Asphalt modifier with long-acting slow-release negative oxygen ion-far infrared function as well as preparation method and application of asphalt modifier

Abstract

The invention relates to an asphalt modifier with a long-acting slow-release negative oxygen ion-far infrared function as well as a preparation method and application of the asphalt modifier, and belongs to the technical field of crossing of road engineering materials and ecological environment functional materials. In order to solve the problem that negative oxygen ion release of existing modified asphalt is not lasting, the invention provides an asphalt modifier with a long-acting slow-release negative oxygen ion-far infrared function, and the asphalt modifier comprises tourmaline powder, a lanthanide rare earth tailing compound, a porous inorganic carrier and a surface modifier. A tourmaline-rare earth oxide-porous carrier ternary composite system is adopted, a functional microstructure with a high surface electric field, valence state regulation and control and rich contact interfaces is constructed in an asphalt matrix, negative oxygen ions can be continuously generated from air and a road surface water film, and slow-release output in the whole life cycle is achieved. The tourmaline powder with the specific particle size has the far infrared radiation characteristic at the same time, ideal conditions are created for negative oxygen ion generation by regulating and controlling the microenvironment humidity, and continuous release of the negative oxygen ions is further promoted.

Description

Technical Field

[0001] This invention belongs to the interdisciplinary field of road engineering materials and ecological environment functional materials, and particularly relates to a long-acting slow-release negative oxygen ion-far-infrared function asphalt modifier, its preparation method and application. Background Technology

[0002] Tourmaline and other mineral-based negative ion materials, due to their unique spontaneous polarization properties, have been widely used in functional ceramics, artificial stone, and coatings. Studies have shown that particle size optimization, rare earth doping, and heat treatment can significantly enhance their negative ion release capacity. In road engineering applications, tourmaline-modified asphalt exhibits good environmental benefits; appropriate amounts of tourmaline powder can effectively reduce dust emissions during asphalt mixture construction and improve the working environment. However, because tourmaline powder is rich in hydrophilic groups such as hydroxyl groups, its interfacial compatibility with hydrophobic asphalt is poor, leading to phase separation and agglomeration during storage and construction. This not only reduces the uniformity of the mixture, causing localized stress concentration and early pavement damage, but also severely hinders the effective contact between tourmaline and air and water molecules, resulting in a significant reduction in negative ion release efficiency. Although increasing the tourmaline content can alleviate this problem to some extent, excessive addition will deteriorate the rheological properties of the asphalt material, affecting its workability during construction and impairing its crack resistance at low temperatures.

[0003] Meanwhile, although far-infrared functional road materials can reduce road surface temperature and delay asphalt aging, their design is completely disconnected from negative ion function. Existing research mostly focuses on single performance indicators and lacks systematic research on the synergistic effects of material functions. In particular, negative ion materials are easily encapsulated in asphalt systems, and their function is limited to the initial stage of construction or the surface area, making it difficult to achieve long-term slow release; while far-infrared materials simply pursue cooling effects and fail to form a synergistic effect with the release of negative oxygen ions.

[0004] Therefore, there is an urgent need to develop an integrated modified asphalt technology that combines long-lasting negative oxygen ion release, far-infrared temperature regulation, and excellent road performance. Through material modification and structural optimization, environmental benefits and pavement functions can be synergistically improved. Summary of the Invention

[0005] To address the problems of insufficient coupling between the existing negative oxygen ion function and the asphalt pavement structure, the short-lasting release of negative oxygen ions, the poor dispersibility of tourmaline in asphalt, and the lack of synergy between the far-infrared function and the negative oxygen ion function, this invention provides a long-lasting, slow-release negative oxygen ion-far-infrared asphalt modifier, its preparation method, and its application.

[0006] The technical solution of the present invention:

[0007] A long-lasting, slow-release negative oxygen ion-far-infrared functional asphalt modifier, containing the following components in parts by weight:

[0008] The mixture comprises 20-60 parts tourmaline powder, 10-40 parts lanthanide rare earth tailings compound, 5-30 parts porous inorganic carrier, and 0.5-5 parts surface modifier; the median particle size of the tourmaline powder is 1000-1350 mesh, and the particle size of the lanthanide rare earth tailings compound is 1500-3000 mesh.

