Self-temperature-adjusting and tail gas purifying type ecological asphalt pavement structure and construction method thereof

Abstract

The invention provides a self-temperature-regulating and tail gas purifying type ecological asphalt pavement structure and a construction method thereof, which are based on a'material-function-structure 'integrated design and realize collaborative improvement of ecological functions and structural performance of an asphalt pavement. In the aspect of tail gas purification, a cascade reaction system is constructed through a visible light response type catalyst and a catalytic type alkaline purifying agent, deep purification and harmlessness of tail gas pollutants are achieved, and the problems of catalyst acidosis inactivation and secondary pollution are effectively avoided. In the aspect of temperature regulation and control, the environment response layer is combined with a thermochromism and radiation refrigeration mechanism, road surface heat absorption is reduced, heat dissipation is enhanced, phase change latent heat of the phase change temperature regulation layer is matched for buffering temperature fluctuation, the road surface temperature is cooperatively maintained in a photocatalysis efficient interval, the urban heat island effect can be relieved, and the tail gas purification efficiency can be improved. In the aspect of structural performance, the durability of the ecological function and the durability of the pavement structure are jointly guaranteed by combining the inhibiting effect of the temperature regulation and control function on freeze-thaw damage of the structure.

Description

Technical Field

[0001] This invention belongs to the field of road engineering technology, specifically relating to a self-regulating temperature and exhaust gas purification type ecological asphalt pavement structure and its construction method. Background Technology

[0002] With the acceleration of urbanization, while road transportation systems drive socio-economic development, they also trigger two major environmental problems: the urban heat island effect and air pollution. Asphalt pavements, due to their inherent dark color, absorb a large amount of solar radiation, resulting in extremely high surface temperatures in summer. This not only exacerbates the urban heat island effect but also affects the performance and lifespan of pavement materials. On the other hand, traditional pavement systems have always been reactive in environmental governance, lacking the ability to actively purify pollutants such as nitrogen oxides (NOx) and hydrocarbons (HC) emitted from vehicle exhaust, making it difficult to meet the development needs of green transportation infrastructure.

[0003] To endow roads with ecological functions, researchers have attempted to introduce functional materials such as photocatalytic purification and phase change temperature regulation into pavement engineering. However, existing functional pavement technologies generally suffer from limitations such as single function, lack of synergistic mechanisms, and insufficient long-term effectiveness. Specifically, in terms of exhaust gas purification, existing technologies such as the photocatalytic asphalt mixture disclosed in patent CN107473633A, while capable of degrading some exhaust gases, neglect the acidic byproducts (such as HNO3 and NO2) generated by the photocatalytic reaction. -(And so on) The migration of these byproducts with rainwater may lead to eutrophication and soil acidification risks. These byproducts can also clog catalyst pores, causing irreversible chemical deactivation. Furthermore, the photocatalysts used in these technologies often rely on ultraviolet excitation, resulting in limited utilization of visible light and making it difficult to achieve efficient catalytic purification around the clock. Regarding temperature regulation, existing technologies, such as patent CN119571691A, use wide-temperature-range phase change materials to mitigate the heat island effect. While they possess some heat storage and temperature regulation capabilities, they are essentially passive temperature control methods and cannot reduce heat input at the source. Under sustained high temperatures, they are prone to heat storage saturation and failure. Although radiative cooling materials can reduce solar radiation absorption through high reflectivity, and thermochromic materials can dynamically adjust thermal gain through optical properties to achieve a certain degree of active cooling, the temperature regulation capabilities of a single material are still insufficient to cope with complex and variable external thermal environments. More importantly, existing research has failed to effectively reconcile the inherent conflict between temperature regulation and purification functions. Photocatalytic reactions typically exhibit optimal activity within the 30-50℃ range. However, the extreme high temperatures (above 60℃) of asphalt pavements in summer can cause photocatalysts (such as nano-TiO2) to undergo thermal deactivation, resulting in a sharp drop in efficiency. Furthermore, existing solutions often overlook the detrimental effects of moisture on functional materials. Without effective drainage design, moisture retention in the pavement structure not only directly corrodes functional materials, leading to the degradation of phase change components and catalyst performance, but also hinders the discharge of reaction products, causing pore blockage and severely impacting the long-term stability of the system.

[0004] In summary, current eco-friendly pavement technologies mostly remain at the level of simple physical superposition of functional materials, neglecting the inherent contradictions and synergistic potential of different functions in terms of working mechanisms and environmental requirements. Due to the lack of systematic interface coordination and structural integration design, particularly ignoring the crucial role of moisture management in maintaining long-term functional effectiveness, the overall system efficiency is low. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention proposes a self-regulating temperature-regulating and exhaust gas purification type ecological asphalt pavement structure and its construction method. It can achieve efficient synergy between self-regulating temperature-regulating and exhaust gas purification functions. The aim is to achieve the synergistic effect of temperature regulation and purification through a composite functional surface layer. Combined with the structural protection of a waterproof and frost-resistant subbase and a drainage base layer, it jointly constructs an efficient, stable, and long-lasting ecological pavement solution to comprehensively improve the overall ecological benefits and service life of the pavement.

[0006] To achieve the above objectives, the solution of the present invention is: One of the technical solutions of the present invention: This invention provides a self-regulating temperature-regulating and exhaust gas-purifying ecological asphalt pavement structure, which comprises, from bottom to top, a soil base layer, a water-proof and frost-resistant cushion layer, a drainage base layer for quickly removing infiltrated water, and a composite functional surface layer; the composite functional surface layer is composed of a lower phase change temperature-regulating layer and an upper porous environmental response layer bonded together by a middle high thermal conductivity adhesive layer.

[0007] The phase change temperature regulating layer is made of phase change temperature regulating polyurethane modified asphalt mixture, with a phase change temperature of 30-50℃.

[0008] The porous environmental response layer is a porous structure layer with a porosity of 18-25%. It is composed of open-graded asphalt mixture and internally loaded with composite functional materials for purifying exhaust gas and responding to changes in ambient temperature. The internal moisture can penetrate downward to the drainage base layer and be quickly drained away.

[0009] The high thermal conductivity adhesive layer is made of high thermal conductivity modified asphalt and is used to enhance interlayer thermal conductivity.

[0010] The phase change temperature regulating layer and the composite functional material in the porous environmental response layer work together to maintain the working temperature of the porous environmental response layer within the range of 30-50℃, thereby smoothing out road surface temperature fluctuations and improving exhaust gas purification efficiency.

[0011] Furthermore, the phase change temperature regulating layer uses AC-20 type dense-graded asphalt mixture, which is composed of phase change temperature regulating modified asphalt, coarse aggregate, fine aggregate, and mineral filler in a mass ratio of (4-5):(55-65):(30-40):(4-7). The coarse aggregate has a particle size of 4.75-19mm; the fine aggregate has a particle size of 0.075-4.75mm; and the mineral filler is limestone powder with a particle size of less than 0.075mm. The particle size of the mineral filler (mineral powder) "less than 0.075mm" generally refers to all particles that can pass through a 0.075mm sieve (i.e., a 200-mesh sieve).

[0012] The phase change temperature-regulating modified asphalt is made by adding 3-5 parts by mass of phase change temperature-regulating polyurethane and 3 parts by mass of SBS modified asphalt to 100 parts by mass of No. 70 base asphalt.

[0013] Among them, the phase change temperature-regulating polyurethane uses polyethylene glycol (PEG) with molecular weights of 4000 and 6000 in a mass ratio of 1:(0.5-2) as the composite soft segment, and controls the molar ratio of diphenylmethane diisocyanate (MDI), polyethylene glycol (PEG) and chain extender 1,4-butanediol (BDO) to be (1.8-2.2):1.0:(0.95-1.05).

[0014] Its preparation process includes: S1. Raw material pretreatment: Dehydrate the PEG composite soft segments at 110-130℃ under vacuum for 1-3 hours; S2. Prepolymer Synthesis: Under an inert atmosphere, dehydrated PEG is mixed with MDI and catalyst and reacted at 75-85℃ for 2-3 hours to generate prepolymer. S3. Chain extension reaction: Add a measured amount of chain extender BDO to the obtained prepolymer and carry out the chain extension reaction at 65-75℃ with stirring for 0.5-1.5h. S4. Curing and post-treatment: The reaction product is transferred into a mold and cured at 85-95℃ for 10-14 hours, and then dried under vacuum to obtain the phase change temperature-regulating polyurethane.

[0015] Specifically, the preparation method of phase change temperature-regulating modified asphalt is as follows: S1. Heat 100 parts by weight of No. 70 base asphalt to 175°C, add SBS modified asphalt, and shear for 30 minutes using a high-speed shearing machine at a speed of 5000 rpm. S2. Add phase change temperature-regulating polyurethane, maintain the temperature at 175℃, and continue shearing at 5000rpm for 30min to obtain phase change temperature-regulating modified asphalt.

