WO2025043709A1 - Water damage resistant asphalt modifier, preparation method therefor and use thereof - Google Patents

Abstract

The present invention relates to the technical field of road building materials. Disclosed are a water damage resistant asphalt modifier, a preparation method therefor and a use thereof. The method for preparing the water damage resistant asphalt modifier comprises the following steps: S1: performing pulverization treatment on a decommissioned wind power blade and then performing sieving to obtain decommissioned wind power blade powder; S2, mixing the decommissioned wind power blade powder in step S1 with a silane coupling agent hydrolysis solution, and then drying to obtain siliconized decommissioned wind power blade powder; and S3, mixing the siliconized decommissioned wind power blade powder in step S2 with an elastomer, and then performing melt blending, crushing and sieving to obtain the water damage resistant asphalt modifier. The water damage resistant asphalt modifier is used for preparing modified asphalt and a modified asphalt mixture, and the working performance and the road performance of the modified asphalt and the modified asphalt mixture are significantly improved.

Description

A water-damage-resistant asphalt modifier and its preparation method and application

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of Chinese patent application 202311088004.5 filed on August 28, 2023, the contents of which are incorporated herein by reference.

Technical Field

The invention relates to the technical field of road construction materials, and in particular to an anti-water damage asphalt modifier and a preparation method and application thereof.

Background Art

FRP is a thermosetting composite material with glass fiber as reinforcing material and epoxy resin, unsaturated polyester resin and polyurethane resin as matrix resin. Waste FRP refers to the waste scraps, substandard products and composite materials that cannot meet the working performance requirements and need to be disposed of in the production, transportation, sales and use of FRP-related industries and enterprises. The traditional treatment methods of waste FRP include landfill and burning, but the above treatment methods do not fully utilize the mechanical properties and residual value of waste FRP, and also require a large amount of land resources, and cause serious pollution to groundwater and air. Retired wind turbine blades contain a large amount of glass fiber. Faced with a large number of retired wind turbine blades in the future, how to reuse them in a resource-based and high-value manner has become a problem of general concern in the industry. Therefore, it is of great significance to develop a low-cost and high-efficiency method for regenerating retired wind turbine blades and make them into products with high added value and meeting performance requirements.

In order to improve the quality of asphalt pavement and extend the life of asphalt pavement, the international community proposed the use of SBS modified asphalt for pavement in the 1990s. SBS is a thermoplastic copolymer with a triblock structure formed by the polymerization reaction of butadiene and styrene, which is divided into two types: linear structure and star structure. Under room temperature conditions, the polystyrene hard segment (PS segment) in the SBS macromolecular structure will aggregate with each other to form physical cross-linking points due to its high cohesive energy, making SBS exhibit rubber elasticity. Based on the unique structural characteristics and performance advantages of SBS, using it for asphalt modification can significantly improve the low-temperature cracking resistance and high-temperature rutting resistance of asphalt. Therefore, SBS modified asphalt has been widely used in the construction of high-grade highways.

Due to the high price of SBS, the cost of road construction remains high. In recent years, research has been conducted on how to use low-cost, high-quality new materials to replace the more expensive SBS while ensuring that the durability of asphalt pavement is not affected. However, there is currently no ideal modified asphalt material.

Summary of the invention

The purpose of the present invention is to overcome the problems of the prior art in that retired wind turbine blades are difficult to dispose of and the SBS modified asphalt is expensive, and to provide an anti-water damage asphalt modifier and a preparation method and application thereof. Water-damaged asphalt modifier has the characteristics of excellent performance, low price and simple preparation method.

In order to achieve the above object, the present invention provides a method for preparing a water damage resistant asphalt modifier, which comprises the following steps:

S1: Powdering and sieving the retired wind turbine blades to obtain retired wind turbine blade powder;

S2: mixing the retired wind turbine blade powder in step S1 with a silane coupling agent hydrolysis solution, and then drying to obtain siliconized retired wind turbine blade powder;

S3: The siliconized retired wind turbine blade powder in step S2 is mixed with an elastomer, and then melt-blended, crushed and sieved to obtain a water-damage resistant asphalt modifier.

Preferably, in step S1, the content of glass fiber in the retired wind turbine blade is greater than 70% by weight.

Preferably, in step S1, the particle size of the retired wind turbine blade powder is ≤0.3 mm.

Preferably, in step S2, the silane coupling agent hydrolysis solution is obtained by mixing the silane coupling agent, water and anhydrous ethanol, wherein the weight ratio of the silane coupling agent, water and anhydrous ethanol is 14-19:6-11:100.

Preferably, the weight ratio of the retired wind turbine blade powder to the silane coupling agent is 100:10-20.

Preferably, in step S2, the mixing conditions include: temperature of 55-85° C. and time of 10-60 min.

Preferably, in step S3, the weight ratio of the siliconized retired wind turbine blade powder to the elastomer is 100:15-45.

Preferably, the elastomer is selected from SBR, SBS, SIS, SEBS, IIR or EVA.

Preferably, in step S3, the conditions for melt blending include: temperature of 50-70°C, rotation speed of 40-70 rpm, and time of 15-40 min.

Preferably, the crushing is freeze-crushing.

Preferably, in step S3, the particle size of the water-damage resistant asphalt modifier is ≤0.3 mm.

The second aspect of the present invention provides a water damage resistant asphalt modifier prepared by the above method.

The third aspect of the present invention provides a modified asphalt, which comprises a base asphalt and a modifier, wherein the modifier is the water damage resistant asphalt modifier described above and optionally SBS.

Preferably, the weight ratio of the modifier to the base asphalt is 1-20:100.

A fourth aspect of the present invention provides a method for preparing the modified asphalt described above, the method comprising: mechanically mixing the modifier with the molten base asphalt.

A fifth aspect of the present invention provides a modified asphalt mixture, which comprises modified asphalt, aggregate and mineral powder; wherein the modified asphalt is the modified asphalt described above.