[0009] Furthermore, the CeO2 content in the lanthanide rare earth tailings compound is 60-80 wt%; the porous inorganic carrier comprises the following components by mass percentage: diatomaceous earth 40-50 wt%, expanded perlite 20-25 wt%, and porous ceramic micro powder 30-40 wt%; the surface modifier is silane coupling agent KH-560 (γ-glycidoxypropyltrimethoxysilane).

[0010] Furthermore, the mass ratio of CeO2 in tourmaline powder to lanthanide rare earth tailings compounds is 2.4 ± 0.5.

[0011] A method for preparing a long-acting, slow-release negative oxygen ion-far-infrared functional asphalt modifier, comprising the following steps:

[0012] Step 1: Tourmaline pretreatment and ultrafine treatment:

[0013] Tourmaline coarse powder is crushed to 150~400 mesh, calcined at 600~800℃ for 1~2 hours, and then ultrafinely pulverized by ball milling to obtain tourmaline powder with a median particle size of 1000~1350 mesh.

[0014] Step 2: Preparation of negative oxygen ion powder by combining tourmaline powder with lanthanide rare earth tailings compounds:

[0015] The tourmaline powder obtained in step one is mixed with lanthanide rare earth tailings compounds and then ground at 200-400 r / min for 2-6 h to obtain composite powder; the obtained composite powder is calcined at 700-900℃ for 0.5-1 h to obtain negative oxygen ion powder.

[0016] Step 3: Prepare negative oxygen ion-porous carrier composite powder;

[0017] Diatomaceous earth, expanded perlite, and porous ceramic powder are stirred and mixed evenly, and then calcined to obtain an activated porous inorganic carrier; the negative oxygen ion powder obtained in step two is stirred and mixed with the activated porous inorganic carrier to obtain a negative oxygen ion-porous carrier composite powder.

[0018] Step 4: Preparation of negative oxygen ion-far-infrared functional modifier:

[0019] The surface modifier is dissolved in an ethanol-water mixture to obtain a modified liquid with a concentration of 1.0~5.0wt%. The modified liquid is sprayed onto the surface of the negative oxygen ion-porous carrier composite powder obtained in step three at 60~80℃. The mixture is stirred continuously at 200~500r / min for 1.5~2h. The resulting wet powder is dried at 100~110℃ for 4~6h and then sieved to obtain the surface-modified negative oxygen ion-far-infrared functional asphalt modifier.

[0020] Furthermore, the roasting temperature in step three is 200~400℃, and the roasting time is 2~3h; the stirring and mixing time is 30~60min.

[0021] Furthermore, in step four, the volume ratio of ethanol to water in the ethanol-water mixed solution is 9:1, and the sieving is performed through a 200-300 mesh sieve to ensure that the powder particle size is suitable for uniform dispersion of the asphalt system.

[0022] Application of a long-acting slow-release negative oxygen ion-far-infrared functional asphalt modifier in the preparation of modified asphalt binders, modified asphalt mixtures and modified asphalt pavement structures.

[0023] Furthermore, the asphalt binder comprises the following components in parts by weight: 84-92 parts of base asphalt and 8-16 parts of negative oxygen ion-far-infrared functional modifier;

[0024] The preparation method of the asphalt binder is as follows: heating the base asphalt to 160~170℃, adding negative oxygen ion-far-infrared functional asphalt modifier to the base asphalt, stirring at 2000~3000r / min for 20~40min, then reducing the stirring speed to 50~200r / min and stirring for 10~20min, and keeping it warm for 0.5~2h to mature and develop, thereby obtaining the modified asphalt binder.

[0025] Furthermore, the modified asphalt mixture comprises the modified asphalt binder, coarse and fine aggregates, and mineral powder;

[0026] The modified asphalt mixture is prepared by heating coarse and fine aggregates to 160-180°C, heating the modified asphalt binder to 160-170°C, adding the modified asphalt binder to the coarse and fine aggregates and mineral powder according to the target asphalt-aggregate ratio, and wet mixing in a forced mixing machine for 45-90 seconds to obtain the modified asphalt mixture.