[0016] As a temperature buffer layer, the phase change temperature regulation layer efficiently absorbs the residual heat from the upper layer after intelligent thermal management, as well as the heat generated by the road surface itself, storing the heat in the form of latent heat of phase change and preventing heat transfer to the roadbed. At the same time, at night or when the temperature drops, it slowly releases heat with the help of latent heat of phase change, providing stable temperature support for the upper environmental response layer and avoiding fluctuations in catalyst performance caused by sudden temperature changes. Together with the intelligent thermal management composite agent, it actively regulates the road surface temperature within a suitable range, which not only alleviates the heat island effect but also provides a suitable temperature environment for the upper purification reaction, thereby ensuring the long-term synergy of temperature regulation and purification functions.

[0017] Furthermore, the porous environmental response layer uses OGFC-13 type open-graded asphalt mixture, which is composed of the following components: 4.5-5.5 parts high-viscosity asphalt, 78-85 parts coarse aggregate, 8-12 parts fine aggregate, 2.0-4.0 parts mineral powder filler, and 3.0-4.5 parts composite functional materials.

[0018] Furthermore, the absolute viscosity of high-viscosity asphalt at 60℃ is not less than 20000 Pa·s. In the field of road engineering, high-viscosity asphalt is not a single chemical substance, but a special asphalt binder with ultra-high viscosity and excellent bonding properties. The coarse aggregate has a particle size of 2.36-13.2 mm; the fine aggregate has a particle size of 0.075-2.36 mm; the mineral powder filler is limestone mineral powder with a particle size of less than 0.075 mm; the composite functional material is added during the preparation of the mixture by replacing part of the mineral powder filler by an equal mass, the replacement amount being the number of parts of the composite functional material. This means that in the mixture design stage, a portion (mass share) of the mineral powder filler in the original OGFC-13 mixture ratio is replaced with an equal mass of composite functional material. For example, if the original design is 4.0 parts of mineral powder filler, and 1.5 parts are replaced, then 2.5 parts of mineral powder filler and 1.5 parts of composite functional material are actually added, for a total "filler + functional material" amount of 4.0 parts.

[0019] Furthermore, the composite functional material is composed of multi-stage exhaust gas purifier and intelligent thermal management composite agent in a mass ratio of (4-7):(2-3).

[0020] "Multi-stage" refers to the fact that the exhaust gas purifier contains two or more components with different mechanisms of action (visible light responsive catalyst and catalytic alkaline purifier), forming a graded and synergistic purification process for different pollutants in the exhaust gas.

[0021] The multi-stage exhaust gas purifier refers to a composition consisting of a visible light-responsive catalyst for photocatalytic oxidation and a catalytic alkaline purifier for adsorption, neutralization, and deep degradation in a mass ratio of (3-5):(1-2).

[0022] Among them, the visible light responsive catalyst is nitrogen-fluorine co-doped titanium dioxide (NF-TiO2) with surface modified by silane coupling agent KH-550.

[0023] The preparation method of nitrogen-fluorine co-doped titanium dioxide (NF-TiO2) modified with silane coupling agent KH-550 includes the following steps: S1. Disperse nano-titanium dioxide in deionized water to prepare a suspension with a concentration of 20-80 g / L. Add a nitrogen-containing compound and a fluorine-containing compound to obtain a precursor. The nitrogen-containing compound is selected from urea or triethanolamine, and the fluorine-containing compound is ammonium fluoride. The reaction conditions are a hydrothermal reaction at 120-180℃ for 6-12 hours. The amount of nitrogen-containing compound added is 5-30 wt% of the mass of nano-titanium dioxide, and the amount of fluorine-containing compound added is 2-10 wt% of the mass of nano-titanium dioxide. S2. The obtained precursor is subjected to solid-liquid separation, and the product is washed with deionized water and anhydrous ethanol until the washing solution is neutral. Then the product is dried at 70-90℃ for 4-8h to obtain nitrogen-fluorine co-doped titanium dioxide (NF-TiO2) powder. S3. Disperse the obtained NF-TiO2 powder in an ethanol solution with a concentration of 1-2 wt% of silane coupling agent KH-550, stir and react for 2-6 hours, and then separate and dry to obtain a visible light responsive catalyst.

[0024] Ordinary nano-sized NF-TiO2 powder is prone to agglomeration due to its high surface energy, resulting in a reduction in effective catalytic area. Nitrogen-fluorine co-doping significantly enhances the material's photocatalytic performance: by narrowing the band gap, it extends the photoresponse range from the ultraviolet to the visible light region, greatly improving the utilization rate of sunlight; simultaneously, by suppressing the recombination of photogenerated electron-hole pairs, the material can exhibit excellent exhaust gas purification functions even under natural light conditions. To further improve the material's applicability in asphalt, the surface of the doped NF-TiO2 is modified using the silane coupling agent KH-550, changing its surface from hydrophilic to oleophilic, achieving uniform and stable dispersion in asphalt and avoiding agglomeration. Regarding interfacial bonding, KH-550 firmly bonds with NF-TiO2 through chemical bonds, and its long organic chains form an interlocking structure with asphalt molecules, stably anchoring the catalyst within the asphalt matrix. This bonding method allows the material to maintain long-term stability under harsh road conditions such as traffic loads and rain erosion, ensuring the sustained effectiveness of its purification function.

[0025] The catalytic alkaline purifying agent is a compound composed of an alkaline neutralizing material and an adsorption-catalysis bifunctional material in a mass ratio of (2-4):1; the alkaline neutralizing material is selected from one or more of shell powder and steel slag; the adsorption-catalysis bifunctional material is fullerene-modified hydrotalcite (C60-LDHs).

[0026] The preparation method of C60-LDHs includes the following steps: S1. Magnesium nitrate and aluminum nitrate are reacted using a co-precipitation method according to Mg². + With Al³ + A mixed salt solution was prepared in a molar ratio of (2-4):1. Under nitrogen atmosphere protection, the solution was co-precipitated with a mixed alkaline solution of sodium hydroxide and sodium carbonate in a molar ratio of (2.0-2.5):1 for 1-3 hours at 60-80℃ and constant pH value of 10 to obtain hydrotalcite slurry. S2. The hydrotalcite slurry obtained in step S1 is crystallized, centrifuged, and washed until neutral to obtain hydrotalcite (LDHs) carrier; S3. Disperse fullerene in the organic solvent toluene, mix it with the LDHs support obtained in step S2, and stir the mixture at 50-70℃ for 6-18 hours to load the fullerene onto the surface of the hydrotalcite. After separation and drying, C60-LDHs are obtained.

[0027] Modifying hydrotalcite with fullerenes achieves a triple optimization of the material's structure and function: First, hydrotalcite, with its layered structure, rapidly adsorbs gaseous pollutants, while fullerenes simultaneously initiate catalytic degradation. This synergistic process transforms the passive storage mode of traditional adsorption materials into an active purification mechanism, effectively preventing material failure due to adsorption saturation. Second, fullerenes, as highly efficient electron transport media, significantly enhance the reaction rate and promote the generation of various highly reactive free radicals, thereby achieving efficient and deep removal of nitrogen oxides, sulfur oxides, and volatile organic compounds. Third, the stable composite interface formed by surface anchoring between fullerenes and hydrotalcite significantly enhances the material's durability in complex road environments such as rainwater erosion and vehicle loads, providing a reliable guarantee for long-term stable exhaust gas purification performance.

[0028] In summary, the multi-stage exhaust gas purifier achieves deep purification and harmlessness of pollutants through the synergistic effect of visible light-responsive catalysts and catalytic alkaline purifiers: the visible light-responsive catalysts perform primary photocatalytic oxidation of pollutants under light excitation, generating NO2. - and NO3 - Acidic byproducts are immediately adsorbed and neutralized by the alkaline components in the catalytic alkaline purifier, generating stable salts such as Ca(NO2)2, thus preventing the acidic environment from poisoning the catalyst. At the same time, the adsorption-catalysis bifunctional material, with its excellent adsorption and catalytic performance, further enriches and completely degrades the residual pollutants and intermediate products, ultimately generating CO2 and H2O. This effectively solves the problems of catalyst deactivation and secondary pollution caused by the accumulation of acidic byproducts while improving purification efficiency.

[0029] The intelligent thermal management composite agent is composed of thermochromic microcapsules and radiative cooling materials in a mass ratio of (1-2):1. The capsule wall of the thermochromic microcapsule is melamine-formaldehyde resin modified by nano-silica copolymerization, and the core is a color-developing system of tetradecyl alcohol and crystal violet lactone-bisphenol A. The color-changing threshold is 35℃. It turns into a light color when the temperature is above 35℃, which can efficiently reflect sunlight and reduce heat input from the source.

[0030] The radiation cooling material is a porous silica aerogel powder with a particle size distribution of 50-200nm. It has high solar reflectivity and high emissivity (>0.9) in the mid-infrared atmospheric window band of 8-13μm. It continuously dissipates heat into outer space through radiation, achieving continuous cooling without energy consumption.

