Anti-split warm mix asphalt and method of making same

Abstract

This invention relates to the field of asphalt technology and discloses an anti-splitting warm-mix asphalt and its preparation method. The anti-splitting warm-mix asphalt of this invention comprises 100 parts by weight of asphalt and 2-6 parts by weight of a warm-mix agent. The warm-mix agent contains a large number of ester and amide polar groups, which form hydrogen bonds with phenols, naphthenic acids, and other substances in the asphalt, resulting in good compatibility between the warm-mix agent and the asphalt matrix. The warm-mix agent contains three-dimensional branched molecular chains that form an interpenetrating network with the asphalt, allowing for uniform dispersion and penetration into the asphalt matrix, forming loosely structured hydrogen-bonded aggregates within the asphalt to achieve a viscosity-reducing effect. The three-dimensional branched molecular chains of the warm-mix agent contain multiple terminal alkenyl groups, which undergo thermal cross-linking reactions with the alkenyl groups of the asphalt during high-temperature mixing, forming stable chemical bonds and a three-dimensional chemical cross-linking network. This improves the mechanical properties of the asphalt and asphalt mixtures, exhibiting higher splitting strength and Marshall stability.

Description

Technical Field

[0001] This invention relates to the field of asphalt technology, specifically to a splitting-resistant warm mix asphalt and its preparation method. Background Technology

[0002] Asphalt possesses excellent waterproof, anti-corrosion, and adhesive properties, and is widely used in pipelines, buildings, roads, and bridges. However, asphalt has a high viscosity and typically requires high-temperature melting during mixing and paving. At high temperatures, asphalt releases toxic and harmful gases such as nitrogen oxides and sulfur oxides, and high temperatures also cause thermo-oxidative aging, affecting its performance. Therefore, warm-mix treatment is necessary to reduce the mixing and paving temperature of asphalt mixtures, save mixing energy, and reduce harmful gas emissions throughout the mixing and paving process. Furthermore, in low-temperature environments, if asphalt mixtures are not warm-mixed, the asphalt pavement is difficult to compact, affecting its service life.

[0003] Currently, warm-mix asphalt is mainly achieved using methods such as viscosity reducers, surfactants, and mechanical foaming. Among these, warm-mix agents with viscosity-reducing mechanisms have the most significant effect on lowering the mixing temperature of asphalt mixtures. The warm-mix agent of this invention can insert into the asphalt molecular chains, reducing the forces between asphalt resins, inhibiting the aggregation of asphalt resins, resulting in excellent viscosity reduction and warm-mix / warm-laying effects, and significantly improving the mechanical properties of asphalt mixtures. Publication number CN114085426B discloses a viscosity-reducing modifier obtained by reacting higher fatty acids, diethylenetriamine, and catalysts, which has good viscosity-reducing effects and improves the high-temperature resistance of asphalt concrete; however, this patent does not improve the mechanical strength or other properties of asphalt mixtures. Summary of the Invention

[0004] This invention solves the problems of high viscosity and low mechanical properties such as crack resistance in asphalt.

[0005] The technical solution of this invention: A splitting-resistant warm-mix asphalt, comprising 100 parts by weight of asphalt and 2-6 parts by weight of warm-mix agent; the preparation method of the splitting-resistant warm-mix asphalt is as follows: (1) Nitrogen gas was introduced into the flask, and dichloromethane and fumarate chloride were added in an ice-water bath. After stirring, a dichloromethane solution containing enol monomer and triethylamine was added dropwise. After esterification, the mixture was extracted and washed with water. The organic layer was dried with anhydrous magnesium sulfate to remove water. After rotary evaporation, the crude product was separated by column chromatography to obtain the vinyl maleic acid diester monomer. The reaction formula is: .

[0006] (2) Add N,N-dimethylformamide, vinyl maleic acid diester monomer, N,N'-bis(2-mercaptoethyl)butane-1,4-diamide and benzoin dimethyl ether to a flask, place it under a UV lamp for irradiation reaction, pour the solution into water, stir and filter, wash the filter cake with petroleum ether, dry it to obtain warm stirring agent.

[0007] (3) Add asphalt to the container, heat it, add warm mix agent, stir and mix well to obtain split-resistant warm mix asphalt.

[0008] Furthermore, in (1), the esterification reaction is carried out at a temperature of 20-30℃ for 2-3 hours.

