regenerated micropowder is a multi-step synergistic activation process, the mechanism of which encompasses three aspects: heat treatment, alkali-activated chemical reaction, and surface modification with organic coupling agents. First, the recycled micropowder from construction waste undergoes high-temperature calcination, which destroys the originally stable silicate and aluminate mineral crystal structures, causing an amorphous transformation. Previously bound active ions such as silicon, aluminum, and calcium are released, and the specific surface area significantly increases, providing higher surface energy and more reaction sites for subsequent reactions. The subsequent alkali activation step is the core of chemical activation, involving mixing the calcined micropowder with a strongly alkaline solution of sodium hydroxide and sodium silicate. In this strongly alkaline environment, the active silicate and aluminum species dissolved from the surface and interior of the micropowder undergo complex depolymerization-repolymerization reactions with alkali metal ions, generating products such as sodium silicate gel or hydrated calcium silicate with gelling properties. This forms a highly surface-active hydrated product layer on the surface and between the micropowder particles, containing abundant hydroxyl functional groups. The final key step is surface organic modification using a titanate coupling agent. The selected titanate coupling agent contains both alkoxy groups capable of reacting with hydroxyl groups on the surface of inorganic materials and long-chain organic groups. Under heating and stirring conditions, the alkoxy groups in the titanate molecules encounter a large number of hydroxyl groups on the surface of the micro-powder after alkali activation, resulting in an ester exchange reaction. Titanium atoms form strong Ti-O-Ca covalent bonds with oxygen atoms on the surface of the micro-powder, while releasing the corresponding alcohols. Through this reaction, the titanate coupling agent is chemically bonded to the surface of the micro-powder particles in the form of a monolayer, extending its hydrophobic long-chain organic groups outward. Thus, the recycled micro-powder from construction waste completes its transformation from "inert waste" to "high-performance functional filler": its surface has both active sites formed through alkali activation that can further interact with cement hydration products, and long organic chains with excellent compatibility with asphalt grafted through chemical bonds. This achieves both strong adhesion to inorganic aggregates and close compatibility with organic asphalt in asphalt mixtures, significantly improving the overall performance of the mixture.

[0028] As a preferred technical solution of the present invention, in step C1, the mass ratio of sodium hydroxide, sodium silicate and deionized water is (5-10):(3-6):(15-25).

[0029] As a preferred embodiment of the present invention, in step C2, the reaction time at 80-90°C is 30-40 minutes.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] (1) The core technical effect of this invention lies in the successful solution of the performance degradation problem when combining warm mix technology with solid waste utilization through the synergistic design of three functional compounds. The dynamic imine crosslinking warm mix modifier effectively reduces the viscosity of asphalt through the reversible breaking of dynamic bonds during the mixing of the mixture, realizing low-temperature construction; while during the service of the road surface, the recovery of dynamic bonds significantly enhances the elasticity and self-healing ability of the material. The siloxane-asphalt amphiphilic coupling agent, as the key "molecular bridge", strongly enhances the chemical bonding force between the asphalt matrix and all inorganic interfaces such as recycled micro powder and steel slag sand, fundamentally improving the water stability and durability of the mixture. The alkali-activated-esterified active recycled micro powder transforms the inert construction waste powder into a highly active functional filler through stepwise modification. The synergistic effect of these three constitutes the cornerstone of the high performance of the mixture.

[0032] (2) This invention achieves efficient synergy and complementary performance of three types of solid waste: recycled construction waste powder, waste plastics, and waste tire rubber powder. After specific pretreatment, the waste plastics and waste tire rubber powder serve as reinforcing and elastic phases, respectively, in the system constructed from functional compounds, forming a stable composite network structure. This enables the final product to simultaneously possess excellent high-temperature rutting resistance, low-temperature crack resistance, and fatigue resistance, overcoming the limitation of single-property modification of individual solid wastes. Furthermore, the steel slag sand introduced into the formulation further enriches the types of solid waste utilization and may contribute additional wear resistance and skeleton strength.

[0033] (3) The overall technical solution of the present invention brings significant environmental and economic benefits. The production temperature of the entire mixture is significantly lower than that of the traditional process, which directly reduces fuel consumption and harmful gas emissions. More importantly, this solution provides a high-value-added large-scale utilization channel for difficult-to-treat solid wastes such as construction waste, waste plastics and waste tires, reduces dependence on natural sand and gravel and traditional polymer modifiers, lowers raw material costs, conforms to the green and low-carbon sustainable development direction, and has broad prospects for industrial application. Detailed Implementation

[0034] To facilitate understanding of the present invention, the following embodiments are provided. Those skilled in the art should understand that these embodiments are merely illustrative and should not be construed as limiting the scope of the invention.

[0035] The sources of some components in the examples and comparative examples are as follows:

[0036] The 1,3,5-benzenetriformaldehyde was purchased from Zhengzhou Alpha Chemical Co., Ltd.