A sixth aspect of the present invention provides a method for preparing the modified asphalt mixture as described above, the method comprising the following steps:

(1) Preheating aggregate and mineral powder, and preheating modified asphalt to a molten state;

(2) Add the molten modified asphalt and mineral powder to the aggregate in turn and mix them.

Compared with the prior art, the present invention has the following advantages:

(1) In the method described in the present invention, the silanol groups generated by the hydrolysis of the silane coupling agent react with the silanol groups on the surface of the retired wind turbine blade powder, thereby increasing the non-polar groups on the surface of the retired wind turbine blade powder. The retired wind turbine blade powder is then melt-blended with the elastomer in a certain ratio so that the elastomer interacts with the non-polar groups on its surface to achieve chemical coating modification. The retired wind turbine blade powder is synergistically treated with the silane coupling agent and the elastomer to improve the compatibility of the retired wind turbine blade powder with asphalt. The prepared anti-water damage asphalt modifier is used to prepare modified asphalt by the above method, which can increase the softening temperature of asphalt to a certain extent without significantly increasing the viscosity and affecting the working performance of the modified asphalt. The prepared modified asphalt is used to prepare a modified asphalt mixture, which can significantly improve the water stability of the asphalt mixture, while improving the permanent deformation resistance, high temperature performance and low temperature performance of the asphalt mixture, thereby achieving the high-quality improvement effect of the wind turbine blade asphalt modifier on the asphalt mixture.

(2) The water-damage resistant asphalt modifier prepared by the method of the present invention is low-cost and can be used to partially or completely replace the common polymer modifiers in the asphalt pavement field. It has significant cost advantages and can greatly reduce the economic costs incurred in road construction.

(3) The method described in the present invention uses retired wind turbine blades as the main raw material to prepare asphalt modifiers, which can effectively solve the serious problems such as resource waste and environmental pollution caused by the wave of wind turbine blade retirement, and realize the large-scale development and resource utilization of retired wind turbine blades. It is a green and efficient recycling solution with significant economic benefits and engineering value.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a process flow chart of a method for preparing a water-damage resistant asphalt modifier according to the present invention;

FIG2 is a SEM image of the retired wind turbine blade powder prepared in Example 1 of the present invention, magnified 500 times;

FIG3 is a SEM image of the retired electric blade powder prepared in Example 1 of the present invention, magnified 5000 times;

FIG4 is a SEM image of the water damage resistant asphalt modifier prepared in Example 1 of the present invention, magnified 500 times;

FIG5 is a SEM image of the water-damage resistant asphalt modifier prepared in Example 1 of the present invention, magnified 5000 times.

DETAILED DESCRIPTION

The specific implementation of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described herein is only used to illustrate and explain the present invention, and is not used to limit the present invention.

The endpoints and any values of the ranges disclosed in this article 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 endpoint values of each range, the endpoint values of each range and the 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 regarded as specifically disclosed in this article.

In one aspect, the present invention provides a method for preparing a water-damage resistant asphalt modifier, as shown in FIG. The following steps are involved:

S1: Powdering and sieving the retired wind turbine blades to obtain retired wind turbine blade powder;

S2: mixing the retired wind turbine blade powder in step S1 with a silane coupling agent hydrolysis solution, and then drying to obtain siliconized retired wind turbine blade powder;

S3: The siliconized retired wind turbine blade powder in step S2 is mixed with an elastomer, and then melt-blended, crushed and sieved to obtain a water-damage resistant asphalt modifier.

In the present invention, the main components of the retired wind turbine blades are glass fiber and epoxy resin.

In a preferred embodiment, in step S1, the content of glass fiber in the retired wind turbine blade is greater than 70% by weight.

In a preferred embodiment, in step S1, the retired wind turbine blades after the pulverization treatment are sieved through a 50-mesh sieve to obtain the sieved material, and the particle size of the obtained retired wind turbine blade powder is ≤0.3 mm.

In a preferred embodiment, in step S2, the silane coupling agent hydrolysis solution is obtained by mixing the silane coupling agent, water and anhydrous ethanol.

According to some embodiments of the present invention, in step S2, the silane coupling agent hydrolysis solution is obtained by adding the silane coupling agent to a mixture of anhydrous ethanol and water, mixing, and standing at room temperature (15-30° C.) for 10-60 minutes; specifically, the standing time can be 10 minutes, 20 minutes, 30 minutes, 40 minutes, 50 minutes or 60 minutes.

In order to improve the hydrolysis effect of the silane coupling agent, in a preferred embodiment, in step S2, the weight ratio of the silane coupling agent, water and anhydrous ethanol is 14-19:6-11:100; specifically, the weight ratio of the silane coupling agent, water and anhydrous ethanol can be 14:6:100, 14:7:100, 14:8:100, 14:9:100, 14:10:100, 14:11:100, 15:6:100, 15:7:100, 15:8:100, 15:9:100, 15:10:100, 15:11:100, 16:6:100, 1 100, 19:6:100, 19:7:100, 19:8:100, 19:9:100, 19:10:100 or 19:11:100.

In a preferred embodiment, in step S2, the mixing method is stirring in a water bath, and the conditions include: the water bath temperature is 55-85°C, and the stirring time is 10-60 min; specifically, the water bath temperature can be 55°C, 60°C, 65°C, 70°C, 75°C, 80°C or 85°C, and the stirring time can be 10 min, 20 min, 30 min, 40 min, 50 min or 60 min.

In a preferred embodiment, in step S2, the silane coupling agent is selected from one or more of KH550, KH560, and KH570.

In order to further improve the chemical modification effect of the retired wind turbine blade powder, in step S2, the weight ratio of the retired wind turbine blade powder to the silane coupling agent is 100:10-20; specifically, the weight ratio of the retired wind turbine blade powder to the silane coupling agent can be 100:10, 100:11, 100:11.7, 100:12, 100:12.2, 100:13, 100:14, 100:15, 100:16, 100:17, 100:17.5, 100:18, 100:19 or 100:20.

