Induction heating self-repairing asphalt concrete and preparation and repairing method thereof

Abstract

The invention relates to the technical field of road engineering, in particular to induction heating self-repairing asphalt concrete and a preparation and repairing method thereof. The induction heating self-repairing asphalt concrete is prepared from 75 to 83.5 parts of heat shielding functional coating coarse aggregate, 12 to 15 parts of fine aggregate and 4.5 to 10 parts of mineral powder, the heat shielding functional coating coarse aggregate comprises a heat shielding material, a polymer emulsion and a coarse aggregate. The heat shielding functional coating coarse aggregate further comprises 3-6 parts of asphalt and 1-4 parts of a high-conductivity material. According to the induction heating self-repairing asphalt concrete disclosed by the invention, the temperature of asphalt mortar can be quickly increased to 130-160 DEG C by utilizing an alternating electromagnetic field, and micro cracks are quickly repaired through flowing of asphalt; the used heat shielding function coating coarse aggregate can enhance the bonding effect of the aggregate, reduce abrasion and breakage of the aggregate in the forming process, regulate and control heat flow conduction and energy distribution, reduce heat loss and ensure that asphalt mortar is in a high-temperature flowing state for a long time, so that the induction heating self-repairing efficiency of the asphalt concrete is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of road engineering, in particular to an inductive heating self-repairing asphalt concrete and a preparation and repair method thereof. BACKGROUND

[0002] Due to the effects of climate environment and traffic load, the asphalt pavement is prone to aging, and then cracking, which not only destroys the continuity and flatness of the pavement, but also easily causes the water infiltration of the road surface to erode the roadbed and accelerate the damage of the pavement. Cracks have become the primary problem to be solved in the maintenance of asphalt pavement, but the existing maintenance technology is passive repair after the pavement appears aging and cracks, which has high cost, poor effect and seriously affects the traffic efficiency, and therefore it is urgent to develop more advanced crack repair technology. Using the self-healing property of asphalt to heal the micro-cracks in the bud state before the macro-disease of the asphalt pavement is an advanced maintenance concept of asphalt pavement. The inductive heating self-repairing method is to add high-conductive materials that can be heated by electromagnetic induction into the asphalt concrete, to raise the temperature of the asphalt concrete, reduce the viscosity of the asphalt, and improve the capillary flow and molecular diffusion rate of the asphalt, so as to achieve the purpose of repairing cracks. This method has the advantages of fast heating rate, high healing efficiency and repeated implementation, and is a micro-crack repair technology with broad application prospects.

[0003] However, after inductive heating, the heat of the asphalt mortar containing high-conductive materials is rapidly transferred to the aggregate, resulting in rapid temperature rise of the aggregate and rapid temperature drop of the asphalt mortar, which not only wastes heat, but also reduces the crack repair effect of the asphalt mixture.

[0004] Therefore, it is urgent to have certain technology to ensure that the inductive heating can realize the regulation of heat conduction and energy distribution, so that the asphalt mortar is in a high-temperature flow state for a long time, so as to improve the crack repair effect of the asphalt mixture. SUMMARY

[0005] In view of this, the present application provides an inductive heating self-repairing asphalt concrete and a preparation and repair method thereof, the inductive heating self-repairing asphalt concrete comprising 75-83.5 parts of thermal shielding functional coating coarse aggregate, 12-15 parts of fine aggregate, 4.5-10 parts of mineral powder, 3-6 parts of asphalt and 1-4 parts of high-conductivity material, wherein the thermal shielding functional coating coarse aggregate is composed of thermal shielding material, polymer emulsion and coarse aggregate. When the inductive heating self-repairing asphalt concrete appears micro-cracks, a high-frequency alternating magnetic field with a heating power of 5-15 kW and a resonant frequency of 100-150 kHz is used to act on the damaged asphalt concrete at a lift distance of 10-50 mm, so that the high-conductivity material and the asphalt mortar containing the high-conductivity material are rapidly heated to 130-160℃, the thermal shielding functional coating aggregate is used to realize the regulation and control of heat conduction and energy distribution, the heat loss of the aggregate during inductive heating is reduced, the heat loss during the heating of the asphalt mortar is hindered, the asphalt mortar is ensured to be in a high-temperature state for a long time, and the micro-cracks in the asphalt concrete are repaired quickly and efficiently through the flow of asphalt. In addition, the thermal shielding functional coating can also enhance the bonding effect of the aggregate, optimize the contact interface area of the aggregate and asphalt, and reduce the wear and breakage of the aggregate during the molding process. The technical scheme of the present application is as follows: In a first aspect, the present application provides an inductive heating self-repairing asphalt concrete, the raw material components of which include mineral aggregate, asphalt and high-conductivity material; the mineral aggregate includes coarse aggregate, fine aggregate and mineral powder, and the surface of the coarse aggregate is coated with a thermal shielding functional coating, which contains thermal shielding material and polymer emulsion.

[0006] Preferably, the mineral aggregate includes 75-83.5% of coarse aggregate, 12-15% of fine aggregate and 4.5-10% of mineral powder, based on the total mass percentage of the mineral aggregate being 100%; and the mineral aggregate further includes 3-6 parts of asphalt and 1-4 parts of high-conductivity material, based on the total mass of the mineral aggregate being 100 parts.

[0007] Further preferably, the mix proportion type of the inductive heating self-repairing asphalt concrete includes AC, SMA and OGFC, according to the Technical Specification for Construction of Highway Asphalt Pavement (JTG F40-2004).

[0008] Preferably, the mass ratio of the thermal shielding material to the polymer emulsion is (1-5): 100.

