Dual-effect application method for waste wind turbine blade as bituminous road material

Abstract

The present invention relates to the technical field of solid waste treatment. Disclosed is a dual-effect application method for a waste wind turbine blade as a bituminous road material. The method comprises the following steps: (1) removing the balsa wood and the core material of a waste wind turbine blade to obtain a recovered wind turbine blade; and (2) pulverizing and sieving the recovered wind turbine blade, using sieved wind turbine blade powder having a particle size of less than or equal to 0.3 mm as an asphalt modifier, and using sieved wind turbine blade particles having a particle size of greater than 0.3 mm and less than or equal to 2.36 mm as a blade aggregate to prepare a bituminous mixture. The method can effectively solve the problems of large accumulation amount, low recovery efficiency, difficulty in value-added application and the like of existing decommissioned wind turbine blades.

Description

A dual-effect application method of discarded wind turbine blades as asphalt road construction material

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of Chinese patent application No. 202311090320.6 filed on August 28, 2023, the contents of which are incorporated herein by reference. Technical Field

[0003] The present invention relates to the technical field of solid waste treatment, and in particular to a dual-effect application method of discarded wind turbine blades as asphalt road construction materials. Background Art

[0004] The large-scale development of my country's wind power industry began in 2004. According to preliminary market research, by the end of 2019, the national installed capacity reached 209 million kilowatts, with approximately 130,000 wind turbines. The blade composite material consumption for each kilowatt of wind turbine is generally around 15 kilograms, with a total composite material consumption of up to 350.4 million tons, and a service life generally expected to be 2025. With the rapid development of the wind energy industry, by 2025, my country's retired blades will reach 8,112 tons. After 2025, the total number of retired blades will increase rapidly, with the total amount expected to reach 412,784 tons in 2028 and approximately 715,664 tons in 2029. Therefore, how to effectively dispose of the waste from retired wind turbines has become an urgent issue.

[0005] Because wind turbine blades are made of thermoset glass fiber reinforced polymer (GFRP) composite materials, their primary characteristics are non-biodegradability, high temperature resistance, and corrosion resistance. Therefore, simple disposal methods such as stacking, landfilling, and incineration no longer meet the national policy requirements for environmental protection and resource utilization. To fully realize the resource recycling of wind turbine blades, several companies and researchers at home and abroad have applied their recycling to various applications. For example, a Danish company uses recycled blades to create bicycle sheds through design and cutting; a Dutch company uses them to create amusement pools; a Chinese company pulverizes blades for 3D printing and additive manufacturing of low-strength structures; and researchers at a Chinese university are also experimenting with pulverizing blades for wallboard manufacturing. While these recycling methods demonstrate significant social value, they still suffer from low consumption and low added value, making large-scale value-added applications difficult. At present, the recycling methods of retired wind turbine blades mainly include thermal recovery, chemical recovery and mechanical recovery. However, due to their physical and chemical properties such as insolubility, high modulus, etc., mechanical crushing is definitely one of the simplest and most feasible recycling methods in engineering applications.

[0006] With the large-scale and continuous retirement of wind turbine blades in my country over the next few years, the recycling market is expected to reach a peak and maintain a long-term trend, and the comprehensive disposal of retired blades will gradually become a normal issue. According to domestic research, there is currently no effective disposal solution for retired blades, and their large-scale, high-quality consumption is a prominent problem.

[0007] Summary of the Invention

[0008] The purpose of the present invention is to overcome the problem in the prior art that it is difficult to achieve large-scale value-added application of discarded wind turbine blades, and to provide a dual-effect application method for discarded wind turbine blades and a method for preparing modified asphalt and asphalt mixture. This method can effectively solve the current problems of large accumulation of retired wind turbine blades, low recycling efficiency and difficulty in value-added application.

[0009] In order to achieve the above-mentioned object, the present invention provides a dual-effect application method of discarded wind turbine blades as asphalt road construction materials, which comprises the following steps:

[0010] (1) Removing the balsa wood and core material from discarded wind turbine blades to obtain recycled wind turbine blades;

[0011] (2) The recycled wind turbine blades are powdered and sieved, and the wind turbine blade powder with a particle size of ≤0.3 mm is used as an asphalt modifier, and the wind turbine blade particles with a particle size greater than 0.3 mm and less than or equal to 2.36 mm are used as blade aggregate to prepare asphalt mixture.