[0031] This intelligent thermal management composite agent achieves functional complementarity between thermochromic microcapsules and radiative cooling materials. The microcapsules dynamically regulate solar heat absorption through reversible color-changing properties, actively reducing heat input at high temperatures, while the radiative cooling materials continuously dissipate heat through atmospheric windows, compensating for the microcapsules' insufficient continuous cooling capacity. Together, they form a dual regulation mechanism of dynamic reflection and continuous heat dissipation, overcoming the limitations of single materials in temperature regulation, effectively reducing heat accumulation on the road surface, and reducing the heat burden on the underlying phase change temperature regulation layer.

[0032] The preparation method of thermochromic microcapsules includes the following steps: S1. Preparation of wall material prepolymer: Melamine and formaldehyde are reacted at 60-80℃ under alkaline conditions with the pH adjusted to 8-9 using triethanolamine at a molar ratio of 1:(2-4) to form an aqueous solution of melamine-formaldehyde resin prepolymer. S2. Preparation of core emulsion: The core material, including tetradecyl alcohol, crystal violet lactone, and bisphenol A, is compounded into a composite colorimetric system at a mass ratio of (50-100):(0.5-2):(1-4). After heating and melting, it is sheared and dispersed at high speed at 6000-10000 rpm in an aqueous solution containing styrene-maleic anhydride copolymer (SMA) emulsifier to form a stable core emulsion. S3. In-situ polymerization and modification: The obtained core emulsion and prepolymer aqueous solution are mixed at a mass ratio of 1:(0.5-2), and 5-20% of nano silica as a modifier is added as a total mass of wall material. The in-situ polymerization reaction is carried out at 50-70℃ for 2-4 hours under acidic conditions with a pH of 3.5-5.0. S4. Post-processing: After the reaction is completed, the system is adjusted to neutral to terminate the reaction. After separation and washing, the system is vacuum dried at 40-60℃ for 8-12 hours to obtain the thermochromic microcapsules.

[0033] The preparation method of this thermochromic microcapsule is based on the classic melamine-formaldehyde in-situ polymerization encapsulation technology. The improvement lies in the key optimization of the emulsification system and the wall material composite process. In this method, oleophilic nano-silica acts as a nano-reinforcing filler, forming a composite network with the melamine-formaldehyde wall material. This significantly enhances the compressive strength and toughness of the microcapsule shell, enabling it to withstand the mechanical stress during asphalt mixture mixing, paving, and compaction, thus preventing prolonged service life of the temperature-regulating pavement due to cracking failure. Simultaneously, nano-silica improves the density and thermal stability of the wall material. Combined with the stable interface formed by the SMA emulsifier, it effectively prevents leakage or deterioration of the core material during high-temperature construction and use of asphalt concrete, ensuring the long-term stability of the phase change temperature-regulating function. Furthermore, the SMA emulsifier imparts good compatibility between the microcapsule surface and asphalt, while the rough surface of the nano-silica further enhances interfacial adhesion, preventing the microcapsules from clumping or floating in the mixture, ensuring uniform dispersion and functional performance in the pavement.

[0034] Furthermore, the coating amount of the high thermal conductivity adhesive layer is 0.8-1.2 L / m²; it is made by high-speed shearing composite of SBS modified bitumen and high thermal conductivity graphite powder with a particle size of not less than 800 mesh, accounting for 3-8% of its mass, in order to improve the interlayer heat conduction capacity and stability.

[0035] The preparation method of high thermal conductivity bonding material includes the following steps: S1. Base asphalt pretreatment: Weigh the SBS modified asphalt, place it in a heating container at 175℃, and stir it until it is fully melted to a fluid state; S2. High thermal conductivity filler dispersion: High thermal conductivity graphite powder is slowly added to molten asphalt, and a high-speed shearing device is used to continuously shear at a speed of 5000 rpm for 30 minutes to make the graphite powder uniformly dispersed in the asphalt and form a preliminary composite system. S3. Curing and stabilization treatment: The sheared composite asphalt material is transferred to an environment of 165℃, stirred at a low speed of 300rpm and kept warm for 45min to remove internal air bubbles, promote the compatibility and stability of the system, and finally obtain the high thermal conductivity adhesive layer material.

[0036] Furthermore, the drainage base course utilizes asphalt-stabilized crushed stone (ATPB-25) with a porosity of 18-25%, composed of 3-4 parts high-viscosity asphalt and 96-97 parts aggregate. In the field of road engineering, the "Specifications for Design of Highway Asphalt Pavement" (JTG D50-2017) typically requires asphalt-stabilized crushed stone base courses (such as ATPB) used for drainage to have a high interconnected porosity. 18-25% is a typical and generally accepted porosity range for such materials to achieve effective drainage. Porosity below this range may affect drainage efficiency; porosity above this range may compromise structural stability.

[0037] The aggregate is a discontinuously graded aggregate with a particle size of 4.75-26.5 mm. The aggregate conforms to the ATPB-25 gradation requirements in the "Technical Specification for Construction of Asphalt Pavement on Highways" (JTG F40-2017), with a nominal maximum particle size of 26.5 mm. After static compaction, the mixture should have a target porosity of 18-25% and possess good skeletal void structure and drainage function.

[0038] Specifically, the aggregates include: 30 parts of coarse aggregate with a particle size of 19-26.5 mm, 25 parts of coarse aggregate with a particle size of 9.5-19 mm, 20 parts of medium aggregate with a particle size of 4.75-9.5 mm, 15 parts of fine aggregate with a particle size of 2.36-4.75 mm, 8 parts of fine aggregate with a particle size of 0.075-2.36 mm, and 2 parts of limestone powder with a particle size less than 0.075 mm.

[0039] Furthermore, the waterproof and frost-heave-resistant cushion layer includes a waterproof layer. To enhance the waterproof and frost-heave-resistant effect, a sandwich-type composite waterproof layer consisting of a first geotextile, a geomembrane, and a second geotextile is laid on top of the waterproof layer. Graded gravel is then spread and compacted on the waterproof layer. Its maximum nominal particle size is no greater than 31.5 mm, the particle size distribution conforms to the requirements of the "Technical Specifications for Construction of Highway Pavement Base Course" (JTG / T F20-2015), and the compaction degree is no less than 96%. To control project quality, the plasticity index of the gravel used is less than 9, and the crushing value is no greater than 35%.

[0040] Specifically, the graded sand and gravel includes: 25 parts of coarse aggregate with a particle size of 19-37.5mm, 35 parts of medium aggregate with a particle size of 4.75-19mm, 25 parts of fine aggregate with a particle size of 0.6-4.75mm, and 15 parts of mineral powder filler with a particle size of less than 0.6mm.

[0041] The drainage base course and the waterproof and frost-resistant subbase work together to achieve rapid drainage and isolation of moisture in the pavement structure, effectively preventing frost heave deformation, asphalt spalling and structural damage caused by moisture retention in the pavement system. At the same time, it avoids water erosion damage to phase change temperature regulating materials and composite functional materials, so as to ensure the integrity of the pavement structure and the durability of its ecological functions.

[0042] The second technical solution of the present invention: A construction method for a self-regulating temperature-regulating and exhaust gas-purifying ecological asphalt pavement structure includes the following steps: S1. Subgrade construction: The subgrade is compacted to obtain a subgrade with a compaction degree of not less than 93% and a thickness of 20-30cm. S2. Construction of waterproof and frost-resistant cushion layer: A waterproof layer is laid on the soil base layer, which includes a first geotextile, a geomembrane and a second geotextile stacked in sequence; then graded sand and gravel are spread on the waterproof layer and compacted to obtain a waterproof and frost-resistant cushion layer with a compaction degree of not less than 97% and a thickness of 15-20cm. S3. Drainage base construction: On the waterproof and frost-resistant cushion layer, a large-pore asphalt-stabilized crushed stone mixture is spread and compacted by static pressure to obtain a drainage base with a thickness of 8-12cm. S4. Construction of phase change temperature regulation layer: S4.1. Prepare phase change temperature-regulating modified asphalt by mixing aggregate with the phase change temperature-regulating modified asphalt at 160-165℃ to obtain AC-20 type phase change temperature-regulating layer mixture. S4.2. Spread the phase change temperature regulating layer mixture on the drainage base layer, control the spreading temperature to be not lower than 150℃, and roll it to a compaction degree of not less than 97% to form a phase change temperature regulating layer with a thickness of 3-4cm. S5. Construction of high thermal conductivity adhesive layer: Spray high thermal conductivity modified asphalt on the surface of the phase change temperature regulating layer to form a high thermal conductivity adhesive layer; S6. Construction of porous environmental response layer: S6.1. The composite functional material and high viscosity asphalt are premixed at 165-170℃ using a high-speed shear apparatus, and then mixed with aggregates at 170-175℃ to obtain OGFC-13 type environmentally responsive layer mixture. S6.2. Spread the environmentally responsive layer mixture on the high thermal conductivity bonding layer, control the spreading temperature to be not lower than 160℃, and use a light roller to compact it to a compaction degree of 90-95%, forming a porous environmentally responsive layer with a thickness of 3-4cm. S7. Curing and Opening to Traffic: After construction is completed, the road surface can be opened to traffic only after it has cooled naturally to below 50°C.