In a preferred embodiment, in step S2, drying is carried out in an oven, and the drying conditions include: a temperature of 85°C-125°C, and a time of 80min-180min; specifically, the temperature can be 85°C, 90°C, 95°C, 100°C, 105°C, 110°C, 115°C, 120°C or 125°C, and the time can be 80min, 100min, 120min, 140min, 160min or 180min.

In order to further improve the ability of the anti-water damage asphalt modifier and the matrix asphalt to combine, in a preferred embodiment, in step S3, the weight ratio of the siliconized retired wind turbine blade powder to the elastomer is 100:15-45; specifically, the weight ratio of the siliconized retired wind turbine blade powder to the elastomer can be 100:15, 100:20, 100:25, 100:30, 100:35, 100:38, 100:40 or 100:45.

In a preferred embodiment, the elastomer is selected from styrene-butadiene rubber (SBR), styrene-butadiene-styrene block copolymer (SBS), block copolymer of styrene and isoprene (SIS), hydrogenated styrene-butadiene block copolymer (SEBS), butyl rubber (IIR) or ethylene-vinyl acetate copolymer (EVA).

In a preferred embodiment, in step S3, the conditions for melt blending include: a temperature of 50-70°C, a rotation speed of 40-70rpm, and a time of 15-40min; specifically, the temperature may be 50°C, 55°C, 60°C, 65°C or 70°C, the rotation speed may be 40rpm, 45rpm, 50rpm, 55rpm, 60rpm, 65rpm or 70rpm, and the time may be 15min, 20min, 25min, 30min, 35min or 40min.

In a preferred embodiment, in step S3, the crushing is freeze crushing.

In a preferred embodiment, in step S3, the water-damage resistant asphalt modifier is sieved through a 50-mesh sieve to obtain the sieve residue, and the particle size of the water-damage resistant asphalt modifier is ≤0.3 mm.

The anti-water damage asphalt modifier prepared by the method described in the present invention improves the compatibility of the retired wind turbine blade powder with the matrix asphalt by treating the retired wind turbine blade powder with the silane coupling agent hydrolysis solution and the elastomer, thereby improving the performance of the asphalt, and then improving the working performance and road performance of the asphalt mixture. This may be because the treatment of the retired wind turbine blade powder with the silane coupling agent hydrolysis solution increases the non-polar groups on the surface of the retired wind turbine blade powder, allowing the elastomer to interact with the non-polar groups on its surface to achieve chemical coating modification, and the technical effect described in the present invention is achieved by the synergistic treatment of the retired wind turbine blade powder with the silane coupling agent and the elastomer.

The second aspect of the present invention provides a water damage resistant asphalt modifier prepared by the above method.

In the present invention, the water damage resistant asphalt modifier prepared by the above method can be used alone or mixed with an existing asphalt modifier, for example, it can be mixed with SBS.

The third aspect of the present invention provides a modified asphalt, which comprises a base asphalt and a modifier, wherein the modifier is the water damage resistant asphalt modifier described above and optionally SBS.

In a preferred embodiment, the weight ratio of the modifier to the base asphalt is 1-20:100, more preferably 3-10:100; specifically, the weight ratio of the modifier to the base asphalt can be 3:100, 4:100, 5:100, 6:100, 7:100, 8:100, 9:100 or 10:100.

In a preferred embodiment, when the modifier is the anti-water damage asphalt modifier and SBS described above, the weight of the anti-water damage asphalt modifier accounts for 30-100% of the total weight of the modifier; specifically, it can be 30%, 40%, 50%, 60%, 70%, 80%, 90% or 100%.

A fourth aspect of the present invention provides a method for preparing the modified asphalt described above, the method comprising: mechanically mixing the modifier with the molten base asphalt.

In order to improve the performance of the modified asphalt and ensure that the modifier is fully dispersed or dissolved and swelled in the base asphalt, in a preferred embodiment, the mechanical blending includes the following steps:

A1: High-speed shear stirring is performed by high-speed shearing equipment, with a shear rate of 2500-4000r/min, a stirring time of 40-60min, and a stirring temperature of 150-210℃;

A2: Low-speed shear stirring is performed by low-speed shear equipment, with a shear rate of 200-1500r/min, a stirring time of 60-240min, and a stirring temperature of 150-210°C.

In a specific embodiment, in step A1, the shear rate can be 2500r/min, 3000r/min, 3500r/min or 4000r/min; the stirring time can be 40min, 50min or 60min; the stirring temperature can be 150℃, 160℃, 170℃, 180℃, 190℃, 200℃ or 210℃.

In a specific embodiment, in step A2, the shear rate can be 200 r/min, 500 r/min, 800 r/min, 1000 r/min or 1500 r/min; the stirring time can be 60 min, 120 min, 180 min or 240 min; the stirring temperature can be 150°C, 160°C, 170°C, 180°C, 190°C, 200°C or 210°C.

A fifth aspect of the present invention provides a modified asphalt mixture, which comprises modified asphalt, aggregate and mineral powder; wherein the modified asphalt is the modified asphalt described above.

In the present invention, there is no special requirement for the selection of the aggregate and mineral powder, and they may be various aggregates and mineral powders conventionally used in the art.

A sixth aspect of the present invention provides a method for preparing the modified asphalt mixture as described above, the method comprising the following steps:

(1) Preheating aggregate and mineral powder, and preheating modified asphalt to a molten state;

(2) Add the molten modified asphalt and mineral powder to the aggregate in turn and mix them.

In a preferred embodiment, in step (1), the preheating temperature of the aggregate and the mineral powder is 170-210°C, the preheating time is 1-8h, and the preheating temperature of the modified asphalt to a molten state is 165-190°C; specifically, the preheating temperature of the aggregate and the mineral powder may be 170°C, 180°C, 190°C, 200°C or 210°C, the preheating time may be 1h, 2h, 3h, 4h, 5h, 6h, 7h or 8h, and the preheating temperature of the modified asphalt to a molten state may be 165°C, 170°C, 175°C, 180°C, 185°C or 190°C.