[0037] The stearoyl chloride was purchased from Hubei Chengfeng Chemical Co., Ltd.

[0038] The isopropyl tris(dioctyl pyrophosphoryloxy) titanate was purchased from Hangzhou Jessica Chemical Co., Ltd.

[0039] Example 1

[0040] This embodiment provides a method for preparing warm-mix asphalt mixture based on recycled construction waste micropowder as a functional filler.

[0041] First, a dynamic imine crosslinking warm-stir modifier was prepared. Under an argon atmosphere, 100.0 g of polyether diamine and 150.0 g of anhydrous xylene were added sequentially to a 500 mL three-necked round-bottom flask equipped with a mechanical stirrer, thermometer, constant-pressure dropping funnel, and reflux separator. The stirring was started and the oil bath was heated to 80 °C and maintained until the polyether diamine was completely dissolved to form a homogeneous solution. Subsequently, a pre-prepared 1,3,5-benzenetriformaldehyde solution (prepared by dissolving 10.0 g of 1,3,5-benzenetriformaldehyde in 50.0 g of anhydrous xylene) was slowly added dropwise through the constant-pressure dropping funnel, controlling the dropping rate to ensure uniform addition over 60 min. After the addition was complete, the oil bath temperature was raised to 115 °C to maintain the reaction mixture under mild reflux. The separator was turned on, and the reaction continued for 7.0 h. During this period, the water byproduct generated in the reaction was removed by azeotropic removal through the separator. After the reaction was complete, the oil bath was removed, and the reaction solution was allowed to cool naturally to 38°C. Under vigorous stirring, the viscous reaction solution was slowly poured into a 2L beaker containing 1000mL of petroleum ether, and a pale yellow fibrous solid immediately precipitated. After standing for 30 minutes, the solid product was collected by vacuum filtration using a Buchner funnel. The filter cake was washed three times with 200mL of petroleum ether each time to thoroughly remove residual solvent and unreacted small molecules. The washed solid was transferred to a watch glass and placed in a vacuum drying oven at 40°C. It was continuously dried at a vacuum of -0.095MPa for 26 hours to obtain a dry, pale yellow, brittle solid, namely the dynamic imine crosslinking warm-stir modifier. This solid was then sealed and stored for later use.

[0042] Next, the siloxane-asphaltene amphiphilic coupling agent was prepared. In a 250 mL dry round-bottom flask, 50.0 g of aminopropyltriethoxysilane and 100.0 g of anhydrous tetrahydrofuran were added, the flask was sealed with a rubber stopper, and gently shaken to mix thoroughly. The flask was placed in an ice-salt bath to cool and maintain the internal temperature of the reaction system at 3 °C. Under magnetic stirring, a solution consisting of 25.0 g of stearoyl chloride dissolved in 50.0 g of anhydrous tetrahydrofuran was slowly added dropwise using a constant-pressure dropping funnel. The dropping rate was strictly controlled to ensure that the reaction temperature remained below 10 °C. The dropping process took approximately 40 min. After the addition was complete, the ice-salt bath was removed, and the reaction mixture was allowed to continue to react with stirring at room temperature (approximately 25 °C) for 12.0 h. After the reaction was complete, the reaction flask was connected to a rotary evaporator and subjected to vacuum distillation at a water bath temperature of 40°C and a vacuum degree of -0.09 MPa for 3.0 h to remove most of the tetrahydrofuran solvent, yielding a light yellow, waxy viscous substance. This viscous substance was dissolved in 30.0 mL of dichloromethane and subjected to vacuum rotary evaporation again under the same conditions to completely remove the dichloromethane and any possible trace amounts of the byproduct hydrogen chloride, finally yielding approximately 60.0 g of a light yellow, transparent, viscous liquid, which is the siloxane-asphaltene amphiphilic coupling agent, and was sealed and stored in a desiccator.

[0043] Next, alkali-activated esterified activated regenerated micro powder was prepared. 200.0 g of recycled construction waste micro powder was weighed and spread evenly in a corundum crucible, which was then placed in a box-type muffle furnace. The temperature was programmed to rise to 750°C at a rate of 5°C / min, and calcined at this temperature for 1.5 h. The power was then turned off, and the material was allowed to cool to room temperature with the furnace to obtain the activated matrix. The cooled activated matrix was transferred to a high-speed mixer (preheated to 60°C), and stirring was started. A pre-prepared alkali activator solution (prepared by dissolving 8.0 g of sodium hydroxide granules and 5.0 g of solid sodium silicate with a modulus of 3.2 in 20.0 g of deionized water, and allowing it to stand for 12 h) was evenly sprayed onto the churning micro powder using a spraying device. After spraying, wet mixing continued for 4.0 min to ensure the micro powder was evenly wetted by the alkali solution, forming an aggregated wet mixture. The wet mixture was transferred into a plastic mold and placed in a constant temperature and humidity curing chamber. It was cured at 80℃ and relative humidity ≥95% for 22.0 hours. After curing, the agglomerated material was removed and dried in a 105℃ forced-air drying oven until constant weight (approximately 6 hours). The dried lumps were then pre-crushed using a mortar and pestle and placed into a high-speed mixer preheated to 60℃. While stirring, a titanate coupling agent solution (prepared by uniformly mixing 12.0g isopropyl tris(dioctyl pyrophosphate) titanate with 24.0g anhydrous ethanol) was atomized and sprayed into the mixture. The material temperature inside the mixer was maintained at 85℃ for 35 minutes. After the reaction, the material was transferred to a vacuum drying oven and dried at 60℃ and -0.09MPa for 4 hours. Finally, the dried material was crushed using a small pulverizer and passed through a 0.075mm square-hole sieve to obtain alkali-activated esterified active regenerated micro powder, which was then bagged for later use.