[0009] Preferably, the total mass of the thermal shielding functional coating is calculated by the following formula: wherein, is the total mass of the thermal shielding functional coating, in grams; ​Specifically, the specific surface area of the coarse aggregate is preferably 0.1-0.4 mm, and the specific surface area of the coarse aggregate is preferably 0.1-0.4 mm. 2 ; Specifically, the specific surface area of the coarse aggregate is preferably 0.1-0.4 mm, and the specific surface area of the coarse aggregate is preferably 0.1-0.4 mm. Specifically, the specific surface area of the coarse aggregate is preferably 0.1-0.4 mm, and the specific surface area of the coarse aggregate is preferably 0.1-0.4 mm. Specifically, the specific surface area of the coarse aggregate is preferably 0.1-0.4 mm, and the specific surface area of the coarse aggregate is preferably 0.1-0.4 mm. 3 Specifically, the specific surface area of the coarse aggregate is preferably 0.1-0.4 mm, and the specific surface area of the coarse aggregate is preferably 0.1-0.4 mm. 3 .

[0010] Further preferably, the thickness of the heat shielding functional coating is 0.1-0.4 mm.

[0011] Specifically, the film thickness of the prepared heat shielding functional coating coarse aggregate is preferably 0.1-0.4 mm, and the film thickness of the heat shielding functional coating coarse aggregate is preferably 0.1-0.4 mm. If the film thickness is too large, the gradation will be affected, the heat shielding effect will not change much, and the cost of the mixture will increase. If the film thickness is too small, the film will be damaged during the mixing and compaction process of the mixture, resulting in poor heat shielding effect.

[0012] Further preferably, the particle size of the coarse aggregate is 4.75-16 mm.

[0013] Specifically, the particle size of the coarse aggregate selected in the heat shielding functional coating coarse aggregate is 4.75-16 mm. The specific surface area of the aggregate with a particle size of 0-4.75 mm is large, the heat absorption is small, the coating is prone to agglomeration, the gradation is easy to change, and the cost is large and the benefit is low.

[0014] Preferably, the heat shielding material includes one or more of SiO2 aerogel, polysiloxane, graphene, acrylate resin and epoxy resin.

[0015] Preferably, the asphalt includes one or more of base asphalt, SBS modified asphalt and high viscosity modified asphalt; the polymer emulsion includes one or more of polyurethane emulsion, EVA emulsion, silicone emulsion and epoxy resin emulsion; and the high-conductive material includes one or more of steel wool fiber, iron powder, nanocrystalline soft magnetic alloy and silicon steel sheet.

[0016] Further, the high-conductive material is preferably steel wool fiber, and the heat shielding material is preferably SiO2 aerogel.

[0017] Further preferably, the diameter of the steel wool fiber is 90-120 μm, and the length is 4-8 mm.

[0018] In a second aspect, the present application provides a preparation method of the inductive heating self-repairing asphalt concrete as described in the first aspect, comprising the following steps: S1-1, uniformly mix the heat shielding material with the polymer emulsion to obtain a heat shielding coating emulsion; S1-2, wash and dry the coarse aggregate, completely immerse the coarse aggregate in the heat shielding coating emulsion, and take out and dry and solidify to obtain the heat shielding functional coating coarse aggregate.

[0019] Further preferably, in the step S1-1, specifically comprising: shearing the heat shielding material with the polymer emulsion at 3000 revolutions per minute for 20 minutes.

[0020] Specifically, the heat shielding coating emulsion can realize the regulation of heat conduction and energy distribution, optimize the contact interface region of the coarse aggregate and the asphalt, and reduce the wear and breakage of the aggregate in the molding process.

[0021] Further preferably, in the step S1-2, specifically comprising: completely immersing the washed coarse aggregate in the heat shielding coating emulsion for 10 seconds, then taking out and drying and solidifying, and repeating the above operation 1 to 4 times to prepare the heat shielding functional coating coarse aggregate with a film thickness of 0.1 to 0.4 mm.

[0022] Preferably, the preparation method of the inductive heating self-repairing asphalt concrete further comprises the following steps: S1, heating the heat shielding functional coating coarse aggregate, the fine aggregate, and the asphalt for use; S2, turning on the stirrer, and sequentially adding the heat shielding functional coating coarse aggregate, the fine aggregate, and the high-conductivity material, and heat preserving and stirring; S3, adding the asphalt and the mineral powder during the stirring process, and obtaining the inductive heating self-repairing asphalt concrete after uniform stirring.

[0023] Preferably, in the step S1, the heat shielding functional coating coarse aggregate and the fine aggregate are heated to 175℃, and the asphalt is heated to 155 to 180℃; in the step S2, the heat preservation temperature is 165 to 175℃.

[0024] In a third aspect, the present application provides a repairing method of the inductive heating self-repairing asphalt concrete according to the first aspect, comprising the following steps: applying an alternating magnetic field to the damaged inductive heating self-repairing asphalt concrete, so that the high-conductivity material in the concrete generates Joule heat, thereby heating the asphalt mortar containing the high-conductivity material to 130 to 160℃, and repairing the micro-cracks in the asphalt concrete through the flow of the asphalt.

[0025] Preferably, the heating power of the alternating magnetic field is 5 to 15 kW. When the heating power is less than 5 kW, the temperature of the asphalt mortar cannot reach 130℃; when the heating power is greater than 15 kW, the temperature rising speed of the asphalt mortar is too fast, which is difficult to control within 130 to 160℃, and the aging of the asphalt is aggravated when the temperature is higher than 160℃.

[0026] Preferably, the resonant frequency of the alternating magnetic field is 100-150 kHz. When the resonant frequency is less than 50 kHz, the magnetic domain flips slowly at low frequency, and the hysteresis loss is dominant, which has much lower thermal efficiency than the magnetostrictive effect; when the resonant frequency is greater than 150 kHz, the energy penetration depth is reduced, the heating is uneven, and the device compatibility is relatively low, which is easy to interfere with the surrounding electronic equipment.