In order to improve the working performance and road performance of asphalt mixture, in a preferred embodiment, in step (1), the weight ratio of the total weight of the aggregate and the mineral powder to the modified asphalt is 100:4-6; specifically, the weight ratio of the total weight of the aggregate and the mineral powder to the modified asphalt can be 100:4, 100:4.5, 100:5, 100:5.5 or 100:6.

In a preferred embodiment, in step (1), the weight proportion of the mineral powder is 4-6% of the total weight of the aggregate and the mineral powder; specifically, it can be 4%, 4.5%, 5%, 5.5% or 6%.

In a preferred embodiment, step (2) specifically comprises the following steps:

B1: Mix the preheated aggregate for 5-25s;

B2: adding the molten modified asphalt to the material obtained in step B1, and then stirring for 10-60 seconds;

B3: Add the preheated mineral powder to the material obtained in step B2, and then stir for 60-300 seconds.

According to some embodiments of the present invention, the mixing processes in steps B1-B3 can all be performed in a stirring pot.

Further preferably, the mixing temperatures in steps B1-B3 are each independently 180-195°C; specifically, the mixing temperature may be 180°C, 185°C, 190°C or 195°C.

In a specific embodiment, in step B1, the mixing time can be 5s, 10s, 15s, 20s or 25s; in step B2, the mixing time can be 10s, 13s, 15s, 20s, 25s, 30s, 35s, 40s, 45s, 50s, SSs or 60s; in step B3, the mixing time can be 60s, 90s, 100s, 120s, 150s, 180s, 210s, 240s, 270s, 300s.

The following examples further illustrate the water damage resistance asphalt modifier and its preparation method and application described in the present invention. The examples are implemented based on the technical solution of the present invention, and provide detailed implementation methods and specific operation processes, but the protection scope of the present invention is not limited to the following examples.

The experimental methods of the following examples, unless otherwise specified, are all conventional methods in the art. The experimental materials of the following examples, unless otherwise specified, are all commercially available.

Table 1

Note: ^1.1 Modifier dosage is the percentage of modifier in the weight of base asphalt; ^2.2 Oil-stone ratio is the percentage of modified asphalt or base asphalt in the total weight of aggregate and mineral powder; ^3.3 SBS dosage is the percentage of SBS in the weight of modifier; ^4.4 Water damage resistant asphalt modifier dosage is the percentage of water damage resistant asphalt modifier in the weight of modifier.

Example 1

The modifier dosage, asphalt-to-stone ratio, SBS dosage and water damage resistance asphalt modifier dosage are shown in Table 1;

Preparation of anti-water damage asphalt modifier M1:

S1: Powder the retired wind turbine blades and sieve the sieve through a 50-mesh sieve to obtain the retired wind turbine blade powder (rWTB) with a particle size of ≤0.3 mm (see Figures 2 and 3 for the microscopic morphology);

S2: adding KH550 to a mixed solution of anhydrous ethanol and water, mixing the mixture, and then standing at room temperature for 20 minutes to obtain a silane coupling agent hydrolysis solution, wherein the weight ratio of KH550, water and anhydrous ethanol is 15:8:100, and then adding 100g of the rWTB obtained in step S1 to 100g of the silane coupling agent hydrolysis solution, stirring in a 60°C water bath for 20 minutes, surface modifying the rWTB, and then drying in an oven at 105°C for 120 minutes to obtain siliconized retired wind turbine blade powder (Si-rWTB);

S3: 100 g of Si-rWTB obtained in step S2 was mixed with 20 g of styrene-butadiene rubber (SBR), and then melt blended at a temperature of 55° C., a rotation speed of 50 rpm, and a time of 20 min.

After the melt blending is completed, the mixture is frozen and crushed, and then sieved through a 50-mesh sieve to obtain the anti-water damage asphalt modifier M1 with a particle size of ≤0.3 mm;

Preparation of modified asphalt N1:

A1: 0.08 kg of the water damage resistance asphalt modifier M1 prepared above was added to 2 kg of molten base asphalt for mechanical blending. First, high-speed shear stirring was performed at 170°C using a high-speed shearing device with a shear rate of 3000 r/min and a stirring time of 60 min.

A2: Continue to transfer the product obtained in step A1 to a low-speed shear device for low-speed shear stirring at 170°C, with a shear rate of 500 r/min and a stirring time of 3 h to prepare modified asphalt N1;

Preparation of modified asphalt mixture L1:

(1) Select the AC type dense gradation commonly used in highway pavement, weigh 20 kg of aggregates of corresponding sizes and mineral powder (the weight proportion of mineral powder is 4%), and then preheat them in an oven at 180°C for 3 hours. At 170°C, preheat 0.8 kg of the modified asphalt N1 prepared above to a molten state;

(2) The aggregate was added into a stirring pot at 185°C and mixed for 10 seconds. Then, the molten modified asphalt N1 was added and mixed for another 20 seconds. Finally, the preheated mineral powder was added and mixed for another 90 seconds. The machine was stopped and the materials were unloaded to prepare the modified asphalt mixture L1.

Example 2

The modifier dosage, asphalt-to-stone ratio, SBS dosage and water damage resistance asphalt modifier dosage are shown in Table 1;

Preparation of anti-water damage asphalt modifier M2:

S1: Powder the retired wind turbine blades and sieve the sieve through a 50-mesh sieve to obtain the retired wind turbine blade powder (rWTB) with a particle size of ≤0.3 mm. The microscopic morphology thereof is shown in Figures 2 and 3;

S2: adding KH550 to a mixed solution of anhydrous ethanol and water, mixing the mixture, and then standing at room temperature for 30 minutes to obtain a silane coupling agent hydrolysis solution, wherein the weight ratio of KH550, water and anhydrous ethanol is 14:6:100, and then adding 100g of rWTB obtained in step S1 to 100g of the silane coupling agent hydrolysis solution, stirring in a 65°C water bath for 30 minutes, surface modifying the rWTB, and then drying in an oven at 95°C for 150 minutes to obtain siliconized retired wind turbine blade powder (Si-rWTB);

S3: 100 g of Si-rWTB obtained in step S2 was mixed with 25 g of styrene-butadiene rubber (SBR), and then melt blended at a temperature of 60° C., a rotation speed of 50 rpm, and a time of 25 min.

