Anti-aging ultra-thin surface material and preparation method and application thereof

Abstract

This invention relates to the field of road engineering construction technology, specifically disclosing an anti-aging ultrathin overlay material, its preparation method, and its application. The invention provides an anti-aging ultrathin overlay material whose raw material components include base asphalt, waste rubber powder, waste plastics, steel slag powder, wear-resistant aggregate, waste oil, algae-based biochar, compatibilizer, and anti-stripping agent. This invention uses base asphalt as the continuous phase, and through the synergistic effect with waste rubber powder, waste plastics, and waste oil, constructs a high-viscosity, high-elasticity composite binder. Simultaneously, steel slag powder and algae-based biochar are introduced to form an anti-aging and shear-resistant filler system, which, together with the wear-resistant aggregate, constitutes a highly interlocked skeleton structure. This structure endows the ultrathin overlay material with excellent anti-aging properties, thereby overcoming the shortcomings of existing technologies.

Description

Technical Field

[0001] This invention relates to the field of road construction technology, and in particular to an anti-aging ultrathin overlay material, its preparation method, and its application. Background Technology

[0002] The reason why existing ultra-thin overlays are prone to "failure" after a period of use is often not due to insufficient initial strength, but rather insufficient anti-aging ability: the overlay layer is thin and has a large specific surface area. When exposed to air, ultraviolet rays and water vapor for a long time, the asphalt binder is more likely to undergo thermal-oxidative and photo-oxidative aging. After aging, the light components of the asphalt binder volatilize and oxidation products accumulate, leading to the gradual hardening and embrittlement of the asphalt binder, a decrease in bonding and stress relaxation ability, and thus the appearance of microcracks and interface defects earlier. The poor anti-aging performance of ultra-thin overlays directly reduces the rutting resistance and wear resistance of asphalt pavements. On the one hand, the binder hardens and its ductility decreases after aging, the asphalt film becomes thinner and more easily damaged, the adhesion between aggregates weakens, and the surface layer is more prone to loosening and peeling, resulting in a decrease in wear resistance and the ability to maintain anti-skid texture. On the other hand, ultra-thin overlays are more sensitive to the influence of the underlying layer. Their rutting performance is more easily affected by the conditions of the underlying layer due to the thin layer characteristics. When aging leads to microcracks in the layer or between layers and a decrease in adhesion, the shear deformation under wheel load is more difficult to be "dissipated" by the viscoelastic system, resulting in local slippage and structural loosening, which manifests as rutting being more likely to develop and more obvious undulation. Furthermore, problems such as delamination and loosening will be further amplified, ultimately leading to a worse rutting resistance, faster wear, and a significantly shortened service life.

[0003] Existing anti-aging ultra-thin overlay materials mainly rely on high-viscosity polymer modification or single antioxidant / UV-resistant additives in the raw material components. While initial performance is significantly improved, durability is insufficient under the combined effects of climate change and traffic loads. In addition, some anti-aging additives have limited compatibility with asphalt, which can easily lead to uneven dispersion or performance fluctuations during construction.

[0004] Therefore, developing an ultrathin overlay with good component compatibility, excellent durability and good anti-aging properties is of great practical significance for the development of road materials. Summary of the Invention

[0005] In view of this, the present invention provides an anti-aging ultrathin overlay material, its preparation method and application. The present invention uses base asphalt as the continuous phase, and constructs a high-viscosity and high-elasticity composite binder using waste rubber powder-waste plastic-waste oil. Steel slag micro powder-algae-based biochar form an anti-aging and shear-resistant filler system, which, together with wear-resistant aggregate, forms a highly interlocked skeleton, giving the ultrathin overlay material excellent anti-aging properties. Moreover, the present invention utilizes the synergistic effect of each component to effectively avoid the problems of interface debonding and structural instability in the ultrathin overlay material, thereby maintaining long-term rutting resistance and wear resistance, and making up for the shortcomings of the prior art.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution: The first aspect of this invention provides an anti-aging ultra-thin overlay material, comprising the following raw material components in parts by weight: 90-100 parts of base asphalt, 10-25 parts of waste rubber powder, 5-15 parts of waste plastic, 5-12 parts of steel slag powder, 5-8 parts of wear-resistant aggregate, 2-8 parts of waste oil, 1-5 parts of algae-based biochar, 1-3 parts of compatibilizer, and 1-3 parts of anti-stripping agent.