[0027] Preferably, the alternating magnetic field is applied at a lift-off distance of 10-50 mm. The magnetic flux density of the alternating magnetic field decreases exponentially with the distance, and when the lift-off distance is less than 10 mm, the magnetic flux density is too high, the eddy current is concentrated in the conductive material to generate local high temperature, which is easy to cause the asphalt to age and volatilize, and even cause the aggregate to expand and crack; when the lift-off distance is greater than 50 mm, the magnetic field penetration depth is insufficient, which leads to the weakening of the eddy current effect of the conductive material and the significant reduction of the heating rate.

[0028] Compared with the prior art, the present application has the following advantages: (1) The heat shielding functional coating aggregate prepared by the present application can realize the regulation of heat conduction and energy distribution, reduce the heat transfer between the asphalt mortar and the coarse aggregate, reduce the heat loss of the asphalt mortar after induction heating, ensure that the asphalt mortar is in a high temperature state for a long time, and quickly and efficiently repair the micro-cracks in the asphalt concrete through the flow of asphalt.

[0029] (2) The heat shielding functional coating of the present application can also enhance the bonding effect of the coarse aggregate, optimize the contact interface area of the aggregate and the asphalt, and reduce the wear and breakage of the aggregate during the molding process.

[0030] (3) During induction heating, the present application controls the temperature of the asphalt mortar in the crack area by heat input, avoids the local over-high temperature of the asphalt mortar caused by the heat absorption of the coarse aggregate, and can achieve better repair effect. DETAILED DESCRIPTION

[0031] The embodiments of the present application will be described in detail below, and the described embodiments are exemplary and are intended to explain the present application, but cannot be understood as a limitation of the present application.

[0032] It should be noted that the terms "first", "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. Further, in the description of the present application, unless otherwise specified, the meaning of "multiple" is two or more.

[0033] In this document, the terms "containing", "including" or "comprising" are open expressions, that is, they include the contents indicated by the present application, but do not exclude other aspects.

[0034] In this document, the terms "optional," "optionally," or "may" means that the subsequently described event or circumstance can or can not occur, and that the description includes instances where the event or circumstance occurs and instances where it does not.

[0035] The technical solutions in the embodiments of the present application will be described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments of the present application, all the other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0036] The materials used in the present application are all purchased from the market, specifically: aggregate (basalt) and mineral powder (basalt mineral powder) are from Leshan, Sichuan; SBS modified asphalt and high-viscosity modified asphalt are from Chongqing Zhixiang Paving Co., Ltd.; steel wool fiber is purchased from Dezhou Fangyuan Steel Wool Fiber Co., Ltd.; SiO2 aerogel, polysiloxane, and graphene are purchased from Xi'an Qiyue Biological Technology Co., Ltd.; iron powder, nanocrystalline soft magnetic alloy, and silicon steel sheet are purchased from Yunlu Co., Ltd.; acrylate resin is purchased from Shanghai Guangyi Chemical Co., Ltd.; and epoxy resin is purchased from Japan Chemicals Co., Ltd.

[0037] Example 1

[0038] The present embodiment provides a preparation and repair method of inductive heating self-repairing asphalt concrete, specifically including: First, OGFC-13 grading is used, and the fractions of each raw material according to the OGFC mixture proportioning design method are: 9.5~16mm coarse aggregate 31.5 parts, 4.75~9.5mm coarse aggregate 52.0 parts, 0~4.75mm fine aggregate 12 parts, mineral powder 4.5 parts; and SBS modified asphalt 4.7 parts, steel wool fiber 2 parts; each part is 120g.

[0039] The preparation method is specifically as follows: SiO2 aerogel and water-based polyurethane emulsion are mixed at a mass ratio of 5:100, a high-speed shearing machine is used for shearing at 3000 r / min for 20 min to prepare a thermal shielding coating emulsion; the two-grade coarse aggregates with a size of 9.5-16 mm and 4.75-9.5 mm are completely immersed in the thermal shielding coating emulsion for 10 s; then the thermal shielding coating emulsion is taken out and dried or solidified, and then the above operation is repeated twice to prepare the thermal shielding functional coating coarse aggregate with a film thickness of 0.2 mm; the thermal shielding functional coating coarse aggregate and the ordinary fine aggregate are heated to 175 ℃, the SBS modified asphalt is heated to 160 ℃, a stirrer is started, the thermal shielding functional coating coarse aggregate, the ordinary fine aggregate and the steel wool are added in sequence, the temperature is kept at 175 ℃ for 1 min, and then the asphalt and the mineral powder are added, and the stirring is continued for 1 min; the inductive heating SBS modified asphalt mixture test piece is formed by using the Marshall compaction method and the wheel rolling method at 165 ℃.

[0040] The repair method is specifically as follows: the semi-circular bending test is carried out at 5 ℃ to break the test piece; at a lifting distance of 10 mm, the broken SBS modified asphalt mixture test piece is rapidly heated to 160 ℃ (the asphalt mastic temperature on the upper surface of the test piece) by using a high-frequency alternating magnetic field with a heating power of 9 kW and a resonant frequency of 123 kHz, and is naturally cooled for 2 h; the semi-circular bending test is carried out again on the repaired SBS modified asphalt mixture test piece at 5 ℃.

[0041] Example 2

[0042] The embodiment provides a preparation and repair method of an inductive heating self-repairing asphalt concrete, and the difference from the example 1 is that high-viscosity modified asphalt is used, and the embodiment specifically comprises the following steps: Firstly, the OGFC-13 grading is used, and the mass percentages of the raw materials according to the OGFC mixture proportioning design method are as follows: 31.5 parts of 9.5-16 mm coarse aggregate, 52.0 parts of 4.75-9.5 mm coarse aggregate, 12 parts of 0-4.75 mm fine aggregate, 4.5 parts of mineral powder, 4.7 parts of high-viscosity modified asphalt and 2 parts of steel wool fiber; each part is 120 g.

