Two-component normal-temperature modified asphalt mixture suitable for expressway rapid repair and preparation method thereof

Abstract

The application belongs to the technical field of asphalt mixture, and particularly provides a two-component normal-temperature modified asphalt mixture suitable for expressway rapid repair and a preparation method thereof. The mixture comprises the following raw materials in percentage by weight: 1-6% of two-component waterborne epoxy resin, 0.5-3% of curing agent, 1-4% of micro-silica powder, 0.5-3% of anti-stripping agent, and the balance of AC-16 cold-mixed asphalt; the anti-stripping agent is composed of catechol modified polysiloxane and polyitaconic acid-dodecyl glucoside ester at a mass ratio of 1:0.4-1:1.2. The application forms a three-dimensional network through the normal-temperature cross-linking and curing of the two-component waterborne epoxy resin, thereby improving the early strength; the hydrophobic barrier is formed by the catechol modified polysiloxane and is wetly anchored to the aggregate surface, the chemical adsorption layer and the interface transition layer are formed by the polyitaconic acid-dodecyl glucoside ester, and the water stability and the interface adhesion performance of the mixture are significantly improved by the two, thereby meeting the requirements of expressway rapid repair and rapid traffic opening.

Description

Technical Field

[0001] This application belongs to the field of asphalt mixture technology, and in particular relates to a two-component room temperature modified asphalt mixture suitable for rapid repair of highways and its preparation method. Background Technology

[0002] Over long-term service, asphalt pavements on highways are prone to potholes, cracks, and loosening due to factors such as traffic loads, temperature changes, and water erosion. If these defects are not repaired promptly, they will accelerate pavement structural damage, severely impacting driving safety and comfort. Highway maintenance requires rapid reopening to traffic; therefore, ambient temperature repair materials have gained widespread attention due to their heat-free application, ease of application, and rapid curing speed.

[0003] Cold-mix asphalt is a commonly used material for ambient temperature repairs. However, traditional cold-mix asphalt mixtures generally suffer from low early strength, poor water stability, and insufficient adhesion to aggregates. Especially in humid or low-temperature environments, moisture easily penetrates the asphalt-aggregate interface, leading to asphalt film peeling, loosening and damage of the mixture, making it difficult to meet the requirements for immediate reopening of highways after rapid repairs.

[0004] To improve the performance of cold-mix asphalt mixtures, existing technologies typically employ methods such as adding anti-stripping agents and polymer modification. Anti-stripping agents can improve the adhesion between asphalt and aggregates, but their effectiveness is significantly affected by environmental humidity; adhesion performance often decreases markedly under wet conditions. Furthermore, a single type of anti-stripping agent cannot simultaneously address multiple issues such as the hydrophobic barrier at the interface, chemical anchoring, and the stability of the interfacial transition layer, resulting in limited improvements in the water stability and early strength of the mixture.

[0005] Therefore, there is an urgent need to develop a two-component, room-temperature modified asphalt mixture suitable for rapid repair of highways, which can have excellent early strength, water stability and interfacial adhesion properties under normal temperature construction conditions, so as to meet the engineering requirements of rapid repair and rapid reopening of traffic. Summary of the Invention

[0006] To address the aforementioned issues, this application provides a two-component, room-temperature modified asphalt mixture suitable for rapid repair of highways and its preparation method.

[0007] This application first provides a raw material comprising the following weight percentages: 1%~6% two-component waterborne epoxy resin, 0.5%~3% curing agent, 1%~4% microsilica powder, 0.5%~3% anti-stripping agent, and the balance being AC-16 cold-mix asphalt; wherein the anti-stripping agent is composed of catechol-modified polysiloxane and polyitacrylic acid-dodecyl glucoside ester in a mass ratio of 1:0.4~1:1.2.

[0008] Furthermore, the weight percentages of each raw material are as follows: 3% for two-component waterborne epoxy resin, 1.5% for curing agent, 2% for silica fume, 1.5% for anti-stripping agent, and the balance is AC-16 cold-mix asphalt.

[0009] Furthermore, the two-component waterborne epoxy resin has an epoxy equivalent of 500~800 and a viscosity of 500~1200 mPa·s.

[0010] Furthermore, the curing agent has an active hydrogen content of 18,000 to 32,000 and a viscosity of 1,500 to 3,500 mPa·s.