[0007] Compared to existing technologies, this invention uses base asphalt as the continuous phase and constructs a high-viscosity and high-elasticity composite modified binder with waste rubber powder, waste plastics and waste oils. It also combines steel slag powder, algae-based biochar and wear-resistant aggregate to establish an anti-aging functional filler system. Furthermore, it combines compatibilizer and anti-stripping agent to form a highly interlocking skeleton, thereby suppressing the rutting resistance degradation caused by binder aging and interface failure after long-term service of existing ultra-thin overlays.

[0008] This invention introduces algae-based biochar, which utilizes the UV shielding ability of its carbonaceous skeleton and the free radical scavenging ability of its oxygen-containing functional groups to effectively inhibit the photo-oxidative aging chain reaction at the microscopic level. This not only reduces UV penetration and surface energy input, thus reducing free radical generation, but also quenches free radicals through active sites and inhibits the accumulation of oxidation products, thereby significantly delaying the hardening and embrittlement of the binder and the degradation of adhesion. This fundamentally improves the long-term rutting resistance and wear resistance of the thin-layer coating.

[0009] Waste oil, as a low-viscosity regulating component, can first supplement the light phase of the system and improve the wettability of the system, making waste plastics easier to swell and disperse in asphalt, reducing the tendency of agglomeration and phase separation, while alleviating the risk of excessive stiffness and embrittlement caused by waste plastics, so that the composite modified system can maintain a reasonable viscoelastic balance.

[0010] Preferably, the algae-based biochar has a moisture content ≤2%, an ash content of 8%-10%, and a specific surface area ≥150m². 2 / g, with a particle size of 5-30μm.

[0011] The present invention defines the algae-based biochar to make it more stable during mixing and construction, to have sufficient UV shielding and free radical capture capabilities at the microscopic level, and to enhance the cohesion and shear structure stability of mortar at the macroscopic level. This significantly delays the interface debonding and skeleton deformation or even collapse caused by the aging of ultra-thin overlay binder, and ultimately achieves a simultaneous improvement in rutting resistance and wear resistance.

[0012] Preferably, the method for preparing the algae-based biochar includes the following steps: S1. Dehydrate, wash, and dry the algal biomass, then ball-mill it to obtain dry algal powder; S2. Under an inert atmosphere, the dried algae powder is heated to 480-550℃ for sintering and then cooled to obtain algae-based biochar.

[0013] More preferably, in S1, the algal biomass includes any one or more of green algae, brown algae, or red algae.

[0014] More preferably, in S1, the water content of the solid material obtained after dehydration is ≤20%.

[0015] More preferably, in S1, the ball milling speed is 300-600 rpm and the ball milling time is 30-40 min.

[0016] More preferably, in S2, the sintering time is 3-6 hours.

[0017] In a further preferred embodiment, in S2, the temperature is raised to 480-550℃ using a programmed temperature rise method, with a heating rate of 5-10℃ / min.

[0018] Preferably, the particle size of the waste rubber powder is 150-350 μm.

[0019] Waste rubber powder swells in hot asphalt and absorbs lightweight components to form an elastic network, improving high-temperature elastic recovery and shear deformation resistance, making the thin layer more effective at dissipating stress and reducing permanent deformation under wheel load. Preferably, the total content of polyethylene and / or polypropylene in the waste plastic is ≥80 wt%.

[0020] Waste plastics form a rigid reinforcing phase in asphalt, increasing the softening point and high-temperature modulus of the binder and enhancing its resistance to rutting.

[0021] Preferably, the particle size of the steel slag powder is 5-20 μm; Steel slag powder has a rough surface and alkaline properties. On the one hand, it can be used as a microfiller to improve the cohesion and structural stability of mortar and increase the shear strength of asphalt film. On the other hand, it can enhance the chemical adhesion between asphalt and aggregate and reduce debonding and micro-slipping caused by water damage.

[0022] This invention uses waste rubber powder, steel slag powder and wear-resistant aggregate to form a gradation. By using a reasonable aggregate ratio, a continuous interlocking skeleton can be formed, reducing the dependence on asphalt mortar and thus significantly improving the resistance to rutting.

[0023] Preferably, the particle size of the wear-resistant aggregate is 30-150 μm.

[0024] Wear-resistant aggregates provide a high-strength interlocking skeleton and an anti-polishing surface, making the skeleton less susceptible to wear and damage during rutting development.

[0025] Preferably, the wear-resistant aggregate is basalt, calcined bauxite and waste ceramic powder in a mass ratio of 3:2:1 to 5:2:1.