[0027] Furthermore, the modified asphalt pavement structure consists of a surface layer, a subbase layer, a base course, and a subbase course. The surface layer is a modified asphalt pavement structure layer obtained by on-site paving and compaction of the modified asphalt mixture with a factory temperature controlled at 155~175℃. The subbase layer is a conventional AC-13, AC-20, or SMA-6 modified asphalt mixture, and the base course and subbase course use conventional graded crushed stone or water-stabilized materials.

[0028] The beneficial effects of this invention are:

[0029] This invention creatively employs a ternary composite system of tourmaline-rare earth oxides-porous carrier to construct a functional microstructure within an asphalt matrix. This microstructure possesses high surface electric field, valence state regulation, and abundant contact interfaces, enabling the continuous generation of negative oxygen ions from air and road surface water films. The open porous framework, in synergy with the road surface void system, provides a stable air exchange channel, preventing the functional powder from being completely encapsulated. This transforms the release of negative oxygen ions from an early, short-lived release into a sustained-release output throughout the entire lifespan.

[0030] This invention selects tourmaline powder of a specific particle size as the core functional material. Its unique crystal structure endows it with dual functional properties of generating negative oxygen ions and radiating far-infrared radiation. This invention introduces tourmaline powder into modified asphalt to construct a spectrally selective modified pavement system, significantly enhancing the material's ability to reflect and re-radiate far-infrared wavelengths of sunlight. Under high-temperature sunlight conditions, it can form an effective temperature control effect: on the one hand, it slows down the aging and rutting development of asphalt materials by reducing the road surface temperature; on the other hand, it creates an ideal environment for the continuous generation of negative oxygen ions by regulating the microenvironmental temperature and humidity conditions. Simultaneously, far-infrared radiation promotes the vibrational dissociation of water molecules at the functional interface, while moderate cooling maintains a stable water film thickness. The synergistic effect of these two factors further promotes the long-term stable release of negative oxygen ions. The integrated functional design of the core material in this invention breaks through the limitations of traditional technologies that suffer from single function and insufficient synergy, providing an innovative solution for the development of multifunctional and environmentally friendly pavements.

[0031] The modified asphalt pavement system of this invention can form a stable negative oxygen ion release field under normal service conditions, providing continuous purification of the air in the road boundary layer. The released negative ions effectively neutralize the surface charge of suspended particulate matter, promoting sedimentation; simultaneously, they have an oxidative decomposition effect on certain gaseous pollutants. During the construction phase, the introduction of functional materials can alter the charged characteristics of asphalt fumes, reducing the concentration and toxicity of construction fumes through a dual pathway of electrostatic adsorption and catalytic conversion, thereby improving environmental friendliness.

[0032] This invention significantly improves the compatibility and dispersion stability of functional powders in asphalt systems through surface modification. Under optimized dosage conditions, key performance indicators such as the rheological properties of the modified asphalt remain within reasonable ranges, ensuring both material functionality and maintaining good low-temperature crack resistance and water stability. Furthermore, the construction process parameters of the modified asphalt provided by this invention are basically the same as those of conventional modified asphalt, allowing for direct application using existing mixing, paving, and compaction equipment without the need for additional specialized equipment, thus exhibiting good engineering adaptability and economic efficiency.

[0033] The modified asphalt pavement structure provided by this invention is suitable for cultural tourism and health care roads such as forest parks, health and wellness towns, and lakeside roads in scenic areas, as well as slow-traffic systems in residential and public spaces such as sidewalks, greenways, campus roads, and internal roads of residential communities. It is used to improve local air quality and microclimate, supporting the construction goals of health and wellness communities, livable urban areas, and ecological landscape corridors. It can also be used in scenarios with high requirements for environmental comfort and air quality, such as roads around hospitals and rehabilitation institutions, internal roads of elderly care communities, running tracks in sports parks, viewing platforms in scenic areas, and plaza paving. Furthermore, it can be used to upgrade existing pavements through ultra-thin overlays, micro-surfacing, and functional overlay layers, or combined with urban renewal projects, smart roads, and green and low-carbon demonstration projects to form a series of functional asphalt pavement products and complete application solutions. Attached Figure Description

[0034] Figure 1 The image is a 500x magnified SEM image of the long-acting, slow-release negative oxygen ion-far-infrared functional asphalt modifier prepared in Example 1.

[0035] Figure 2 The image is a 2000x magnified SEM image of the long-acting, slow-release negative oxygen ion-far-infrared functional asphalt modifier prepared in Example 1.