[0012] Preferably, in step (1), the glass fiber content in the discarded wind turbine blades is greater than 70% by weight.

[0013] Preferably, the method further comprises preparing modified asphalt by using the asphalt modifier, specifically by mechanically blending the modifier with molten matrix asphalt, wherein the modifier contains the asphalt modifier and an optional SBS modifier.

[0014] Preferably, the weight ratio of the modifier to the base asphalt is (1-10):100.

[0015] Preferably, the weight ratio of the asphalt modifier to the SBS modifier is (2-6):1.

[0016] Preferably, the mechanical blending conditions include: temperature of 150-210° C. and time of 100-300 min.

[0017] Preferably, the method also includes preparing an asphalt mixture using the aggregate, specifically: preheating the blade aggregate, limestone aggregate and mineral powder, and then mixing the preheated blade aggregate, limestone aggregate and mineral powder with molten asphalt, wherein the asphalt is the modified asphalt and / or matrix asphalt.

[0018] Preferably, the ratio of the weight of the asphalt to the total weight of the blade aggregate, the limestone aggregate and the mineral powder is (4-6):100.

[0019] Preferably, the preheating conditions of the blade aggregate, the limestone aggregate and the mineral powder include: a temperature of 170-210° C. and a time of 1-8 hours.

[0020] Preferably, the preparation process of the molten asphalt comprises: heating the asphalt at 165-190° C. to a molten state.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The dual-effect application method of discarded wind turbine blades provided by the present invention is a green and harmless retired wind turbine blade recycling solution that can be developed on a large scale and utilized as a resource. It has significant economic benefits and engineering value, and has huge environmental, economic and social benefits. This method uses retired wind turbine blades as the main raw material to prepare both asphalt modifiers for asphalt road construction and aggregates for asphalt mixtures, achieving dual-effect utilization of retired wind turbine blades, killing two birds with one stone, and realizing large-scale development and resource utilization of discarded wind turbine blades. At the same time, the use of the prepared asphalt modifier can reduce the use of SBS modifiers, and the prepared aggregates replace the use of traditional basalt aggregates in asphalt mixtures, which can significantly reduce the economic costs incurred in road construction. DETAILED DESCRIPTION

[0023] The following is a detailed description of the specific embodiments of the present invention. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention and are not intended to limit the present invention.

[0024] The endpoints of the ranges and any values ​​disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoints of each range, the endpoints of each range and individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered to be specifically disclosed herein.

[0025] The present invention provides a dual-effect application method for discarded wind turbine blades, which comprises the following steps:

[0026] (1) Removing the balsa wood and core material from discarded wind turbine blades to obtain recycled wind turbine blades;

[0027] (2) The recycled wind turbine blades are powdered and sieved, and the wind turbine blade powder with a particle size of ≤0.3 mm is used as an asphalt modifier, and the wind turbine blade particles with a particle size greater than 0.3 mm and less than or equal to 2.36 mm are used as blade aggregate to prepare asphalt mixture.

[0028] The discarded wind turbine blades mainly contain glass fiber, resin, PVC core material and balsa wood. In order to achieve the dual-effect application described in the present invention, the balsa wood part and PVC core material in the discarded wind turbine blades need to be removed before processing the discarded wind turbine blades.

[0029] In the dual-effect application method described in the present invention, after the specific components in the discarded wind turbine blades are powdered and screened, the specific small-particle size (≤0.3mm) wind turbine blade powder and the specific large-particle size (greater than 0.3mm and less than or equal to 2.36mm) wind turbine blade particles are used as asphalt modifiers for asphalt road construction and small-particle aggregates for preparing asphalt mixtures, respectively, to achieve large-scale development and resource utilization of discarded wind turbine blades.

