Application of asphalt sealant in microwave heating maintenance of asphalt pavement

Abstract

The application discloses application of asphalt filling sealant in microwave heating maintenance of asphalt pavement, and the asphalt filling sealant comprises the following components in percentage by mass: 55-74% of base asphalt, 15-34% of waste tire rubber powder, 10-25% of magnetic loss type wave absorbing material and 1-4% of dispersion stabilizer; the asphalt filling sealant is heated in a microwave mode when used for maintenance of the asphalt pavement, has a fast heating rate, good heating depth and uniformity, good self-healing effect, stable healing strength recovery rate after multiple healings, and can effectively avoid aging of the asphalt after multiple healings, and has important practical value.

Description

Technical Field

[0001] This invention relates to the field of highway asphalt pavement technology, specifically to the application of an asphalt sealant in microwave heating curing of asphalt pavement. Background Technology

[0002] Asphalt pavement is a common type of road surface, and cracking is the most common defect. Once asphalt pavement cracks, its durability will drop sharply. If cracks are not treated in time, under the influence of changing environment and repeated vehicle traffic, micro-cracks will expand and connect into larger macro-cracks, which will then develop into potholes and other defects requiring significant manpower and resources for repair, resulting in a waste of resources and money. Crack sealing is currently the most convenient and quick method for crack treatment. The performance of the sealant determines the degree of crack recovery. To ensure that the sealant has good viscoelastic properties, waste tire rubber powder modified asphalt is generally used as the sealant for asphalt pavement cracks. However, most sealants can only be used once and cannot be used multiple times. At the same time, when traditional heating methods are used to reheat asphalt sealant for repair, a long heating time is required to heat the sealant to a certain depth, causing irreversible aging of the sealant and the asphalt mixture, and the uniformity of heating cannot be guaranteed.

[0003] Microwave heating technology is a novel road maintenance process characterized by rapid heating rate, high efficiency, and high heating uniformity. Waste tire rubber powder is an electrically depleting microwave absorbing material. It can absorb microwave energy, making the waste tire rubber powder sealant a heating element. After microwave heating, the waste tire rubber powder sealant achieves self-healing of cracks due to thermal expansion and flow. However, in the microwave heating of asphalt, traditional asphalt exhibits significantly low microwave heating efficiency. Furthermore, waste tire rubber powder, as a single electrically depleting microwave absorbing material, has a small bandwidth, relatively weak absorption, and poor impedance matching, failing to fully utilize its absorption capacity, severely limiting the application of microwave heating technology. Therefore, it is urgent to find a way to apply microwave heating to the use of asphalt sealant while simultaneously enabling the sealant to fully utilize its microwave absorption capacity. Summary of the Invention

[0004] The purpose of this invention is to provide an application of asphalt sealant in microwave heating curing of asphalt pavement. It has a fast heating rate, good heating depth and uniformity, good self-healing effect, and stable strength recovery rate after multiple healings. It effectively avoids the aging phenomenon of asphalt after multiple healings and has important practical value.

[0005] To achieve the above objectives, the technical solution of the present invention is implemented as follows:

[0006] This invention provides an application of an asphalt sealant in microwave heating for curing asphalt pavements. The asphalt sealant comprises, by weight percentage, the following components: 55%–74% base asphalt, 15%–34% waste tire rubber powder, 10%–25% magnetic loss absorbing material, and 1%–4% dispersant stabilizer. The asphalt sealant is used for microwave heating when curing asphalt pavements.

[0007] According to the above scheme, the microwave power is 600W to 1200W; the microwave time is 1 to 3 minutes.

[0008] According to the above scheme, the base asphalt is selected from No. 70, No. 90 or No. 110 base asphalt.

[0009] According to the above scheme, the waste tire rubber powder has a particle size of 24-50 mesh, a relative density of 1.10-1.25, and a moisture content of less than 1.0. The waste tire rubber powder is an electrical loss type microwave absorbing material.

[0010] According to the above scheme, the magnetic loss type absorbing material is one or more of the following: calcined steel slag powder, magnetite powder, zinc ferrite powder, manganese ferrite powder, and magnetite.

[0011] According to the above scheme, the dispersant stabilizer is one of furfural oil and castor oil. The dispersant stabilizer can adjust the asphalt composition and reduce the asphalt viscosity to prepare the potting compound with more uniform shearing.