[0036] Figure 3 The image is a 10,000x magnified SEM image of the long-acting, slow-release negative oxygen ion-far-infrared functional asphalt modifier prepared in Example 1.

[0037] Figure 4 The image is a 500x magnified SEM image of the long-acting, slow-release negative oxygen ion-far-infrared functional asphalt modifier prepared in Example 2.

[0038] Figure 5 The image is a 2000x magnified SEM image of the long-acting, slow-release negative oxygen ion-far-infrared functional asphalt modifier prepared in Example 2.

[0039] Figure 6 The image is a 10,000x magnified SEM image of the long-acting, slow-release negative oxygen ion-far-infrared functional asphalt modifier prepared in Example 2.

[0040] Figure 7 SEM image of a porous inorganic carrier magnified 500 times;

[0041] Figure 8 SEM image of a porous inorganic carrier magnified 1000 times;

[0042] Figure 9 SEM image of a porous inorganic carrier magnified 5000 times;

[0043] Figure 10 The curve of continuous release of negative oxygen ions of the modified asphalt pavement prepared in Example 3;

[0044] Figure 11 The graph shows the continuous release curve of negative oxygen ions from the modified asphalt pavement prepared in Example 4. Detailed Implementation

[0045] The technical solution of the present invention will be further described below with reference to embodiments, but it is not limited thereto. Any modifications or equivalent substitutions to the technical solution of the present invention without departing from the spirit and scope of the technical solution of the present invention should be covered within the protection scope of the present invention. In the following embodiments, the process equipment or apparatus not specifically specified are all conventional equipment or apparatus in the art. Unless otherwise specified, the raw materials used in the embodiments of the present invention are all commercially available; unless otherwise specified, the technical means used in the embodiments of the present invention are all conventional means well known to those skilled in the art.

[0046] Example 1

[0047] This embodiment provides a long-acting, slow-release negative oxygen ion-far-infrared functional asphalt modifier and its preparation method.

[0048] This embodiment of the long-acting, slow-release negative oxygen ion-far-infrared functional asphalt modifier contains the following components in parts by weight:

[0049] The mixture consists of 40 parts of tourmaline powder with a median particle size of 1000 mesh, 20 parts of lanthanide rare earth tailings compound, 25 parts of porous inorganic carrier, and 2 parts of surface modifier; the lanthanide rare earth tailings compound contains 70 wt% CeO2 and has a particle size of 1500 mesh.

[0050] In this embodiment, the mass ratio of tourmaline powder to CeO2 in lanthanide rare earth tailings compounds is 2.85 to balance the release efficiency of negative oxygen ions and the stability of the material.

[0051] In this embodiment, the porous inorganic carrier is composed of the following components in mass percentage: 50 wt% diatomaceous earth, 20 wt% expanded perlite, and 30 wt% porous ceramic powder.

[0052] In this embodiment, the surface modifier is silane coupling agent KH-560.

[0053] The preparation method of the long-acting slow-release negative oxygen ion-far-infrared functional asphalt modifier in this embodiment is as follows:

[0054] Step 1: Tourmaline pretreatment and ultrafine treatment:

[0055] Tourmaline coarse powder was crushed to 400 mesh, calcined at 700℃ for 2 hours to activate the crystal structure, and then ultra-finely pulverized by ball milling to obtain tourmaline powder with a median particle size of 1000 mesh.

[0056] Step 2: Preparation of negative oxygen ion powder by combining tourmaline powder with lanthanide rare earth tailings compounds:

[0057] The tourmaline powder and lanthanide rare earth tailings compound obtained in step one were placed in a planetary ball mill and ground at 300 r / min for 4 h to ensure that the lanthanide rare earth tailings compound and tourmaline powder were in full contact to obtain composite powder. The obtained composite powder was calcined at 800℃ for 1 h to stabilize the crystal phase and improve the surface charge activity, so as to obtain negative oxygen ion powder that can release negative oxygen ions and far-infrared waves.

[0058] Step 3: Prepare negative oxygen ion-porous carrier composite powder;

[0059] Diatomaceous earth, expanded perlite, and porous ceramic powder were stirred and mixed evenly, and then calcined at 300℃ for 2 hours to remove moisture and organic matter, thus obtaining an activated porous inorganic carrier.