[0030] In the present invention, the pulverization and screening can be performed using conventional equipment and methods, or according to independently developed methods, as long as wind turbine blade powder with a particle size of ≤0.3 mm and wind turbine blade particles with a particle size greater than 0.3 mm and less than or equal to 2.36 mm can be obtained, respectively. In specific operations, the recycled wind turbine blades are pulverized and then passed through a 2.36 mm sieve to remove the undersize material; then passed through a 0.3 mm sieve to remove the undersize material to obtain wind turbine blade powder with a particle size of ≤0.3 mm, and the oversize material is removed to obtain wind turbine blade particles with a particle size greater than 0.3 mm and less than or equal to 2.36 mm.

[0031] In some preferred embodiments, in step (1), the glass fiber content in the discarded wind turbine blades is greater than 70% by weight.

[0032] Furthermore, the method also includes preparing modified asphalt using the asphalt modifier, specifically: mechanically blending the modifier with molten matrix asphalt, wherein the modifier contains the asphalt modifier (i.e., wind turbine blade powder with a particle size of ≤0.3mm) and an optional SBS modifier.

[0033] In the present invention, the asphalt modifier can be used alone or in combination with an SBS modifier. Herein, the SBS modifier is a well-known modifier in the art and can be purchased commercially.

[0034] In order to obtain modified asphalt that meets road use requirements, it is necessary to reasonably control the usage ratio of the modifier to the base asphalt. In some preferred embodiments, the weight ratio of the modifier to the base asphalt can be (1-10):100.

[0035] When the modifier is the asphalt modifier (i.e. wind turbine blade powder with a particle size of ≤0.3 mm) mentioned above and compounded with an SBS modifier, preferably, the weight ratio of the asphalt modifier to the SBS modifier can be (2-6):1.

[0036] In some specific embodiments, the temperature of the mechanical blending can be 150-210° C., and the time of the mechanical blending can be 100-300 min.

[0037] In a preferred embodiment, the step of mechanical blending is:

[0038] 1) High-speed stirring is performed using a high-speed shearing device at a shear rate of 2500-4000 r / min, a stirring time of 40-60 min, and a stirring temperature of 150-210° C.;

[0039] 2) low-speed stirring is performed by a low-speed shearing device, with a shear rate of 200-1500 r / min, a stirring time of 60-240 min, and a stirring temperature of 150-210° C.

[0040] Furthermore, the method also includes preparing an asphalt mixture using the blade aggregate, specifically: preheating the blade aggregate (i.e., wind turbine blade particles with a particle size greater than 0.3 mm and less than or equal to 2.36 mm), limestone aggregate and mineral powder, and then mixing the preheated blade aggregate, limestone aggregate and mineral powder with molten asphalt, wherein the asphalt is the modified asphalt (i.e., the modified asphalt prepared by the asphalt modifier as described above) and / or matrix asphalt.

[0041] In asphalt mixtures, aggregates include large-size aggregates and small-size aggregates, and the composition of the aggregates depends on the specific type of asphalt mixture. In the present invention, the asphalt mixture mix can be designed based on, but not limited to, AC-type dense-graded asphalt mixtures used for highway pavement. Conventional limestone aggregate serves as the large-size aggregate, while the blade aggregate described in the present invention (i.e., wind turbine blade particles with a particle size greater than 0.3 mm and less than or equal to 2.36 mm) can serve as the small-size aggregate.

[0042] In a specific embodiment, the particle size of the mineral powder and the particle size of the limestone aggregate can refer to the particle size of the mineral powder and the limestone aggregate used in the preparation of different types of asphalt mixtures in the art, which will not be repeated here. For example, reference can be made to the standard JTG F40-2004 "Technical Specifications for Highway Asphalt Pavement Construction".

[0043] During the preparation of an asphalt mixture using the blade aggregate, the asphalt can be a conventional base asphalt or a modified asphalt prepared using the asphalt modifier described above. Preferably, the asphalt is the modified asphalt described above. In a preferred embodiment, the weight ratio of the asphalt to the total weight of the blade aggregate, the limestone aggregate, and the mineral powder can be (4-6):100, for example, 4:100, 4.5:100, 5:100, 5.5:100, or 6:100.

[0044] In a more preferred embodiment, the amount of the mineral powder is 4-6 weight % of the total weight of the blade aggregate, the limestone aggregate and the mineral powder, for example, it can be 4 weight %, 4.5 weight %, 5 weight %, 5.5 weight % or 6 weight %.