[0012] According to the above scheme, the asphalt sealant is prepared by the following method:

[0013] 1) Heat the base asphalt at 180-190℃ for 90-120 minutes to soften it to a flowable state that can be sheared at high speed;

[0014] 2) Add waste tire rubber powder to the fluid matrix asphalt obtained in step 1), maintain the temperature at 180-190℃, and shear at high speed at 3500-4500 rpm for 50-70 minutes to obtain waste tire rubber powder modified asphalt binder.

[0015] 3) Add magnetic loss absorbing material and dispersant stabilizer to the waste tire rubber powder modified asphalt binder obtained in step 2), continue to maintain the temperature at 180-190℃, and uniformly shear at 3500-4500 rpm for 50-70 minutes to obtain asphalt grout.

[0016] According to the above scheme, the asphalt sealant meets the technical requirements of cold-type sealant, and can achieve self-healing of asphalt pavement cracks under microwave heating conditions.

[0017] The beneficial effects of this invention are as follows:

[0018] 1. This invention provides an application of asphalt sealant in microwave heating for asphalt pavement maintenance. The asphalt sealant is heated using microwaves during asphalt pavement maintenance. In the asphalt sealant, waste tire rubber powder and magnetic loss-absorbing materials respectively generate dielectric and magnetic losses, improving the impedance matching of the resulting asphalt pavement sealant. During microwave heating, this results in a good synergistic effect, effectively converting microwave energy into heat energy. The heating speed is fast, the self-healing effect is good, and the performance remains stable after multiple healing cycles. Simultaneously, it exhibits strong adhesion to aggregates in pavement crack sections, strong elastic recovery, and can treat deep cracks, demonstrating broad application prospects.

[0019] 2. This invention uses microwave heating. Microwave heating does not involve heat conduction but directly converts electromagnetic energy into heat energy. In order to achieve uniform and rapid heating, waste tire rubber powder and magnetic loss absorbing material need to be uniformly dispersed in the matrix asphalt. This invention adjusts the asphalt composition and reduces the viscosity of the asphalt by adding a dispersant stabilizer, so as to obtain more uniform asphalt filling during high-speed shearing, which promotes the rapid and uniform microwave heating process and is beneficial to the strength recovery after self-healing.

[0020] 3. Furthermore, in this invention, high-speed shearing is first used to achieve uniform dispersion of waste tire rubber powder in the matrix asphalt. Then, high-speed shearing is used to promote uniform dispersion of magnetic loss type microwave absorbing material and dispersion stabilizer. High-speed shearing combined with dispersion stabilizer results in highly uniform potting compound, which is beneficial for rapid and uniform heating and asphalt self-healing during microwave heating. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the process for testing the self-healing properties of the asphalt sealant obtained in this embodiment of the invention. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. 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 of ordinary skill in the art without creative effort are within the protection scope of the present invention.

[0023] Example 1

[0024] An application of an asphalt sealant in the maintenance of asphalt pavements is provided, which is heated by microwave; wherein:

[0025] The asphalt potting compound comprises the following weight percentages: 55% No. 70 base asphalt, 28% waste tire rubber powder, 15% magnetic loss absorbing material, and 2% dispersion stabilizer.

[0026] The above-mentioned asphalt potting compound is prepared by the following method:

[0027] 1) By mass percentage, 55% of No. 70 base asphalt is placed in a mixing tank, and then the mixing tank is placed in a constant temperature oil bath and heated for 120 minutes. The oil bath temperature is between 185℃.

[0028] 2) After the base asphalt in the mixing tank has softened to a flowable state that can be sheared at high speed, the oil bath temperature of the high-speed shearing machine is kept at 180℃. 28% waste tire rubber powder is added, and the high-speed shearing machine is started. High-speed shearing is carried out at a speed of 4000rpm for 60min. The high-speed shearing process is continuously kept at a constant temperature in the oil bath to obtain waste tire rubber powder modified asphalt binder.

[0029] 3) After preparing the waste tire rubber powder modified asphalt binder, keep the oil bath temperature of the high-speed shearing apparatus constant, then add 15% magnetic loss type microwave absorbing material and 2% dispersant stabilizer, and use a high-speed shearing apparatus to uniformly shear at 4000 rpm for 60 minutes. This yields an enhanced microwave-heated self-healing asphalt grouting adhesive based on matched impedance.