[0060] Add the negative oxygen ion powder obtained in step two and the activated porous inorganic carrier into a stirring device and stir for 45 minutes to allow the negative oxygen ion powder to enter the pores of the porous inorganic carrier and be uniformly loaded on its surface to form a micro-composite structure, thus obtaining negative oxygen ion-porous carrier composite powder.

[0061] Step 4: Preparation of negative oxygen ion-far-infrared functional modifier:

[0062] Silane coupling agent KH-560 was dissolved in an ethanol-water mixture with a volume ratio of 9:1 to obtain a modified liquid with a concentration of 3.0 wt%. The modified liquid was sprayed onto the surface of the negative oxygen ion-porous carrier composite powder obtained in step three at 70°C. The mixture was stirred continuously at 300 r / min for 2 h to allow the modified liquid to gradually hydrolyze and form a uniform and dense organic coating layer on the powder surface. The resulting wet powder was dried at 110°C for 4 h and then sieved through a 200-300 mesh sieve to ensure that the powder particle size was suitable for uniform dispersion in the asphalt system, thus obtaining a surface-modified negative oxygen ion-far-infrared functional asphalt modifier.

[0063] Example 2

[0064] This embodiment provides a long-acting, slow-release negative oxygen ion-far-infrared functional asphalt modifier and its preparation method.

[0065] This embodiment of the long-acting, slow-release negative oxygen ion-far-infrared functional asphalt modifier contains the following components in parts by weight:

[0066] The mixture contains 25 parts of tourmaline powder with a median particle size of 1350 mesh, 10 parts of lanthanide rare earth tailings compound, 60 parts of porous inorganic carrier, and 1 part of surface modifier; among which, the lanthanide rare earth tailings compound contains 90 wt% CeO2 and has a particle size of 1500 mesh.

[0067] In this embodiment, the mass ratio of tourmaline powder to CeO2 in lanthanide rare earth tailings compounds is 2.78 to balance the release efficiency of negative oxygen ions and the stability of the material.

[0068] In this embodiment, the porous inorganic carrier is composed of the following components by mass percentage: diatomaceous earth 40wt%, expanded perlite 25wt%, and porous ceramic micro powder 35wt%.

[0069] In this embodiment, the surface modifier is silane coupling agent KH-560.

[0070] The preparation method of the long-acting slow-release negative oxygen ion-far-infrared functional asphalt modifier in this embodiment is as follows:

[0071] Step 1: Tourmaline pretreatment and ultrafine treatment:

[0072] Tourmaline coarse powder was crushed to 400 mesh, calcined at 700℃ for 2 hours to activate the crystal structure, and then ultra-finely pulverized by ball milling to obtain tourmaline powder with a median particle size of 1000 mesh.

[0073] Step 2: Preparation of negative oxygen ion powder by combining tourmaline powder with lanthanide rare earth tailings compounds:

[0074] The tourmaline powder and lanthanide rare earth tailings compound obtained in step one were placed in a planetary ball mill and ground at 300 r / min for 4 h to ensure that the lanthanide rare earth tailings compound and tourmaline powder were in full contact to obtain composite powder. The obtained composite powder was calcined at 800℃ for 1 h to stabilize the crystal phase and improve the surface charge activity, so as to obtain negative oxygen ion powder that can release negative oxygen ions and far-infrared waves.

[0075] Step 3: Prepare negative oxygen ion-porous carrier composite powder;

[0076] Diatomaceous earth, expanded perlite, and porous ceramic powder were stirred and mixed evenly, and then calcined at 300℃ for 2 hours to remove moisture and organic matter, thus obtaining an activated porous inorganic carrier.

[0077] Add the negative oxygen ion powder obtained in step two and the activated porous inorganic carrier into a stirring device and stir for 45 minutes to allow the negative oxygen ion powder to enter the pores of the porous inorganic carrier and be uniformly loaded on its surface to form a micro-composite structure, thus obtaining negative oxygen ion-porous carrier composite powder.