[0045] In a more preferred embodiment, the amount of the blade aggregate is 18-25 weight % of the total weight of the blade aggregate, the limestone aggregate and the mineral powder, for example, it can be 18 weight %, 19 weight %, 20 weight %, 21 weight %, 22 weight %, 23 weight %, 24 weight % or 25 weight %.

[0046] In some specific embodiments, the method for preparing asphalt mixture specifically includes: first preheating the blade aggregate, limestone aggregate and mineral powder to preheat the asphalt to a molten state; then adding the molten asphalt and mineral powder to the blade aggregate and limestone aggregate in sequence and mixing them to obtain an asphalt mixture.

[0047] In a preferred embodiment, the preheating temperature of the blade aggregate, the limestone aggregate and the mineral powder may be 170-210° C., and the preheating time of the blade aggregate, the limestone aggregate and the mineral powder may be 1-8 hours.

[0048] In a preferred embodiment, the preparation process of the molten asphalt includes: heating the asphalt at 165-190° C. to a molten state.

[0049] In some more preferred embodiments, the method for preparing asphalt mixture specifically includes:

[0050] S1. Mix the preheated blade aggregate and limestone aggregate at 180-195°C for 5-25 seconds;

[0051] S2. Adding molten asphalt to the blade aggregate and limestone aggregate and continuing to mix for 10-60 seconds;

[0052] S3. Add the preheated mineral powder to the mixture of asphalt, blade aggregate and limestone aggregate and mix for 60-300 seconds to obtain an asphalt mixture.

[0053] The present invention will be described in detail below through examples, but the protection scope of the present invention is not limited thereto.

[0054] In the following embodiments and comparative examples, the discarded wind turbine blades are blades retired from a domestic wind farm; the matrix asphalt used is No. 70 matrix asphalt provided by a domestic company, the limestone aggregate is limestone crushed stone provided by a domestic factory, and the mineral powder is limestone fine powder provided by a domestic factory.

[0055] Example 1

[0056] Powdering and sieving:

[0057] The balsa wood and core material of discarded wind turbine blades with a glass fiber content of 75% by weight are removed to obtain recycled wind turbine blades, which are then powdered and sieved. The sieved wind turbine blade powder with a particle size of ≤0.3mm is used as an asphalt modifier, and the sieved wind turbine blade particles with a particle size greater than 0.3mm and less than or equal to 2.36mm are used as blade aggregates to prepare asphalt mixture.

[0058] Preparation of modified asphalt:

[0059] 2000g of base asphalt was heated and melted at a melting temperature of 170°C for 70 minutes. Then, 40g of asphalt modifier was added to the molten base asphalt. Mechanical blending was first performed using a high-speed shear device at 170°C with a shear rate of 3000r / min and high-speed stirring for 60 minutes. Subsequently, the mixture was transferred to a low-speed shear device and continued to be stirred at 170°C for 3 hours with a shear rate of 500r / min to ensure that the asphalt modifier was fully dispersed or dissolved and swelled in the base asphalt. Finally, modified asphalt was obtained.

[0060] Preparation of asphalt mixture:

[0061] According to the AC type dense-graded asphalt mixture for highway pavement, 20 kg of blade aggregate, limestone aggregate and mineral powder of corresponding sizes were weighed (wherein the blade aggregate content was 22 wt% and the mineral powder content was 5 wt%), and placed in an oven at 180°C for preheating for 3 hours. 1 kg of the modified asphalt prepared above was heated to a molten state at 170°C. Then, the preheated blade aggregate and limestone aggregate were added to a stirring pot at 185°C and stirred for 10 seconds. The molten modified asphalt was then added to the stirring pot and stirred for 20 seconds. Finally, the preheated mineral powder was added and continued to be stirred. After 90 seconds, the machine was stopped and the material was discharged to obtain an asphalt mixture.

[0062] Example 2

[0063] Powdering and sieving:

[0064] The balsa wood and core material of discarded wind turbine blades with a glass fiber content of 80% by weight are removed to obtain recycled wind turbine blades, which are then powdered and sieved. The sieved wind turbine blade powder with a particle size of ≤0.3mm is used as an asphalt modifier, and the sieved wind turbine blade particles with a particle size greater than 0.3mm and less than or equal to 2.36mm are used as blade aggregates to prepare asphalt mixture.