After the melt blending is completed, the mixture is frozen and crushed, and then sieved through a 50-mesh sieve to obtain the anti-water damage asphalt modifier M2 with a particle size of ≤0.3 mm;

Preparation of modified asphalt N2:

A1: 0.08 kg of the water damage resistance asphalt modifier M2 prepared above was added to 2 kg of molten base asphalt for mechanical blending. First, high-speed shear stirring was performed at 180°C using a high-speed shearing device with a shear rate of 3500 r/min and a stirring time of 60 min.

A2: Continue to transfer the product obtained in step A1 to a low-speed shear device for low-speed shear stirring at 180°C, with a shear rate of 500 r/min and a stirring time of 3 h to prepare modified asphalt N2;

Preparation of modified asphalt mixture L2:

(1) Select the AC type dense gradation commonly used in highway pavement, weigh 20 kg of aggregate of corresponding size and mineral powder (the weight proportion of mineral powder is 5%), and then preheat it in an oven at 185°C for 4 hours. At 170°C, preheat 1 kg of the modified asphalt N2 prepared above to a molten state;

(2) The aggregate was added into a stirring pot at 185°C and mixed for 20 seconds. Then, molten modified asphalt N2 was added and mixed for 30 seconds. Finally, preheated mineral powder was added and mixed for 160 seconds. The machine was stopped and the materials were unloaded to prepare modified asphalt mixture L2.

Example 3

The modifier dosage, asphalt-to-stone ratio, SBS dosage and water damage resistance asphalt modifier dosage are shown in Table 1;

Preparation of anti-water damage asphalt modifier M3:

S1: Powdering the retired wind turbine blades and sieving the sieve through a 50-mesh sieve to obtain the retired wind turbine blade powder (rWTB) with a particle size of ≤0.3 mm;

S2: KH550 is added to a mixed solution of anhydrous ethanol and water, and then allowed to stand at room temperature for 30 minutes to obtain a silane coupling agent hydrolysis solution, wherein the weight ratio of KH550, water and anhydrous ethanol is 19:11:100, and then 100g of rWTB obtained in step S1 is added to 120g of the silane coupling agent hydrolysis solution. The rWTB was surface modified by stirring in a 70°C water bath for 40 min, and then placed in an oven at 115°C for 100 min to obtain siliconized retired wind turbine blade powder (Si-rWTB).

S3: 100 g of Si-rWTB obtained in step S2 was mixed with 30 g of styrene-butadiene rubber (SBR), and then melt blended at a temperature of 65° C., a rotation speed of 55 rpm, and a time of 25 min.

After the melt blending is completed, the mixture is frozen and crushed, and then sieved through a 50-mesh sieve to obtain the anti-water damage asphalt modifier M3 with a particle size of ≤0.3 mm;

Preparation of modified asphalt N3:

A1: 0.08 kg of the water damage resistance asphalt modifier M3 prepared above was added to 2 kg of molten base asphalt for mechanical blending. First, high-speed shear stirring was performed at 175°C using a high-speed shearing device with a shear rate of 3000 r/min and a stirring time of 100 min.

A2: Continue to transfer the product obtained in step A1 to a low-speed shear device for low-speed shear stirring at 175°C, with a shear rate of 800 r/min and a stirring time of 3 h to prepare modified asphalt N3;

Preparation of modified asphalt mixture L3:

(1) Select the AC type dense gradation commonly used in highway pavement, weigh 20 kg of aggregates of corresponding sizes and mineral powder (the weight proportion of mineral powder is 6%), and then preheat them in an oven at 190°C for 6 hours. At 180°C, preheat 1.2 kg of the modified asphalt N3 prepared above to a molten state;

(2) The aggregate was added into a stirring pot at 190°C and mixed for 15 seconds. Then, the molten modified asphalt N3 was added and mixed for 25 seconds. Finally, the preheated mineral powder was added and mixed for 100 seconds. The machine was stopped and the materials were unloaded to prepare the modified asphalt mixture L3.

Example 4

The modifier dosage, asphalt-to-stone ratio, SBS dosage and water damage resistance asphalt modifier dosage are shown in Table 1;

Preparation of modified asphalt mixture L4:

(1) Select the AC type dense gradation commonly used in highway pavement, weigh 20 kg of aggregates of corresponding sizes and mineral powder, and then preheat them in an oven at 180° C. for 3 h. Preheat 1 kg of modified asphalt N1 prepared in Example 1 to a molten state at 170° C.;

(2) The aggregate was added into a stirring pot at 185° C. and mixed for 10 seconds. Then, the molten modified asphalt N1 was added and mixed for another 20 seconds. Finally, the preheated mineral powder was added and mixed for another 90 seconds. The machine was stopped and the materials were unloaded to prepare the modified asphalt mixture L4.

Example 5

The modifier dosage, asphalt-to-stone ratio, SBS dosage and water damage resistance asphalt modifier dosage are shown in Table 1;

Preparation of modified asphalt mixture L5:

(1) Use the AC type dense gradation commonly used in highway pavement, weigh 20 kg of aggregates of corresponding sizes and mineral powder, Then, preheat the mixture in an oven at 180°C for 3 hours, and preheat 1.2 kg of modified asphalt N1 prepared in Example 1 to a molten state at 170°C.