[0009] Furthermore, in (1), the ratio of transbutenedioic acid chloride, enol monomer, and triethylamine is 1 mol: (2-2.1) mol: (2-2.1) mol.

[0010] Furthermore, the structural formula of the enol monomer in (1) is , where a is 8-10.

[0011] Furthermore, in (2), the ratio of vinyl maleic acid diester monomer, N,N'-bis(2-mercaptoethyl)butane-1,4-diamide, and benzoin dimethyl ether is 1 mol: (1.41-1.47) mol: (0.02-0.03) mol.

[0012] Furthermore, in (2), the wavelength range of the ultraviolet lamp is 320-400nm, the power is 20-50W, and the reaction time is 30-90min.

[0013] Furthermore, in (3), the heating temperature is 130-145℃ and the stirring time is 20-40min.

[0014] The beneficial technical effects of this invention are as follows: A vinyl maleic acid diester monomer containing three alken groups and N,N'-bis(2-mercaptoethyl)butane-1,4-diamide containing two thiol groups undergo a thiol-alkene photoaddition polymerization reaction to obtain a warm mix agent for asphalt. The warm mix agent contains a large number of polar ester and amide groups, which form hydrogen bonds with phenols, naphthenic acids, and other substances in asphalt, giving the warm mix agent good compatibility with the asphalt matrix. The warm mix agent contains three-dimensional branched molecular chains, which form an interpenetrating network with asphalt, allowing it to be uniformly dispersed and penetrated into the asphalt matrix, forming loosely structured hydrogen-bonded aggregates in the asphalt, thus achieving a viscosity-reducing effect.

[0015] The long-chain alkyl groups contained in the warm mix agent of this invention spread out in the asphalt binder to form a solubilization layer, which acts as a shield and can break down the network structure formed by the asphalt binder. At the same time, it inhibits the aggregation of the asphalt binder. The long-chain alkyl groups reduce the friction between the asphalt binders through lubrication, thereby achieving a good viscosity-reducing warm mix effect. It significantly reduces the viscosity of the asphalt and achieves the warm mix effect. It can also make the asphalt have good processing fluidity and mechanical properties when mixed at medium and high temperatures.

[0016] The three-dimensional branched molecular chain of the warm mix additive of the present invention contains multiple terminal alkenyl groups. During the high-temperature mixing process, it undergoes a thermal cross-linking reaction with the alkenyl groups of asphalt to form stable chemical bonds and a three-dimensional chemical cross-linking network, which improves the mechanical properties of asphalt and asphalt mixtures and has higher splitting strength and Marshall stability. Detailed Implementation

[0017] The technical solution of the present invention will be further illustrated below through specific embodiments. However, the following examples are merely simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention is determined by the claims.

[0018] N,N'-bis(2-mercaptoethyl)butane-1,4-diamide was prepared according to the method described in the journal article J. Am. Chem. SOC. 1989, 111, 6805-6809, "ChemInform Abstract: Topologically Constrained Bifunctional Intercalators: DNA Intercalation by a Macrocyclic Bisacridine". The structural formula is as follows: .

[0019] Example 1: (1) Nitrogen gas was introduced into the flask, and 200 mL of dichloromethane and 60 mmol of fumaric acid chloride were added in an ice-water bath. After stirring, 200 mL of dichloromethane solution containing 126 mmol of 10-undecen-1-ol (CAS No. 112-43-6) and 120 mmol of triethylamine was added dropwise. The mixture was stirred at 25 °C for 2 h. The mixture was extracted and washed with water, and the organic layer was dried with anhydrous magnesium sulfate to remove water. After rotary evaporation, the crude product was separated by column chromatography to obtain vinyl maleic acid diester monomer.

[0020] (2) Add 700-800 mL of N,N-dimethylformamide, 100 mmol of vinyl maleic acid diester monomer, 141 mmol of N,N'-bis(2-mercaptoethyl)butane-1,4-diamide and 2.3 mmol of benzoin dimethyl ether to a flask, place it under a 30 W UV lamp (center wavelength 365 nm), irradiate and stir for 60 min, pour the solution into water, stir and filter, wash the filter cake with petroleum ether, dry, and obtain the warm stirring agent.

[0021] (3) Add 2kg of asphalt to the container, heat to 145℃, add 40g of warm mix agent, stir for 40min to obtain anti-splitting warm mix asphalt.