[0011] Furthermore, the mass ratio of the catechol-modified polysiloxane to polyitacrylic acid-dodecyl glucoside ester is 1:0.6-0.7.

[0012] Furthermore, the catechol-modified polysiloxane is prepared by a method comprising the following steps: 3,4-dihydroxybenzaldehyde and amino-terminated polydimethylsiloxane are reacted under reflux in ethanol with glacial acetic acid as a catalyst, and then reduced, purified and dried with a reducing agent to obtain the catechol-modified polysiloxane.

[0013] Furthermore, the polyitaconic acid-dodecyl glucoside ester is prepared by a method comprising the following steps: esterification reaction of polyitaconic acid and dodecyl glucoside in the presence of a condensing agent and a catalyst, followed by precipitation purification and drying to obtain polyitaconic acid-dodecyl glucoside ester.

[0014] Furthermore, the AC-16 cold-mix asphalt is a cold-mix asphalt mixture base material that conforms to the AC-16 gradation in JTG F40-2004.

[0015] This application also provides a method for preparing the above-mentioned two-component room-temperature modified asphalt mixture suitable for rapid repair of highways, characterized by comprising the following steps: Mix the curing agent with AC-16 cold-mix asphalt according to the specified ratio for 3-8 minutes; Add the two-component waterborne epoxy resin to the obtained mixture, continue stirring for 3-8 minutes, then add the silica powder and anti-stripping agent, and mix for 5-15 minutes to obtain the final product.

[0016] Furthermore, the anti-stripping agent is prepared by pre-mixing catechol-modified polysiloxane and polyitacrylic acid-dodecyl glucoside ester in a specific ratio before addition.

[0017] Compared with the prior art, this application has the following beneficial effects: 1. This application employs a two-component waterborne epoxy resin and curing agent that cross-link and cure at room temperature to form a three-dimensional network structure, significantly improving the early strength and mechanical properties of the mixture and shortening the time before traffic can resume after repair. Based on this, catechol-modified polysiloxane is added. The hydrophobic polysiloxane backbone is compatible with the non-polar components of asphalt, forming a hydrophobic barrier at the asphalt-aggregate interface to prevent moisture intrusion. Catechol groups, through hydrogen bonding, π-π stacking, and coordination with metal ions on the aggregate surface, achieve wet anchoring on the aggregate surface, improving wet adhesion performance.

[0018] 2. This application incorporates polyitacic acid-dodecyl glucoside ester into the system. The polyitacic acid backbone and residual carboxyl groups form strong coordination bonds and a chemisorption layer with metal ions on the aggregate surface through the carboxyl groups. Simultaneously, the carboxyl groups can form hydrogen bonds with hydroxyl groups on the aggregate surface, significantly improving the adhesion strength of the asphalt-aggregate interface. The hydroxyl groups on the sugar rings of the dodecyl glucoside chain segments linked by ester bonds can further form a hydrogen bond network with polar sites on the aggregate surface. Long-chain alkyl groups extend into the asphalt phase and are compatiblely entangled with the saturated and aromatic components in the asphalt through van der Waals forces, forming a stable interfacial transition layer. Furthermore, its amphiphilic molecular structure can be oriented at the aggregate-asphalt interface in solvent-based cold-mix asphalt systems, reducing interfacial tension and inhibiting water intrusion, thereby improving the water stability and early strength of the mixture.

[0019] 3. In the mixture system of this application, catechol-modified polysiloxane mainly provides a hydrophobic barrier and wet anchoring function, but when used alone, its improvement on stress transfer between the asphalt phase and the aggregate phase is limited. Polyitacrylic acid-dodecyl glucoside mainly provides chemical adsorption and interfacial transition layer stabilization, but when used alone, it is easily competitively adsorbed by water molecules in a humid environment, weakening the anchoring effect. When the two are combined, the catechol-modified polysiloxane forms a dense hydrophobic layer on the aggregate surface, effectively repelling moisture and providing a dry anchoring microenvironment for the carboxyl groups and glycocyclic hydroxyl groups of polyitacrylic acid-dodecyl glucoside. Simultaneously, the long-chain alkyl groups of polyitacrylic acid-dodecyl glucoside intertwine with asphalt molecules, enhancing the flexibility and stress transfer capacity of the interfacial transition layer and compensating for the insufficient compatibility between polysiloxane segments and asphalt. The synergistic effect of the two results in a multi-stabilized structure at the asphalt-aggregate interface, combining hydrophobic barrier, chemical anchoring, and flexible transition layer functions, significantly improving the water stability and early strength of the mixture. Detailed Implementation

[0020] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the embodiments of this application. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0022] When using “including,” “having,” and “contains” as described herein, the intention is to cover non-exclusive inclusion, unless an explicit qualifying term such as “only,” “consisting of,” etc., is used, in which case another component may be added.