[0030] In this embodiment, the magnetic loss type absorbing material is hot-burned steel slag powder, specifically, its particle size is less than 0.075 mm; the waste tire rubber powder has a particle size of 40 mesh, a relative density of 1.10 to 1.25, and a moisture content of less than 1.0.

[0031] In this embodiment, the dispersant stabilizer is furfural oil.

[0032] The asphalt sealant obtained in this embodiment was microwave-heated and its performance was tested, then compared with that of a control sample. Control sample 1 and control sample 2 were prepared using the following methods:

[0033] Comparison Sample 1-1

[0034] The specific preparation method is the same as in Example 1, except that 55% of No. 70 base asphalt is added to 28% waste tire rubber powder, followed by 15% mineral powder and 2% dispersant stabilizer, and no magnetic loss type absorbing material is added.

[0035] In this embodiment, the mineral powder does not have wave-absorbing ability and is only used to control the relative content of waste tire rubber powder in asphalt, specifically its particle size is less than 0.075mm.

[0036] Comparison Sample 1-2

[0037] The specific preparation method is the same as in Example 1, except that 55% of No. 70 base asphalt is added to 28% mineral powder, followed by 15% hot-burned steel slag powder and 2% dispersant stabilizer, and waste tire rubber powder is not added.

[0038] In this embodiment, the mineral powder does not have the ability to absorb waves; it is only used to control the relative content of magnetic loss type absorbing material in asphalt, specifically, its particle size is less than 0.075 mm.

[0039] The specific performance testing methods for the asphalt sealant and the control sample obtained in this embodiment are as follows:

[0040] The heating characteristics of the potting compound were tested by microwave heating: 30g of potting compound was poured into a test cup and placed in a microwave oven with parameters of 800W and 2.45GHz. After microwave heating for 1 minute, its surface temperature was tested.

[0041] BBR beam specimens were used for pull-out self-healing tests: the strength recovery rate after microwave heating following specimen fracture was used to characterize its healing performance. The specific steps were as follows: First, a 35mm × 1.5mm × 2mm crack was cut into the beam specimen using a cutting machine. The sample was then placed in a UTM-25 universal testing machine and kept at -10℃ for 4 hours. After the heat treatment, a three-point bending failure was performed on the semi-circular specimen. The mixture specimen was then fixed with clamps, the crack width was controlled to 4mm, and three sides of the specimen were sealed with heat-resistant tape. After cooling at room temperature for 4 hours, the prepared potting compound was heated to 200°C and poured into the crack. It was then cooled at room temperature for 2 hours and placed in a UTM-25 universal testing machine at -10°C for 4 hours. The tensile peak value F0 at the first failure was recorded. The specimen was then placed in a microwave oven with parameters of 800W and 2.45GHz for 2 minutes of microwave heating, after which heating was stopped and the specimen was cooled. Finally, the specimen was placed in the universal testing machine at -10°C for 4 hours and subjected to tensile failure. The tensile peak value F1 at the second failure was recorded. Repeating the above steps allows for multiple healing processes. When using the universal testing machine to break the specimen, the spindle rises at a speed of 5 mm / min, and the experimental temperature is -10°C, primarily to ensure that the specimen undergoes brittle fracture without creep. The test method is as follows: Figure 1 As shown, the formula for calculating the strength recovery rate of asphalt concrete after a pull-out test is: The results of the thermal properties test of the asphalt sealant and the control sample are shown in Table 1 below, and the results of the healing performance test of the asphalt sealant and the control sample are shown in Table 2 below.

[0042] Table 1. Test results of the thermal properties of the asphalt sealant obtained in Example 1 and the control sample.

[0043]

[0044] Table 2. Healing performance test results of the asphalt sealant obtained in Example 1 and the control sample.

[0045]

[0046]

[0047] As shown in Tables 1 and 2, the surface temperature of the potting compound prepared from 28% waste tire rubber powder and 15% calcined steel slag powder significantly increased after microwave heating for 1 minute. Meanwhile, the combined surface temperature of control samples 1-1 and 1-2 after microwave heating for 1 minute was still lower than that of this potting compound. The healing effect of this potting compound was also significantly improved, maintaining high strength and stable performance even after multiple healing cycles.