[0043] In step (S4.1), the aggregate includes coarse aggregate with a particle size of 4.75-19 mm, fine aggregate with a particle size of 0.075-4.75 mm, and mineral fillers with a particle size less than 0.075 mm; and / or, In step (S6.1), the aggregate includes coarse aggregate with a particle size of 2.36-13.2 mm, fine aggregate with a particle size of 0.075-2.36 mm, and mineral powder filler with a particle size of less than 0.075 mm.

[0044] Compared with the prior art, the present invention has the following beneficial effects: (1) This invention achieves efficient synergy and mutual promotion of the self-regulating temperature regulation function and exhaust gas purification function of the road system through the structural design of the composite functional surface layer. Specifically, the intelligent thermal management composite agent in the environmental response layer has dynamic temperature regulation characteristics. The thermochromic microcapsules can automatically adjust the solar light absorption rate according to temperature changes, while the radiative cooling material continuously dissipates heat through the atmospheric window. The synergistic effect of the two effectively reduces the heat input of the road surface, thereby reducing the heat accumulation of the road surface and reducing the heat load of the phase change temperature regulation layer under high temperature environment. The lower phase change temperature regulation layer efficiently absorbs and stores the excess heat from the upper layer through the latent heat storage and release of the phase change material. While blocking the transfer of heat from the road surface to the roadbed, it effectively suppresses the road surface temperature fluctuation and provides continuous and stable temperature support for the upper porous environmental response layer. The two work together to regulate the working temperature of the porous environmental response layer at the photocatalytic suitable window of 30-50℃, which not only effectively alleviates the urban heat island effect, but also creates a stable and efficient reaction environment for exhaust gas purification, thereby solving the problems of catalyst "thermal deactivation" and phase change material "thermal saturation" caused by high temperature.

[0045] (2) This invention achieves deep purification and harmless treatment of pollutants through the synergistic effect of a visible light-responsive catalyst and a catalytic alkaline purifier. The visible light-responsive catalyst can be efficiently activated under natural light conditions, and performs primary catalytic oxidation of pollutants such as nitrogen oxides (NOx) in exhaust gas to generate acidic products such as nitric acid (HNO3) and nitrite (NO2). - ) and nitrates (NO3) - Intermediate products such as CO2 and H2O are adsorbed and neutralized by the catalytic alkaline purifier, which then converts them into stable salts. Simultaneously, the adsorption-catalysis dual-function material further enriches residual pollutants, completely degrading them into harmless CO2 and H2O. This multi-stage synergistic mechanism effectively solves the problems of catalyst deactivation and secondary pollution caused by the accumulation of acidic byproducts while improving purification efficiency, achieving a virtuous cycle and long-term stability in the purification process.

[0046] (3) This invention achieves synergistic gains in ecological function and structural performance through an integrated design of "material-function-structure". Functionally, the open-graded porous structure of the environmental response layer provides a more abundant reaction interface for the multi-stage exhaust gas purification materials and intelligent thermal management composites, directly improving the efficiency of exhaust gas purification and dynamic temperature regulation. Structurally, the environmental response layer, phase change temperature regulation layer, and drainage base layer together form an efficient vertical drainage channel, enabling rapid migration and discharge of moisture, thereby promptly flushing away stable salts and other byproducts generated by the exhaust gas purification reaction, preventing pore blockage and moisture damage to the composite functional materials and phase change temperature regulation materials, and eliminating the risk of structural defects such as frost heave and peeling caused by moisture retention. In terms of performance, the intelligent thermal management composite and phase change materials, through dynamic temperature regulation, smooth out road surface temperature fluctuations and effectively suppress the damage to the structure caused by freeze-thaw cycles. This systematic synergistic design allows each layer to promote each other while maintaining its own function, ensuring the long-term effectiveness of ecological function and improving the overall structural durability. Attached Figure Description

[0047] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0048] Figure 1 This is a schematic diagram of the structure of a collaborative self-regulating temperature and exhaust gas purification ecological asphalt pavement system according to an embodiment of the present invention.

[0049] Attached reference numerals: 1-soil base layer, 2-waterproof and frost-resistant cushion layer, 3-drainage base layer, 4-composite functional surface layer, 4.1-phase change temperature regulating layer, 4.2-porous environmental response layer. Detailed Implementation

[0050] This invention provides a self-regulating temperature-regulating and exhaust gas-purifying ecological asphalt pavement structure and its construction method.

[0051] Various exemplary embodiments of the present invention will now be described in detail. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of protection of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0052] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0053] It should be noted that any aspects not described in detail in this invention are conventional practices in the field and are not the focus of this invention.

[0054] The following embodiments of the present invention provide a schematic diagram of the structure of a synergistic self-regulating temperature control and exhaust gas purification ecological asphalt pavement system. Figure 1 As shown.

[0055] All raw materials used in the following examples and comparative examples of this invention are commercially available products. Specifically, the commercial nano-titanium dioxide used was purchased from Ningbo Luofei Nanotechnology Co., Ltd.; the ammonium fluoride, crystal violet lactone, bisphenol A, tetradecyl alcohol, magnesium nitrate, aluminum nitrate, sodium hydroxide, sodium carbonate, melamine, formaldehyde solution (37%), glacial acetic acid, 1,4-butanediol, fullerene (C60), toluene, and anhydrous ethanol used were all purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.; the urea and triethanolamine used were purchased from Sinopharm Chemical Reagent Co., Ltd.; the SMA emulsifier used was purchased from Luoyang Yefang New Material Technology Co., Ltd.; the polyethylene glycol (PEG 4000 / 6000) used was purchased from Shanghai Maclean Biochemical Technology Co., Ltd.; and the silane coupling agent KH-550 used... Purchased from Nanjing Chenggong Organosilicon Materials Co., Ltd.; the nanoporous silica aerogel powder used was purchased from Shandong Shuoxin Materials Co., Ltd.; the high thermal conductivity graphite powder used was purchased from Qingdao Yanhai Carbon Materials Co., Ltd.; the matrix asphalt used was Shell 70 asphalt produced by Zhenjiang Shell (China) Asphalt Co., Ltd.; and the high viscosity asphalt used was purchased from Shanghai Chengjian Rili Special Asphalt Co., Ltd.

[0056] Example 1 This embodiment provides a self-regulating temperature and exhaust gas purification type ecological asphalt pavement structure, which includes, from bottom to top, a soil base layer 1, a water-proof and frost-resistant cushion layer 2, a drainage base layer 3, and a composite functional surface layer 4.

[0057] The composite functional surface layer 4 is composed of a lower phase change temperature regulating layer 4.1 and an upper porous environmental response layer 4.2 bonded together by a middle high thermal conductivity adhesive layer.

[0058] (1) Porous environmental response layer 4.2 and its core materials The porous environmental response layer 4.2 adopts OGFC-13 type open-graded asphalt mixture, which is composed of high viscosity asphalt, coarse aggregate with a particle size of 2.36-13.2mm, fine aggregate with a particle size of 0.075-2.36mm, limestone mineral powder filler with a particle size of less than 0.075mm, and composite functional materials in a mass ratio of 5:82:10:3:4.

[0059] The composite functional material is composed of multi-stage exhaust gas purifier and intelligent thermal management composite agent in a mass ratio of 6:2.5.

[0060] The multi-stage exhaust gas purifier is composed of a visible light responsive catalyst and a catalytic alkaline purifier in a mass ratio of 4:1.5.

[0061] The visible light responsive catalyst is NF-TiO2 with its surface modified by silane coupling agent KH-550. The preparation method of NF-TiO2 includes the following steps: S1. Weigh 10g of commercial nano titanium dioxide and disperse it in 200mL of deionized water. Add 0.5g of ammonium fluoride and 2g of urea as dopant sources in sequence. Transfer the mixed solution into a stainless steel reactor lined with polytetrafluoroethylene and hydrothermally react at 120℃ for 12h.

[0062] S2. After the reaction is complete, allow the mixture to cool naturally to room temperature, centrifuge the product, and wash it three times with deionized water and anhydrous ethanol, respectively.

[0063] S3. The washed product was placed in an 80℃ forced-air drying oven and dried for 6 hours to obtain nitrogen-fluorine co-doped titanium dioxide powder.

[0064] S4. The above powder was dispersed in a 1 wt% ethanol solution of silane coupling agent KH-550, stirred for 2 h, and then centrifuged and dried again to obtain a surface-modified visible light responsive catalyst, denoted as NF-TiO2.

[0065] The catalytic alkaline purifier is a compound composed of alkaline neutralizing material (shell powder) and adsorption-catalysis bifunctional material (fullerene-modified hydrotalcite (C60-LDHs)) in a mass ratio of 1.5:1.

[0066] The preparation method of C60-LDHs includes the following steps: S1. Solution preparation: Mix magnesium nitrate and aluminum nitrate according to Mg² + With Al³ + Dissolve the salts in deionized water at a molar ratio of 3:1 to prepare a mixed salt solution with a total metal ion concentration of 1.0 mol / L; at the same time, prepare a mixed alkaline solution with a NaOH concentration of 2.0 M and a Na2CO3 concentration of 0.5 M for later use.