[0023] The terms "preferred," "more preferably," "better," and "even better" used in this application refer to embodiments of this application that provide certain beneficial effects under certain circumstances. However, other embodiments may also be preferred under the same or other circumstances. Furthermore, the description of one or more preferred embodiments does not imply that other embodiments are unavailable, nor is it intended to exclude other embodiments from the scope of this application. That is, in this application, "preferred," "more preferably," "better," and "even better" are merely descriptions of implementations or embodiments with better effects, but do not constitute a limitation on the scope of protection of this application.

[0024] In this application, terms such as "further," "even more," and "particularly" are used for descriptive purposes and indicate differences in content, but should not be construed as limiting the scope of protection of this application.

[0025] In this application, "at least one" means one or more, such as one, two, or more. "Multiple" or "several" means at least two, such as two, three, etc., and "multi-layered" means at least two layers, such as two layers, three layers, etc., unless otherwise explicitly specified. In the description of this application, "several" means at least one, such as one, two, etc., unless otherwise explicitly specified.

[0026] When a numerical range is disclosed herein, the range is considered continuous and includes the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Furthermore, when the range refers to integers, it includes every integer between the minimum and maximum values ​​of the range. Additionally, when multiple ranges are provided to describe a feature or characteristic, the ranges may be combined. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges to which they are incorporated.

[0027] Unless otherwise specified, all steps in this application may be performed sequentially or randomly. For example, the method comprising steps (a) and (b) indicates that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the mention that the method may also include step (c) indicates that step (c) may be added to the method in any order; for example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc. Unless otherwise stated, singular terms may include plural forms and should not be construed as having a quantity of one.

[0028] The present application will be further illustrated by the following examples, but these examples do not limit the scope of the present application.

[0029] When numerical ranges are given in the embodiments, it should be understood that, unless otherwise stated in this application, both endpoints of each numerical range and any value between the two endpoints may be selected. Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. All reagents or instruments whose manufacturers are not specified are conventional products that can be purchased commercially. In addition to the specific methods, equipment, and materials used in the embodiments, based on the knowledge of the prior art possessed by one of ordinary skill in the art and the description in this application, any prior art methods, equipment, and materials similar to or equivalent to those described, used, or made by the methods, equipment, and materials in the embodiments of this application may be used to implement this application.

[0030] Preparation Example 1 The preparation method of catechol-modified polysiloxane includes the following steps: 3.45 g of 3,4-dihydroxybenzaldehyde and 150 mL of anhydrous ethanol are added to a 250 mL three-necked flask, the mixture is purged with nitrogen, and 0.3 mL of glacial acetic acid is added as a catalyst; then 50 g of amino-terminated polydimethylsiloxane (amine value about 0.5 mmol / g, Mn about 3000) is added, the mixture is stirred and dissolved at room temperature, and then heated to 60 °C and refluxed for 8 h; after the reaction is completed, the mixture is cooled in an ice bath at 0-5 °C, and 1.42 g of sodium borohydride is slowly added, and the mixture is stirred at room temperature for 3 h after the addition is complete; ethanol is removed by rotary evaporation under reduced pressure, the residue is purified by methanol precipitation 2-3 times to remove unreacted small molecules, and the residue is dried under vacuum at 40 °C to constant weight to obtain a pale yellow viscous liquid.