[0048] Example 2

[0049] An application of an asphalt sealant in the maintenance of asphalt pavements is provided, which is heated by microwave; wherein:

[0050] The asphalt potting compound comprises the following weight percentages: 60% base asphalt No. 70, 20% waste tire rubber powder, 19% magnetic loss absorbing material, and 1% dispersion stabilizer.

[0051] The above-mentioned asphalt potting compound is prepared by the following method:

[0052] 1) By mass percentage, 60% of No. 70 base asphalt is placed in a mixing tank, and then the mixing tank is placed in a constant temperature oil bath and heated for 120 minutes. The oil bath temperature is between 185℃.

[0053] 2) After the base asphalt in the mixing tank has softened to a flowable state that can be sheared at high speed, the oil bath temperature of the high-speed shearing device is kept at 180℃. 20% waste tire rubber powder is added, and the high-speed shearing device is started. High-speed shearing is carried out at a speed of 4000rpm for 60min. The high-speed shearing process is continuously kept at a constant temperature in the oil bath to obtain waste tire rubber powder modified asphalt binder.

[0054] 3) After preparing the waste tire rubber powder modified asphalt binder, keep the oil bath temperature of the high-speed shearing apparatus constant, then add 19% magnetic loss type microwave absorbing material and 1% dispersing stabilizer, and use a high-speed shearing apparatus to uniformly shear at 4000 rpm for 60 minutes. This yields an enhanced microwave-heated self-healing asphalt potting compound based on matched impedance.

[0055] In this embodiment, the magnetic loss absorbing material is magnetite powder, specifically, its particle size is less than 0.075 mm. The waste tire rubber powder has a particle size of 40 mesh, a relative density of 1.10 to 1.25, and a moisture content of less than 1.0.

[0056] In this embodiment, the dispersant stabilizer is castor oil.

[0057] The performance of the enhanced microwave-heated self-healing asphalt grout based on matched impedance obtained in this embodiment was tested and compared with that of the control samples. Control samples 2-1 and 2-2 were prepared by the following method:

[0058] Comparison Sample 2-1

[0059] The specific preparation method is the same as in Example 2, except that 60% of No. 70 base asphalt is added with 20% waste tire rubber powder, followed by 19% mineral powder and 1% dispersant stabilizer, and no magnetic loss type absorbing material is added.

[0060] In this embodiment, the mineral powder does not have wave-absorbing ability and is only used to control the relative content of waste tire rubber powder in asphalt, specifically its particle size is less than 0.075mm.

[0061] Comparison Sample 2-2

[0062] The specific preparation method is the same as in Example 2, except that 60% of the No. 70 base asphalt is added with 20% mineral powder and then 19% magnetite powder and 1% dispersant stabilizer, and no waste tire rubber powder is added.

[0063] In this embodiment, the mineral powder does not have the ability to absorb waves; it is only used to control the relative content of magnetic loss type absorbing material in asphalt, specifically, its particle size is less than 0.075 mm.

[0064] The specific performance testing methods for the asphalt sealant and the control sample obtained in this embodiment are as described in Example 1. The test results of the heat generation characteristics of the asphalt sealant and the control sample are shown in Table 3 below, and the test results of the healing performance of the asphalt sealant and the control sample are shown in Table 4 below.

[0065] Table 3. Test results of the thermal properties of the asphalt sealant obtained in Example 2 and the control sample.

[0066]

[0067] Table 4. Healing performance test results of the asphalt sealant obtained in Example 1 and the control sample.

[0068]

[0069] As shown in Tables 3 and 4, the surface temperature of the potting compound prepared from 20% waste tire rubber powder and 19% magnetite powder significantly increased after microwave heating for 1 minute. Meanwhile, the combined surface temperature of control samples 2-1 and 2-2 after microwave heating for 1 minute was still lower than that of this potting compound. The healing effect of this potting compound was also significantly improved, maintaining high strength even after multiple healing cycles.

[0070] Example 3

[0071] An application of an asphalt sealant in the maintenance of asphalt pavements is provided, which is heated by microwave; wherein:

[0072] The asphalt potting compound comprises the following weight percentages: 55% base asphalt No. 90, 25% waste tire rubber powder, 19% magnetic loss absorbing material, and 1% dispersion stabilizer.

[0073] The above-mentioned asphalt potting compound is prepared by the following method:

[0074] 1) By mass percentage, 55% of No. 90 base asphalt is placed in a mixing tank, and then the mixing tank is placed in a constant temperature oil bath and heated for 120 minutes. The oil bath temperature is between 185℃.