[0043] The preparation method is specifically as follows: SiO2 aerogel and water-based polyurethane emulsion are mixed at a mass ratio of 5:100, a high-speed shearing machine is used for shearing at 3000 r / min for 20 min to prepare a thermal shielding coating emulsion; the two-grade coarse aggregates of 9.5-16 mm and 4.75-9.5 mm are completely immersed in the thermal shielding coating emulsion for 10 s; then the thermal shielding coating emulsion is taken out and dried or solidified, and then the above operation is repeated twice to prepare the thermal shielding functional coating coarse aggregate with a film thickness of 0.2 mm; the thermal shielding functional coating coarse aggregate and the ordinary fine aggregate are heated to 175 ℃, the high-viscosity modified asphalt is heated to 160 ℃, the stirrer is started, the thermal shielding functional coating coarse aggregate, the ordinary fine aggregate and the steel wool are added in sequence, the temperature is kept at 175 ℃ for 1 min, and then the asphalt and the mineral powder are added, and the stirring is continued for 1 min; the Marshall compaction method and the wheel rolling method are used to form the inductively heated high-viscosity modified asphalt mixture test piece at 165 ℃.

[0044] The repair method is specifically as follows: the semi-circular bending test is carried out at 5 ℃ to break the test piece; at a lifting distance of 10 mm, the broken high-viscosity modified asphalt mixture test piece is rapidly heated to 160 ℃ (the asphalt mastic temperature on the upper surface of the test piece) by using a high-frequency alternating magnetic field with a heating power of 9 kW and a resonant frequency of 123 kHz, and is naturally cooled for 2 h; the semi-circular bending test is carried out again on the repaired high-viscosity modified asphalt mixture test piece at 5 ℃.

[0045] Example 3

[0046] The embodiment provides a preparation and repair method of inductively heated self-repairing asphalt concrete, which is different from the embodiment 1 in that an OGFC-16 grading is used, and specifically includes the following steps. Firstly, the OGFC-16 grading is used, and the parts of each raw material according to the OGFC mixture proportioning design method are as follows: 32 parts of 9.5-16 mm coarse aggregate, 51.5 parts of 4.75-9.5 mm coarse aggregate, 12 parts of 0-4.75 mm fine aggregate, 4.5 parts of mineral powder, 3 parts of SBS modified asphalt and 2 parts of steel wool fiber; each part is 120 g.

[0047] The preparation method is specifically as follows: SiO2 aerogel and water-based polyurethane emulsion are mixed at a mass ratio of 5:100, a high-speed shearing machine is used for shearing at 3000 r / min for 20 min to prepare a thermal shielding coating emulsion; the two-grade coarse aggregates of 9.5-16 mm and 4.75-9.5 mm are completely immersed in the thermal shielding coating emulsion for 10 s; then the thermal shielding coating emulsion is taken out and dried or solidified, and then the above operation is repeated twice to prepare the thermal shielding functional coating coarse aggregate with a film thickness of 0.2 mm; the thermal shielding functional coating coarse aggregate and the ordinary fine aggregate are heated to 175 ℃, the SBS modified asphalt is heated to 160 ℃, the stirrer is started, the thermal shielding functional coating coarse aggregate, the ordinary fine aggregate and the steel wool are sequentially added, the temperature is kept at 175 ℃ for 1 min, and then the asphalt and the mineral powder are added, and the stirring is continued for 1 min; the inductive heating SBS modified asphalt mixture test piece is formed by using the Marshall compaction method and the wheel rolling method at 165 ℃.

[0048] The repair method is specifically as follows: the semi-circular bending test is carried out at 5 ℃ to break the test piece; at a lifting distance of 10 mm, the broken SBS modified asphalt mixture test piece is rapidly heated to 160 ℃ (the asphalt mastic temperature on the upper surface of the test piece) by using a high-frequency alternating magnetic field with a heating power of 9 kW and a resonant frequency of 123 kHz, and is naturally cooled for 2 h; the semi-circular bending test is carried out again on the repaired SBS modified asphalt mixture test piece at 5 ℃.

[0049] Example 4

[0050] The embodiment provides a preparation and repair method of an inductive heating self-repairing asphalt concrete, and the difference from the example 1 is that SMA-13 grading is used, and the embodiment specifically comprises the following steps. Firstly, SMA-13 grading is used, and the parts of each raw material according to the SMA mixture proportioning design method are as follows: 9.5-16 mm coarse aggregate 40 parts, 4.75-9.5 mm coarse aggregate 35 parts, 0-4.75 mm fine aggregate 15 parts, mineral powder 10 parts, SBS modified asphalt 6 parts, and steel wool fiber 2 parts; each part is 120 g.

[0051] The preparation method is specifically as follows: SiO2 aerogel and water-based polyurethane emulsion are mixed at a mass ratio of 5:100, a high-speed shearing machine is used for shearing at 3000 r / min for 20 min to prepare a thermal shielding coating emulsion; the two-grade coarse aggregates with a size of 9.5-16 mm and 4.75-9.5 mm are completely immersed in the thermal shielding coating emulsion for 10 s; then the coarse aggregates are taken out and dried or solidified, and then the above operation is repeated twice to prepare the thermal shielding functional coating coarse aggregate with a film thickness of 0.2 mm; the thermal shielding functional coating coarse aggregate and the ordinary fine aggregate are heated to 175 ℃, the SBS modified asphalt is heated to 160 ℃, a stirrer is started, the thermal shielding functional coating coarse aggregate, the ordinary fine aggregate and the steel wool are sequentially added, the temperature is kept at 175 ℃ for 1 min, and then the asphalt and the mineral powder are added, and the stirring is continued for 1 min; the inductive heating SBS modified asphalt mixture test piece is formed by using the Marshall compaction method and the wheel rolling method at 165 ℃.

