High-modulus agent for durable high-modulus asphalt mixture and preparation method of high-modulus agent

Abstract

The invention belongs to the field of road engineering materials, and relates to a high-modulus agent for a durable high-modulus asphalt mixture and a preparation method of the high-modulus agent. The high-modulus agent comprises the following raw materials in parts by mass: 20-40% of high-temperature asphalt, 10-15% of rubber powder modified asphalt, 8-20% of Fischer-Tropsch synthesis residue wax, 2-5% of liquid coumarone resin, 20-40% of solid coumarone resin, 4-8% of powdered styrene-butadiene rubber, 0.5-3% of sulfur, 1-5% of 2-mercaptobenzothiazole and 3-8% of oxidized polyethlene wax, wherein the total mass is 100%. According to the high-modulus agent, by-products and residues generated in the production process of petrochemical engineering, coal chemical engineering and basic chemical engineering products serve as main raw materials, through secondary processing and functional modification, the prepared high-modulus agent can greatly improve the modulus of an asphalt mixture, the low-temperature crack resistance, water damage resistance and fatigue durability of the asphalt mixture are not reduced, and meanwhile the high-modulus agent is low in cost and suitable for industrial production. The use is convenient.

Description

Technical Field

[0001] The invention belongs to the field of road engineering materials and relates to a high modulus agent, in particular to a high modulus agent for durable high modulus asphalt mixture and a preparation method thereof. Background Art

[0002] With the increasing traffic volume on my country's expressways and the characteristics of large axle loads and channelized traffic, asphalt pavements are prone to significant permanent deformation and accumulated rutting under high temperature and continuous load. The appearance of rutting on asphalt pavements seriously affects the service quality and driving safety of high-grade pavements, and directly affects the service life of asphalt pavements, resulting in increased maintenance costs and posing a safety hazard to transportation.

[0003] Existing research results show that increasing the modulus of asphalt concrete in the middle and upper layers can greatly improve the high temperature performance and crack resistance of asphalt pavement, and reduce the risk of rutting and cracking of asphalt pavement. Therefore, many scientific research institutions have conducted experiments on high modulus asphalt concrete and developed high modulus asphalt modifiers. The so-called high modulus asphalt concrete refers to a dynamic modulus greater than 14000MPa at a temperature of 15°C and a loading frequency of 10Hz. High modulus asphalt modifiers are the most direct and effective way to increase the modulus of asphalt concrete.

[0004] At present, my country's high-performance high modulus agents still mainly rely on imported products (including French PRI Company, German Rub Company, etc.). Imported products have been verified by a large number of physical projects, with mature technology and reliable quality, but the general price is high, which greatly affects the promotion and use of products. The price of domestic high modulus agents is lower than that of imported products, but there are differences between domestic high modulus agents and imported products in key properties such as instant solubility, compressibility, crack resistance, and fatigue resistance. In addition, although the price of domestic high modulus agents is greatly optimized compared with imported products, it still exceeds the range that the current road construction and maintenance market can bear.

[0005] At the same time, as a major producer and consumer of petrochemicals, coal chemicals and basic chemicals, my country has not fully explored the value of by-products and residues produced in the production process of many chemical products. Some materials are idle, and some materials are consumed in a reduced, low-value, and extensive manner, resulting in a huge waste of resources. However, after secondary processing and modification, a large part of these materials can greatly improve the high temperature performance, low temperature performance, water damage resistance and durability of asphalt pavements in asphalt pavement construction and maintenance projects, and have good social and economic value.