[0078] Step 4: Preparation of negative oxygen ion-far-infrared functional modifier:

[0079] Silane coupling agent KH-560 was dissolved in an ethanol-water mixture with a volume ratio of 9:1 to obtain a modified liquid with a concentration of 3.0 wt%. The modified liquid was sprayed onto the surface of the negative oxygen ion-porous carrier composite powder obtained in step three at 70°C. The mixture was stirred continuously at 300 r / min for 2 h to allow the modified liquid to gradually hydrolyze and form a uniform and dense organic coating layer on the powder surface. The resulting wet powder was dried at 110°C for 4 h and then sieved through a 200-300 mesh sieve to ensure that the powder particle size was suitable for uniform dispersion in the asphalt system, thus obtaining a surface-modified negative oxygen ion-far-infrared functional asphalt modifier.

[0080] Figures 1-9 These are SEM images at different magnifications of the long-acting, slow-release negative oxygen ion-far-infrared functional asphalt modifier and porous inorganic carrier prepared in Examples 1 and 2. Figures 7-9 The images are SEM images of a porous inorganic carrier without added negative ion powder at different magnifications. It can be seen that the pores inside the carrier are evenly distributed, the micropores and interconnected pores are well developed, and there is a lot of effective pore space that can carry negative ion powder. Figures 1-3 The image shows the SEM image of the negative oxygen ion-far-infrared functional modifier prepared in Example 1. It can be observed that the negative ion powder is uniformly distributed and closely adheres to the surface of the porous inorganic carrier. Most of the micropores are filled or partially covered by the negative ion powder, forming a continuous "negative ion powder-carrier" composite interface structure, which is beneficial for achieving the slow release and stable output of negative oxygen ions within the porous framework. Figures 4-6 The image shows the SEM image of the negative oxygen ion-far-infrared functional modifier prepared in Example 2. Its overall morphology is basically the same as that in Example 1, but the negative ion powder fills the carrier pores to a lower degree, and some pores are still in an open state. The specific surface area is relatively small, and the contact area with air and moisture during actual service is less than that in Example 1. The corresponding negative oxygen ion release level and persistence are both lower than those in Example 1.

[0081] comprehensive Figures 1-9 As can be seen, by constructing a composite microstructure in which "negative ion powder is embedded in the pores of a porous carrier and forms a dense interface layer", this invention can significantly improve the loading efficiency and sustained-release capacity of negative ion powder compared to a single porous carrier or an unoptimized formulation, demonstrating obvious structural optimization and functional enhancement effects.

[0082] Example 3

[0083] This embodiment provides modified asphalt binder, modified asphalt mixture, and modified asphalt pavement structure prepared from the negative oxygen ion-far-infrared functional asphalt modifier prepared in Example 1.

[0084] The modified asphalt binder in this embodiment consists of 90 parts by weight of base asphalt and 10 parts by weight of the negative oxygen ion-far-infrared functional modifier prepared in Example 1.

[0085] The preparation method of asphalt binder is as follows: heat the base asphalt to 170℃, maintain a certain fluidity, add negative oxygen ion-far-infrared functional asphalt modifier to the base asphalt, stir at 3000r / min for 30min, then reduce the stirring speed to 100r / min and stir for 15min to eliminate air bubbles, and keep warm and mature for 1h to obtain modified asphalt binder.

[0086] The modified asphalt mixture in this embodiment is prepared from modified asphalt binder and mixture gradation AC-13;

[0087] The preparation method of modified asphalt mixture is as follows: the mixture gradation AC-13 is heated to 180°C, the modified asphalt binder is heated to 170°C, the modified asphalt binder is added to the mixture gradation AC-13 at a target asphalt-aggregate ratio of 5.0%, and the mixture is wet-mixed in a forced mixing machine for 60 seconds to obtain the modified asphalt mixture.

[0088] The modified asphalt pavement structure in this embodiment consists of a surface layer, a subbase layer, a base course, and a subbase course. The surface layer is a 4cm thick functional modified asphalt pavement structure layer made by paving and compacting the modified asphalt mixture at a factory temperature controlled at 165℃. The subbase layer is a conventional mixture gradation AC-13, and the base course and subbase course use conventional gradation crushed stone or water-stabilized materials.

[0089] In this embodiment, the porosity of the modified asphalt pavement structure is controlled at 3-6% to balance the release channels for negative oxygen ions and road performance.