[0052] The repair method is specifically as follows: the semi-circular bending test is performed at 5 ℃ to break the test piece; at a lifting distance of 10 mm, the broken SBS modified asphalt mixture test piece is rapidly heated to 160 ℃ (the asphalt mastic temperature on the upper surface of the test piece) by using a high-frequency alternating magnetic field with a heating power of 9 kW and a resonant frequency of 123 kHz, and is naturally cooled for 2 h; the semi-circular bending test is performed on the repaired SBS modified asphalt mixture test piece again at 5 ℃.

[0053] Example 5

[0054] The embodiment provides a preparation and repair method of an inductive heating self-repairing asphalt concrete, which is different from the embodiment 1 in that the steel wool fiber is 1 part; and the rest is the same.

[0055] Example 6

[0056] The embodiment provides a preparation and repair method of an inductive heating self-repairing asphalt concrete, which is different from the embodiment 1 in that the steel wool fiber is 4 parts; and the rest is the same.

[0057] Example 7

[0058] The embodiment provides a preparation and repair method of an inductive heating self-repairing asphalt concrete, which is different from the embodiment 1 in that, in the repair method, the broken SBS modified asphalt mixture test piece is rapidly heated to 150 ℃, and the rest is the same.

[0059] Example 8

[0060] The embodiment provides a preparation and repair method of an inductive heating self-repairing asphalt concrete, which is different from the embodiment 1 in that, in the repair method, the broken SBS modified asphalt mixture test piece is rapidly heated to 140 ℃, and the rest is the same.

[0061] Example 9

[0062] The embodiment provides a preparation and repairing method of the inductive heating self-repairing asphalt concrete, and the difference from the embodiment 1 is that in the repairing method, the SBS modified asphalt mixture test piece after being broken is rapidly heated to 130 DEG C, and the rest is the same.

[0063] Embodiment 10

[0064] The embodiment provides a preparation and repairing method of the inductive heating self-repairing asphalt concrete, and the difference from the embodiment 1 is that in the preparation method, the mass ratio of the SiO2 aerogel and the polyurethane emulsion is 1:100, and the rest is the same.

[0065] Embodiment 11

[0066] The embodiment provides a preparation and repairing method of the inductive heating self-repairing asphalt concrete, and the difference from the embodiment 1 is that in the preparation method, the mass ratio of the SiO2 aerogel and the polyurethane emulsion is 2:100, and the rest is the same.

[0067] Embodiment 12

[0068] The embodiment provides a preparation and repairing method of the inductive heating self-repairing asphalt concrete, and the difference from the embodiment 1 is that in the preparation method, the mass ratio of the SiO2 aerogel and the polyurethane emulsion is 3:100, and the rest is the same.

[0069] Embodiment 13

[0070] The embodiment provides a preparation and repairing method of the inductive heating self-repairing asphalt concrete, and the difference from the embodiment 1 is that in the preparation method, the mass ratio of the SiO2 aerogel and the polyurethane emulsion is 4:100, and the rest is the same.

[0071] Embodiment 14

[0072] The embodiment provides a preparation and repairing method of the inductive heating self-repairing asphalt concrete, and the difference from the embodiment 1 is that in the preparation method, the SiO2 aerogel is replaced by polysiloxane, and the rest is the same.

[0073] Embodiment 15

[0074] The embodiment provides a preparation and repairing method of the inductive heating self-repairing asphalt concrete, and the difference from the embodiment 1 is that in the preparation method, the SiO2 aerogel is replaced by graphene, and the rest is the same.

[0075] Embodiment 16

[0076] The embodiment provides a preparation and repairing method of the inductive heating self-repairing asphalt concrete, and the difference from the embodiment 1 is that in the preparation method, the SiO2 aerogel is replaced by acrylate resin, and the rest is the same.

[0077] Example 17

[0078] The present example provides a preparation and repair method of inductive heating self-repairing asphalt concrete, which is different from example 1 in that in the preparation method, the SiO2 aerogel is replaced by epoxy resin, and the rest is the same.

[0079] Example 18

[0080] The present example provides a preparation and repair method of inductive heating self-repairing asphalt concrete, which is different from example 1 in that in the preparation method, the steel wool fiber is replaced by iron powder, and the rest is the same.

[0081] Example 19

[0082] The present example provides a preparation and repair method of inductive heating self-repairing asphalt concrete, which is different from example 1 in that in the preparation method, the steel wool fiber is replaced by nanocrystalline soft magnetic alloy, and the rest is the same.

[0083] Example 20

[0084] The present example provides a preparation and repair method of inductive heating self-repairing asphalt concrete, which is different from example 1 in that in the preparation method, the steel wool fiber is replaced by silicon steel sheet, and the rest is the same.

[0085] Example 21

[0086] The present example provides a preparation and repair method of inductive heating self-repairing asphalt concrete, which is different from example 1 in that in the preparation method, the coating is 1 time, and the heat shielding functional coating coarse aggregate with a film layer thickness of 0.1 mm is prepared, and the rest is the same.

[0087] Example 22

[0088] The present example provides a preparation and repair method of inductive heating self-repairing asphalt concrete, which is different from example 1 in that in the preparation method, the coating is 3 times, and the heat shielding functional coating coarse aggregate with a film layer thickness of 0.3 mm is prepared, and the rest is the same.

[0089] Example 23

[0090] The present example provides a preparation and repair method of inductive heating self-repairing asphalt concrete, which is different from example 1 in that in the preparation method, the coating is 4 times, and the heat shielding functional coating coarse aggregate with a film layer thickness of 0.4 mm is prepared, and the rest is the same.

[0091] Comparative Example 1 The present comparative example provides a preparation and repair method of ordinary heating repairing asphalt concrete, which is different from example 1 in that the heat shielding functional coating coarse aggregate is not used, and only ordinary coarse aggregate is used, which specifically comprises: Firstly, OGFC-13 gradation is adopted, and the parts of each raw material according to the OGFC mixture proportioning design method are as follows: 9.5~16mm coarse aggregate 31.5 parts, 4.75~9.5mm coarse aggregate 52.0 parts, 0~4.75mm fine aggregate 12 parts, mineral powder 4.5 parts, SBS modified asphalt 4.7 parts, and steel wool fiber 2.0 parts; each part is 120g.