[0067] S2. Coprecipitation synthesis: Under nitrogen protection, at 60°C and with continuous stirring, the mixed salt solution and the mixed alkali solution are added to the reactor in a co-current dropwise manner, and the pH of the reaction system is controlled at 10.0 throughout the process.

[0068] S3. Crystallization and Washing: After the addition is complete, the reaction is continued to be stirred at 60℃ for 24 hours. After the reaction is completed, the resulting slurry is centrifuged and washed with deionized water until neutral to obtain Mg-Al-CO3LDHs slurry.

[0069] S4. Fullerene loading: Weigh fullerene (C60) to a ratio of 1:20 of the theoretical dry basis mass of LDHs in step S1. Dissolve the fullerene in toluene, and then mix the solution with the Mg-Al-CO3LDHs slurry obtained in step S3. Stir the mixture at 60°C for 12 hours.

[0070] S5. Post-processing: After the reaction is complete, the product is centrifuged and washed successively with toluene and anhydrous ethanol. The obtained solid is dried under vacuum at 60°C, and finally ground and sieved to obtain C60-LDHs powder.

[0071] The intelligent thermal management composite agent is composed of thermochromic microcapsules and a radiative cooling material in a mass ratio of 1.5:1; the radiative cooling material is a porous silica aerogel powder with a particle size distribution of 50-200 nm. Particle sizes that are too small (<50 nm) are prone to severe agglomeration, making uniform dispersion in asphalt difficult and potentially leading to a decrease in the emissivity of the atmospheric window (8-13 μm); while particle sizes that are too large (>200 nm) may cause Mie scattering in the solar spectrum (especially visible light), increasing sunlight absorption and weakening the cooling effect, while also potentially affecting the smoothness and durability of the road surface. A particle size distribution of 50-200 nm provides a better balance between high solar reflectivity, high atmospheric window emissivity, material dispersibility, and road performance.

[0072] The preparation method of thermochromic microcapsules includes the following steps: S1. Preparation of melamine-formaldehyde prepolymer: Add 12.6g of melamine, 24g of 37% formaldehyde solution, and 30mL of deionized water to a 250mL beaker, and adjust the pH to 8.5 with triethanolamine. Stir the reaction mixture in a 70℃ water bath for 1h until the solution is clear and transparent, then cool to room temperature for later use.

[0073] S2. Preparation of core emulsion: Weigh 0.1g crystal violet lactone, 0.2g bisphenol A and 10g tetradecyl alcohol, and melt-mix them in a 60℃ water bath to obtain the core; under a high-speed shear rate of 8000rpm, slowly drop the core mixture into 200mL of deionized water containing 2g SMA emulsifier, and continue emulsifying for 15min to obtain a stable core emulsion.

[0074] S3. Microencapsulation reaction: The core emulsion was transferred to a four-necked flask and stirred at 300 rpm in a constant temperature water bath at 55°C. 2 g of lipophilic nano-silica was added as a copolymer modifier and dispersed for 30 min. The prepolymer solution obtained in S1 was slowly added dropwise, and the pH of the system was adjusted to 4.0 with glacial acetic acid. The reaction was carried out for 3 h.

[0075] S4. Post-processing: After the reaction is completed, the pH is adjusted back to 7.0 with triethanolamine to terminate the reaction, and the mixture is cooled, filtered, washed three times alternately with deionized water and anhydrous ethanol, dried under vacuum at 50°C for 12 hours, and passed through a 400-mesh sieve to obtain the thermochromic microcapsule product.

[0076] (2) Phase change temperature regulating layer 4.1 and its core materials: The phase change temperature regulating layer 4.1 uses AC-20 type dense-graded asphalt mixture. Its component ratio (by mass parts) is: 4.5 parts of phase change temperature regulating modified asphalt, 60 parts of coarse aggregate (particle size 4.75-19mm), 35 parts of fine aggregate (particle size 0.075-4.75mm), and 5.5 parts of limestone mineral powder filler.

[0077] The preparation method of the phase change temperature-regulating polyurethane used in the phase change temperature regulation modification is as follows: polyethylene glycol (PEG) with molecular weights of 4000 and 6000 is mixed in a mass ratio of 1:2 as a composite soft segment, and the molar ratio of the key materials is controlled as MDI:PEG:BDO = 2.2:1.0:1.05.

[0078] Its specific preparation process includes: S1. Raw material pretreatment: The PEG mixture in the specified proportion is stirred and dehydrated for 2 hours at 120°C and -0.095 MPa vacuum.

[0079] S2. Prepolymer synthesis: Under nitrogen protection, dehydrated PEG was reacted with molten MDI and the catalyst dibutyltin dilaurate at 80°C for 2 hours.

[0080] S3. Chain extension reaction: Add a measured amount of chain extender BDO to the prepolymer and continue the reaction at 70°C and 600 rpm for 1 hour.

[0081] S4. Curing and post-treatment: Pour the product into a mold, cure at 90°C for 12 hours, and then vacuum dry at 60°C for 24 hours to obtain the phase change temperature-regulating polyurethane.

[0082] The phase change temperature-regulating polyurethane prepared above was tested using differential scanning calorimetry (DSC). The test conditions were: nitrogen atmosphere, heating / cooling rate 5℃ / min, temperature range 0-80℃. The test results showed that the phase change temperature range of this material is 32-48℃ (phase change onset temperature approximately 32℃, phase change peak temperature approximately 40℃, phase change end temperature approximately 48℃), and the phase change enthalpy is not less than 85 J / g. This phase change temperature range falls entirely within the 30-50℃ range.

[0083] (3) High thermal conductivity adhesive layer material: The coating amount of the high thermal conductivity adhesive layer is 1L / m²; it is made by high-speed shearing composite of SBS modified bitumen and 3% by mass of high thermal conductivity graphite powder with a particle size of not less than 800 mesh.

[0084] The preparation method of the high thermal conductivity bonding material includes the following steps: S1. Base Asphalt Pretreatment: Weigh 500g of SBS modified asphalt, place it in a heating container at 175℃, and stir until it is fully melted to a fluid state.

[0085] S2. Dispersion of high thermal conductivity filler: Slowly add 25g of high thermal conductivity graphite powder with a particle size of 800 mesh to the molten asphalt, and continuously shear at a speed of 5000rpm for 30min using a high-speed shearing device to uniformly disperse the graphite powder in the asphalt and form a preliminary composite system.

[0086] S3. Curing and stabilization treatment: The sheared composite asphalt material is transferred to an environment of 165℃, stirred at a low speed of 300rpm and kept warm for 45min to remove internal air bubbles, promote the compatibility and stability of the system, and finally obtain the high thermal conductivity adhesive layer material.

[0087] (4) Composition of drainage base layer and waterproof and frost-resistant cushion layer: The drainage base course 3 uses large-pore asphalt-stabilized crushed stone (ATPB-25). Its composition is: a mass ratio of high-viscosity asphalt to discontinuously graded aggregate of 3.5:96.5. The aggregate gradation conforms to the requirements of ATPB-25 in the "Technical Specification for Construction of Highway Asphalt Pavement" (JTGF40-2017), and its specific composition (by mass) may include: 30 parts coarse aggregate with a particle size of 19-26.5mm, 25 parts coarse aggregate with a particle size of 9.5-19mm, 20 parts medium aggregate with a particle size of 4.75-9.5mm, 15 parts fine aggregate with a particle size of 2.36-4.75mm, 8 parts fine aggregate with a particle size of 0.075-2.36mm, and 2 parts limestone powder with a particle size less than 0.075mm. After static compaction, the effective porosity of this drainage base course is not less than 18%, and the permeability coefficient is not less than 1.0×10⁻⁶. -2 cm / s ensures its core function of rapid drainage.

[0088] The waterproof and frost-resistant cushion layer 2 is formed by compacting graded gravel to a compaction degree of not less than 97%. By mass percentage, the graded gravel comprises: 25 parts coarse aggregate with a particle size of 19-37.5 mm, 35 parts medium aggregate with a particle size of 4.75-19 mm, 25 parts fine aggregate with a particle size of 0.6-4.75 mm, and 15 parts mineral powder filler with a particle size less than 0.6 mm. This mix proportion falls within the requirements of the "Technical Specifications for Construction of Highway Pavement Base Course" (JTG / T F20-2015) and can form a good skeleton-dense structure.

[0089] To enhance the waterproofing and frost heave prevention effect, a composite waterproof layer is set between the soil base layer and the cushion layer. This waterproof layer is composed of a first geotextile, an HDPE geomembrane, and a second geotextile in sequence.

[0090] (5) The construction method of the self-regulating temperature and exhaust gas purification type ecological asphalt pavement structure in this embodiment includes the following steps: S1, Subgrade 1 Construction: The subgrade is leveled and compacted to form a subgrade 1 with a compaction degree (tested by sand filling method) of not less than 93% and a thickness of 25cm.