[0006] Based on the above reasons, it is necessary to develop a high modulus agent for durable high modulus asphalt mixture, so that the high modulus agent has good workability during use, is easy to dissolve and disperse; the asphalt mixture added with the high modulus agent has good compaction, high temperature stability, low temperature crack resistance, water damage resistance and fatigue durability, and at the same time, it has the characteristics of low cost, green and environmental protection, easy use, and easy promotion and application. Summary of the invention

[0007] In order to solve the defects existing in the promotion and application of high modulus agents in the current highway asphalt pavement construction and maintenance projects in my country, the present invention provides a high modulus agent for durable high modulus asphalt mixture and a preparation method thereof. The composite high modulus agent uses by-products and residues generated in the production process of petrochemical, coal chemical and basic chemical products as main raw materials. Through secondary processing and functional modification, the prepared high modulus agent can greatly improve the modulus of asphalt mixture without reducing its low-temperature crack resistance, water damage resistance and fatigue durability. At the same time, it is low-cost, green and environmentally friendly, easy to use and easy to promote.

[0008] To achieve the above purpose, the technical solution adopted by the present invention is as follows: A high modulus agent for a durable high modulus asphalt mixture comprises the following raw materials in parts by mass: 20%-40% high-temperature asphalt, 10%-15% rubber powder modified asphalt, 8%-20% Fischer-Tropsch slag wax, 2%-5% liquid coumarone resin, 20%-40% solid coumarone resin, 4%-8% powdered styrene-butadiene rubber, 0.5%-3% sulfur, 1%-5% 2-mercaptobenzothiazole, and 3%-8% oxidized polyethylene wax, and the total mass satisfies 100%.

[0009] Preferably, the high temperature asphalt has a softening point of 95°C-120°C, an average molecular weight of 3000-5000, and an ash content of less than or equal to 0.2%; Preferably, the content of waste tire rubber powder in the rubber powder modified asphalt is 15%-25%, and the solubility of trichloroethylene is greater than or equal to 95%; Preferably, the Fischer-Tropsch synthesis slag wax is a mixture of a catalyst and wax obtained by Fischer-Tropsch synthesis, wherein the solid catalyst content in the Fischer-Tropsch synthesis slag wax is less than or equal to 10%, and the wax content is greater than or equal to 90%; Preferably, the softening point of the liquid coumarone resin is 5°C-25°C; Preferably, the solid coumarone resin has a softening point of 110°C-135°C and an ash content of less than or equal to 0.15%; Preferably, the maximum particle size of the powdered styrene-butadiene rubber is less than or equal to 0.6 mm, and the average molecular weight is 200,000-300,000; Preferably, the sulfur meets the technical requirements of the superior product in the national standard "Industrial Sulfur" (GB / T 2449-2006); Preferably, the melting point of the 2-mercaptobenzothiazole is 177-181°C; Preferably, the softening point of the oxidized polyethylene wax is greater than or equal to 100° C., and the average molecular weight is 3000-5000.

[0010] The present invention also provides a method for preparing a high modulus agent for a durable high modulus asphalt mixture, the method comprising the following steps: Step 1. Weigh the high-temperature asphalt in proportion and put it into the reactor filled with 180℃-190℃ rubber-modified asphalt, maintain the temperature unchanged, and force stirring for 10-20 minutes; Step 2. Add liquid coumarone resin to step 1, maintain the temperature unchanged, and force stirring for 3-5 minutes; Step 3. Add solid coumarone resin, Fischer-Tropsch slag wax and oxidized polyethylene wax to step 2, maintain the temperature unchanged, and force stirring for 10-15min; Step 4. Add powdered styrene-butadiene rubber to step 3, maintain the temperature unchanged, and force stirring for 20-30 minutes; Step 5. Add sulfur and 2-mercaptobenzothiazole to step 4, maintain the temperature unchanged, and force stirring for 20-30 minutes; Step 6. The product obtained in step 5 is put into a steel belt granulator for granulation to obtain a high modulus agent.

[0011] As a priority, the high modulus agent prepared according to the above steps, according to the usage of 0.3%-1.5% of the total weight of the asphalt mixture, the asphalt mixture performance indicators can meet the requirements of Table 1. The code of the test method in Table 1 is the corresponding code of the test method in the "Test Procedure for Asphalt and Asphalt Mixture in Highway Engineering".