[0090] Example 4

[0091] This embodiment provides modified asphalt binder, modified asphalt mixture, and modified asphalt pavement structure prepared from the negative oxygen ion-far-infrared functional asphalt modifier prepared in Example 2.

[0092] The modified asphalt binder in this embodiment consists of 92 parts by weight of base asphalt and 8 parts by weight of the negative oxygen ion-far-infrared functional modifier prepared in Example 2.

[0093] The preparation method of asphalt binder is as follows: heat the base asphalt to 170℃, maintain a certain fluidity, add negative oxygen ion-far-infrared functional asphalt modifier to the base asphalt, stir at 3000r / min for 30min, then reduce the stirring speed to 100r / min and stir for 15min to eliminate air bubbles, and keep warm and mature for 1h to obtain modified asphalt binder.

[0094] The modified asphalt mixture in this embodiment is prepared from modified asphalt binder and mixture gradation AC-13;

[0095] The preparation method of modified asphalt mixture is as follows: the mixture gradation AC-13 is heated to 180°C, the modified asphalt binder is heated to 170°C, the modified asphalt binder is added to the mixture gradation AC-13 at a target asphalt-aggregate ratio of 5.2%, and the mixture is wet-mixed in a forced mixing machine for 60 seconds to obtain the modified asphalt mixture.

[0096] The modified asphalt pavement structure in this embodiment consists of a surface layer, a subbase layer, a base course, and a subbase course. The surface layer is a 4cm thick functional modified asphalt pavement structure layer made by paving and compacting the modified asphalt mixture at a factory temperature controlled at 165℃. The subbase layer is a conventional mixture gradation AC-13, and the base course and subbase course use conventional gradation crushed stone or water-stabilized materials.

[0097] In this embodiment, the porosity of the modified asphalt pavement structure is controlled at 3-6% to balance the release channels for negative oxygen ions and road performance.

[0098] Figure 10 and Figure 11 The graphs show the continuous release curves of negative oxygen ions from the modified asphalt pavements prepared in Examples 3 and 4, respectively. Figure 10 and Figure 11 The graphs show the continuous release curves of negative oxygen ions from the modified asphalt pavements prepared in Examples 3 and 4, respectively, over a period of 0–24 h. Figure 10 As can be seen, the negative oxygen ion release curve of the modified asphalt pavement in Example 3 shows an overall "S"-shaped rise and enters a plateau period. Compared with ordinary asphalt pavement and the control pavement with only tourmaline powder, its negative oxygen ion release concentration per unit area is significantly increased, and it remains above the "fresh air" level throughout the entire test period, indicating that the present invention significantly improves the negative oxygen ion release intensity of the road surface. Figure 11 The results show that although the peak value of the modified asphalt pavement in Example 4 is slightly lower than that in Example 3, the curve is flatter in the middle and later stages, the decay rate is lower, and the release of negative oxygen ions remains basically stable for a longer period of time, demonstrating obvious slow-release characteristics and service life continuity.

[0099] comprehensive Figure 10 and Figure 11It is evident that by regulating the modifier formulation and porous carrier structure, this invention improves the release level of negative oxygen ions on the one hand and prolongs the effective release time on the other. Compared with existing unmodified pavements or pavements modified with only single tourmaline, it has significant technological progress in both release intensity and release persistence.

Claims

1. A long-acting, slow-release negative oxygen ion-far-infrared functional asphalt modifier, characterized in that, Components containing the following parts by weight: The mixture comprises 20-60 parts tourmaline powder, 10-40 parts lanthanide rare earth tailings compound, 5-30 parts porous inorganic carrier, and 0.5-5 parts surface modifier; the median particle size of the tourmaline powder is 1000-1350 mesh, and the particle size of the lanthanide rare earth tailings compound is 1500-3000 mesh.

2. The long-acting slow-release negative oxygen ion-far-infrared functional asphalt modifier according to claim 1, characterized in that, The CeO2 content in the lanthanide rare earth tailings compound is 60-80 wt%; the porous inorganic carrier comprises the following components by mass percentage: diatomaceous earth 40-50 wt%, expanded perlite 20-25 wt%, and porous ceramic micro powder 30-40 wt%; the surface modifier is silane coupling agent KH-560.

3. The long-acting slow-release negative oxygen ion-far-infrared functional asphalt modifier according to claim 2, characterized in that, The mass ratio of CeO2 in tourmaline powder to lanthanide rare earth tailings compounds is 2.4 ± 0.