[0022] Example 2: (1) Nitrogen gas was introduced into the flask, and 200 mL of dichloromethane and 60 mmol of fumaric acid chloride were added in an ice-water bath. After stirring, 200 mL of dichloromethane solution containing 126 mmol of 9-decen-1-ol (CAS No. 13019-22-2) and 120 mmol of triethylamine was added dropwise. The mixture was stirred at 20 °C for 3 h. The mixture was extracted and washed with water, and the organic layer was dried with anhydrous magnesium sulfate to remove water. After rotary evaporation, the crude product was separated by column chromatography to obtain vinyl maleic acid diester monomer.

[0023] (2) Add 700-800 mL of N,N-dimethylformamide, 100 mmol of vinyl maleic acid diester monomer, 147 mmol of N,N'-bis(2-mercaptoethyl)butane-1,4-diamide and 2 mmol of benzoin dimethyl ether to a flask, place it under a 50 W UV lamp (center wavelength 365 nm), irradiate and stir for 30 min, pour the solution into water, stir and filter, wash the filter cake with petroleum ether, dry, and obtain the warm stirring agent.

[0024] (3) Add 2kg of asphalt to the container, heat to 145℃, add 65g of viscosity reducer, stir for 30min to obtain anti-splitting warm mix asphalt.

[0025] Example 3: (1) Nitrogen gas was introduced into the flask, and 250 mL of dichloromethane and 60 mmol of transbutenedioic acid chloride were added in an ice-water bath. After stirring, 250 mL of dichloromethane solution containing 120 mmol of 10-undecen-1-ol (CAS No. 112-43-6) and 120 mmol of triethylamine was added dropwise. The mixture was stirred at 30 °C for 2 h. The mixture was extracted and washed with water, and the organic layer was dried with anhydrous magnesium sulfate to remove water. After rotary evaporation, the crude product was separated by column chromatography to obtain vinyl maleic acid diester monomer.

[0026] (2) Add 700-800 mL of N,N-dimethylformamide, 100 mmol of vinyl maleic acid diester monomer, 144 mmol of N,N'-bis(2-mercaptoethyl)butane-1,4-diamide and 2 mmol of benzoin dimethyl ether to a flask, place it under a 20 W UV lamp (center wavelength 365 nm), irradiate and stir for 90 min, pour the solution into water, stir and filter, wash the filter cake with petroleum ether, dry, and obtain the warm stirring agent.

[0027] (3) Add 2kg of asphalt to the container, heat to 130℃, add 90g of warm mix agent, stir for 30min to obtain anti-splitting warm mix asphalt.

[0028] Example 4: (1) Nitrogen gas was introduced into the flask, and 250 mL of dichloromethane and 60 mmol of fumaric acid chloride were added in an ice-water bath. After stirring, 250 mL of dichloromethane solution containing 120 mmol of 10-undecen-1-ol (CAS No. 112-43-6) and 126 mmol of triethylamine was added dropwise. The mixture was stirred at 25 °C for 3 h. The mixture was extracted and washed with water, and the organic layer was dried with anhydrous magnesium sulfate to remove water. After rotary evaporation, the crude product was separated by column chromatography to obtain vinyl maleic acid diester monomer.

[0029] (2) Add 700-800 mL of N,N-dimethylformamide, 100 mmol of vinyl maleic acid diester monomer, 141 mmol of N,N'-bis(2-mercaptoethyl)butane-1,4-diamide and 3 mmol of benzoin dimethyl ether to a flask, place it under a 20 W UV lamp (center wavelength 365 nm), irradiate and stir for 90 min, pour the solution into water, stir and filter, wash the filter cake with petroleum ether, dry, and obtain the warm stirring agent.

[0030] (3) Add 2kg of asphalt to the container, heat to 140℃, add 120g of warm mix agent, stir for 20min to obtain anti-splitting warm mix asphalt.

[0031] Comparative Example 1 differs from Example 1 in that no warm mix additive is added to the asphalt.

[0032] Comparative Example 2 differs from Example 1 in that it uses ethylene glycol dimercaptoacetate instead of N,N'-bis(2-mercaptoethyl)butane-1,4-diamide.