(2) The aggregate was added into a stirring pot at 185°C and mixed for 10 seconds. Then, the molten modified asphalt N1 was added and mixed for another 20 seconds. Finally, the preheated mineral powder was added and mixed for another 90 seconds. The machine was stopped and the materials were unloaded to prepare the modified asphalt mixture L5.

Example 6

The modifier dosage, asphalt-to-stone ratio, SBS dosage and water damage resistance asphalt modifier dosage are shown in Table 1;

Preparation of modified asphalt N6:

A1: 0.1 kg of the anti-water damage asphalt modifier M2 prepared in Example 2 was added to 2 kg of molten base asphalt for mechanical blending. First, high-speed shear stirring was performed at 180° C. using a high-speed shearing device, with a shear rate of 3500 r/min and a stirring time of 60 min.

A2: Continue to transfer the product obtained in step A1 to a low-speed shear device for low-speed shear stirring at 180°C, with a shear rate of 500 r/min and a stirring time of 3 h to prepare modified asphalt N6;

Preparation of modified asphalt mixture L6:

(1) Select the AC type dense gradation commonly used in highway pavement, weigh 20 kg of aggregates of corresponding sizes and mineral powder (the weight proportion of mineral powder is 5%), and then preheat them in an oven at 185°C for 4 hours. Preheat 1 kg of the modified asphalt N6 prepared above to a molten state at 170°C;

(2) The aggregate was added into a stirring pot at 185°C and mixed for 20 seconds. Then, the molten modified asphalt N6 was added and mixed for 30 seconds. Finally, the preheated mineral powder was added and mixed for 160 seconds. The machine was stopped and the materials were unloaded to prepare the modified asphalt mixture L6.

Example 7

The modifier dosage, asphalt-to-stone ratio, SBS dosage and water damage resistance asphalt modifier dosage are shown in Table 1;

Preparation of modified asphalt N7:

A1: 0.12 kg of the water damage resistant asphalt modifier M2 prepared in Example 2 was added to 2 kg of molten base asphalt for mechanical blending. First, high-speed shear stirring was performed at 180° C. using a high-speed shearing device, with a shear rate of 3500 r/min and a stirring time of 60 min.

A2: Continue to transfer the product obtained in step A1 to a low-speed shear device for low-speed shear stirring at 180°C, with a shear rate of 500 r/min and a stirring time of 3 h to prepare modified asphalt N7;

Preparation of modified asphalt mixture L7:

(1) Select the AC type dense gradation commonly used in highway pavement, weigh 20 kg of aggregates of corresponding sizes and mineral powder (the weight proportion of mineral powder is 5%), and then preheat them in an oven at 185°C for 4 hours. Preheat 1 kg of the modified asphalt N7 prepared above to a molten state at 170°C;

(2) The aggregate was added into a stirring pot at 185°C and mixed for 20 seconds. Then, the molten modified asphalt N7 was added and mixed for 30 seconds. Finally, the preheated mineral powder was added and mixed for 160 seconds. The machine was stopped and the materials were unloaded to prepare the modified asphalt mixture L7.

Example 8

The modifier dosage, asphalt-to-stone ratio, SBS dosage and water damage resistance asphalt modifier dosage are shown in Table 1;

Preparation of modified asphalt N8:

A1: 0.03 kg of the water damage resistant asphalt modifier M3 prepared in Example 3 and 0.07 kg of SBS were added to 2 kg of molten base asphalt for mechanical blending. First, high-speed shear stirring was performed at 175° C. using a high-speed shearing device, with a shear rate of 3000 r/min and a stirring time of 100 min.

A2: Continue to transfer the product obtained in step A1 to a low-speed shear device for low-speed shear stirring at 175°C, with a shear rate of 800 r/min and a stirring time of 3 h to prepare modified asphalt N8;

Preparation of modified asphalt mixture L8:

(1) Select the AC type dense gradation commonly used in highway pavement, weigh 20 kg of aggregates of corresponding sizes and mineral powder (the weight proportion of mineral powder is 6%), and then preheat them in an oven at 190°C for 6 hours. At 180°C, preheat 1 kg of the modified asphalt N8 prepared above to a molten state;

(2) The aggregate was added into a stirring pot at 190°C and mixed for 15 seconds. Then, the molten modified asphalt N8 was added and mixed for 25 seconds. Finally, the preheated mineral powder was added and mixed for 100 seconds. The machine was stopped and the materials were unloaded to prepare the modified asphalt mixture L8.

Example 9

The modifier dosage, asphalt-to-stone ratio, SBS dosage and water damage resistance asphalt modifier dosage are shown in Table 1;

Preparation of modified asphalt N9:

A1: 0.07 kg of the water-damage-resistant asphalt modifier M3 prepared in Example 3 and 0.03 kg of SBS were added to 2 kg of molten base asphalt for mechanical blending. First, high-speed shear stirring was performed at 175° C. using a high-speed shearing device, with a shear rate of 3000 r/min and a stirring time of 100 min.

A2: Continue to transfer the product obtained in step A1 to a low-speed shear device for low-speed shear stirring at 175°C, with a shear rate of 800 r/min and a stirring time of 3 h to prepare modified asphalt N9;

Preparation of modified asphalt mixture L9:

(1) Select the AC type dense gradation commonly used in highway pavement, weigh 20 kg of aggregates of corresponding sizes and mineral powder (the weight proportion of mineral powder is 6%), and then preheat them in an oven at 190°C for 6 hours. At 180°C, preheat 1 kg of the modified asphalt N9 prepared above to a molten state;

(2) Add the aggregate to a stirring pot at 190°C and mix for 15 seconds. Then, add the molten modified asphalt N9 and continue to mix for 25 seconds. Finally, add the preheated mineral powder and continue to mix for 100 seconds. Stop the machine and unload the materials to prepare To modified asphalt mixture L9.