[0065] Preparation of modified asphalt:

[0066] 2000g of base asphalt was heated and melted at a melting temperature of 170°C for 70 minutes. Then, 60g of asphalt modifier was added to the molten base asphalt. Mechanical blending was first performed using a high-speed shear device at 180°C with a shear rate of 3500r / min and high-speed stirring for 60 minutes. Subsequently, the mixture was transferred to a low-speed shear device and continued to be stirred at 180°C for 3 hours with a shear rate of 500r / min to ensure that the asphalt modifier was fully dispersed or dissolved and swelled in the base asphalt. Finally, modified asphalt was obtained.

[0067] Preparation of asphalt mixture:

[0068] According to the AC type dense-graded asphalt mixture for highway pavement, 20 kg of blade aggregate, limestone aggregate and mineral powder of corresponding sizes were weighed (wherein the blade aggregate content was 22 wt% and the mineral powder content was 5 wt%), and placed in an oven at 185°C for preheating for 4 hours. 1 kg of the modified asphalt prepared above was heated to a molten state at 170°C. Then, the preheated blade aggregate and limestone aggregate were added to a stirring pot at 185°C and stirred for 20 seconds. The molten modified asphalt was then added to the stirring pot and stirred for 30 seconds. Finally, the preheated mineral powder was added and continued to be stirred. After 160 seconds, the machine was stopped and the material was discharged to obtain an asphalt mixture.

[0069] Example 3

[0070] Powdering and sieving:

[0071] The balsa wood and core material of discarded wind turbine blades with a glass fiber content of 85% by weight are removed to obtain recycled wind turbine blades, which are then powdered and sieved. The sieved wind turbine blade powder with a particle size of ≤0.3mm is used as an asphalt modifier, and the sieved wind turbine blade particles with a particle size greater than 0.3mm and less than or equal to 2.36mm are used as blade aggregates to prepare asphalt mixture.

[0072] Preparation of modified asphalt:

[0073] 2000g of base asphalt was heated and melted at a melting temperature of 170°C for 70 minutes. Then, 80g of asphalt modifier was added to the molten base asphalt. Mechanical blending was first performed using a high-speed shear device at 175°C with a shear rate of 3000r / min and high-speed stirring for 100 minutes. Subsequently, the mixture was transferred to a low-speed shear device and continued to be stirred at 175°C for 3 hours with a shear rate of 800r / min to ensure that the asphalt modifier was fully dispersed or dissolved and swelled in the base asphalt. Finally, modified asphalt was obtained.

[0074] Preparation of asphalt mixture:

[0075] According to the AC type dense-graded asphalt mixture for highway pavement, 20 kg of blade aggregate, limestone aggregate and mineral powder of corresponding sizes were weighed (wherein the blade aggregate content was 22 weight % and the mineral powder content was 5 weight %), and placed in a 190°C oven for preheating for 6 hours. 1 kg of the modified asphalt prepared above was heated to a molten state at 180°C. Then, the preheated blade aggregate and limestone aggregate were added to a stirring pot at 190°C and stirred for 15 seconds. The molten modified asphalt was then added to the stirring pot and stirred for 25 seconds. Finally, the preheated mineral powder was added and continued to be stirred. After 100 seconds, the machine was stopped and the material was discharged to obtain an asphalt mixture.

[0076] Example 4

[0077] Powdering and sieving:

[0078] The balsa wood and core material of discarded wind turbine blades with a glass fiber content of 75% by weight are removed to obtain recycled wind turbine blades, which are then powdered and sieved. The sieved wind turbine blade powder with a particle size of ≤0.3mm is used as an asphalt modifier; the sieved wind turbine blade particles with a particle size greater than 0.3mm and less than or equal to 2.36mm are used as blade aggregates to prepare asphalt mixture.