[0091] S2. Construction of the waterproof and frost-resistant cushion layer 2: On the soil base layer 1, a composite waterproof layer consisting of a 200g / m² polyester filament geotextile (first geotextile), a 0.3mm thick HDPE geomembrane, and a 200g / m² polyester filament geotextile (second geotextile) is laid in sequence; graded gravel is spread on the waterproof layer, leveled with a grader, and then compacted with a vibratory roller to a compaction degree of not less than 97%, resulting in a 18cm thick waterproof and frost-resistant cushion layer 2.

[0092] S3, Drainage Base Course 3 Construction: The high-pore asphalt-stabilized crushed stone mixture prepared in proportion is spread out and statically compacted using a double-drum roller to obtain a drainage base course 3 with a thickness of 10cm and a porosity of 20%.

[0093] S4, Phase Change Temperature Regulation Layer 4.1 Construction: S4.1 Mixing of the Asphalt: First, add 4 parts by weight of phase change temperature-regulating polyurethane and 3 parts by weight of SBS modified asphalt to 100 parts by weight of No. 70 base asphalt. Shear the mixture at 170°C using a high-speed shearing machine at 4000 rpm for 45 minutes to obtain phase change temperature-regulating modified asphalt. Then, mix the phase change temperature-regulating modified asphalt with aggregate at 163°C in a mixing plant to obtain the AC-20 type phase change temperature-regulating layer 4.1 mixture.

[0094] S4.2, Paving and Compaction: The phase change temperature regulating layer 4.1 mixture is paved on the drainage base course 3 and compacted using a double steel wheel roller and a pneumatic tire roller, with a compaction degree of not less than 97%, to obtain a phase change temperature regulating layer 4.1 with a thickness of 3.5cm.

[0095] S5. Construction of high thermal conductivity adhesive layer: On the surface of the phase change temperature regulating layer 4.1, high thermal conductivity modified asphalt is evenly sprayed using an intelligent asphalt sprayer at a spraying rate of 1.0L / m² to obtain a high thermal conductivity adhesive layer.

[0096] S6, Porous Environmental Response Layer 4.2 Construction: S6.1 Mixing of the mixture: First, the composite functional material and high viscosity asphalt are pre-mixed at 170℃ using a high-speed shear apparatus at a speed of 3500rpm for 8 minutes to fully disperse the functional material; then, it is mixed with aggregate at 170℃ to prepare OGFC-13 mixture, thus obtaining OGFC-13 type environmental response layer 4.2 mixture.

[0097] S6.2, Paving and Compaction: The porous environmentally responsive layer 4.2 mixture is paved on the high thermal conductivity bonding layer, and the paving temperature is controlled at 165℃. A double-drum vibratory roller is used to compact it to approximately 93% compaction, with a designed porosity of 20%, resulting in a porous environmentally responsive layer 4.2 with a thickness of 3.5cm.

[0098] S7. Curing and Opening to Traffic: After construction is completed, the road surface can be opened to traffic only after it has cooled naturally to below 50°C.

[0099] Example 2 The basic composition, connection relationship and preparation method of the self-regulating temperature and exhaust gas purification type ecological asphalt pavement structure in this embodiment are the same as those in Embodiment 1. The difference is that the proportion of key functional materials is different in Embodiment 2, so as to verify the effectiveness and feasibility of the technical solution under boundary conditions.

[0100] (1) Porous environmental response layer 4.2 and its core materials The environmental response layer 4.2 adopts OGFC-13 type open-graded asphalt mixture, which is composed of high viscosity asphalt, coarse aggregate with a particle size of 2.36-13.2mm, fine aggregate with a particle size of 0.075-2.36mm, limestone mineral powder filler with a particle size of less than 0.075mm, and composite functional materials in a mass ratio of 4.5:78:8:2:3.

[0101] The composite functional material is composed of multi-stage exhaust gas purifier and intelligent thermal management composite agent in a mass ratio of 4:2.

[0102] The multi-stage exhaust gas purifier is prepared by combining a visible light responsive catalyst and a catalytic alkaline purifier in a 3:1 mass ratio.

[0103] The visible light responsive catalyst is NF-TiO2 with a surface modified by silane coupling agent KH-550. The preparation method of NF-TiO2 is the same as in Example 1.

[0104] The catalytic alkaline purifier is a compound composed of alkaline neutralizing material (shell powder) and adsorption-catalysis bifunctional material (fullerene-modified hydrotalcite (C60-LDHs)) in a mass ratio of 1:1; the preparation method of C60-LDHs is the same as in Example 1.

[0105] The intelligent thermal management composite agent is composed of thermochromic microcapsules and radiative cooling material in a mass ratio of 1:1; the radiative cooling material is porous silica aerogel powder with a particle size distribution of 50-200nm; the preparation method of the thermochromic microcapsules is the same as in Example 1.

[0106] (2) Phase change temperature regulating layer 4.1 and its core materials: The phase change temperature regulating layer 4.1 uses AC-20 type dense-graded asphalt mixture. Its component ratio (by mass parts) is: 4.0 parts of phase change temperature regulating modified asphalt, 55 parts of coarse aggregate (particle size 4.75-19mm), 30 parts of fine aggregate (particle size 0.075-4.75mm), and 4 parts of limestone mineral powder filler.

[0107] The preparation method of the phase change temperature-regulating polyurethane used in the phase change temperature regulation modification is the same as in Example 1.

[0108] (3) High thermal conductivity adhesive layer material: The coating amount of the high thermal conductivity adhesive layer and the preparation method of the high thermal conductivity adhesive material are the same as in Example 1.

[0109] (4) Composition of drainage base layer and waterproof and frost-resistant cushion layer: The drainage base layer 3 is made of large-pore asphalt-stabilized crushed stone (ATPB-25), the same as in Example 1.

[0110] (5) The construction method of the self-temperature regulating and exhaust gas purification type ecological asphalt pavement structure in this embodiment is the same as that in embodiment 1.

[0111] Example 3 The basic composition, connection relationship and preparation method of the self-regulating temperature and exhaust gas purification type ecological asphalt pavement structure in this embodiment are the same as those in Embodiment 1. The difference is that the proportion of key functional materials is different in Embodiment 4, so as to verify the effectiveness and feasibility of the technical solution under boundary conditions.

[0112] (1) Porous environmental response layer 4.2 and its core materials The porous environmental response layer 4.2 adopts OGFC-13 type open-graded asphalt mixture, which is composed of high viscosity asphalt, coarse aggregate with a particle size of 2.36-13.2mm, fine aggregate with a particle size of 0.075-2.36mm, limestone mineral powder filler with a particle size of less than 0.075mm, and composite functional materials in a mass ratio of 5.5:85:12:4:4.5.

[0113] The composite functional material is composed of multi-stage exhaust gas purifier and intelligent thermal management composite agent in a mass ratio of 7:3.

[0114] The multi-stage exhaust gas purifier is prepared by combining a visible light-sensitive catalyst and a catalytic alkaline purifier in a mass ratio of 5:2.

[0115] The visible light responsive catalyst is NF-TiO2 with a surface modified by silane coupling agent KH-550. The preparation method of NF-TiO2 is the same as in Example 1.

[0116] The catalytic alkaline purifier is a compound composed of alkaline neutralizing material (shell powder) and adsorption-catalysis bifunctional material (fullerene-modified hydrotalcite (C60-LDHs)) in a mass ratio of 1:1; the preparation method of C60-LDHs is the same as in Example 1.

[0117] The intelligent thermal management composite agent is composed of thermochromic microcapsules and radiative cooling material in a mass ratio of 2:1; the radiative cooling material is porous silica aerogel powder with a particle size distribution of 50-200nm; the preparation method of the thermochromic microcapsules is the same as in Example 1.

[0118] (2) Phase change temperature regulating layer 4.1 and its core materials: The phase change temperature regulating layer 4.1 uses AC-20 type dense-graded asphalt mixture. Its component ratio (by mass parts) is: 5.0 parts of phase change temperature regulating modified asphalt, 65 parts of coarse aggregate (particle size 4.75-19mm), 40 parts of fine aggregate (particle size 0.075-4.75mm), and 7 parts of limestone mineral powder filler.

[0119] The preparation method of the phase change temperature-regulating polyurethane used in the phase change temperature regulation modification is the same as in Example 1.

[0120] (3) High thermal conductivity adhesive layer material: The coating amount of the high thermal conductivity adhesive layer and the preparation method of the high thermal conductivity adhesive material are the same as in Example 1.

[0121] (4) Composition of drainage base layer and waterproof and frost-resistant cushion layer: The drainage base layer 3 is made of large-pore asphalt-stabilized crushed stone (ATPB-25), the same as in Example 1.

[0122] (5) The construction method of the self-temperature regulating and exhaust gas purification type ecological asphalt pavement structure in this embodiment is the same as that in embodiment 1.

[0123] Comparative Example 1 The only difference between this comparative example and Example 1 is that the composite functional material in the porous environmental response layer is replaced by ordinary limestone powder by an equal mass. This setup aims to verify the core functional contributions of the composite functional material in exhaust gas purification and road surface temperature regulation through comparison.