[0044] Finally, warm-mix asphalt mixture was prepared. 1000.0g of base asphalt was weighed and placed in an asphalt mixing tank heated to 160℃. Under mechanical stirring at 500r / min, 7.0g of the prepared siloxane-asphaltene amphiphilic coupling agent was added first, and stirred for 5min to allow for initial dispersion. Then, 12.0g of the prepared dynamic imine crosslinking warm-mix modifier was added, and the shear speed was rapidly increased to 3500r / min. Stirring was continued under this high-speed shear for 25min until the asphalt became uniform, smooth, and glossy. Subsequently, 30.0g of waste polyethylene plastic granules (particle size 2-4mm) that had been melt-extruded and granulated and surface-treated with γ-aminopropyltriethoxysilane were added, and shearing was continued at 3500r / min for 20min until the plastic granules completely melted and disappeared. Afterward, the mixing tank temperature was set to 150℃, and after the temperature stabilized, 50.0g of 40-mesh waste tire rubber powder activated by 800W microwave irradiation for 120s was added. Immediately reduce the stirring speed to 400 r / min. At this low speed, allow the rubber powder to fully swell in the asphalt for 45 minutes to obtain a homogeneous composite modified asphalt. Keep it warm for later use. Add 450.0 g of limestone crushed stone (particle size 4.75-13.2 mm) and 400.0 g of steel slag sand (particle size 0.075-4.75 mm) to an asphalt mixing pot preheated to 140℃. Dry mix for 10 seconds to ensure uniform aggregate temperature. Then, add 30.0 g of the alkali-activated-esterified active recycled micro powder and 20.0 g of limestone mineral powder (particle size <0.075 mm) to the pot and continue dry mixing for 18 seconds to ensure the filler adheres evenly to the aggregate surface. Quickly pour the composite modified asphalt (temperature approximately 150℃) into the mixing pot and immediately begin wet mixing. Control the mixing pot temperature at 140℃ and the mixing time at 50 seconds to ensure the asphalt completely coats all aggregates and the mixture has a uniform color. The material is discharged immediately after mixing to obtain the desired warm-mix asphalt mixture.

[0045] Example 2

[0046] This embodiment provides a method for preparing warm-mix asphalt mixture based on recycled construction waste micropowder as a functional filler.

[0047] First, a dynamic imine crosslinking warm-stir modifier was prepared. Under an argon atmosphere, 100.0 g of polyether diamine and 150.0 g of anhydrous xylene were added sequentially to a 500 mL three-necked round-bottom flask equipped with a mechanical stirrer, thermometer, constant-pressure dropping funnel, and reflux separator. The stirring was started and the oil bath was heated to 79 °C and maintained until the polyether diamine was completely dissolved to form a homogeneous solution. Subsequently, a pre-prepared 1,3,5-benzenetriformaldehyde solution (prepared by dissolving 9.0 g of 1,3,5-benzenetriformaldehyde in 50.0 g of anhydrous xylene) was slowly added dropwise through the constant-pressure dropping funnel, controlling the dropping rate to ensure uniform addition over 60 min. After the addition was complete, the oil bath temperature was raised to 112 °C to maintain the reaction mixture under mild reflux. The separator was turned on, and the reaction was continued for 6.5 h. During this period, the water byproduct generated in the reaction was removed by azeotropic removal through the separator. After the reaction was complete, the oil bath was removed, and the reaction solution was allowed to cool naturally to 36°C. Under vigorous stirring, the viscous reaction solution was slowly poured into a 2L beaker containing 1000mL of petroleum ether, and a pale yellow fibrous solid immediately precipitated. After standing for 30 minutes, the solid product was collected by vacuum filtration using a Buchner funnel. The filter cake was washed three times with fresh petroleum ether (200mL each time). The washed solid was transferred to a watch glass and placed in a vacuum drying oven at 39°C. It was continuously dried at a vacuum of -0.095MPa for 25 hours to obtain a dry, pale yellow, brittle solid, namely the dynamic imine crosslinking warm-stir modifier. This was then sealed and stored for later use.