[0031] Preparation Example 2 The preparation method of polyitaconic acid-dodecyl glucoside ester includes the following steps: Weigh 5.0 g of polyitaconic acid (number average molecular weight of about 3000, carboxyl content of about 15.4 mmol / g), add 100 mL of anhydrous DMF, stir magnetically at 50 °C until completely dissolved, and cool to room temperature to obtain polyitaconic acid solution; Add 9.5g DCC and 0.47g DMAP to the above polyitacic acid solution, cool to 0-5℃ in an ice-water bath, and stir to activate for 30min; weigh 13.4g dodecyl glucoside, dissolve 30mL of anhydrous DMF, and slowly add it dropwise to the above activation solution through a constant pressure dropping funnel. After 30min, remove the ice bath, stir and react at room temperature in the dark for 24h, filter the resulting reaction solution, and distill the filtrate under reduced pressure to recover most of the DMF, obtaining a viscous concentrate; The concentrated solution was slowly added dropwise to 500 mL of vigorously stirred anhydrous diethyl ether, resulting in the precipitation of a pale yellow viscous solid. After standing for 30 minutes, the supernatant was discarded, and the precipitate was washed twice with a small amount of anhydrous ethanol and dried under vacuum to obtain the final product.

[0032] Example 1 The two-component, room-temperature modified asphalt mixture suitable for rapid repair of highways in this embodiment includes the following raw materials by weight percentage: 3% two-component waterborne epoxy resin, 1.5% curing agent, 2% silica fume, 1.5% anti-stripping agent, and the balance being AC-16 cold-mix asphalt.

[0033] The two-component waterborne epoxy resin has an epoxy equivalent of 650 and a viscosity of 800 (mPa·s, 25℃).

[0034] The curing agent has an active hydrogen content of 25,000 and a viscosity of 2,500 (mPa·s, 24℃).

[0035] The anti-stripping agent is composed of catechol-modified polysiloxane and polyitacrylic acid-dodecyl glucoside ester in a mass ratio of 1:0.65.

[0036] The preparation method of the two-component room temperature modified asphalt mixture suitable for rapid repair of highways in this embodiment includes the following steps: mixing the curing agent and AC-16 asphalt according to the ratio for 5 minutes, then adding the two-component waterborne epoxy resin and continuing to mix for 5 minutes, then adding the silica powder and anti-stripping agent, and continuing to mix for 10 minutes.

[0037] Example 2 The only difference between this embodiment and Example 1 is that the weight percentage of each raw material is as follows: 2% of two-component waterborne epoxy resin, 1% of curing agent, 3% of microsilica powder, 1% of anti-stripping agent, and the balance is AC-16 cold-mix asphalt; the mass ratio of catechol-modified polysiloxane to polyitacrylic acid-dodecyl glucoside ester in the anti-stripping agent is 1:0.4.

[0038] The preparation method is the same as in Example 1.

[0039] Example 3 The only difference between this embodiment and Example 1 is that the weight percentage of each raw material is as follows: 5% of two-component waterborne epoxy resin, 2.5% of curing agent, 1% of microsilica powder, 2% of anti-stripping agent, and the balance is AC-16 cold-mix asphalt; the mass ratio of catechol-modified polysiloxane to polyitacrylic acid-dodecyl glucoside ester in the anti-stripping agent is 1:1.2.

[0040] The preparation method is the same as in Example 1.

[0041] Comparative Example 1 The only difference between this comparative example and Example 1 is that no anti-stripping agent is added, that is, the raw materials do not contain catechol-modified polysiloxane and polyitacrylic acid-dodecyl glucoside ester. The remaining components and preparation methods are the same as in Example 1.

[0042] Comparative Example 2 The only difference between this comparative example and Example 1 is that the anti-stripping agent consists only of catechol-modified polysiloxane, without the addition of polyitacrylic acid-dodecyl glucoside ester.

[0043] Comparative Example 3 The only difference between this comparative example and Example 1 is that the anti-stripping agent consists only of polyitacrylic acid-dodecyl glucoside ester, without the addition of catechol-modified polysiloxane.

[0044] Performance testing 1. Marshall specimens were formed from the mixtures obtained in the examples and comparative examples according to JTG E20-2011 "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering". The Marshall stability, residual stability (water immersion Marshall test), and freeze-thaw splitting strength ratio were tested to evaluate the early strength and water stability of the mixtures. The test results are shown in Table 1.