[0026] More preferably, the calcined bauxite contains ≥80wt% Al2O3 and has a particle size of 30-60μm.

[0027] More preferably, the basalt has an apparent density ≥2.85 g / cm³ and a grain size of 80-150 μm.

[0028] More preferably, the particle size of the waste ceramic powder is 50-80 μm.

[0029] Preferably, the moisture content of the waste oil is ≤0.2wt%, and the acid value of the waste oil is 1-5 mgKOH / g.

[0030] Preferably, the compatibilizer is any one or two of SBS, SEBS, or SBR.

[0031] The non-polar segments in the compatibilizer are compatible with waste plastics, while the polar groups interact strongly with the asphalt colloidal components, oxygen-containing functional groups of biochar, and polar sites on the surface of steel slag, thereby constructing a stable interfacial transition layer at the microscopic level, inhibiting storage stratification and improving morphological stability after shearing.

[0032] Preferably, the anti-stripping agent is at least one of alkylpropylenediamine, alkylpolypropylene polyamine, or oleamide.

[0033] Anti-stripping agents further enhance the adhesion and water-resistant stripping ability of the asphalt-aggregate interface, preventing water intrusion that could lead to interface debonding, structural instability, shear slip, and rutting expansion.

[0034] The second aspect of the present invention provides a method for preparing the anti-aging ultra-thin overlay material, comprising the following steps: heating the base asphalt to 160-180°C, sequentially adding algae-based biochar, steel slag powder, waste rubber powder, waste plastic, waste oil, compatibilizer and anti-stripping agent, mixing evenly to obtain the anti-aging ultra-thin overlay material.

[0035] The third aspect of this invention provides the application of the aforementioned anti-aging ultrathin overlay material in the field of road engineering construction. Detailed Implementation

[0036] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] The base asphalt used in the following examples and comparative examples is No. 90 asphalt.

[0038] The total content of polyethylene and / or polypropylene in the waste plastics used in the following examples and comparative examples is ≥80 wt%.

[0039] The algae-based biochar used in the following examples and comparative examples had a moisture content of 1.38%, an ash content of 9.1%, and a specific surface area of ​​180 m². 2 / g, with a particle size of 20μm.

[0040] The particle size of the waste rubber powder used in the following examples and comparative examples is 200 μm; The particle size of the steel slag powder used in the following examples and comparative examples is 15 μm; The calcined bauxite used in the following examples and comparative examples contained 87.9 wt% Al2O3 and had a particle size of 50 μm.

[0041] The basalt used in the following examples and comparative examples has an apparent density of 2.97 g / cm³ and a grain size of 100 μm.

[0042] The particle size of the waste ceramic powder used in the following examples and comparative examples is 80 μm.

[0043] The waste oils used in the following examples and comparative examples have a moisture content of 0.11 wt% and an acid value of 4 mg KOH / g.

[0044] Unless otherwise specified, all materials used in this invention are commercially available products.

[0045] Example 1 This embodiment provides an anti-aging ultra-thin cover material and its preparation method, specifically including the following: The anti-aging ultra-thin cover material includes the following raw material components in parts by weight: 98 parts of No. 90 base asphalt, 18 parts of waste rubber powder, 6 parts of waste plastic, 8 parts of steel slag powder, 7 parts of wear-resistant aggregate, 3 parts of waste oil, 4 parts of algae-based biochar, 2 parts of SBS and 2 parts of alkylpropylenediamine.

[0046] The preparation method of the anti-aging ultra-thin overlay material includes the following steps: heating the base asphalt to 170°C, adding algae-based biochar, steel slag powder, waste rubber powder, waste plastic, waste oil, compatibilizer and anti-stripping agent in sequence, mixing evenly to obtain the anti-aging ultra-thin overlay material.

[0047] The preparation method of the algae-based biochar includes the following steps: S1. Dehydrate, wash and dry 1 kg of green algae, and ball mill it at 500 rpm for 35 minutes to obtain dried algae powder. S2. Under an inert atmosphere, the dried algae powder is heated to 520°C at a heating rate of 8°C / min and sintered for 5 hours, then cooled to obtain algae-based biochar.

[0048] The wear-resistant aggregate is composed of basalt, calcined bauxite, and waste ceramic powder in a mass ratio of 4:2:1.