[0048] Next, the siloxane-asphaltene amphiphilic coupling agent was prepared. In a 250 mL dry round-bottom flask, 50.0 g of aminopropyltriethoxysilane and 100.0 g of anhydrous tetrahydrofuran were added, the flask was sealed with a rubber stopper, and gently shaken to mix thoroughly. The flask was placed in an ice-salt bath to cool and maintain the internal temperature of the reaction system at 2 °C. Under magnetic stirring, a solution consisting of 22.0 g of stearoyl chloride dissolved in 50.0 g of anhydrous tetrahydrofuran was slowly added dropwise using a constant-pressure dropping funnel. The dropping rate was strictly controlled to ensure that the reaction temperature remained below 10 °C. The dropping process took approximately 40 min. After the addition was complete, the ice-salt bath was removed, and the reaction mixture was allowed to continue to react with stirring at room temperature (approximately 25 °C) for 12.0 h. After the reaction was complete, the reaction flask was connected to a rotary evaporator and subjected to vacuum distillation at a water bath temperature of 40°C and a vacuum degree of -0.09 MPa for 2.5 h to remove most of the tetrahydrofuran solvent, yielding a light yellow, waxy viscous substance. This viscous substance was dissolved in 30.0 mL of dichloromethane and subjected to vacuum rotary evaporation again under the same conditions, finally yielding approximately 57.0 g of a light yellow, transparent, viscous liquid, which is the siloxane-asphaltene amphiphilic coupling agent, and was sealed and stored in a desiccator.

[0049] Next, alkali-activated esterified activated regenerated micro-powder was prepared. 200.0 g of recycled construction waste micro-powder (particle size ≤ 0.075 mm) was weighed and spread evenly in a corundum crucible, which was then placed in a box-type muffle furnace. The temperature was programmed to rise to 745 °C at a rate of 5 °C / min, and calcined at this temperature for 1.5 h. The power was then turned off, and the material was allowed to cool to room temperature with the furnace to obtain the activated matrix. The cooled activated matrix was transferred to a high-speed mixer (preheated to 60 °C), and stirring was started. A pre-prepared alkali activator solution (prepared by dissolving 7.0 g of sodium hydroxide particles and 4.0 g of solid sodium silicate with a modulus of 3.2 in 18.0 g of deionized water, and allowing it to stand for 12 h) was evenly sprayed onto the churning micro-powder using a spraying device. After spraying, wet mixing continued for 3.5 min to form an agglomerated wet mixture. The wet mixture was transferred into a plastic mold and placed in a constant temperature and humidity curing chamber. It was cured at 79℃ and relative humidity ≥95% for 20.0 hours. After curing, the agglomerated material was removed and dried in a 105℃ forced-air drying oven until constant weight (approximately 6 hours). The dried lumps were then initially crushed using a mortar and pestle, and then fed into a high-speed mixer preheated to 59℃. While stirring, a titanate coupling agent solution (prepared by uniformly mixing 10.0g isopropyltris(dioctylpyrophosphate)titanate with 20.0g anhydrous ethanol) was atomized and sprayed into the mixture using a spray bottle. The material temperature inside the mixer was maintained at 82℃, and the reaction was continued for 32 minutes. After the reaction, the material was transferred to a vacuum drying oven and dried at 60℃ and -0.09MPa for 4 hours. Finally, the dried material was crushed using a small pulverizer and passed entirely through a 0.075mm square-hole sieve to obtain alkali-activated-esterified active regenerated micro powder, which was then bagged for later use.

[0050] Finally, warm-mix asphalt was prepared. 960.0g of base asphalt was weighed and placed in an asphalt mixing tank heated to 158℃. Under mechanical stirring at 500r / min, 5.0g of the prepared siloxane-asphaltene amphiphilic coupling agent was first added, and stirred for 5min to allow for initial dispersion. Then, 10.0g of the prepared dynamic imine crosslinking warm-mix modifier was added, and the shear speed was rapidly increased to 3000r / min. Stirring was continued at this high-speed shear for 22min until the asphalt became uniform, smooth, and glossy. Subsequently, 25.0g of surface-treated waste polyethylene plastic particles (2-4mm in diameter) were added, and shearing was continued at 3000r / min for 18min until the plastic particles completely melted and disappeared. Afterward, the mixing tank temperature was set to 148℃, and after the temperature stabilized, 48.0g of 40-mesh waste tire rubber powder activated by 800W microwave irradiation for 120s was added. Immediately reduce the stirring speed to 350 r / min, allowing the rubber powder to fully swell in the asphalt at this low speed for 42 minutes to obtain homogeneous composite modified asphalt, which is then kept warm for later use. Add 430.0 g of limestone crushed stone (particle size 4.75-13.2 mm) and 380.0 g of steel slag sand (particle size 0.075-4.75 mm) to a laboratory asphalt mixing pot preheated to 138°C, and dry mix for 10 seconds to ensure uniform aggregate temperature. Then, add 25.0 g of the alkali-activated-esterified active recycled micro powder and 15.0 g of limestone mineral powder (particle size <0.075 mm) prepared above to the pot, and continue dry mixing for 16 seconds to ensure the filler adheres evenly to the aggregate surface. Quickly pour the composite modified asphalt (temperature approximately 148°C) into the mixing pot and immediately begin wet mixing. The mixing pot temperature is controlled at 138℃, and the mixing time is 48 seconds to ensure that the asphalt completely coats all aggregates and that the mixture has a uniform color. The mixture is discharged immediately after mixing to obtain the desired warm-mix asphalt mixture.