[0092] The preparation method is specifically as follows: the ordinary coarse aggregate and the ordinary fine aggregate are heated to 175℃, the SBS modified asphalt is heated to 160℃, the stirrer is started, the ordinary coarse aggregate, the ordinary fine aggregate and the steel wool are sequentially added, the temperature is maintained at 175℃, and the stirring is performed for 1min, then the asphalt and the mineral powder are added, and the stirring is continuously performed for 1min; the SBS modified asphalt mixture test piece is formed by using the Marshall compaction method and the wheel rolling method at 165℃.

[0093] The repairing method is specifically as follows: the semi-circular bending test is performed at 5℃ to break the test piece; at a 10mm lifting distance, the broken SBS modified asphalt mixture test piece is rapidly heated to 160℃ (the asphalt mastic temperature on the upper surface of the test piece) by using a high-frequency alternating magnetic field with a heating power of 9kW and a resonant frequency of 123kHz, and is naturally cooled for 2h; the semi-circular bending test is performed again on the repaired SBS modified asphalt mixture test piece at 5℃.

[0094] Comparative Example 2 The present comparative example provides a preparation and repairing method for comparative heating repair of asphalt concrete, which is different from the example 1 in that the three-grade aggregates of 9.5~16mm, 4.75~9.5mm and 2.36~4.75mm are coated with a heat shielding functional coating, and the rest is the same.

[0095] Comparative Example 3 The present comparative example provides a preparation and repairing method for comparative heating repair of asphalt concrete, which is different from the example 1 in that all the aggregates are coated with a heat shielding functional coating, and the rest is the same.

[0096] Comparative Example 4 The present comparative example provides a preparation and repairing method for comparative heating repair of asphalt concrete, which is different from the example 1 in that the coating is performed 5 times in the preparation method, and the heat shielding functional coating coarse aggregate with a film layer thickness of 0.5mm is prepared, and the rest is the same.

[0097] Comparative Example 5 The present comparative example provides a preparation and repairing method for comparative heating repair of asphalt concrete, which is different from the example 1 in that the mass ratio of SiO2 aerogel to polyurethane emulsion is 6:100 in the preparation method, and the rest is the same.

[0098] Comparative Example 6 The comparative example provides a preparation and repair method of a comparative inductive heating self-repairing asphalt concrete, which is different from example 1 in that, in the repair method, the fractured SBS modified asphalt mixture test piece is rapidly heated to 120 DEG C, and the rest is the same.

[0099] Comparative example 7 The comparative example provides a preparation and repair method of a comparative inductive heating self-repairing asphalt concrete, which is different from example 1 in that, in the repair method, the fractured SBS modified asphalt mixture test piece is rapidly heated to 170 DEG C, and the rest is the same.

[0100] In order to systematically evaluate the road performance of the inductive heating self-repairing asphalt concrete, the inductive heating self-repairing asphalt concrete prepared in examples 1-6 and comparative example 1 above is selected for road performance testing, and the specific testing method is as follows: the Marshall test piece and the rut test piece prepared above are subjected to Marshall test according to the Highway Engineering Asphalt and Asphalt Mixture Test Regulation T0709-2011 (JTG E20-2011) to measure the stability thereof; the rut test is performed according to the Highway Engineering Asphalt and Asphalt Mixture Test Regulation T0719-2011 (JTG E20-2011) to measure the dynamic stability thereof; the semi-circular bending test is performed at 5 DEG C according to the American Society for Testing Materials Standard (ASTM D8044-23) to break the test piece, the fractured modified asphalt mixture test piece is rapidly heated to 160 DEG C (the asphalt mastic temperature on the upper surface of the test piece) at a heating power of 9 kW and a resonant frequency of 123 kHz using a high-frequency alternating magnetic field at a 10 mm lifting distance, and is naturally cooled for 2 h; the semi-circular bending test is performed on the repaired modified asphalt mixture test piece at 5 DEG C. The test results are shown in Table 1, and it can be seen that the heat shielding functional coating layer regulates the heat conduction path, reduces heat loss, concentrates energy on the asphalt phase, and significantly improves the healing efficiency by more than 87%, and the OGFC-13 without the coating layer has a recovery rate of only 72% due to heat loss. The road performance is improved to a certain extent due to the protection of the heat shielding functional coating layer on the edges of the aggregate, and the heat shielding functional coating layer has a promoting effect on all gradation types. And the results of examples 5 and 6 show that when the amount of steel wool fiber is 1-4 parts, the performance of the asphalt mixture meets the specification requirements, and with the increase of the amount, the road performance increases first and then decreases, and the application also attempts to use more than 4 parts of steel wool fiber, and the recovery ratio still increases, but the density decreases sharply due to insufficient asphalt wrapping, so that the performance of the asphalt mixture cannot meet the specification requirements.

[0101] Table 1 Road performance of inductive heating self-repairing asphalt concrete

[0102] To systematically evaluate the relationship between the self-healing performance of the inductive heating self-healing asphalt concrete and the heating temperature, the inductive heating self-healing asphalt concrete prepared in the above Examples 1, 7, 8, 9 and Comparative Examples 6, 7 was selected to perform a road performance test, and the specific test method was as follows: according to the American Society for Testing Materials standard (ASTM D8044-23), a semi-circular bending test was performed at 5°C to break the test piece, at a 10 mm lifting distance, a high-frequency alternating magnetic field with a heating power of 9 kW and a resonant frequency of 123 kHz was used to quickly heat the broken SBS modified asphalt mixture test piece to 130-160°C (the temperature of the asphalt mastic on the upper surface of the test piece), and the test piece was naturally cooled for 2 h; a semi-circular bending test was performed on the repaired SBS modified asphalt mixture test piece at 5°C. The test results are shown in Table 2, and it can be seen that the optimal repair temperature of the heat shielding functional coating aggregate OGFC-13 is 160°C, and the repair effect is significantly reduced below 130°C, and there is no additional gain above 160°C, because the asphalt mastic is in a completely flowing state at 160°C.