[0079] Preparation of modified asphalt:

[0080] 2000g of base asphalt was heated and melted at a melting temperature of 170°C for 70 minutes. Then, 32g of asphalt modifier and 8g of SBS modifier were added to the molten base asphalt. Mechanical blending was first performed using a high-speed shear device at 170°C with a shear rate of 3000r / min and high-speed stirring for 60 minutes. Subsequently, the mixture was transferred to a low-speed shear device and continued to be stirred at 170°C for 3 hours with a shear rate of 500r / min to ensure that the asphalt modifier was fully dispersed or dissolved and swelled in the base asphalt. Finally, modified asphalt was obtained.

[0081] Preparation of asphalt mixture:

[0082] According to the AC type dense-graded asphalt mixture for highway pavement, 20 kg of blade aggregate, limestone aggregate and mineral powder of corresponding sizes were weighed (wherein the blade aggregate content was 22 weight % and the mineral powder content was 5 weight %), and placed in an oven at 180°C for preheating for 3 hours. 1 kg of the modified asphalt prepared above was heated at 170°C to a molten state; then, the preheated blade aggregate and limestone aggregate were added to a stirring pot at 185°C and stirred for 10 seconds, and then the molten modified asphalt was added to the stirring pot and stirred for 20 seconds; finally, the preheated mineral powder was added and continued to be stirred. After 90 seconds, the machine was stopped and the material was discharged to obtain an asphalt mixture.

[0083] Example 5

[0084] Powdering and sieving:

[0085] The balsa wood and core material of discarded wind turbine blades with a glass fiber content of 80% by weight are removed to obtain recycled wind turbine blades, which are then powdered and sieved. The sieved wind turbine blade powder with a particle size of ≤0.3mm is used as an asphalt modifier; the sieved wind turbine blade particles with a particle size greater than 0.3mm and less than or equal to 2.36mm are used as blade aggregates to prepare asphalt mixture.

[0086] Preparation of modified asphalt:

[0087] 2000g of base asphalt was heated and melted at a melting temperature of 170°C for 70 minutes. Then, 48g of asphalt modifier and 12g of SBS modifier were added to the molten base asphalt. Mechanical blending was first performed using a high-speed shear device at 170°C with a shear rate of 3500r / min and high-speed stirring for 60 minutes. Subsequently, the mixture was transferred to a low-speed shear device and continued to be stirred at 170°C for 3 hours with a shear rate of 800r / min to ensure that the asphalt modifier was fully dispersed or dissolved and swelled in the base asphalt. Finally, modified asphalt was obtained.

[0088] Preparation of asphalt mixture:

[0089] According to the AC type dense-graded asphalt mixture for highway pavement, 20 kg of blade aggregate, limestone aggregate and mineral powder of corresponding sizes were weighed (wherein the blade aggregate content was 22 wt% and the mineral powder content was 5 wt%), and placed in a 190°C oven for preheating for 4 hours. 1 kg of the modified asphalt prepared above was heated to a molten state at 170°C. Then, the preheated blade aggregate and limestone aggregate were added to a stirring pot at 185°C and stirred for 13 seconds. The molten modified asphalt was then added to the stirring pot and stirred for 25 seconds. Finally, the preheated mineral powder was added and continued to be stirred. After 120 seconds, the machine was stopped and the materials were discharged to obtain an asphalt mixture.

[0090] Comparative Example 1

[0091] The method of Example 1 is implemented, except that in step (1), only the core material of the discarded wind turbine blade is removed, and the balsa wood is not removed, to obtain a recycled wind turbine blade.

[0092] Comparative Example 2

[0093] The method of Example 1 is followed, except that the sieved wind turbine blade powder with a particle size of 0.3 to 0.5 mm is used as an asphalt modifier, and the sieved wind turbine blade particles with a particle size of 0.6 to 1.18 mm are used as blade aggregate to prepare the asphalt mixture.