[0051] Example 3

[0052] This embodiment provides a method for preparing warm-mix asphalt mixture based on recycled construction waste micropowder as a functional filler.

[0053] First, a dynamic imine crosslinking warm-stir modifier was prepared. Under an argon atmosphere, 100.0 g of polyether diamine and 150.0 g of anhydrous xylene were added sequentially to a 500 mL three-necked round-bottom flask equipped with a mechanical stirrer, thermometer, constant-pressure dropping funnel, and reflux separator. Stirring was started and the oil bath was heated to 81 °C and maintained until the polyether diamine was completely dissolved to form a homogeneous solution. Subsequently, a pre-prepared 1,3,5-benzenetriformaldehyde solution (prepared by dissolving 11.0 g of 1,3,5-benzenetriformaldehyde in 50.0 g of anhydrous xylene) was slowly added dropwise through the constant-pressure dropping funnel, controlling the dropping rate to ensure uniform addition over 60 min. After the addition was complete, the oil bath temperature was raised to 118 °C to maintain the reaction mixture under mild reflux. The separator was turned on, and the reaction continued for 7.5 h, during which water, a byproduct of the reaction, was removed via azeotropic removal using the separator. After the reaction was complete, the oil bath was removed, and the reaction solution was allowed to cool naturally to 39°C. Under vigorous stirring, the viscous reaction solution was slowly poured into a 2L beaker containing 1000mL of petroleum ether, and a pale yellow fibrous solid immediately precipitated. After standing for 30 minutes, the solid product was collected by vacuum filtration using a Buchner funnel. The filter cake was washed three times with fresh petroleum ether (200mL each time). The washed solid was transferred to a watch glass and placed in a vacuum drying oven at 41°C. It was continuously dried at a vacuum of -0.095MPa for 28 hours to obtain a dry, pale yellow, brittle solid, namely the dynamic imine crosslinking warm-stir modifier. This solid was then sealed and stored for later use.

[0054] Next, the siloxane-asphaltene amphiphilic coupling agent was prepared. In a 250 mL dry round-bottom flask, 50.0 g of aminopropyltriethoxysilane and 100.0 g of anhydrous tetrahydrofuran were added, the flask was sealed with a rubber stopper, and gently shaken to mix thoroughly. The flask was placed in an ice-salt bath to cool and maintain the internal temperature of the reaction system at 4 °C. Under magnetic stirring, a solution consisting of 28.0 g of stearoyl chloride dissolved in 50.0 g of anhydrous tetrahydrofuran was slowly added dropwise using a constant-pressure dropping funnel. The dropping rate was strictly controlled to ensure that the reaction temperature remained below 10 °C. The dropping process took approximately 40 min. After the addition was complete, the ice-salt bath was removed, and the reaction mixture was allowed to continue stirring at room temperature (approximately 25 °C) for 12.0 h. After the reaction was complete, the reaction flask was connected to a rotary evaporator and subjected to vacuum distillation at a water bath temperature of 40°C and a vacuum degree of -0.09 MPa for 3.5 h to remove most of the tetrahydrofuran solvent, yielding a light yellow, waxy viscous substance. This viscous substance was dissolved in 30.0 mL of dichloromethane and subjected to vacuum rotary evaporation again under the same conditions, finally yielding approximately 62.0 g of a light yellow, transparent, viscous liquid, which is the siloxane-asphaltene amphiphilic coupling agent, and was sealed and stored in a desiccator.

