A low temperature paving asphalt mixture and a method for producing the same

Abstract

The application relates to the technical field of pavement materials, and particularly discloses a low-temperature paving asphalt mixture and a preparation method thereof. The low-temperature paving asphalt mixture comprises the following raw materials in parts by weight: emulsified asphalt 10-15 parts, aggregate 200-300 parts, filler 3-8 parts, rubber powder 1-5 parts, basalt fiber 1-2 parts, viscosity reducer 0.5-1 part and water 10-15 parts; the emulsified asphalt comprises the following raw materials in parts by weight, taking the emulsified asphalt as the total amount: SBS modified asphalt 50-70 parts, emulsifier 1-3 parts, stabilizer 0.05-0.15 parts and distilled water 30-45 parts. The asphalt mixture disclosed by the application can be paved at low temperature, has long mixing time, good workability, can be quickly solidified, and has high early strength.

Description

Technical Field

[0001] This application relates to the field of road material technology, and more specifically, to a low-temperature paving asphalt mixture and its preparation method. Background Technology

[0002] Asphalt is a mixture of various high-molecular-weight compounds with complex chemical compositions, possessing unique rheological properties. Due to its excellent adhesion, anti-aging properties, and waterproofing capabilities, it has long been widely used in waterproofing and sealing materials, road repair, and other applications. Asphalt has a black surface and is an organic cementitious material that enhances the ability of paving aggregates to resist damage to the road surface from traffic and natural factors. Therefore, it is often combined with mineral materials to form asphalt pavements, which are smooth, dust-free, impermeable, and durable.

[0003] Traditional asphalt pavements primarily use hot-mix asphalt (HMA), but due to its inherent limitations, heating the raw materials during mixing during road construction consumes a significant amount of energy; heating during paving causes short-term aging of the asphalt, affecting its road performance; and construction is seasonally restricted, as maintaining the correct construction temperature is difficult in cold winters. Especially in high-altitude and frigid regions, where low temperatures persist for extended periods, the mixture cools rapidly, leading to problems such as clumping and compaction difficulties. Therefore, there is an urgent need to develop a low-temperature asphalt mixture that possesses sufficient workability at low temperatures, can quickly develop strength, and meets traffic requirements. Summary of the Invention

[0004] In order to provide asphalt mixtures with excellent workability and excellent early strength at low temperatures, this application provides a low-temperature paving asphalt mixture and its preparation method.

[0005] In the first aspect, this application provides a low-temperature paving asphalt mixture, which adopts the following technical solution:

[0006] A low-temperature paving asphalt mixture comprises the following raw materials in parts by weight:

[0007] 10-15 parts emulsified asphalt, 200-300 parts aggregate, 3-8 parts filler, 1-5 parts rubber powder, 1-2 parts basalt fiber, 0.5-1 parts viscosity reducer, and 10-15 parts water;

[0008] Based on the total amount of emulsified asphalt, the emulsified asphalt comprises the following raw materials in parts by weight:

[0009] 50-70 parts SBS modified bitumen, 1-3 parts emulsifier, 0.05-0.15 parts stabilizer, and 30-45 parts distilled water.

[0010] By adopting the above technical solution, the raw materials are mixed together, resulting in an asphalt mixture that can be laid at low temperatures. It has a long mixing time, can cure quickly, and has high early strength, which is beneficial for rapid traffic opening. Furthermore, this asphalt mixture can be stored stably, with near-zero residue on the sieve, and exhibits excellent low-temperature crack resistance.

[0011] Preferably, the emulsifier is a cationic emulsifier.

[0012] More preferably, the cationic emulsifier is JY-5RM cationic slow-crack fast-coagulation emulsifier; more preferably, the JY-5RM cationic slow-crack fast-coagulation emulsifier has a pH value of 8-10 and an active substance content of ≥65%.

[0013] By adopting the above technical solution, JY-5RM cationic slow-crack fast-coagulation emulsifier has strong emulsification ability, good adhesion ability, and long mixing time, which makes the aggregate have good adaptability.

[0014] Preferably, the emulsified asphalt also includes an acidic pH adjuster.