[0094] Test Example 1

[0095] Softening point: According to the test method of T 0606 in the "Testing Procedure for Asphalt and Asphalt Mixtures in Highway Engineering" (JTG E20-2011), the softening point of the modified asphalt in the examples and comparative examples was tested using the ring and ball method. The test results are shown in Table 1. Specific testing process: (1) Place the sample ring containing the asphalt sample together with the sample base plate in a constant temperature water tank filled with 5℃±0.5℃ water for at least 15 minutes; (2) Pour freshly boiled water cooled to 5℃ into a beaker, with the water surface slightly lower than the depth mark on the vertical pole; (3) Place the sample ring containing the asphalt sample in step (1) in the circular hole of the middle plate of the bracket, put on the positioning ring, and place it in the beaker, and maintain the water temperature at 5℃±0.5℃. (4) Place the steel ball in the center of the sample in the middle of the positioning ring, immediately start the electromagnetic oscillator to make the water oscillate slightly, and start heating. Adjust the water temperature in the cup to maintain a rise of 5℃±0.5℃ per minute within 3 minutes; (5) The asphalt sample softens due to heat and gradually falls. When it contacts the surface of the lower bottom plate, read the temperature immediately.

[0096] Ductility: Ductility tests were conducted on the modified asphalts in the examples and comparative examples according to the test method T 0605 in the "Test Procedure for Asphalt and Asphalt Mixtures in Highway Engineering" (JTG E20-2011), using test temperatures of 5°C and 10°C and a tensile speed of 5 cm / min±0.25 cm / min. The test results are shown in Table 1. Specific testing procedures: (1) Prepare a ductility test specimen and place it in a ductility tester water tank at 10°C for at least 1.5 hours; (2) Place the specimen in the test area, remove the side mold, and secure the mold end; (3) Start the test for constant temperature stretching, keep the equipment stable, and record the tensile length at break in cm.

[0097] Viscosity: According to the test method of T 0625 in the "Testing Procedure for Asphalt and Asphalt Mixtures in Highway Engineering" (JTG E20-2011), the ductility test of the modified asphalt in the examples and comparative examples was conducted at a test temperature of 135°C. The test results are shown in Table 1. Specific testing procedures: (1) Place the asphalt sample in a viscosity test sample container and keep it warm for 1.5 hours; (2) Insert the selected rotor into the asphalt liquid level in the container to the specified height and continue to keep it warm for more than 15 minutes; (3) Start the viscosity test, observe the change in the viscosity value, read and record the value after it stabilizes, and determine the average of the three readings.

[0098] Table 1

[0099] As shown in Table 1, the modified asphalt prepared using the asphalt modifier described herein exhibits a slight increase in softening point, a slight decrease in ductility, and a slight increase in viscosity. This indicates that the blade modifier has a positive effect on the high-temperature performance of asphalt, does not significantly reduce the asphalt's ductility, and does not significantly affect the workability of the modified asphalt, thus meeting the requirements of asphalt road construction materials. Furthermore, the use of the blade modifier in conjunction with the SBS modifier (Examples 4 and 5) shows no signs of degradation in the modified asphalt's performance, demonstrating that the blade modifier can synergistically enhance the performance of asphalt materials.

[0100] Test Example 2

[0101] Immersion Marshall stability test method: The test was conducted according to the test method T 0709 in the "Test Procedure for Asphalt and Asphalt Mixtures in Highway Engineering" (JTG E20-2011). The results are shown in Table 2.

[0102] Dynamic stability test method: The test was conducted according to the test method T 0719 in the "Test Procedure for Asphalt and Asphalt Mixtures in Highway Engineering" (JTG E20-2011). The results are shown in Table 2.

[0103] Maximum flexural strain test method: The test was conducted according to the test method T 0715 in the "Test Procedure for Asphalt and Asphalt Mixtures in Highway Engineering" (JTG E20-2011). The test temperature was -10°C. The results are shown in Table 2.

[0104] Table 2

[0105] From the results in Table 2, it can be seen that after the asphalt modifier and blade aggregate of the present invention are used in asphalt mixture, the water-immersion Marshall residual stability is significantly improved, the water-immersion Marshall residual stability of the asphalt mixture meets the road use requirements (≥80%), and the water stability of the road surface is enhanced. At the same time, the dynamic stability of the asphalt mixture also significantly exceeds the standard requirement of 1000 times / mm, indicating that the waste blades can improve the high-temperature stability of the asphalt mixture when used as a modifier and aggregate. In addition, the maximum flexural strain of the asphalt mixture increases slightly, indicating that the waste blades will not affect the low-temperature bending performance of the asphalt mixture when used as a modifier and aggregate. It can be seen that the asphalt mixture prepared using the asphalt modifier and blade aggregate of the present invention has good road performance.