[0103] Table 2 Relationship between self-healing performance of inductive heating self-healing asphalt concrete and heating temperature

[0104] To systematically evaluate the relationship between the self-healing performance of the inductive heating self-healing asphalt concrete and the content of the heat shielding material, the inductive heating self-healing asphalt concrete prepared in the above Examples 1, 10-13 and Comparative Example 5 was selected to perform a road performance test, and the specific test method was as follows: according to the American Society for Testing Materials standard (ASTM D8044-23), a semi-circular bending test was performed at 5°C to break the test piece, at a 10 mm lifting distance, a high-frequency alternating magnetic field with a heating power of 9 kW and a resonant frequency of 123 kHz was used to quickly heat the broken SBS modified asphalt mixture test piece to 160°C (the temperature of the asphalt mastic on the upper surface of the test piece), and the test piece was naturally cooled for 2 h; a semi-circular bending test was performed on the repaired SBS modified asphalt mixture test piece at 5°C. The test results are shown in Table 3, and it can be seen that when the content of SiO2 aerogel increases from 1 part to 5 parts, the fracture strength recovery ratio increases from 82% to 91%, indicating that the aerogel significantly optimizes the repair efficiency by controlling the temperature through heat insulation. The recovery ratio of Comparative Example SiO2 aerogel content of 6 parts is the same as that of 5 parts, indicating that when the content of aerogel exceeds 5 parts, the interface adhesion is weakened, the excess aerogel occupies the space on the surface of the aggregate, and the mechanical interlocking between the aggregate and the asphalt is weakened, resulting in a decrease in structural strength.

[0105] Table 3 Relationship between self-healing performance of inductive heating self-healing asphalt concrete and content of heat shielding material

[0106] To systematically evaluate the relationship between the self-healing performance of the induction heating self-healing asphalt concrete and the type of thermal shielding material, the induction heating self-healing asphalt concrete prepared in the above Examples 1, 14-17 was selected for road performance testing. The specific testing method is as follows: according to the American Society for Testing Materials standard (ASTM D8044-23), a semi-circular bending test was performed at 5°C to break the test piece, and at a 10 mm lifting distance, the broken SBS modified asphalt mixture test piece was rapidly heated to 160°C (the temperature of the asphalt mastic on the upper surface of the test piece) using a high-frequency alternating magnetic field with a heating power of 9 kW and a resonant frequency of 123 kHz, and was naturally cooled for 2 h; a semi-circular bending test was performed on the repaired SBS modified asphalt mixture test piece at 5°C. The test results are shown in Table 4, and it can be seen that different thermal shielding materials can improve the fracture strength recovery ratio of OGFC-13 asphalt concrete, among which SiO2 aerogel has the best performance. SiO2 aerogel has an ultra-low thermal conductivity, forms an efficient thermal barrier on the surface of the aggregate, significantly reduces the heat loss to the deep layer of the aggregate, concentrates the energy at the crack interface, and promotes the rapid flow of asphalt to fill; and its porous structure can reflect part of the infrared radiation, further optimizing the uniformity of heat distribution and avoiding local overheating or insufficient temperature rise.

[0107] Table 4 Relationship between self-healing performance of induction heating self-healing asphalt concrete and type of thermal shielding material

[0108] To systematically evaluate the relationship between the self-healing performance of the induction heating self-healing asphalt concrete and the type of thermal shielding material, the induction heating self-healing asphalt concrete prepared in the above Examples 1, 14-17 was selected for road performance testing. The specific testing method is as follows: according to the American Society for Testing Materials standard (ASTM D8044-23), a semi-circular bending test was performed at 5°C to break the test piece, and at a 10 mm lifting distance, the broken SBS modified asphalt mixture test piece was rapidly heated to 160°C (the temperature of the asphalt mastic on the upper surface of the test piece) using a high-frequency alternating magnetic field with a heating power of 9 kW and a resonant frequency of 123 kHz, and was naturally cooled for 2 h; a semi-circular bending test was performed on the repaired SBS modified asphalt mixture test piece at 5°C. The test results are shown in Table 4, and it can be seen that different thermal shielding materials can improve the fracture strength recovery ratio of OGFC-13 asphalt concrete, among which SiO2 aerogel has the best performance. SiO2 aerogel has an ultra-low thermal conductivity, forms an efficient thermal barrier on the surface of the aggregate, significantly reduces the heat loss to the deep layer of the aggregate, concentrates the energy at the crack interface, and promotes the rapid flow of asphalt to fill; and its porous structure can reflect part of the infrared radiation, further optimizing the uniformity of heat distribution and avoiding local overheating or insufficient temperature rise.