[0075] 2) After the base asphalt in the mixing tank has softened to a flowable state that can be sheared at high speed, the oil bath temperature of the high-speed shearing device is kept at 180℃. 25% waste tire rubber powder is added, and the high-speed shearing device is started. High-speed shearing is carried out at a speed of 4000rpm for 60min. The high-speed shearing process is continuously kept at a constant temperature in the oil bath to obtain waste tire rubber powder modified asphalt binder.

[0076] 3) After preparing the waste tire rubber powder modified asphalt binder, keep the oil bath temperature of the high-speed shearing apparatus constant, then add 19% magnetic loss type microwave absorbing material and 1% dispersing stabilizer, and use a high-speed shearing apparatus to uniformly shear at 4000 rpm for 60 minutes. This yields an enhanced microwave-heated self-healing asphalt potting compound based on matched impedance.

[0077] In this embodiment, the magnetic loss absorbing material is zinc ferrite powder, specifically, its particle size is less than 0.075 mm. The waste tire rubber powder has a particle size of 40 mesh, a relative density of 1.10 to 1.25, and a moisture content of less than 1.0.

[0078] In this embodiment, the dispersant stabilizer is furfural oil.

[0079] The performance of the enhanced microwave-heated self-healing asphalt grout based on matched impedance obtained in this embodiment was tested and compared with that of the control samples. Control samples 3-1 and 3-2 were prepared by the following method:

[0080] Comparison Sample 3-1

[0081] The specific preparation method is the same as in Example 3, except that 55% of No. 90 base asphalt is added to 25% waste tire rubber powder, followed by 19% mineral powder and 1% dispersant stabilizer, and no magnetic loss type absorbing material is added.

[0082] In this embodiment, the mineral powder does not have wave-absorbing ability and is only used to control the relative content of waste tire rubber powder in asphalt, specifically its particle size is less than 0.075mm.

[0083] Comparison Sample 3-2

[0084] The specific preparation method is the same as in Example 3, except that 55% of No. 90 base asphalt is added to 25% mineral powder, followed by 19% zinc ferrite powder and 1% dispersant stabilizer, and waste tire rubber powder is not added.

[0085] In this embodiment, the mineral powder does not have the ability to absorb waves; it is only used to control the relative content of magnetic loss type absorbing material in asphalt, specifically, its particle size is less than 0.075 mm.

[0086] The specific performance testing methods for the asphalt sealant and the control sample obtained in this embodiment are as described in Example 1. The test results of the heat generation characteristics of the asphalt sealant and the control sample are shown in Table 5 below, and the test results of the healing performance of the asphalt sealant and the control sample are shown in Table 6 below.

[0087] Table 5. Test results of the thermal properties of the asphalt sealant obtained in Example 3 and the control sample.

[0088]

[0089] Table 6. Healing performance test results of the asphalt sealant obtained in Example 3 and the control sample.

[0090]

[0091] As shown in Tables 5 and 6, the surface temperature of the potting compound prepared from 25% waste tire rubber powder and 19% zinc ferrite powder significantly increased after microwave heating for 1 minute. Meanwhile, the combined surface temperature of control samples 3-1 and 3-2 after microwave heating for 1 minute was still lower than that of this potting compound. The healing effect of this potting compound was also significantly improved, maintaining high strength even after multiple healing cycles.

[0092] Example 4

[0093] An application of an asphalt sealant in the maintenance of asphalt pavements is provided, which is heated by microwave; wherein:

[0094] The asphalt potting compound comprises the following weight percentages: 68% No. 110 base asphalt, 15% waste tire rubber powder, 15% magnetic loss absorbing material, and 2% dispersion stabilizer.

[0095] The above-mentioned asphalt potting compound is prepared by the following method:

[0096] 1) By mass percentage, 68% of No. 110 base asphalt was placed in a mixing tank, and then the mixing tank was placed in a constant temperature oil bath and heated for 120 minutes. The oil bath temperature was between 185℃.

[0097] 2) After the base asphalt in the mixing tank has softened to a flowable state that can be sheared at high speed, the oil bath temperature of the high-speed shearing device is kept at 180℃. 15% waste tire rubber powder is added, and the high-speed shearing device is started. High-speed shearing is carried out at a speed of 4000rpm for 60min. The high-speed shearing process is continuously kept at a constant temperature in the oil bath to obtain waste tire rubber powder modified asphalt binder.