Example 10

The modifier dosage, asphalt-to-stone ratio, SBS dosage and water damage resistance asphalt modifier dosage are shown in Table 1;

Preparation of anti-water damage asphalt modifier M10:

The method of Example 2 is followed, except that 10 g of styrene butadiene rubber (SBR) is used instead of 25 g of styrene butadiene rubber (SBR) in step S3 to obtain a water-damage resistant asphalt modifier M10;

Preparation of modified asphalt N10:

The method of Example 2 is followed, except that the water-damage-resistant asphalt modifier M10 is used in place of the water-damage-resistant asphalt modifier M2 by the same weight to obtain modified asphalt N10;

Preparation of modified asphalt mixture L10:

The method of Example 2 is followed, except that the modified asphalt N2 is replaced by the modified asphalt N10 of the same weight to obtain the modified asphalt mixture L10.

Embodiment 11

The modifier dosage, asphalt-to-stone ratio, SBS dosage and water damage resistance asphalt modifier dosage are shown in Table 1;

Preparation of anti-water damage asphalt modifier M11:

The method of Example 3 is used, except that in step S2, the weight ratio of KH550, water and anhydrous ethanol is 20:11:100, to obtain the water-damage resistant asphalt modifier M11;

Preparation of modified asphalt N11:

The method of Example 3 is followed, except that the water-damage-resistant asphalt modifier M11 is used in place of the water-damage-resistant asphalt modifier M3 by the same weight to obtain modified asphalt N11;

Preparation of modified asphalt mixture L11:

The method of Example 3 was followed, except that the modified asphalt N3 was replaced by the modified asphalt N11 of the same weight to obtain the modified asphalt mixture L11.

Example 12

The modifier dosage, asphalt-to-stone ratio, SBS dosage and water damage resistance asphalt modifier dosage are shown in Table 1;

Preparation of anti-water damage asphalt modifier M12:

The method of Example 3 is followed, except that 10 g of styrene butadiene rubber (SBR) is used instead of 25 g of styrene butadiene rubber (SBR) in step S3 to obtain a water-damage resistant asphalt modifier M12;

Preparation of modified asphalt N12:

The method of Example 8 is followed, except that the water-damage-resistant asphalt modifier M12 is used in place of the water-damage-resistant asphalt modifier M3 by the same weight to obtain modified asphalt N12;

Preparation of modified asphalt mixture L12:

The method of Example 8 is followed, except that the modified asphalt N8 is replaced by the same weight of modified asphalt N12 to obtain modified asphalt mixture L12.

Example 13

The modifier dosage, asphalt-to-stone ratio, SBS dosage and water damage resistance asphalt modifier dosage are shown in Table 1;

Preparation of anti-water damage asphalt modifier M13:

The method of Example 3 is used, except that in step S2, the weight ratio of KH550, water and anhydrous ethanol is 20:11:100, and the water-damage resistant asphalt modifier M13 is obtained;

Preparation of modified asphalt N13:

The method of Example 8 is carried out, except that the anti-water damage asphalt modifier M13 is used in place of the anti-water damage asphalt modifier M3 by the same weight to obtain modified asphalt N13;

Preparation of modified asphalt mixture L13:

The method of Example 8 was followed, except that the modified asphalt N8 was replaced by the same weight of modified asphalt N13 to obtain modified asphalt mixture L13.

Test Case

1. The morphology of the water-damage resistant asphalt modifier prepared in Example 1 was tested using a scanning electron microscope. The test results are shown in Figures 4-5. Figure 4 is a SEM image of the water-damage resistant asphalt modifier prepared in Example 1 magnified 500 times; Figure 5 is a SEM image of the water-damage resistant asphalt modifier prepared in Example 1 magnified 5000 times;

It can be seen from Figures 4-5 that compared with the SEM images of retired wind turbine blade powder (Figures 2-3), the microstructure of the anti-water damage asphalt modifier prepared in Example 1 of the present invention realizes a composite structure of elastomer-coated retired wind turbine blade powder, and the surface is relatively rough, thus having better compatibility with asphalt.

2. The properties of the base asphalt and the modified asphalt obtained in Examples 1-13 were tested. The test indicators included softening point, ductility and viscosity. The test results are shown in Table 2.

Table 2

From the data in Table 2, it can be seen that the anti-water damage asphalt modifier prepared by the present invention is used to prepare modified asphalt, and the softening point is significantly increased, the ductility is slightly improved, and the viscosity is increased. This shows that the anti-water damage asphalt modifier prepared by the present invention can improve the high temperature resistance of asphalt, improve the ductility of asphalt to a certain extent, and will not significantly affect the high temperature working performance of asphalt. At the same time, the anti-water damage asphalt modifier prepared by the present invention is used in conjunction with the SBS modifier, which can show good cooperation ability and promote the improvement of the overall performance of asphalt without producing an exclusive effect. In general, the anti-water damage asphalt modifier prepared by the present invention has a good modification effect on asphalt.

3. The performance of the modified asphalt mixtures obtained in Examples 1-13 was tested, and the test indicators included the water-immersed Marshall residual stability, dynamic stability and maximum bending strain. The test results are shown in Table 3;

(1) Water-immersion Marshall residual stability: According to the test method of "Test Procedure for Asphalt and Asphalt Mixtures for Highway Engineering" (JTG E20-2011 T 0702), the modified asphalt mixture prepared in Examples 1-13 was subjected to Marshall specimen preparation by compaction method. According to the test method of "Test Procedure for Asphalt and Asphalt Mixtures for Highway Engineering" (JTG E20-2011 T 0709), the above-mentioned asphalt mixture specimens were subjected to Marshall stability test by using a Marshall stability tester. The difference between the water-immersion Marshall test and the above-mentioned test is that the specimens need to be kept warm in a constant temperature water tank at 60°C for 48 hours. Furthermore, the percentage of the ratio of the Marshall stability after immersion to the Marshall stability before immersion is taken as the water-immersion Marshall residual stability, which is used to evaluate the water stability of the above-mentioned asphalt mixture. The larger the value, the better the water stability;

(2) Dynamic stability: According to the test method of "Test Procedure for Asphalt and Asphalt Mixtures in Highway Engineering" (JTG E20-2011 T 0719), the high temperature stability test of the asphalt mixture rutting specimens prepared in Examples 1-13 was carried out under the test conditions of a temperature of 60°C and a wheel pressure of 0.7 MPa. The dynamic stability was used as the main index to evaluate the high temperature deformation resistance of the specimens.