[0012] Table 1

[0013] The high modulus agent for durable high modulus asphalt mixture developed by the present invention has the following advantages: 1. Using high-temperature asphalt, rubber powder modified asphalt, Fischer-Tropsch slag wax and other by-products produced in the production process of petrochemicals, coal chemicals and basic chemicals as the main raw materials, it can effectively give play to the characteristics and value of solid waste and low-end materials, making the materials recycled, with low cost and outstanding social benefits; 2. High-temperature asphalt has high softening point, good adhesion, low volatility, chemical stability, high carbon residue rate, high-temperature fluidity, aging resistance, etc. As the main raw material of high modulus agent, it can greatly improve the modulus, viscosity and aging resistance of asphalt mixture; 3. Rubber powder modified asphalt has excellent viscosity, toughness and elasticity. As the main raw material of high modulus agent, it can greatly improve the low temperature crack resistance and fatigue properties of asphalt mixture. At the same time, it is low in cost and can effectively reduce the cost of high modulus agent; 4. Low viscosity, high melting point, good wettability of Fischer-Tropsch slag wax can effectively reduce the high temperature viscosity of other organic polymer components in the high modulus agent, making the high modulus agent have good construction and compaction properties, while not affecting the high temperature performance of the mixture; 5. Liquid coumarone resin has good compatibility with powdered styrene-butadiene rubber, rubber-modified asphalt and high-temperature asphalt. It mainly acts as a tackifier, plasticizer, softener and regenerator in high modulus agents. At the same time, it can effectively remove benzopyrene chemical carcinogens produced under high temperature conditions during the production and application of high modulus agents; 6. Solid coumarone resin has the characteristics of high softening point, is extremely stable to acid and alkali, and has good water resistance, chemical resistance, and light aging resistance, which can greatly improve the strength, modulus and durability of asphalt mixture; 7. Oxidized polyethylene wax has excellent cold resistance, heat resistance and wear resistance, as well as good chemical stability. It has good compatibility with asphalt and can be quickly combined with asphalt without precipitating from asphalt due to state changes. During the asphalt mixing process, it can be evenly melted and dispersed, thereby increasing the viscosity of asphalt, enhancing the ability of asphalt to resist flow, and significantly improving the anti-rutting performance of asphalt mixtures; 8. Powdered styrene-butadiene rubber has a very high molecular weight and plays a major role in reinforcing, viscosity-enhancing and strengthening asphalt mixtures. It can effectively improve the high and low temperature performance of asphalt and improve the road's anti-flowability, low-temperature crack resistance and wear resistance; 9. Sulfur, as a natural stabilizer, can cause various organic polymers of different molecular weights in the high modulus agent to quickly undergo cross-linking reactions and vulcanization under the action of 2-mercaptobenzothiazole accelerator, making the high modulus agent and its material system in the asphalt mixture more stable, thereby greatly improving the comprehensive mechanical properties of the asphalt mixture, such as crack resistance, tensile strength, shear resistance, compression resistance and impact strength. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 A schematic diagram of the process flow of a method for preparing a high modulus agent for a durable high modulus asphalt mixture according to the present invention. DETAILED DESCRIPTION

[0015] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. Example 1

[0016] A high modulus agent for a durable high modulus asphalt mixture comprises the following raw materials in parts by mass: 40% of high-temperature asphalt, 10% of rubber powder modified asphalt, 8% of Fischer-Tropsch slag wax, 4% of liquid coumarone resin, 20% of solid coumarone resin, 8% of powdered styrene-butadiene rubber, 0.5% of sulfur, 1.5% of 2-mercaptobenzothiazole, and 8% of oxidized polyethylene wax, and the total mass meets 100%.