[0055] Next, alkali-activated esterified activated regenerated micro-powder was prepared. 200.0 g of recycled construction waste micro-powder (particle size ≤ 0.075 mm) was weighed and spread evenly in a corundum crucible, which was then placed in a box-type muffle furnace. The temperature was programmed to rise to 755 °C at a rate of 5 °C / min, and calcined at this temperature for 1.5 h. The power was then turned off, and the material was allowed to cool to room temperature with the furnace to obtain the activated matrix. The cooled activated matrix was transferred to a high-speed mixer (preheated to 60 °C), and stirring was started. A pre-prepared alkali activator solution (prepared by dissolving 9.0 g of sodium hydroxide particles and 5.5 g of solid sodium silicate with a modulus of 3.2 in 22.0 g of deionized water, and allowing it to stand for 12 h) was evenly sprayed onto the churning micro-powder using a spraying device. After spraying, wet mixing continued for 4.5 min to form an agglomerated wet mixture. The wet mixture was transferred into a plastic mold and placed in a constant temperature and humidity curing chamber. It was cured at 81℃ and relative humidity ≥95% for 23.0 hours. After curing, the agglomerated material was removed and dried in a 105℃ forced-air drying oven until constant weight (approximately 6 hours). The dried lumps were then pre-crushed using a mortar and pestle and placed into a high-speed mixer preheated to 61℃. While stirring, a titanate coupling agent solution (prepared by uniformly mixing 14.0g isopropyltris(dioctylpyrophosphate)titanate with 28.0g anhydrous ethanol) was atomized and sprayed into the mixture. The material temperature inside the mixer was maintained at 88℃ for 38 minutes. After the reaction, the material was transferred to a vacuum drying oven and dried at 60℃ and -0.09MPa for 4 hours. Finally, the dried material was crushed using a small pulverizer and passed through a 0.075mm square-hole sieve to obtain alkali-activated-esterified active regenerated micro powder, which was then bagged for later use.

[0056] Finally, warm-mix asphalt mixture was prepared. 1040.0g of base asphalt was weighed and placed in an asphalt mixing tank heated to 162℃. Under mechanical stirring at 500r / min, 9.0g of the prepared siloxane-asphaltene amphiphilic coupling agent was first added, and stirred for 5min to allow for initial dispersion. Then, 14.0g of the prepared dynamic imine crosslinking warm-mix modifier was added, and the shear speed was rapidly increased to 3800r / min. Stirring was continued at this high-speed shear for 28min until the asphalt became uniform, smooth, and glossy. Subsequently, 35.0g of surface-treated waste polyethylene plastic particles (particle size 2-4mm) were added, and shearing was continued at 3800r / min for 22min until the plastic particles completely melted and disappeared. Afterward, the mixing tank temperature was set to 152℃, and after the temperature stabilized, 52.0g of 40-mesh waste tire rubber powder activated by 800W microwave irradiation for 120s was added. Immediately reduce the stirring speed to 450 r / min, allowing the rubber powder to fully swell in the asphalt at this low speed for 48 minutes to obtain homogeneous composite modified asphalt, which is then kept warm for later use. Add 470.0 g of limestone crushed stone (particle size 4.75-13.2 mm) and 420.0 g of steel slag sand (particle size 0.075-4.75 mm) to a laboratory asphalt mixing pot preheated to 142°C, and dry mix for 10 seconds to ensure uniform aggregate temperature. Then, add 35.0 g of the alkali-activated-esterified active recycled micro powder and 25.0 g of limestone mineral powder (particle size <0.075 mm) prepared above to the pot, and continue dry mixing for 19 seconds to ensure the filler is evenly adhered to the aggregate surface. Quickly pour the composite modified asphalt (temperature approximately 152°C) into the mixing pot and immediately begin wet mixing. The mixing pot temperature is controlled at 142℃, and the mixing time is 55 seconds to ensure that the asphalt completely coats all aggregates and that the mixture has a uniform color. The mixture is discharged immediately after mixing to obtain the desired warm-mix asphalt mixture.

[0057] Comparative Example 1

[0058] The difference between this comparative example and Example 1 is that the dynamic imine crosslinking warm mix modifier and the siloxane-asphalt amphiphilic coupling agent are not added, and recycled construction waste powder is used instead.

[0059] Comparative Example 2

[0060] The difference between this comparative example and Example 1 is that no siloxane-asphaltene amphiphilic coupling agent was added, and the alkali-activated-esterified active regenerated micro powder was not treated with titanate.

[0061] Comparative Example 3

[0062] The difference between this comparative example and Example 1 is that no alkali-activated-esterified active regenerated micro powder was added, and limestone mineral powder of equal mass was used instead.

[0063] In accordance with national and industry standard testing specifications, the performance of the warm-mix asphalt mixtures based on recycled construction waste powder as functional filler provided in the above embodiments and comparative examples was tested. The testing methods are as follows: all mixture specimens were formed into specimens of specified dimensions by standard compaction or rotary compaction methods and were tested after curing at room temperature for no less than 48 hours.

[0064] First, to evaluate the warm mix effect, the apparent viscosity of the composite modified asphalt at 135℃ was determined using a Blockfield rotational viscometer. The specific steps were as follows: an appropriate amount of sample was placed in a standard sample tube and kept in a constant temperature bath at 135.0℃ for 10.0 min to eliminate thermal history and air bubbles. Then, a No. 27 rotor was selected, and the instrument was started at a low shear rate of 0.5 rpm. After the torque reading stabilized, at least three consecutive and stable readings were recorded and the average value was calculated. The results were reported in Pa·s.