[0049] Example 2 This embodiment provides an anti-aging ultra-thin cover material and its preparation method, specifically including the following: The anti-aging ultra-thin cover material includes the following raw material components in parts by weight: 95 parts of No. 90 base asphalt, 15 parts of waste rubber powder, 10 parts of waste plastic, 12 parts of steel slag powder, 5 parts of wear-resistant aggregate, 4 parts of waste oil, 4 parts of algae-based biochar, 2 parts of SBS and 2 parts of alkylpropylenediamine.

[0050] The preparation method of the anti-aging ultra-thin overlay material includes the following steps: heating the base asphalt to 175°C, adding algae-based biochar, steel slag powder, waste rubber powder, waste plastic, waste oil, compatibilizer and anti-stripping agent in sequence, mixing evenly to obtain the anti-aging ultra-thin overlay material.

[0051] The preparation method of the algae-based biochar includes the following steps: S1. Dehydrate, wash and dry 1 kg of green algae, and ball mill it at 500 rpm for 35 minutes to obtain dried algae powder. S2. Under an inert atmosphere, the dried algae powder is heated to 520°C at a heating rate of 8°C / min and sintered for 5 hours, then cooled to obtain algae-based biochar.

[0052] The wear-resistant aggregate is composed of basalt, calcined bauxite, and waste ceramic powder in a mass ratio of 4:2:1.

[0053] Example 3 This embodiment provides an anti-aging ultra-thin cover material and its preparation method, specifically including the following: The anti-aging ultra-thin cover material includes the following raw material components in parts by weight: 100 parts of No. 90 base asphalt, 20 parts of waste rubber powder, 15 parts of waste plastic, 5 parts of steel slag powder, 6 parts of wear-resistant aggregate, 6 parts of waste oil, 5 parts of algae-based biochar, 2 parts of SBS and 2 parts of alkylpropylenediamine.

[0054] The preparation method of the anti-aging ultra-thin overlay material includes the following steps: heating the base asphalt to 170°C, adding algae-based biochar, steel slag powder, waste rubber powder, waste plastic, waste oil, compatibilizer and anti-stripping agent in sequence, mixing evenly to obtain the anti-aging ultra-thin overlay material.

[0055] The preparation method of the algae-based biochar includes the following steps: S1. Dehydrate, wash and dry 1 kg of green algae, and ball mill it at 500 rpm for 35 minutes to obtain dried algae powder. S2. Under an inert atmosphere, the dried algae powder is heated to 520°C at a heating rate of 8°C / min and sintered for 5 hours, then cooled to obtain algae-based biochar.

[0056] The wear-resistant aggregate is composed of basalt, calcined bauxite, and waste ceramic powder in a mass ratio of 4:2:1.

[0057] Example 4 This embodiment provides an anti-aging ultra-thin cover material and its preparation method, specifically including the following: The anti-aging ultra-thin cover material includes the following raw material components in parts by weight: 95 parts of No. 90 base asphalt, 18 parts of waste rubber powder, 6 parts of waste plastic, 8 parts of steel slag powder, 7 parts of wear-resistant aggregate, 3 parts of waste oil, 4 parts of algae-based biochar, 2 parts of SBS and 2 parts of alkylpropylenediamine.

[0058] The preparation method of the anti-aging ultra-thin overlay material includes the following steps: heating the base asphalt to 170°C, adding algae-based biochar, steel slag powder, waste rubber powder, waste plastic, waste oil, compatibilizer and anti-stripping agent in sequence, mixing evenly to obtain the anti-aging ultra-thin overlay material.

[0059] The preparation method of the algae-based biochar includes the following steps: S1. Dehydrate, wash and dry 1 kg of green algae, and ball mill it at 500 rpm for 35 minutes to obtain dried algae powder. S2. Under an inert atmosphere, the dried algae powder is heated to 520°C at a heating rate of 8°C / min and sintered for 5 hours, then cooled to obtain algae-based biochar.

[0060] The wear-resistant aggregate is composed of basalt, calcined bauxite, and waste ceramic powder in a mass ratio of 4:2:1.

[0061] Example 5 This embodiment provides an anti-aging ultra-thin cover material and its preparation method, specifically including the following: The anti-aging ultra-thin cover material includes the following raw material components in parts by weight: 100 parts of No. 90 base asphalt, 18 parts of waste rubber powder, 6 parts of waste plastic, 8 parts of steel slag powder, 7 parts of wear-resistant aggregate, 3 parts of waste oil, 4 parts of algae-based biochar, 2 parts of SBS and 2 parts of alkylpropylenediamine.