[0017] Preferably, the high temperature asphalt has a softening point of 120°C, an average molecular weight of 5000, and an ash content of 0.2%; As a preferred embodiment, the rubber powder modified asphalt is produced by Fojiao Ketiannuo (Zhenjiang) Materials Co., Ltd., the content of waste tire rubber powder in the rubber powder modified asphalt is 25%, and the solubility of trichloroethylene is 95%; As a priority, the Fischer-Tropsch synthesis slag wax is a mixture of a catalyst and wax obtained by Fischer-Tropsch synthesis, wherein the solid catalyst content in the Fischer-Tropsch synthesis slag wax is 1% and the wax content is 99%, and the Fischer-Tropsch synthesis slag wax is a product of Ningxia Coal Industry Co., Ltd. of the State Energy Group; Preferably, the softening point of the liquid coumarone resin is 5°C; Preferably, the solid coumarone resin has a softening point of 135°C and an ash content of 0.15%; Preferably, the powdered styrene-butadiene rubber has a maximum particle size of 0.6 mm and an average molecular weight of 300,000; Preferably, the sulfur meets the technical requirements of the superior product in the national standard "Industrial Sulfur" (GB / T 2449-2006); Preferably, the melting point of the 2-mercaptobenzothiazole is 177°C; Preferably, the oxidized polyethylene wax has a softening point of 130° C. and an average molecular weight of 5,000.

[0018] The present invention also provides a method for preparing a high modulus agent for a durable high modulus asphalt mixture, the method comprising the following steps: Step 1. Weigh the high-temperature asphalt in proportion and put it into the reactor filled with 190℃ rubber-modified asphalt, maintain the temperature unchanged, and force stirring for 20 minutes; Step 2. Add liquid coumarone resin to step 1, maintain the temperature unchanged, and force stirring for 5 minutes; Step 3. Add solid coumarone resin, Fischer-Tropsch slag wax and oxidized polyethylene wax to step 2, maintain the temperature unchanged, and force stirring for 15 minutes; Step 4. Add powdered styrene-butadiene rubber to step 3, maintain the temperature unchanged, and force stirring for 30 minutes; Step 5. Add sulfur and 2-mercaptobenzothiazole to step 4, maintain the temperature unchanged, and force stirring for 30 minutes; Step 6. The product obtained in step 5 is put into a steel belt granulator for granulation to obtain a high modulus agent.

[0019] As a priority, the high modulus agent prepared according to the above steps is used in an amount of 1.5% of the total weight of the asphalt mixture. The performance indicators of the asphalt mixture are shown in Table 2. The code of the test method in Table 2 is the corresponding code of the test method in the "Test Procedure for Asphalt and Asphalt Mixture in Highway Engineering".

[0020] Table 2 Example 2

[0021] A high modulus agent for a durable high modulus asphalt mixture comprises the following raw materials in parts by mass: 20% of high-temperature asphalt, 15% of rubber powder modified asphalt, 20% of Fischer-Tropsch slag wax, 5% of liquid coumarone resin, 30% of solid coumarone resin, 4% of powdered styrene-butadiene rubber, 2% of sulfur, 1% of 2-mercaptobenzothiazole, and 3% of oxidized polyethylene wax, and the total mass of the raw materials meets 100%.

[0022] Preferably, the high temperature asphalt has a softening point of 95°C, an average molecular weight of 3000-, and an ash content of 0.11%; As a preferred embodiment, the rubber powder modified asphalt is produced by Fojiao Ketiannuo (Zhenjiang) Materials Co., Ltd., the content of waste tire rubber powder in the rubber powder modified asphalt is 15%, and the solubility of trichloroethylene is 97.7%; As a priority, the Fischer-Tropsch synthesis slag wax is a mixture of a catalyst and wax obtained by Fischer-Tropsch synthesis, wherein the solid catalyst content in the Fischer-Tropsch synthesis slag wax is 10% and the wax content is 90%, and the Fischer-Tropsch synthesis slag wax is a product of Ningxia Coal Industry Co., Ltd. of the State Energy Group; Preferably, the softening point of the liquid coumarone resin is 25°C; Preferably, the solid coumarone resin has a softening point of 110°C and an ash content of 0.09%; Preferably, the powdered styrene-butadiene rubber has a maximum particle size of 0.3 mm and an average molecular weight of 200,000; Preferably, the sulfur meets the technical requirements of the superior product in the national standard "Industrial Sulfur" (GB / T 2449-2006); Preferably, the melting point of the 2-mercaptobenzothiazole is 177°C; Preferably, the oxidized polyethylene wax has a softening point of 106° C. and an average molecular weight of 3,000.