[0098] 3) After preparing the waste tire rubber powder modified asphalt binder, keep the oil bath temperature of the high-speed shearing apparatus constant, then add 15% magnetic loss type microwave absorbing material and 2% dispersant stabilizer, and use a high-speed shearing apparatus to uniformly shear at 4000 rpm for 60 minutes. This yields an enhanced microwave-heated self-healing asphalt grouting adhesive based on matched impedance.

[0099] In this embodiment, the magnetic loss absorbing material is zinc ferrite powder, specifically, its particle size is less than 0.075 mm. The waste tire rubber powder has a particle size of 40 mesh, a relative density of 1.10 to 1.25, and a moisture content of less than 1.0.

[0100] In this embodiment, the dispersant stabilizer is castor oil.

[0101] The performance of the enhanced microwave-heated self-healing asphalt grout based on matched impedance obtained in this embodiment was tested and compared with that of the control samples. Control samples 4-1 and 4-2 were prepared by the following method:

[0102] Comparison Sample 4-1

[0103] The specific preparation method is the same as in Example 4, except that 68% of the No. 110 base asphalt is mixed with 15% waste tire rubber powder and then 15% mineral powder and 2% dispersant stabilizer, and no magnetic loss type absorbing material is added.

[0104] In this embodiment, the mineral powder does not have wave-absorbing ability and is only used to control the relative content of waste tire rubber powder in asphalt, specifically its particle size is less than 0.075mm.

[0105] Comparison Sample 4-2

[0106] The specific preparation method is the same as in Example 4, except that 68% of the No. 110 base asphalt is added with 15% mineral powder, then 15% zinc ferrite powder, 2% dispersant and stabilizer, and no waste tire rubber powder is added.

[0107] In this embodiment, the mineral powder does not have the ability to absorb waves; it is only used to control the relative content of magnetic loss type absorbing material in asphalt, specifically, its particle size is less than 0.075 mm.

[0108] The specific performance testing methods for the asphalt sealant and the control sample obtained in this embodiment are as described in Example 1. The test results of the heat generation characteristics of the asphalt sealant and the control sample are shown in Table 7 below, and the test results of the healing performance of the asphalt sealant and the control sample are shown in Table 8 below.

[0109] Table 7. Test results of the thermal properties of the asphalt sealant obtained in Example 4 and the control sample.

[0110]

[0111] Table 8. Healing performance test results of asphalt sealant and control sample in Example 4.

[0112]

[0113] As shown in Tables 7 and 8, the surface temperature of the potting compound prepared from 15% waste tire rubber powder and 15% zinc ferrite powder significantly increased after microwave heating for 1 minute. Meanwhile, the combined surface temperature of control samples 4-1 and 4-2 after microwave heating for 1 minute was still lower than that of this potting compound. The healing effect of this potting compound was also significantly improved, maintaining high strength even after multiple healing cycles.

[0114] Example 5

[0115] An application of an asphalt sealant in the maintenance of asphalt pavements is provided, which is heated by microwave; wherein:

[0116] The asphalt potting compound comprises the following weight percentages: 69% No. 70 base asphalt, 20% waste tire rubber powder, 10% magnetic loss absorbing material, and 1% dispersant and stabilizer.

[0117] The above-mentioned asphalt potting compound is prepared by the following method:

[0118] 1) By mass percentage, 69% of No. 70 base asphalt was placed in a mixing tank, and then the mixing tank was placed in a constant temperature oil bath and heated for 120 minutes. The oil bath temperature was between 185℃.

[0119] 2) After the base asphalt in the mixing tank has softened to a flowable state that can be sheared at high speed, the oil bath temperature of the high-speed shearing device is kept at 180℃. 20% waste tire rubber powder is added, and the high-speed shearing device is started. High-speed shearing is carried out at a speed of 4000rpm for 60min. The high-speed shearing process is continuously kept at a constant temperature in the oil bath to obtain waste tire rubber powder modified asphalt binder.

[0120] 3) After preparing the waste tire rubber powder modified asphalt binder, keep the oil bath temperature of the high-speed shearing apparatus constant, then add 10% magnetic loss type microwave absorbing material and 1% dispersing stabilizer, and use a high-speed shearing apparatus to uniformly shear at 4000 rpm for 60 minutes. This yields an enhanced microwave-heated self-healing asphalt grouting adhesive based on matched impedance.