[0062] The preparation method of the anti-aging ultra-thin overlay material includes the following steps: heating the base asphalt to 170°C, adding algae-based biochar, steel slag powder, waste rubber powder, waste plastic, waste oil, compatibilizer and anti-stripping agent in sequence, mixing evenly to obtain the anti-aging ultra-thin overlay material.

[0063] The preparation method of the algae-based biochar includes the following steps: S1. Dehydrate, wash and dry 1 kg of green algae, and ball mill it at 500 rpm for 35 minutes to obtain dried algae powder. S2. Under an inert atmosphere, the dried algae powder is heated to 520°C at a heating rate of 8°C / min and sintered for 5 hours, then cooled to obtain algae-based biochar.

[0064] The wear-resistant aggregate is composed of basalt, calcined bauxite, and waste ceramic powder in a mass ratio of 4:2:1.

[0065] Comparative Example 1 This comparative example provides an anti-aging ultra-thin cover material. The difference from Example 1 is that the algae-based biochar in the anti-aging ultra-thin cover material is replaced with an equal amount of activated carbon. Other components and processes remain unchanged and will not be described in detail here.

[0066] The anti-aging ultrathin overlay materials obtained from each embodiment and comparative example were subjected to the following tests: Rutting tests (dynamic stability) at room temperature and high temperature (65℃), rutting tests (dynamic stability) under illumination conditions (100h irradiation with 365nm ultraviolet lamp), and four-point bending fatigue life tests were conducted according to the "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" (JTGT 3410-2025). The test results are shown in Table 1. The test results are shown in Table 2.

[0067] Table 1

[0068] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions or improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An anti-aging ultra-thin overlay material, characterized in that: The raw material components include the following mass fractions: base pitch 90-100 parts, waste rubber powder 10-25 parts, waste plastic 5-15 parts, steel slag powder 5-12 parts, wear-resistant aggregate 5-8 parts, waste oil 2-8 parts, algal-based biochar 1-5 parts, compatibilizer 1-3 parts, and anti-stripping agent 1-3 parts.

2. The anti-aging ultra-thin overlay material of claim 1, wherein: The moisture content of the algal-based biochar is ≤2%; the ash content is 8%-10%; the specific surface area is ≥150 m 2 / g, and the particle size is 5-30 μm.

3. The anti-aging ultra-thin overlay material of claim 1, wherein: The preparation method of the algal-based biochar comprises the following steps: S1, dehydrate, wash, and dry the algal biomass, and then ball mill to obtain dried algal powder; S2, under an inert atmosphere, heat the dried algal powder to 480-550℃ for sintering, and then cool to obtain algal-based biochar.

4. The anti-aging ultra-thin overlay material of claim 3, wherein: In S1, the algal biomass includes any one or more of green algae, brown algae, or red algae. In S1, the ball milling speed is 300-600 rpm, and the ball milling time is 30-40 min.

5. The anti-aging ultra-thin overlay material of claim 3, wherein: In S2, the sintering time is 3-6 h. In S2, the temperature is raised to 480-550℃ using a programmed temperature raising method, and the temperature raising rate is 5-10℃ / min.

6. The anti-aging ultra-thin overlay material of claim 1, wherein: The particle size of the waste rubber powder is 150-350μm. The particle size of the steel slag powder is 5-20μm. The particle size of the wear-resistant aggregate is 30-150μm.

7. The anti-aging ultra-thin overlay of claim 1, wherein: The wear-resistant aggregate is basalt, calcined bauxite, and waste ceramic powder at a mass ratio of 3:2:1-5:2:

1. The water content in the waste oil is ≤0.2wt%, and the acid value of the waste oil is 1-5 mgKOH / g. The compatibilizer is any one or two of SBS, SEBS, or SBR. The anti-stripping agent is at least one of alkyl propylene diamine, alkyl polypropylene polyamine, or oleic acid amide.

8. A method of preparing an anti-aging ultra-thin surfacing material as claimed in any one of claims 1-7, characterized by: The method comprises the following steps: heat the base pitch to 160-180℃, and then sequentially add the algal-based biochar, steel slag powder, waste rubber powder, waste plastic, waste oil, compatibilizer, and anti-stripping agent, and mix uniformly to obtain the anti-aging ultra-thin overlay material.

9. Use of the anti-aging ultra-thin overlay material according to any one of claims 1-7 in the field of road engineering construction.

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