[0023] The present invention also provides a method for preparing a high modulus agent for a durable high modulus asphalt mixture, the method comprising the following steps: Step 1. Weigh the high-temperature asphalt according to the proportion, put it into the reactor filled with 180℃ rubber-modified asphalt, maintain the temperature unchanged, and force stirring for 10 minutes; Step 2. Add liquid coumarone resin to step 1, maintain the temperature unchanged, and force stirring for 3 minutes; Step 3. Add solid coumarone resin, Fischer-Tropsch slag wax and oxidized polyethylene wax to step 2, maintain the temperature unchanged, and force stirring for 10 minutes; Step 4. Add powdered styrene-butadiene rubber to step 3, maintain the temperature unchanged, and force stirring for 20 minutes; Step 5. Add sulfur and 2-mercaptobenzothiazole to step 4, maintain the temperature unchanged, and force stirring for 20 minutes; Step 6. The product obtained in step 5 is put into a steel belt granulator for granulation to obtain a high modulus agent.

[0024] As a priority, the high modulus agent prepared according to the above steps is used in an amount of 1.0% of the total weight of the asphalt mixture. The performance indicators of the asphalt mixture are shown in Table 3. The code of the test method in Table 3 is the corresponding code of the test method in the "Test Procedure for Asphalt and Asphalt Mixture in Highway Engineering".

[0025] Table 3 Example 3

[0026] A high modulus agent for a durable high modulus asphalt mixture comprises the following raw materials in parts by mass: 22% of high-temperature asphalt, 10.5% of rubber powder modified asphalt, 9% of Fischer-Tropsch slag wax, 2% of liquid coumarone resin, 40% of solid coumarone resin, 6% of powdered styrene-butadiene rubber, 1.5% of sulfur, 5% of 2-mercaptobenzothiazole, and 4% of oxidized polyethylene wax, and the total mass of the raw materials meets 100%.

[0027] Preferably, the high temperature asphalt has a softening point of 100°C, an average molecular weight of 4000, and an ash content of 0.05%; As a preferred embodiment, the rubber powder modified asphalt is produced by Fojiao Ketiannuo (Zhenjiang) Materials Co., Ltd., the content of waste tire rubber powder in the rubber powder modified asphalt is 18%, and the solubility of trichloroethylene is 96.1%; As a priority, the Fischer-Tropsch synthesis slag wax is a mixture of a catalyst and wax obtained by Fischer-Tropsch synthesis, wherein the solid catalyst content in the Fischer-Tropsch synthesis slag wax is 3% and the wax content is 97%, and the Fischer-Tropsch synthesis slag wax is a product of Ningxia Coal Industry Co., Ltd. of the State Energy Group; Preferably, the softening point of the liquid coumarone resin is 22°C; Preferably, the solid coumarone resin has a softening point of 120°C and an ash content of 0.09%; Preferably, the maximum particle size of the powdered styrene-butadiene rubber is 0.5 mm and the average molecular weight is 260,000; Preferably, the sulfur meets the technical requirements of the superior product in the national standard "Industrial Sulfur" (GB / T 2449-2006); Preferably, the melting point of the 2-mercaptobenzothiazole is 180°C; Preferably, the oxidized polyethylene wax has a softening point of 114° C. and an average molecular weight of 3,900.