5.

4. A method for preparing a long-acting, slow-release negative oxygen ion-far-infrared functional asphalt modifier as described in any one of claims 1-3, characterized in that, The steps are as follows: Step 1: Tourmaline pretreatment and ultrafine treatment: Tourmaline coarse powder is crushed to 150~400 mesh, calcined at 600~800℃ for 1~2 hours, and then ultra-finely pulverized by ball milling to obtain tourmaline powder with a median particle size of 1000~1350 mesh. Step 2: Preparation of negative oxygen ion powder by combining tourmaline powder with lanthanide rare earth tailings compounds: The tourmaline powder obtained in step one is mixed with lanthanide rare earth tailings compounds and then ground at 200-400 r / min for 2-6 h to obtain composite powder; the obtained composite powder is calcined at 700-900℃ for 0.5-1 h to obtain negative oxygen ion powder. Step 3: Prepare negative oxygen ion-porous carrier composite powder; Diatomaceous earth, expanded perlite, and porous ceramic powder are stirred and mixed evenly, and then calcined to obtain an activated porous inorganic carrier; the negative oxygen ion powder obtained in step two is stirred and mixed with the activated porous inorganic carrier to obtain a negative oxygen ion-porous carrier composite powder. Step 4: Preparation of negative oxygen ion-far-infrared functional modifier: The surface modifier is dissolved in an ethanol-water mixture to obtain a modified liquid with a concentration of 1.0~5.0wt%. The modified liquid is sprayed onto the surface of the negative oxygen ion-porous carrier composite powder obtained in step three at 60~80℃. The mixture is stirred continuously at 200~500r / min for 1.5~2h. The resulting wet powder is dried at 100~110℃ for 4~6h and then sieved to obtain the surface-modified negative oxygen ion-far-infrared functional asphalt modifier.

5. The preparation method of the long-acting slow-release negative oxygen ion-far-infrared functional asphalt modifier according to claim 4, characterized in that, The roasting temperature in step three is 200~400℃, and the roasting time is 2~3h; the stirring and mixing time is 30~60min.

6. The preparation method of the long-acting slow-release negative oxygen ion-far-infrared functional asphalt modifier according to claim 4 or 5, characterized in that, In step four, the volume ratio of ethanol to water in the ethanol-water mixed solution is 9:1, and the sieving is performed by passing the solution through a 200-300 mesh sieve.

7. The application of the long-acting slow-release negative oxygen ion-far-infrared functional asphalt modifier as described in claim 1 or 2 in the preparation of modified asphalt binder, modified asphalt mixture and modified asphalt pavement structure.

8. The application according to claim 7, characterized in that, The asphalt binder comprises the following components in parts by weight: 84-92 parts of base asphalt and 8-16 parts of negative oxygen ion-far-infrared functional modifier; The preparation method of the asphalt binder is as follows: heating the base asphalt to 160~170℃, adding negative oxygen ion-far-infrared functional asphalt modifier to the base asphalt, stirring at 2000~3000r / min for 20~40min, then reducing the stirring speed to 50~200r / min and stirring for 10~20min, and keeping it warm for 0.5~2h to mature and develop, thereby obtaining the modified asphalt binder.

9. The application according to claim 8, characterized in that, The modified asphalt mixture comprises the modified asphalt binder, coarse and fine aggregates, and mineral powder. The modified asphalt mixture is prepared by heating coarse and fine aggregates to 160-180°C, heating the modified asphalt binder to 160-170°C, adding the modified asphalt binder to the coarse and fine aggregates and mineral powder according to the target asphalt-aggregate ratio, and wet mixing in a forced mixing machine for 45-90 seconds to obtain the modified asphalt mixture.

10. The application according to claim 9, characterized in that, The modified asphalt pavement structure consists of a surface layer, a subbase layer, a base course, and a subbase course. The surface layer is a modified asphalt pavement structure layer obtained by on-site paving and compaction of the modified asphalt mixture with a factory temperature controlled at 155~175℃. The subbase layer is a conventional AC-13, AC-20, or SMA-6 modified asphalt mixture, and the base course and subbase course use conventional graded crushed stone or water-stabilized materials.

Images