[0065] Secondly, an asphalt mixture rutting test was conducted to evaluate its resistance to permanent deformation at high temperatures. A 300mm × 300mm × 50mm plate-shaped specimen was placed in an environmental chamber at 60.0℃ for at least 5.0 hours to ensure a uniform internal temperature that reached the test temperature. The specimen was then mounted on a rutting tester, and a standard solid rubber test wheel (pressure 0.7MPa) was moved back and forth along the same trajectory at a frequency of 42 times / min. The test lasted for 1.0 hour or until the maximum deformation reached 25mm. The rutting depth was accurately recorded at 45 minutes and 60 minutes after the start of the test. The dynamic stability DS was calculated using the formula DS = (t2 - t1) × N / (d2 - d1), where N is the test wheel's reciprocating speed (times / min), and d1 and d2 are the deformation amounts at times t1 (45 minutes) and t2 (60 minutes), respectively. The results were reported in times / mm.

[0066] Next, a freeze-thaw splitting test was conducted to evaluate water stability. For the freeze-thaw splitting test, standard Marshall specimens formed from the mixtures of each embodiment and comparative example were divided into two groups. The first group, serving as a control group that did not undergo freeze-thaw cycles, was immersed in a constant-temperature water bath at 25.0℃ for 2.0 h, and immediately subjected to a splitting strength test at a loading rate of 50 mm / min, with the splitting strength RT1 measured. The second group, serving as the test group, was first saturated with water in a container with a vacuum of 97.3 kPa for 15.0 min, and after returning to normal pressure, it was immersed for another 30.0 min. Subsequently, it was removed, its surface water was wiped dry, and it was placed in a freezer at -18.0℃ for 16.0 h. Then, it was immediately removed and immersed in a constant-temperature water bath at 60.0℃ for 24.0 h. Finally, it was transferred to a water bath at 25.0℃ for a constant-temperature immersion of 2.0 h, and subjected to a splitting strength test under the same conditions, with the splitting strength RT2 measured. The freeze-thaw splitting strength ratio (TSR) for each case was calculated using the formula TSR=(RT2 / RT1)×100%, and the results were reported as a percentage (%).

[0067] Finally, a water immersion Marshall test was conducted to further verify the resistance to water damage. During the test, standard Marshall specimens formed from the mixtures of each embodiment and comparative example were divided into two groups. The first group of specimens was kept in a constant temperature water bath at 60.0℃ for 30 to 40 minutes, then removed, quickly dried, and their Marshall stability MS1 was measured. The second group of specimens was kept in a constant temperature water bath at 60.0℃ for 48.0 hours, then removed, dried, and their Marshall stability MS2 was measured. The residual water immersion stability MS0 for each example was calculated using the formula MS0 = (MS2 / MS1) × 100%, and the results were reported as a percentage (%).

[0068] The performance test data above are shown in Table 1.

[0069] Table 1 Performance Test Results

[0070] Test Project Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Rotational viscosity at 135℃ (Pa·s) 1.85 1.92 1.80 2.95 2.10 1.88 Dynamic stability (60℃, cycles / mm) 6850 6520 6710 2450 5210 4230 Freeze-thaw splitting strength ratio (TSR) (%) 90.1 88.5 89.4 72.8 79.3 86.0 <![CDATA[Immersion residual stability MS0 (%)]]> 92.5 90.8 91.7 78.2 84.6 89.3

[0071] As can be seen from the above, Examples 1-3 systematically solved all the core problems raised in the background art through the synergistic effect of the three functional compounds.

[0072] First, regarding the issue of performance degradation caused by the direct use of recycled micro powder from construction waste, the mixture of "alkali-activated-esterified active recycled micro powder" used in the example showed a dynamic stability (6520-6850 times / mm) that was much higher than that of Comparative Example 3 (4230 times / mm) which used ordinary mineral powder. This proves that the treatment successfully transformed the inert micro powder into a highly active reinforced filler, thus solving the shortcomings in filler performance.

[0073] Secondly, addressing the incompatibility between warm mix technology and solid waste modification, the viscosity of Example 1 at 35℃ (1.80-1.92 Pa·s) was significantly lower than that of Comparative Example 1 (2.95 Pa·s) without any added functional compounds. This indicates that the "dynamic imine crosslinking warm mix modifier" effectively reduced the viscosity of the system at the mixing temperature, enabling warm mix construction at 135-145℃. At the same time, its dynamic stability data proves that the modifier reconstructed the reinforcing network at the service temperature of the road surface, synergistically with waste plastics and waste tire rubber powder (dynamic stability of Example 1: 6850 cycles / mm vs. dynamic stability of Comparative Example 1: 2450 cycles / mm), overcoming the contradiction between low-temperature construction and high-temperature performance.