[0124] Comparative Example 2 The difference between this comparative example and Example 1 is that the catalytic alkaline purifier in the multi-stage exhaust gas purifier is replaced with an equal mass of surface-modified nitrogen-fluorine co-doped titanium dioxide (NF-TiO2). This setup aims to verify that the absence of alkaline purifier components will prevent the effective treatment of harmful byproducts (such as HNO2 and H2SO3) generated during exhaust gas purification, leading to excessively high acidity on the catalyst surface and deactivation, and failing to solve the secondary pollution problem caused by acidic byproducts.

[0125] Comparative Example 3 The only difference between this comparative example and Example 1 is that no phase change temperature-regulating polyurethane was added during the preparation of the phase change temperature-regulating layer. This setting aims to illustrate that relying solely on the intelligent thermal management composite agent in the environmental response layer makes it difficult to maintain the temperature of the environmental response layer within the optimal range of 30-50°C under continuous heat load, and to verify the crucial role of the phase change temperature-regulating layer in mitigating road surface temperature fluctuations and providing a stable temperature environment for the upper catalytic reaction.

[0126] Comparative Example 4 The difference between this comparative example and Example 1 is that the composite functional surface layer uses a traditional asphalt mixture that does not contain any functional materials. This setup aims to verify that the synergistic self-regulating temperature control and exhaust gas purification ecological functions of the present invention do not come at the expense of the road performance.

[0127] Performance testing and effect verification: To verify the comprehensive effectiveness of the self-regulating temperature and exhaust gas purification type ecological asphalt pavement structure and its construction method proposed in this invention, the following performance tests and comparative analyses were conducted on the above embodiments and comparative examples.

[0128] Performance Test Experiment 1: Basic Road Performance Test To verify the basic road performance of the eco-friendly asphalt pavement system of this invention, a series of standardized tests were conducted on Examples 1-3 and Comparative Example 4 in accordance with the "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" (JTG E20-2011). The dynamic stability at 60℃ was determined using the T0719 rutting test to evaluate its high-temperature rutting resistance; the freeze-thaw splitting strength ratio was determined using the T0729 freeze-thaw splitting test to assess its water stability; and the Marshall stability (kN) of the specimens at the T0709 Marshall test points was verified to confirm its basic mechanical strength.

[0129] Table 1. Basic Road Performance Test Results Table 1 shows the basic road performance test results, indicating that the present invention successfully endows the pavement with ecological functions while still ensuring that its road performance meets engineering application standards. Regarding high-temperature stability, the dynamic stability of Examples 1-3 is slightly lower than that of Comparative Example 4 without added functional materials, but still significantly higher than the specification requirements. This result shows that although the addition of functional materials has a slight impact on the performance of asphalt mixtures, the overall mixture still possesses excellent high-temperature deformation resistance. Regarding water stability, the freeze-thaw splitting strength ratio of Examples 1-3 meets the specification requirements, demonstrating sufficient resistance to water damage. However, it is slightly lower than the freeze-thaw splitting strength of Comparative Example 4 because some functional materials are hydrophilic (such as silica aerogel and hydrotalcite LDHs). During repeated freeze-thaw cycles, compared to the limestone powder used in the traditional mixture in Comparative Example 4, water is more likely to penetrate, remain, and freeze at the heterogeneous interface between these functional particles and asphalt, generating expansion stress, leading to the initiation and propagation of microcracks, resulting in a slight decrease in its freeze-thaw splitting strength.

[0130] Performance Test Experiment 2: Test of Exhaust Gas Purification and By-product Harmless Conversion Efficiency Considering the complex composition of actual vehicle exhaust (containing multiple pollutants such as nitrogen oxides, sulfides, and hydrocarbons), this experiment selected nitrogen oxides (NOx) as a representative component. x (NO) was used as a key evaluation indicator. Samples from Examples 1-3 and Comparative Examples 1-2 were placed in a closed reactor, and a measured amount of NO and NO2 mixture was injected to simulate the main nitrogen oxide components of automobile exhaust. Under simulated sunlight irradiation, a nitrogen oxide analyzer was used to monitor and record the NO levels in the reactor over 30 minutes. x The percentage concentration is used to indirectly quantify the exhaust gas purification efficiency. After completing the above purification tests, to verify that the intermediate products generated by the photocatalytic reaction (such as HNO2 and HNO3) have been effectively converted into environmentally friendly and harmless substances, the sample surface was rinsed with a quantitative amount of deionized water. The eluent was collected, filtered, concentrated, and then NO3 was detected using an ion chromatograph. - and NO2 - The concentration of the target ion was measured. By comparing the differences in the concentration of the target ion in different samples, the ability of this functional layer to avoid the accumulation of acidic byproducts and prevent secondary pollution was indirectly evaluated.

[0131] Table 2. Test Results of Exhaust Gas Purification Performance Based on the test results of exhaust gas purification performance shown in Table 2, the eco-friendly asphalt pavement system provided by this invention exhibits significant advantages in the purification and harmless treatment of vehicle exhaust gas. (NO in Examples 1-3) x The purification efficiency increases with the increase of functional material dosage, proving the effectiveness of the functional materials and the adjustability of the formulation. Reaction byproduct NOx - The concentration analysis data is more convincing: NO3 in the eluent of all examples - The concentration was only 1.3-1.8 mg / L, which contrasts sharply with the high accumulation of acidic byproducts (8.4 mg / L) in Comparative Example 2, which only used photocatalyst. This directly confirms the success of the multi-stage synergistic purification process of the visible light-responsive catalyst and the catalytic alkaline purifier. The former efficiently initiates pollutant degradation, while the latter instantly neutralizes and fixes acidic intermediates. This improves purification efficiency while completely avoiding the risks of catalyst acid poisoning and secondary environmental pollution, achieving a leap from "purification" to "harmlessness." In other words, although increasing the amount of photocatalyst can improve exhaust gas purification efficiency to some extent, the synergistic use of photocatalytic materials and catalytic alkaline purifiers can construct a more complete pollutant conversion pathway, thereby achieving a better overall purification effect.

[0132] Performance Test Experiment 3: Self-Temperature Regulation Performance Test To quantitatively verify the self-regulating temperature capability of this invention, temperature sensors were embedded in the center (2 cm deep) of the environmental response layer and at the interlayer interface of the specimen. The specimen was then placed in an environmental aging chamber. After reaching initial thermal equilibrium in a constant temperature environment of 35°C, a simulated solar light source with an intensity of 1000 W / m² was continuously irradiated for 6 hours to simulate daytime temperature rise. The light source was then turned off, and temperature changes were recorded during a 12-hour natural cooling process. By comparing and analyzing the highest temperature of different specimens and the duration of the temperature plateau in the 30-50°C phase transition range, the self-regulating temperature performance of this invention in suppressing temperature peaks and delaying temperature fluctuations can be quantitatively evaluated. The test results are summarized in Table 3.

[0133] Table 3. Test results of self-regulating temperature performance According to the self-regulating temperature performance test results in Table 3, Examples 1-3 using the complete structure of this invention exhibit a significant synergistic temperature regulation effect. Test data shows that these examples significantly reduced the maximum operating temperature of the environmental response layer and simultaneously formed a clear temperature regulation plateau. Specifically, when the pavement temperature entered the phase change operating range of 30-50℃, the rate of temperature change slowed significantly. The temperature plateau duration of Example 3 reached 7.0 h, Example 1 was 6.8 h, while Comparative Example 3, lacking a phase change temperature regulation layer, only maintained it for 5.5 h, and Comparative Example 4, with a traditional asphalt pavement structure, produced almost no temperature regulation effect (0.2 h). The establishment and extension of this temperature plateau directly proves that this invention achieves effective regulation of pavement operating temperature through material and structural design. The emergence of this temperature plateau highly coincides with the phase change temperature range (32-48℃) of the phase change temperature-regulating polyurethane determined by DSC testing in Example 1. This directly proves that the phase change temperature-regulating material undergoes a phase change and absorbs / releases a large amount of latent heat within the 30-50℃ range, contributing to the active buffering and stabilization of pavement temperature.

[0134] The essence of this temperature control capability lies in the synergistic mechanism of the layered structure: the intelligent thermal management composite in the upper porous environmental response layer dynamically regulates the absorption and dissipation of solar radiation heat through thermochromic properties and radiative cooling effects; the lower phase change temperature regulating layer efficiently stores and releases latent heat through the melting and crystallization process of the phase change material within the phase change temperature range of 30-50℃. A high thermal conductivity bonding layer forms a tight thermal coupling connection between the two layers. When the road surface temperature approaches 50℃, the phase change material absorbs heat and undergoes a solid-liquid phase change, effectively inhibiting further temperature rise; when the temperature tends to decrease, the phase change material releases latent heat of crystallization, slowing down the cooling rate. This interconnected temperature control mechanism not only significantly smooths out road surface temperature fluctuations but also creates and maintains a continuously stable optimal reaction temperature environment for the upper exhaust gas purification function, transforming the traditional mutually restrictive relationship between temperature control and pollutant degradation into a mutually reinforcing synergistic relationship.