[0106] Test Case 3 Cost Comparison

[0107] In order to analyze the economic benefits of using asphalt modifiers made from discarded wind turbine blades in road engineering materials, SBS modifier, which is commonly used to improve the quality of asphalt pavement, was used as a comparison object.

[0108] Table 3 Cost comparison between asphalt modifier and SBS modifier prepared from discarded wind turbine blades

[0109] After analysis, it was found that the technical solution of using discarded wind turbine blades to prepare modified asphalt has significant economic benefits: the use of asphalt modifiers can reduce the use of SBS and greatly reduce the economic costs incurred in road construction.

[0110] Table 3 shows that the estimated price per tonne of asphalt modifier made from discarded wind turbine blades with a particle size of less than 0.3 mm is 1,615 yuan. Compared to the SBS modifier (15,800 yuan / ton), the profit from this asphalt modifier is 14,185 yuan / ton, demonstrating a clearly profitable, value-added application with significant economic benefits and engineering value.

[0111] For the above cost analysis, assuming that a 1km two-way four-lane road (length 1000m × width 12m × thickness 0.17m = 2040m) is laid 3) asphalt pavement, based on typical mix ratios, requires approximately 5,140.8 tons of asphalt mixture and 11.75 tons of modifier. Therefore, using SBS would cost approximately 185,700 yuan, while using asphalt modifier would only cost approximately 18,900 yuan, resulting in a profit of approximately 166,800 yuan.

[0112] In general, the use of discarded wind turbine blades to prepare modified asphalt and modified asphalt mixtures can generate significant economic benefits, achieve the goal of large-scale consumption to a large extent, and is an effective way to utilize resources and achieve environmental benefits.

[0113] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, various simple variations of the technical solution of the present invention may be made, including combining the various technical features in any other appropriate manner. These simple variations and combinations should also be regarded as disclosed in the present invention and fall within the scope of protection of the present invention.

Claims

1. A dual-effect application method of waste wind turbine blades as asphalt road construction materials, characterized in that: The method comprises the following steps: (1) Removing the balsa wood and core material of the discarded wind turbine blades to obtain recycled wind turbine blades; (2) The recycled wind turbine blades are powdered and sieved, and the wind turbine blade powder with a particle size of ≤0.3 mm is used as an asphalt modifier, and the wind turbine blade particles with a particle size greater than 0.3 mm and less than or equal to 2.36 mm are used as blade aggregates to prepare asphalt mixture.

2. The method according to claim 1, characterized in that In step (1), the glass fiber content in the discarded wind turbine blades is greater than 70% by weight.

3. The method according to claim 1 or 2, characterized in that: The method further comprises preparing modified asphalt by using the asphalt modifier, specifically, mechanically blending the modifier with molten base asphalt, wherein the modifier contains the asphalt modifier and an optional SBS modifier.

4. The method according to claim 3, characterized in that The weight ratio of the modifier to the base asphalt is (1-10):

100.

5. The method according to claim 4, characterized in that The weight ratio of the asphalt modifier to the SBS modifier is (2-6):

1.

6. The method according to claim 3, characterized in that The mechanical blending conditions include: temperature of 150-210° C. and time of 100-300 min.

7. The method according to claim 3, characterized in that The method also includes preparing an asphalt mixture using the blade aggregate, specifically: preheating the blade aggregate, limestone aggregate and mineral powder, and then mixing the preheated blade aggregate, limestone aggregate and mineral powder with molten asphalt, wherein the asphalt is the modified asphalt and / or base asphalt.

8. The method according to claim 7, characterized in that The ratio of the weight of the asphalt to the total weight of the blade aggregate, the limestone aggregate and the mineral powder is (4-6):

100.

9. The method according to claim 7 or 8, characterized in that: The preheating conditions of the blade aggregate, the limestone aggregate and the mineral powder include: a temperature of 170-210° C. and a time of 1-8 hours.

10. The method according to claim 7 or 8, characterized in that: The preparation process of the molten asphalt includes: heating the asphalt at 165-190° C. to a molten state.

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