[0074] Finally, addressing the issue of poor interfacial bonding in simple blends of multiple solid wastes, the superior water damage resistance of the example (freeze-thaw splitting strength ratio 88.5-90.1%, water immersion residual stability 90.8-92.5%) far exceeds that of Comparative Example 2 (freeze-thaw splitting strength ratio 79.3%, water immersion residual stability 84.6%), which lacks the "siloxane-asphaltaceous amphiphilic coupling agent." This demonstrates that the coupling agent establishes strong chemical bonds between asphalt, recycled micro powder, steel slag, and polymers, solving the fundamental problem of weak interfacial adhesion.

[0075] In summary, through precise functional design, the embodiments of the present invention achieve a significant reduction in energy consumption while synergistically improving the comprehensive road performance of various solid waste modified asphalt mixtures.

Claims

1. A warm-mix asphalt mixture based on recycled construction waste powder as a functional filler, characterized in that, Including the following parts by weight of raw materials: Base asphalt: 80-120 parts by weight; Dynamic imine crosslinking type warm stir modifier: 1.5-3.0 parts by weight; Siloxane-asphaltic amphiphilic coupling agent: 0.5-2.0 parts by weight; Alkali-activated esterified active regenerated micro powder: 20-50 parts by weight; Waste plastic pellets: 2-8 parts by weight; Waste tire rubber powder: 4-12 parts by weight; Limestone crushed stone: 40-50 parts by weight; Steel slag sand: 30-55 parts by weight; Limestone powder: 10-30 parts by weight.

2. The warm-mix asphalt mixture based on recycled construction waste powder as a functional filler according to claim 1, characterized in that, The preparation method of the dynamic imine crosslinking type warm stir modifier includes: A1, under an argon atmosphere, adding polyether diamine and anhydrous xylene to a reactor, heating to 78-82℃ to dissolve; adding a xylene solution containing 1,3,5-benzenetriformaldehyde dropwise; heating to 110-120℃ and refluxing to obtain a reaction solution; A2, cooling the reaction solution to 35-40℃, pouring it into petroleum ether to precipitate, filtering to obtain a solid product, washing the solid product with petroleum ether, and vacuum drying at 38-42℃.

3. The warm-mix asphalt mixture based on recycled construction waste powder as a functional filler according to claim 2, characterized in that, In step A1, the mass ratio of polyether diamine to 1,3,5-benzyltriformaldehyde is 100:(8-12).

4. The warm-mix asphalt mixture based on recycled construction waste powder as a functional filler according to claim 2, characterized in that, In step A2, the vacuum drying time at 38-42℃ is 24-30 hours.

5. The warm-mix asphalt mixture based on recycled construction waste powder as a functional filler according to claim 1, characterized in that, The preparation method of the siloxane-asphaltene amphiphilic coupling agent includes: B1, adding aminopropyltriethoxysilane and anhydrous tetrahydrofuran to a reaction flask and cooling to 0-5℃; adding dropwise a solution composed of stearoyl chloride and anhydrous tetrahydrofuran; after the dropwise addition is complete, heating to room temperature for reaction; B2, after the reaction is complete, rotary evaporating under reduced pressure at 38-42℃ to obtain the product, dissolving the product in dichloromethane and then rotary evaporating again.

6. The warm-mix asphalt mixture based on recycled construction waste powder as a functional filler according to claim 5, characterized in that, In step B1, the mass ratio of aminopropyltriethoxysilane to stearoyl chloride is 5:(2-3).

7. The warm-mix asphalt mixture based on recycled construction waste powder as a functional filler according to claim 5, characterized in that, In step B2, the time for rotary evaporation under reduced pressure at 38-42℃ is 2-4 hours.

8. The warm-mix asphalt mixture based on recycled construction waste powder as a functional filler according to claim 1, characterized in that, The preparation method of the alkali-activated-esterified active regenerated micro powder includes: C1, calcining the construction waste regenerated micro powder at 740-760℃ and cooling to obtain an active matrix; adding the active matrix to a mixer, adding an alkali activator composed of sodium hydroxide, sodium silicate and deionized water, and wet mixing to obtain a wet mixture; C2, allowing the wet mixture to stand at 78-82℃ to obtain a settled material; drying the settled material at 104-106℃, putting it into a mixer at 58-62℃, adding an ethanol solution of isopropyl tris(dioctyl pyrophosphate oxy) titanate, and reacting at 80-90℃; finally, vacuum drying at 58-62℃, crushing and sieving.

9. The warm-mix asphalt mixture based on recycled construction waste powder as a functional filler according to claim 8, characterized in that, In step C1, the mass ratio of sodium hydroxide, sodium silicate and deionized water is (5-10):(3-6):(15-25).

10. The warm-mix asphalt mixture based on recycled construction waste powder as a functional filler according to claim 8, characterized in that, In step C2, the reaction time at 80-90℃ is 30-40 minutes.