[0135] Comprehensive test results demonstrate that this invention successfully constructs an ecological pavement system with reliable road performance, thorough exhaust gas purification, and intelligent temperature control. Its technical effectiveness is not a simple superposition of functions, but rather a result of hierarchical synergistic gains, effectively solving the technical challenges of traditional ecological pavements such as single function, conflicting effectiveness, and difficulty in achieving long-term sustainability.

[0136] The above embodiments are intended to illustrate the implementation of the present invention in detail, but they do not represent the full scope of the present invention. Any obvious modifications or substitutions made based on these embodiments without departing from the core concept of the present invention should be included within the protection scope of the present invention.

Claims

1. A self-regulating temperature-regulating and exhaust gas-purifying ecological asphalt pavement structure, characterized in that, The ecological asphalt pavement structure consists of, from bottom to top, a soil base layer (1), a water-proof and frost-resistant cushion layer (2), a drainage base layer (3), and a composite functional surface layer (4); the composite functional surface layer (4) is composed of a lower phase change temperature regulating layer (4.1) and an upper porous environmental response layer (4.2) bonded together by a middle high thermal conductivity bonding layer. The phase change temperature regulating layer (4.1) is made of phase change temperature regulating polyurethane modified asphalt mixture; The porous environmental response layer (4.2) is a porous structure layer with a porosity of 18-25%, which is composed of open-graded asphalt mixture and composite functional materials; The high thermal conductivity adhesive layer is made of high thermal conductivity modified asphalt; The phase change temperature regulating layer (4.1) and the composite functional material in the porous environmental response layer (4.2) work together to maintain the working temperature of the porous environmental response layer (4.2) within the range of 30-50℃, thereby smoothing out road surface temperature fluctuations and improving exhaust gas purification efficiency.

2. The self-regulating temperature and exhaust gas purification type ecological asphalt pavement structure according to claim 1, characterized in that, The phase change temperature regulating layer (4.1) is made of AC-20 type dense-graded asphalt mixture and consists of the following components: 4-5 parts phase change temperature-regulating modified asphalt, 55-65 parts coarse aggregate, 30-40 parts fine aggregate, 4-7 parts mineral filler; and / or, The phase change temperature-regulating modified asphalt is made by adding 3-5 parts by mass of phase change temperature-regulating polyurethane and 3 parts by mass of SBS modified asphalt to 100 parts by mass of base asphalt. The coarse aggregate has a particle size of 4.75-19 mm; The fine aggregate has a particle size of 0.075-4.75 mm; The mineral filler is limestone powder with a particle size of less than 0.075 mm.

3. The self-regulating temperature and exhaust gas purification type ecological asphalt pavement structure according to claim 1, characterized in that, The porous environmental response layer (4.2) is made of OGFC-13 type open-graded asphalt mixture and consists of the following components: 4.5-5.5 parts high-viscosity asphalt, 78-85 parts coarse aggregate, 8-12 parts fine aggregate, 2.0-4.0 parts mineral powder filler, and 3.0-4.5 parts composite functional materials.

4. The self-regulating temperature and exhaust gas purification type ecological asphalt pavement structure according to claim 3, characterized in that, The high-viscosity asphalt has an absolute viscosity of not less than 20,000 Pa·s at 60°C; The coarse aggregate has a particle size of 2.36-13.2 mm; The fine aggregate has a particle size of 0.075-2.36 mm; The mineral powder filler is limestone mineral powder with a particle size of less than 0.075 mm; The composite functional material is added during the preparation of the mixture by replacing a portion of the mineral powder filler by an equal mass, with the replacement amount being the number of parts of the composite functional material.

5. A self-regulating temperature-regulating and exhaust gas-purifying ecological asphalt pavement structure according to any one of claims 1-4, characterized in that, The composite functional material is composed of multi-stage exhaust gas purifier and intelligent thermal management composite agent in a mass ratio of (4-7):(2-3); The multi-stage exhaust gas purifier is composed of a visible light-responsive catalyst and a catalytic alkaline purifier in a mass ratio of (3-5):(1-2); and / or, The visible light responsive catalyst is nitrogen-fluorine co-doped titanium dioxide with a surface modified by a silane coupling agent; and / or, The catalytic alkaline purifying agent is a compound composed of an alkaline neutralizing material and an adsorption-catalysis bifunctional material in a mass ratio of (2-4):1; and / or, The alkaline neutralizing material is selected from one or more of shell powder and steel slag; the adsorption-catalysis bifunctional material is fullerene-modified hydrotalcite.

6. The self-regulating temperature and exhaust gas purification type ecological asphalt pavement structure according to claim 5, characterized in that, The intelligent thermal management composite agent is composed of thermochromic microcapsules and radiative cooling materials in a mass ratio of (1-2):1; and / or, The capsule wall of the thermochromic microcapsule is melamine-formaldehyde resin copolymerized with nano-silica, and the core is a colorimetric system of tetradecyl alcohol and crystal violet lactone-bisphenol A, with a color change threshold of 35°C; the radiation cooling material is porous silica aerogel powder with a particle size distribution of 50-200 nm.

7. The self-regulating temperature-regulating and exhaust gas purification type ecological asphalt pavement structure according to claim 1, characterized in that, The coating amount of the high thermal conductivity adhesive layer is 0.8-1.2 L / m²; it is composed of SBS modified bitumen and 3-8% by mass of high thermal conductivity graphite powder with a particle size of not less than 800 mesh.

8. The self-regulating temperature-regulating and exhaust gas purification type ecological asphalt pavement structure according to claim 1, characterized in that, The drainage base course (3) is made of asphalt-stabilized crushed stone with a porosity of 18-25%, and is composed of the following components: 3-4 parts high-viscosity asphalt and 96-97 parts aggregate; The aggregate is a graded aggregate with a particle size of 4.75-26.5 mm.

9. The self-regulating temperature-regulating and exhaust gas purification type ecological asphalt pavement structure according to claim 1, characterized in that, The waterproof and frost-resistant cushion layer (2) includes a waterproof layer and a sandwich-type composite layer consisting of a first geotextile, a geomembrane and a second geotextile on the waterproof layer, and graded sand and gravel are spread and compacted on the waterproof layer, with a compaction degree of not less than 96%.

10. A construction method for a self-regulating temperature-regulating and exhaust gas-purifying ecological asphalt pavement structure as described in any one of claims 1-9, characterized in that, Includes the following steps: S1, Subgrade (1) Construction: The subgrade is compacted to obtain a subgrade (1) with a compaction degree of not less than 93% and a thickness of 20-30cm. S2, Construction of the waterproof and frost-resistant cushion layer (2): A waterproof layer is laid on the soil base (1), the waterproof layer comprising a first geotextile, a geomembrane and a second geotextile stacked in sequence; then graded sand and gravel are spread on the waterproof layer and compacted to obtain a waterproof and frost-resistant cushion layer (2) with a compaction degree of not less than 96% and a thickness of 15-20cm. S3, Drainage base course (3) construction; large-pore asphalt stabilized crushed stone mixture is spread on the waterproof and frost-resistant cushion layer (2), and a drainage base course (3) with a thickness of 8-12cm is obtained by static compaction. S4, Phase Change Temperature Regulation Layer (4.1) Construction: S4.1 Preparation of phase change temperature-regulating modified asphalt: Aggregate and the phase change temperature-regulating modified asphalt are mixed at 160-165℃ to obtain AC-20 type phase change temperature-regulating layer (4.1) mixture; S4.

2. Spread the phase change temperature regulating layer (4.1) mixture on the drainage base layer (3), control the spreading temperature to be not lower than 150℃, and roll it to a compaction degree of not lower than 96% to form a phase change temperature regulating layer (4.1) with a thickness of 3-4cm. S5. Construction of high thermal conductivity bonding layer: Spray high thermal conductivity modified asphalt on the surface of the phase change temperature regulating layer (4.1) to form a high thermal conductivity bonding layer; S6. Construction of porous environmental response layer (4.2): S6.

1. The composite functional material and high viscosity asphalt are premixed at 165-170℃ using a high-speed shearing apparatus, and then mixed with aggregate at 170-175℃ to obtain the OGFC-13 type porous environmental response layer (4.2) mixture. S6.

2. Spread the porous environmental response layer (4.2) mixture on the high thermal conductivity bonding layer, control the spreading temperature to be not lower than 160℃, and use a light roller to compact it to a compaction degree of 90-95%, forming a porous environmental response layer (4.2) with a thickness of 3-4cm. S7. Curing and Opening to Traffic: After construction is completed, traffic may only be opened after the road surface has naturally cooled to below 50°C; and / or, In step (S4.1), the aggregate includes coarse aggregate with a particle size of 4.75-19 mm, fine aggregate with a particle size of 0.075-4.75 mm, and mineral fillers with a particle size less than 0.075 mm; and / or, In step (S6.1), the aggregate includes coarse aggregate with a particle size of 2.36-13.2 mm, fine aggregate with a particle size of 0.075-2.36 mm, and mineral powder filler with a particle size of less than 0.075 mm.

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