[0033] (1) Add 700-800 mL of N,N-dimethylformamide, 100 mmol of vinyl maleic acid diester monomer, 141 mmol of ethylene glycol dimercaptoacetate and 2.3 mmol of benzoin dimethyl ether to a flask, place it under a 30 W UV lamp (center wavelength 365 nm), irradiate and stir for 60 min, pour the solution into water, stir and filter, wash the filter cake with petroleum ether, dry, and obtain the warm stirring agent.

[0034] (2) Add 2kg of asphalt to the container, heat to 145℃, add 40g of viscosity reducer, stir for 40min to obtain warm mix asphalt.

[0035] Comparative Example 3 differs from Example 1 in that methyl allyl alcohol is used instead of 10-undecen-1-ol.

[0036] (1) Nitrogen gas was introduced into the flask, and 200 mL of dichloromethane and 60 mmol of fumaric acid chloride were added in an ice-water bath. After stirring, 200 mL of a dichloromethane solution containing 126 mmol of methyl allyl alcohol and 120 mmol of triethylamine was added dropwise. The mixture was stirred at 25 °C for 2 h. The mixture was then extracted and washed with water. The organic layer was dried over anhydrous magnesium sulfate to remove water. After rotary evaporation, the crude product was separated by column chromatography to obtain the vinyl maleic acid diester monomer, with the structural formula as follows: .

[0037] (2) Add 700-800 mL of N,N-dimethylformamide, 100 mmol of vinyl maleic acid diester monomer, 141 mmol of N,N'-bis(2-mercaptoethyl)butane-1,4-diamide and 2.3 mmol of benzoin dimethyl ether to a flask, place it under a 30 W UV lamp (center wavelength 365 nm), irradiate and stir for 60 min, pour the solution into water, stir and filter, wash the filter cake with petroleum ether, dry, and obtain the warm stirring agent.

[0038] (3) Add 2kg of asphalt to the container, heat to 145℃, add 40g of warm mix agent, stir for 40min to obtain warm mix asphalt.

[0039] Comparative Example 4: Succinoyl chloride was used instead of trans-butenedioyl chloride.

[0040] (1) Nitrogen gas was introduced into the flask, and 200 mL of dichloromethane and 60 mmol of succinyl chloride were added in an ice-water bath. After stirring, 200 mL of a dichloromethane solution containing 126 mmol of 10-undecen-1-ol (CAS No. 112-43-6) and 120 mmol of triethylamine was added dropwise. The mixture was stirred at 25 °C for 2 h. The mixture was then extracted and washed with water. The organic layer was dried over anhydrous magnesium sulfate. After rotary evaporation, the crude product was separated by column chromatography to obtain the vinyl succinate diester monomer, with the structural formula as follows: .

[0041] (2) Add 700-800 mL of N,N-dimethylformamide, 100 mmol of vinyl maleic acid diester monomer, 141 mmol of N,N'-bis(2-mercaptoethyl)butane-1,4-diamide and 2.3 mmol of benzoin dimethyl ether to a flask, place it under a 30 W UV lamp (center wavelength 365 nm), irradiate and stir for 60 min, pour the solution into water, stir and filter, wash the filter cake with petroleum ether, dry, and obtain the warm stirring agent.

[0042] (3) Add 2kg of asphalt to the container, heat to 145℃, add 40g of warm mix agent, stir for 40min to obtain warm mix asphalt.

[0043] The asphalt was heated to 135-160℃ and stirred for 5 minutes. The viscosity of the asphalt was then tested using a rotational viscometer.

[0044] The ductility of asphalt was tested according to GB / T 4508-2010 standard.

[0045] Asphalt mixtures were prepared and their mechanical properties were tested according to JTG F40-2004 and JTG E20-2011 standards. The asphalt-aggregate ratio was 5%, the coarse aggregate was basalt, the fine aggregate was limestone, the mineral powder was limestone mineral powder, and the gradation type was ARAC-13.