(3) Maximum flexural strain: According to the test method of "Test Procedure for Asphalt and Asphalt Mixtures in Highway Engineering" (JTG E20-2011 T 0715), the asphalt mixture specimens prepared in Examples 1-13 were tested at a loading rate of 50 mm/min at a low temperature of -10°C. The low-temperature performance of the specimens was evaluated by the maximum flexural strain at the time of specimen failure.

Table 3

It can be seen from the data in Table 3 that the modified asphalt prepared by the present invention is used to prepare modified asphalt mixtures. The water-immersion Marshall residual stability of the modified asphalt mixtures prepared in Examples 1-9 and Examples 12-13 all meet the road requirements (≥85%). In some preferred embodiments, the value exceeds 94%, and the high-temperature performance of the modified asphalt mixtures is also significantly improved. In addition, for the maximum bending-tensile strain at low temperature, the water-damage-resistant asphalt modifiers prepared in Examples 1-9 and Examples 12-13 meet the standard technical requirements (≥2500). In general, the asphalt mixture modified by the water-damage-resistant asphalt modifier prepared by the present invention has good road performance, especially in terms of improving water stability.

4. The economic benefits of the application of the water-damage resistant asphalt modifier of the present invention in road engineering materials are analyzed, and the commonly used asphalt modifier SBS is used as a reference object. The costs of the two are shown in Table 4.

Table 4

From the data in Table 4, we can see that the estimated unit price of water-damage resistant asphalt modifier with a particle size less than 0.3 mm is 3,615 yuan/ton, while the unit price of modifier SBS is 15,800 yuan/ton. Therefore, the cost difference between the two is 12,185 yuan/ton.

According to the above cost analysis, assuming that a 1-kilometer two-way four-lane asphalt pavement (length 1000m×width 12m×thickness 0.17m= ^2040m3 ) is laid, according to the commonly used engineering mix ratio, it roughly requires 5140.8 tons of asphalt mixture and 11.75 tons of asphalt modifier; in view of this, the expenditure cost of using the modifier SBS is about 185,700 yuan, while the expenditure cost of using the anti-water damage asphalt modifier described in the present invention is about 42,500 yuan. In summary, laying a 1-kilometer two-way four-lane asphalt pavement (length 1000m×width 12m×thickness 0.17m= ^2040m3 ) can save 143,200 yuan, which has significant economic benefits and engineering value.

Therefore, the water-damage resistant asphalt modifier of the present invention can reduce the use of the modifier SBS and greatly reduce the economic cost generated in road construction. The technical solution of preparing modified asphalt and modified asphalt mixture using the water-damage resistant asphalt modifier of the present invention has significant economic benefits.

The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims (14)

A method for preparing a water damage resistant asphalt modifier, characterized in that the method comprises the following steps: S1: Powdering and sieving the retired wind turbine blades to obtain retired wind turbine blade powder; S2: mixing the retired wind turbine blade powder in step S1 with a silane coupling agent hydrolysis solution, and then drying to obtain siliconized retired wind turbine blade powder; S3: The siliconized retired wind turbine blade powder in step S2 is mixed with an elastomer, and then melt-blended, crushed and sieved to obtain a water-damage resistant asphalt modifier. The method according to claim 1, characterized in that, in step S1, the content of glass fiber in the retired wind turbine blade is greater than 70 weight %. The method according to claim 1 or 2 is characterized in that, in step S1, the particle size of the retired wind turbine blade powder is ≤0.3 mm. The method according to claim 1, characterized in that in step S2, the silane coupling agent hydrolysis solution is obtained by mixing the silane coupling agent, water and anhydrous ethanol, wherein the weight ratio of the silane coupling agent, water and anhydrous ethanol is 14-19:6-11:100; Preferably, the weight ratio of the retired wind turbine blade powder to the silane coupling agent is 100:10-20. The method according to claim 1 or 4, characterized in that in step S2, the mixing conditions include: temperature of 55-85°C and time of 10-60 min. The method according to claim 1, characterized in that in step S3, the weight ratio of the siliconized retired wind turbine blade powder to the elastomer is 100:15-45; Preferably, the elastomer is selected from SBR, SBS, SIS, SEBS, IIR or EVA. The method according to claim 1 or 6, characterized in that in step S3, the conditions for melt blending include: temperature of 50-70°C, rotation speed of 40-70rpm, and time of 15-40min; Preferably, the crushing is freeze-crushing. The method according to claim 1 is characterized in that, in step S3, the particle size of the anti-water damage asphalt modifier is ≤0.3 mm. A water damage resistant asphalt modifier prepared by the method described in any one of claims 1 to 8. A modified asphalt, characterized in that the modified asphalt comprises base asphalt and a modifier, wherein the modifier is the anti-water damage asphalt modifier according to claim 9 and optional SBS. The modified asphalt according to claim 10 is characterized in that the weight ratio of the modifier to the base asphalt is 1-20:100. A method for preparing modified asphalt as claimed in claim 10 or 11, characterized in that the method comprises: mechanically blending the modifier with the molten base asphalt. A modified asphalt mixture, characterized in that the modified asphalt mixture comprises modified asphalt, aggregate and mineral powder; Wherein, the modified asphalt is the modified asphalt according to claim 10 or 11. A method for preparing the modified asphalt mixture according to claim 13, characterized in that the method comprises the following steps: (1) Preheating aggregate and mineral powder, and preheating modified asphalt to a molten state; (2) Add the molten modified asphalt and mineral powder to the aggregate in turn and mix them.