[0121] In this embodiment, the magnetic loss absorbing material is manganese ferrite powder, specifically, its particle size is less than 0.075 mm. The waste tire rubber powder has a particle size of 40 mesh, a relative density of 1.10 to 1.25, and a moisture content of less than 1.0.

[0122] In this embodiment, the dispersant stabilizer is furfural oil.

[0123] The performance of the enhanced microwave-heated self-healing asphalt grout based on matched impedance obtained in this embodiment was tested and compared with that of the control samples. Control samples 5-1 and 5-2 were prepared by the following method:

[0124] Comparison Sample 5-1

[0125] The specific preparation method is the same as in Example 5, except that 69% of the No. 110 base asphalt is added with 20% waste tire rubber powder, followed by 10% mineral powder and 1% dispersant stabilizer, and no magnetic loss type absorbing material is added.

[0126] In this embodiment, the mineral powder does not have wave-absorbing ability and is only used to control the relative content of waste tire rubber powder in asphalt, specifically its particle size is less than 0.075mm.

[0127] Comparison Sample 5-2

[0128] The specific preparation method is the same as in Example 5, except that 69% of the No. 110 base asphalt is added with 20% mineral powder, then 10% manganese ferrite powder and 1% dispersant stabilizer, and no waste tire rubber powder is added.

[0129] In this embodiment, the mineral powder does not have the ability to absorb waves; it is only used to control the relative content of magnetic loss type absorbing material in asphalt, specifically, its particle size is less than 0.075 mm.

[0130] The specific performance testing methods for the asphalt sealant and the control sample obtained in this embodiment are as described in Example 1. The test results of the heat generation characteristics of the asphalt sealant and the control sample are shown in Table 9 below, and the test results of the healing performance of the asphalt sealant and the control sample are shown in Table 10 below.

[0131] Table 9. Test results of the thermal properties of the asphalt sealant obtained in Example 5 and the control sample.

[0132]

[0133] Table 10. Healing performance test results of the asphalt sealant obtained in Example 5 and the control sample.

[0134]

[0135] As shown in Tables 9 and 10, the surface temperature of the potting compound prepared from 20% waste tire rubber powder and 10% manganese ferrite powder significantly increased after microwave heating for 1 minute. Meanwhile, the combined surface temperature of control samples 5-1 and 5-2 after microwave heating for 1 minute was still lower than that of this potting compound. The healing effect of this potting compound was also significantly improved, maintaining high strength even after multiple healing cycles.

[0136] Example 6

[0137] An application of an asphalt sealant in the maintenance of asphalt pavements is provided, which is heated by microwave; wherein:

[0138] The asphalt potting compound comprises the following weight percentages: 58% base asphalt No. 90, 25% waste tire rubber powder, 15% magnetic loss absorbing material, and 2% dispersion stabilizer.

[0139] The above-mentioned asphalt potting compound is prepared by the following method:

[0140] 1) By mass percentage, 58% of No. 90 base asphalt was placed in a mixing tank, and then the mixing tank was placed in a constant temperature oil bath and heated for 120 minutes. The oil bath temperature was between 185℃.

[0141] 2) After the base asphalt in the mixing tank has softened to a flowable state that can be sheared at high speed, the oil bath temperature of the high-speed shearing device is kept at 180℃. 25% waste tire rubber powder is added, and the high-speed shearing device is started. High-speed shearing is carried out at a speed of 4000rpm for 60min. The high-speed shearing process is continuously kept at a constant temperature in the oil bath to obtain waste tire rubber powder modified asphalt binder.

[0142] 3) After preparing the waste tire rubber powder modified asphalt binder, keep the oil bath temperature of the high-speed shearing apparatus constant, then add 15% magnetic loss type microwave absorbing material and 2% dispersant stabilizer, and use a high-speed shearing apparatus to uniformly shear at 4000 rpm for 60 minutes. This yields an enhanced microwave-heated self-healing asphalt grouting adhesive based on matched impedance.

[0143] In this embodiment, the magnetic loss absorbing material is magnetite powder, specifically, its particle size is less than 0.075 mm. The waste tire rubber powder has a particle size of 40 mesh, a relative density of 1.10 to 1.25, and a moisture content of less than 1.0.