[0028] The present invention also provides a method for preparing a high modulus agent for a durable high modulus asphalt mixture, the method comprising the following steps: Step 1. Weigh the high-temperature asphalt in proportion and put it into the reactor filled with 185℃ rubber-modified asphalt, maintain the temperature unchanged, and force stirring for 18 minutes; Step 2. Add liquid coumarone resin to step 1, maintain the temperature unchanged, and force stirring for 4 minutes; Step 3. Add solid coumarone resin, Fischer-Tropsch slag wax and oxidized polyethylene wax to step 2, maintain the temperature unchanged, and force stirring for 13 minutes; Step 4. Add powdered styrene-butadiene rubber to step 3, maintain the temperature unchanged, and force stirring for 25 minutes; Step 5. Add sulfur and 2-mercaptobenzothiazole to step 4, maintain the temperature unchanged, and force stirring for 21 minutes; Step 6. The product obtained in step 5 is put into a steel belt granulator for granulation to obtain a high modulus agent.

[0029] As a priority, the high modulus agent prepared according to the above steps is used in an amount of 0.3% of the total weight of the asphalt mixture. The performance indicators of the asphalt mixture are shown in Table 4. The code of the test method in Table 4 is the corresponding code of the test method in the "Test Procedure for Asphalt and Asphalt Mixture in Highway Engineering".

[0030] Table 4

[0031] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A high modulus agent for durable high modulus asphalt mixture, characterized in that: The raw materials include the following by mass: high-temperature asphalt 20%-40%, rubber powder modified asphalt 10%-15%, Fischer-Tropsch slag wax 8%-20%, liquid coumarone resin 2%-5%, solid coumarone resin 20%-40%, powdered styrene-butadiene rubber 4%-8%, sulfur 0.5%-3%, 2-mercaptobenzothiazole 1%-5%, oxidized polyethylene wax 3%-8%, and the total mass meets 100%; The high temperature asphalt has a softening point of 95°C-120°C, an average molecular weight of 3000-5000, and an ash content of less than or equal to 0.2%; The content of waste tire rubber powder in the rubber powder modified asphalt is 15%-25%, and the solubility of trichloroethylene is greater than or equal to 95%; The Fischer-Tropsch synthesis slag wax is a mixture of a catalyst and wax obtained by Fischer-Tropsch synthesis, wherein the solid catalyst content in the Fischer-Tropsch synthesis slag wax is less than or equal to 10%, and the wax content is greater than or equal to 90%; The softening point of the liquid coumarone resin is 5°C-25°C; The solid coumarone resin has a softening point of 110°C-135°C and an ash content of less than or equal to 0.15%; The maximum particle size of the powdered styrene-butadiene rubber is less than or equal to 0.6 mm, and the average molecular weight is 200,000-300,000; The sulfur meets the technical requirements of the superior product in the national standard "Industrial Sulfur" (GB / T 2449-2006); The melting point of the 2-mercaptobenzothiazole is 177-181°C; The softening point of the oxidized polyethylene wax is greater than or equal to 100° C., and the average molecular weight is 3000-5000.

2. The method for preparing a high modulus agent for durable high modulus asphalt mixture according to claim 1, characterized in that: The method comprises the following steps: Step 1. Weigh the high-temperature asphalt in proportion and put it into the reactor filled with 180℃-190℃ rubber-modified asphalt, maintain the temperature unchanged, and force stirring for 10-20 minutes; Step 2. Add liquid coumarone resin to step 1, maintain the temperature unchanged, and force stirring for 3-5 minutes; Step 3. Add solid coumarone resin, Fischer-Tropsch slag wax and oxidized polyethylene wax to step 2, maintain the temperature unchanged, and force stirring for 10-15min; Step 4. Add powdered styrene-butadiene rubber to step 3, maintain the temperature unchanged, and force stirring for 20-30 minutes; Step 5. Add sulfur and 2-mercaptobenzothiazole to step 4, maintain the temperature unchanged, and force stirring for 20-30 minutes; Step 6. The product obtained in step 5 is put into a steel belt granulator for granulation to obtain a high modulus agent.

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