[0109] Table 5 Relationship between self-healing performance of induction heating self-healing asphalt concrete and type of thermal shielding material

[0110] To evaluate the road performance of the induction heating self-healing asphalt concrete, the induction heating self-healing asphalt concrete prepared in the above Examples 1, 21-23 and Comparative Example 4 was first selected for road performance testing. The specific testing methods are as follows: the Marshall test pieces and rut test pieces prepared in the above examples were subjected to Marshall test according to the Highway Engineering Asphalt and Asphalt Mixture Test Procedures T0709-2011 (JTG E20-2011) to measure the stability thereof; the rut test was performed according to the Highway Engineering Asphalt and Asphalt Mixture Test Procedures T0719-2011 (JTG E20-2011) to measure the dynamic stability thereof; the semi-circular bending test was performed at 5°C according to the American Society for Testing Materials Standard (ASTM D8044-23) to break the test piece, at a 10 mm lifting distance, the broken modified asphalt mixture test piece was rapidly heated to 160°C (the asphalt mastic temperature on the upper surface of the test piece) using a high-frequency alternating magnetic field with a heating power of 9 kW and a resonant frequency of 123 kHz, and was naturally cooled for 2 h; the semi-circular bending test was performed on the repaired modified asphalt mixture test piece at 5°C. The test results are shown in Table 6, which shows that the fracture strength recovery ratio of the mixture gradually increases with the increase of the coating times, but the performance of the concrete decreases seriously when the coating times exceed 4 times, and 2 times is the best coating times, too many coating times cause the variation of the gradation, and the change of the angularity of the aggregate is also large, thus leading to the deterioration of the Marshall stability and dynamic stability of the asphalt mixture.

[0111] Table 6 Relationship between road performance, self-healing performance and coating times of induction heating self-healing asphalt concrete

[0112] In order to evaluate the road performance of the induction heating self-repairing asphalt concrete, the induction heating self-repairing asphalt concrete prepared in Example 1 and Comparative Examples 2 and 3 is selected to perform road performance test. The specific test method is as follows: the Marshall test piece and the rut test piece prepared in the above examples are subjected to Marshall test according to Highway Engineering Asphalt and Asphalt Mixture Test Regulation T0709-2011 (JTGE20-2011) to measure the stability thereof; the rut test is performed according to Highway Engineering Asphalt and Asphalt Mixture Test Regulation T0719-2011 (JTG E20-2011) to measure the dynamic stability thereof; the semi-circular bending test is performed at 5℃ according to the American Society for Testing Materials Standard (ASTM D8044-23) to break the test piece, the modified asphalt mixture test piece after breaking is rapidly heated to 160℃ (the temperature of asphalt mastic on the upper surface of the test piece) at a heating power of 9kW and a resonant frequency of 123kHz using a high-frequency alternating magnetic field, and is naturally cooled for 2h; the semi-circular bending test is performed on the modified asphalt mixture test piece after repair at 5℃. The test results are shown in Table 7, and it can be seen that the fine aggregate has a large specific area, absorbs less heat, is easy to agglomerate during coating, is easy to change the gradation, and has a large cost and low benefit.

[0113] Table 7 Relationship between road performance and self-repairing performance of induction heating self-repairing asphalt concrete and thermal shielding function coating aggregate particle size

[0114] The above-described embodiments are part of the embodiments of the present application, rather than all the embodiments. The detailed description of the embodiments of the present application is not intended to limit the scope of the claimed application, but only represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

Claims

1. An inductively heated self-healing asphalt concrete, characterized in that, The raw material components include mineral aggregate, asphalt and high-conductive material; the mineral aggregate includes coarse aggregate, fine aggregate and mineral powder, the surface of the coarse aggregate is coated with a heat shielding functional coating, and the heat shielding functional coating contains heat shielding material and polymer emulsion.

2. The inductively heated self-healing asphalt concrete of claim 1, wherein, The mineral aggregate includes 75-83.5% of coarse aggregate, 12-15% of fine aggregate and 4.5-10% of mineral powder, accounting for 100% of the total mass of the mineral aggregate; and further includes 3-6 parts of asphalt and 1-4 parts of high-conductive material, accounting for 100 parts of the total mass of the mineral aggregate.

3. The inductively heated self-healing asphalt concrete of claim 1, wherein, The mass ratio of the heat shielding material to the polymer emulsion is (1-5):

100.

4. The inductively heated self-healing asphalt concrete of claim 1, wherein, The thickness of the heat shielding functional coating is 0.1-0.4 mm.

5. The inductively heated self-healing asphalt concrete of claim 1, wherein, The particle size of the coarse aggregate is 4.75-16 mm.

6. The inductively heated self-healing asphalt concrete of claim 1, wherein, The heat shielding material includes one or more of SiO2 aerogel, polysiloxane, graphene, acrylate resin and epoxy resin.

7. The inductively heated self-healing asphalt concrete of claim 1, wherein, The asphalt includes one or more of base asphalt, SBS modified asphalt and high-viscosity modified asphalt; the polymer emulsion includes one or more of polyurethane emulsion, EVA emulsion, silicone emulsion and epoxy resin emulsion; and the high-conductive material includes one or more of steel wool fiber, iron powder, nanocrystalline soft magnetic alloy and silicon steel sheet.

8. A method of producing the inductively heatable self-healing asphalt concrete according to any one of claims 1 to 7, characterized in that The method includes the following steps: S1-1, uniformly mixing the heat shielding material and the polymer emulsion to obtain heat shielding coating emulsion; S1-2, washing and drying the coarse aggregate, completely immersing the coarse aggregate in the heat shielding coating emulsion, and taking out and drying and solidifying to obtain heat shielding functional coating coarse aggregate.

9. The method of claim 8, wherein the induction heating self-healing asphalt concrete is prepared by a method comprising: The method further includes the following steps: S1, heating the heat shielding functional coating coarse aggregate, fine aggregate and asphalt for use; S2, starting the stirrer, and sequentially adding the heat shielding functional coating coarse aggregate, fine aggregate and high-conductive material, and heating and stirring; S3, adding the asphalt and mineral powder during the stirring process, and obtaining the induction heating self-repairing asphalt concrete after uniform stirring.

10. A method of repairing inductive heating self-healing asphalt concrete as claimed in any one of claims 1 to 7, characterized in that, The method includes the following steps: Applying an alternating magnetic field to the damaged induction heating self-repairing asphalt concrete to generate Joule heat in the high-conductive material in the concrete, thereby heating the asphalt mortar containing the high-conductive material to 130-160℃, and repairing the micro-cracks in the asphalt concrete through the flow of the asphalt.

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