[0144] In this embodiment, the dispersant stabilizer is castor oil.

[0145] The performance of the enhanced microwave-heated self-healing asphalt grout based on matched impedance obtained in this embodiment was tested and compared with that of the control samples. Control samples 6-1 and 6-2 were prepared by the following method:

[0146] Comparison Sample 6-1

[0147] The specific preparation method is the same as in Example 6, except that 58% of No. 90 base asphalt is added to 25% waste tire rubber powder, followed by 15% mineral powder and 2% dispersant stabilizer, and no magnetic loss type absorbing material is added.

[0148] In this embodiment, the mineral powder does not have wave-absorbing ability and is only used to control the relative content of waste tire rubber powder in asphalt, specifically its particle size is less than 0.075mm.

[0149] Comparison Sample 6-2

[0150] The specific preparation method is the same as in Example 6, except that 58% of No. 90 base asphalt is added to 25% mineral powder, then 15% magnetite powder and 2% dispersant stabilizer are added, and waste tire rubber powder is not added.

[0151] In this embodiment, the mineral powder does not have the ability to absorb waves; it is only used to control the relative content of magnetic loss type absorbing material in asphalt, specifically, its particle size is less than 0.075 mm.

[0152] Comparison Sample 6-3

[0153] The specific preparation method is the same as in Example 6, except that 60% of No. 90 base asphalt is added to 25% waste tire rubber powder and then 15% magnetite powder, without adding a dispersant or stabilizer.

[0154] The specific performance testing methods for the asphalt sealant and the control sample obtained in this embodiment are as described in Example 1. The test results of the heat generation characteristics of the asphalt sealant and the control sample are shown in Table 11 below, and the test results of the healing performance of the asphalt sealant and the control sample are shown in Table 12 below.

[0155] Table 11. Test results of the thermal properties of the asphalt sealant obtained in Example 6 and the control sample.

[0156]

[0157] Table 12 Healing performance test results of the asphalt sealant obtained in Example 6 and the control sample

[0158]

[0159] As shown in Tables 11 and 12, the surface temperature of the potting compound prepared from 25% waste tire rubber powder and 15% maghematite powder significantly increased after microwave heating for 1 minute. However, the heating rate of control sample 6-3 (without dispersant) was lower than that of control sample 6-2 (with dispersant). Furthermore, the combined surface temperature of control samples 6-1 and 6-2 after microwave heating for 1 minute was still lower than that of this potting compound. The healing effect of this potting compound was also significantly improved, maintaining high strength even after multiple healing cycles. The dispersant can improve the uniformity of the potting compound, thereby increasing its self-healing rate.

[0160] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An application of an asphalt sealant in microwave heating curing of asphalt pavements, characterized in that, The asphalt sealant, by weight percentage, comprises the following components: 55%–74% base asphalt, 15%–34% waste tire rubber powder, 10%–25% magnetic loss absorbing material, and 1%–4% dispersant and stabilizer; the asphalt sealant is heated by microwave when used for asphalt pavement maintenance; wherein: The dispersing stabilizer is one of furfural oil and castor oil; The asphalt potting compound is prepared through the following steps: 1) Heat the base asphalt at 180~190℃ for 90~120min to soften it to a flowable state that can be sheared at high speed; 2) Add waste tire rubber powder to the fluid matrix asphalt obtained in step 1), maintain the temperature at 180~190℃, and shear at high speed at 3500~4500rpm for 50~70min to obtain waste tire rubber powder modified asphalt binder. 3) Add magnetic loss type microwave absorbing material and dispersant stabilizer to the waste tire rubber powder modified asphalt binder obtained in step 2), continue to maintain the temperature at 180~190℃, and uniformly shear at high speed at 3500~4500rpm for 50~70min to obtain asphalt grouting adhesive.

2. The application according to claim 1, characterized in that, The microwave power is 600W~1200W; the microwave time is 1~3min.

3. The application according to claim 1, characterized in that, The base asphalt is selected from No. 70, No. 90 or No. 110 base asphalt.

4. The application according to claim 1, characterized in that, The waste tire rubber powder has a particle size of 24-50 mesh and a relative density of 1.10-1.

25.

5. The application according to claim 1, characterized in that, The magnetic loss type absorbing material is one or more of the following: calcined steel slag powder, magnetite powder, zinc ferrite powder, manganese ferrite powder, and magnetite.

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