[0046] Table 1 Properties of Warm Mix Asphalt Compared to Comparative Example 1, the asphalt in Examples 1-4 contained a warm mix additive, which contains a large number of ester and amide polar groups. These groups form hydrogen bonds with phenols, naphthenic acids, and other substances in the asphalt, resulting in good compatibility between the warm mix additive and the asphalt matrix. The warm mix additive contains three-dimensional branched molecular chains that form an interpenetrating network with the asphalt, allowing it to be evenly dispersed and penetrate into the asphalt resin matrix. It forms loosely structured hydrogen-bonded aggregates in the asphalt, achieving a viscosity-reducing effect. Furthermore, the long-chain alkyl groups extend to form a solubilization layer, acting as a shield and breaking down the network structure formed by the asphalt resin matrix. This also inhibits the aggregation of the asphalt resin matrix. The long-chain alkyl groups also reduce friction between the asphalt resin matrix through lubrication, thus achieving a good viscosity-reducing effect. This significantly reduces the viscosity of the asphalt, achieving the warm mix effect. Even when mixed at medium to high temperatures, the asphalt can still have good processing fluidity and mechanical properties. The three-dimensional branched molecular chain of the warm mix additive contains multiple terminal alkenyl groups. During the high-temperature mixing process, it undergoes a thermal cross-linking reaction with the alkenyl groups of asphalt to form stable chemical bonds and a three-dimensional chemical cross-linking network, which improves the mechanical properties of asphalt and asphalt mixtures, and has higher splitting strength and Marshall stability.

[0047] The ethylene glycol dimercaptoacetic acid ester and the prepared warm mix agent of Comparative Example 2 do not contain amide bonds, have weaker compatibility with asphalt and weaker hydrogen bonding, have a lower viscosity reduction effect than Example 1, have higher viscosity, and have lower splitting strength and Marshall stability of asphalt mixtures than Example 1.

[0048] Comparative Example 3: Methyl allyl alcohol and viscosity reducer do not contain long-chain alkyl groups, resulting in poor viscosity reduction, high viscosity of asphalt, and low splitting strength and Marshall stability of asphalt mixture.

[0049] The vinyl maleate diester monomer in Comparative Example 4 contains only one alkenyl group. The viscosity reducer obtained by polymerization with N,N'-bis(2-mercaptoethyl)butane-1,4-diamide has a linear structure and does not have a branched molecular chain. It has a very poor viscosity reducing effect and a large viscosity. In addition, the linear molecular chain has a low content of terminal alkenyl groups, resulting in a low degree of chemical crosslinking with asphalt. The splitting strength and Marshall stability of the asphalt mixture are significantly lower than those in Example 1.

[0050] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A type of splitting-resistant warm-mix asphalt, characterized in that, The anti-splitting warm mix asphalt comprises 100 parts by weight of asphalt and 2-6 parts by weight of warm mix agent; The warm mixing agent is prepared by adding N,N-dimethylformamide, vinyl maleic acid diester monomer, N,N'-bis(2-mercaptoethyl)butane-1,4-diamide, and benzoin dimethyl ether to a flask, placing it under a UV lamp for irradiation and reaction, pouring the solution into water, stirring, filtering, washing the filter cake, and drying to obtain the warm mixing agent.

2. The anti-splitting warm mix asphalt according to claim 1, characterized in that, The ratio of the vinyl maleate diester monomer, N,N'-bis(2-mercaptoethyl)butane-1,4-diamide, and benzoin dimethyl ether is 1 mol: (1.41-1.47) mol: (0.02-0.03) mol.

3. The anti-splitting warm mix asphalt according to claim 1, characterized in that, The ultraviolet lamp has a wavelength range of 320-400nm, a power of 20-50W, and a reaction time of 30-90min.

4. The anti-split warm mix asphalt according to claim 1, characterized in that, The method for preparing the vinyl maleic acid diester monomer is as follows: nitrogen gas is introduced into a flask, dichloromethane and fumarate chloride are added in an ice-water bath, and after stirring, a dichloromethane solution containing enol monomer and triethylamine is added dropwise. After esterification reaction, extraction and washing are performed, and the crude product is separated by column chromatography to obtain the vinyl maleic acid diester monomer.

5. The anti-split warm mix asphalt according to claim 4, characterized in that, The esterification reaction is carried out at a temperature of 20-30℃ for 2-3 hours.

6. The anti-splitting warm mix asphalt according to claim 4, characterized in that, The ratio of transbutenedioic acid chloride, enol monomer, and triethylamine is 1 mol: (2-2.1) mol: (2-2.1) mol.

7. The anti-splitting warm mix asphalt according to claim 6, characterized in that, The structural formula of the enol monomer is as follows: , where a is 8-10.

8. A method for preparing split-resistant warm-mix asphalt as described in any one of claims 1-7, characterized in that, The preparation method is as follows: add asphalt to a container, heat to 130-145℃, add warm mix agent, stir for 20-40 minutes to obtain split-resistant warm mix asphalt.

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