[0045] Table 1. Comprehensive test data of the mixtures in the examples and comparative examples. Analysis of the data in Table 1 shows that the Marshall stability, residual stability, and freeze-thaw splitting strength ratio of Examples 1-3 are significantly higher than those of Comparative Examples 1-3. This indicates that the early strength and water stability of the mixture are significantly improved after adding the anti-stripping agent composed of catechol-modified polysiloxane and polyitacrylic acid-dodecyl glucoside ester. In particular, in Example 1, the performance indicators are optimal when the two anti-stripping agents are combined at a mass ratio of 1:0.65, demonstrating the combined effect of the two. When Comparative Examples 2 and 3 use only one anti-stripping agent, the performance improvement is limited, indicating that a single component cannot simultaneously meet the requirements of hydrophobic barrier, chemical anchoring, and interfacial transition layer stability.

[0046] In addition, the mixture obtained in Example 1 can be paved and compacted within 30 minutes after mixing at room temperature, and can be opened to traffic after 2 hours of curing, meeting the construction needs of rapid repair of highways.

[0047] Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A two-component, room-temperature modified asphalt mixture suitable for rapid repair of highways, characterized in that: The raw materials include the following weight percentages: 1%~6% two-component waterborne epoxy resin, 0.5%~3% curing agent, 1%~4% microsilica powder, 0.5%~3% anti-stripping agent, and the balance being AC-16 cold-mix asphalt; the anti-stripping agent is composed of catechol-modified polysiloxane and polyitacrylic acid-dodecyl glucoside ester in a mass ratio of 1:0.4~1:1.

2.

2. The two-component, room-temperature modified asphalt mixture suitable for rapid repair of highways according to claim 1, characterized in that: The weight percentages of each raw material are as follows: 3% two-component waterborne epoxy resin, 1.5% curing agent, 2% silica fume, 1.5% anti-stripping agent, and the balance is AC-16 cold-mix asphalt.

3. The two-component, room-temperature modified asphalt mixture suitable for rapid repair of highways according to claim 1, characterized in that: The two-component waterborne epoxy resin has an epoxy equivalent of 500~800 and a viscosity of 500~1200 mPa·s.

4. The two-component, room-temperature modified asphalt mixture suitable for rapid repair of highways according to claim 1, characterized in that: The curing agent has an active hydrogen content of 18,000 to 32,000 and a viscosity of 1,500 to 3,500 mPa·s.

5. The two-component, room-temperature modified asphalt mixture suitable for rapid repair of highways according to claim 1, characterized in that: The mass ratio of the catechol-modified polysiloxane to polyitacrylic acid-dodecyl glucoside ester is 1:0.6-0.

7.

6. The two-component, room-temperature modified asphalt mixture suitable for rapid repair of highways according to claim 1, characterized in that: The catechol-modified polysiloxane is prepared by a method comprising the following steps: 3,4-dihydroxybenzaldehyde and amino-terminated polydimethylsiloxane are reacted by heating and reflux in ethanol under the catalysis of glacial acetic acid, and then reduced, purified and dried with a reducing agent to obtain the catechol-modified polysiloxane.

7. The two-component, room-temperature modified asphalt mixture suitable for rapid repair of highways according to claim 1, characterized in that: The polyitaconic acid-dodecyl glucoside ester is prepared by a method comprising the following steps: esterification reaction of polyitaconic acid and dodecyl glucoside in the presence of a condensing agent and a catalyst, followed by precipitation purification and drying to obtain polyitaconic acid-dodecyl glucoside ester.

8. The two-component, room-temperature modified asphalt mixture suitable for rapid repair of highways according to claim 1, characterized in that: The AC-16 cold-mix asphalt is a cold-mix asphalt mixture base material that conforms to the AC-16 gradation in JTG F40-2004.

9. A method for preparing a two-component, room-temperature modified asphalt mixture suitable for rapid repair of highways as described in any one of claims 1-10, characterized in that: Includes the following steps: Mix the curing agent with AC-16 cold-mix asphalt according to the specified ratio for 3-8 minutes; Add the two-component waterborne epoxy resin to the obtained mixture, continue stirring for 3-8 minutes, then add the silica powder and anti-stripping agent, and mix for 5-15 minutes to obtain the final product.

10. The method for preparing a two-component, room-temperature modified asphalt mixture suitable for rapid repair of highways according to claim 9, characterized in that: Before adding the anti-stripping agent, catechol-modified polysiloxane and polyitacrylic acid-dodecyl glucoside ester are mixed evenly in a certain proportion.

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