[0015] Further preferably, the acidic pH adjuster is selected from either hydrochloric acid or acetic acid. More preferably, the acidic pH adjuster is hydrochloric acid. The mass concentration of the hydrochloric acid is 36%-38%.

[0016] The cationic emulsifier (JY-5RM cationic slow-crack fast-coagulation emulsifier) ​​of this application has better emulsification effect when used under acidic conditions. The acidic pH adjuster can provide an acidic environment. In this application, the pH adjuster can be hydrochloric acid or acetic acid, preferably hydrochloric acid, as hydrochloric acid has a wider adjustment range and is easier to control its addition amount.

[0017] Preferably, the stabilizer is polyvinyl alcohol and anhydrous calcium chloride, and the mass ratio of polyvinyl alcohol to anhydrous calcium chloride is (1-2):(0.5-1).

[0018] By adopting the above technical solution, the organic stabilizer polyvinyl alcohol and the inorganic stabilizer anhydrous calcium chloride work together to give emulsified asphalt good storage stability and improve mixing time and mixing stability during construction. The emulsified asphalt exhibits the best storage stability when the mass ratio of polyvinyl alcohol to anhydrous calcium chloride is (1-2):(0.5-1), especially 1.3:0.8.

[0019] Preferably, the emulsified asphalt is prepared by the following method;

[0020] Heat distilled water to 70-80℃, dissolve polyvinyl alcohol in hot water, and after it is completely dissolved, lower the temperature of the aqueous solution to 60-65℃, add emulsifier and calcium chloride, stir well, and then add an acidic pH adjuster to obtain a soap solution with a pH of 2-3.

[0021] While stirring, hot SBS modified asphalt at a temperature of 80-100℃ is slowly added to the soap solution and stirred evenly to obtain emulsified asphalt.

[0022] More preferably, the emulsified asphalt is prepared by the following method;

[0023] Heat distilled water to 70-80℃, dissolve polyvinyl alcohol in hot water, and after it is completely dissolved, lower the temperature of the aqueous solution to 60-65℃, add emulsifier and calcium chloride, stir well, and then add an acidic pH adjuster to obtain a soap solution with a pH of 2-3.

[0024] In an environment where the stirring speed of the soap solution is 3000-3400 r / min, hot SBS modified asphalt at a temperature of 80-100℃ is slowly added to the soap solution. During the slow addition of hot SBS modified asphalt, the stirring speed can be gradually increased without boiling or splashing, up to 6000 r / min. After the SBS modified asphalt is added, stir for another 20-30 minutes. The SBS modified asphalt forms uniform and fine particles that are stably and evenly dispersed in the soap solution, resulting in a fine and uniform brown emulsified asphalt.

[0025] The emulsified asphalt produced by adopting the above technical solution exhibits stable storage and excellent quality; specifically, its softening point is 55-58℃, its ductility at 5℃ is 30-35cm, and its storage stability after 1 day is 0.07-0.25%. Controlling the stirring speed of the soap solution is beneficial for obtaining homogeneous and stable emulsified asphalt, and can reduce splashing, losses, and operational safety.

[0026] Preferably, the viscosity reducer is selected from any one of EV-DAT viscosity reducer, LRD-oil-based viscosity reducer, and sodium laurylamide viscosity reducer. More preferably, the viscosity reducer is EV-DAT viscosity reducer.

[0027] By adopting the above technical solution, the addition of viscosity reducer can reduce the viscosity of asphalt mixture during hot paving, thereby adapting to the shrinkage stress of asphalt pavement caused by cooling, preventing cracking of pavement, improving the early strength of asphalt pavement, and preventing cracking of asphalt pavement.

[0028] Preferably, the oil-stone ratio is 4%-5%.

[0029] By adopting the above technical solution, using EV-DAT viscosity reducer, and controlling the asphalt-aggregate ratio at 4%-5%, the early strength of the asphalt mixture is enhanced while ensuring that it has a certain viscosity.

[0030] Preferably, the coarse aggregate includes coarse aggregate and fine aggregate, and the coarse aggregate includes at least one of basalt and steel slag. More preferably, the coarse aggregate is basalt and steel slag, and the weight ratio of basalt to steel slag is (0.5-1):(1.5-2.3).

[0031] By adopting the above technical solution, the coarse aggregate includes at least one of basalt and steel slag, which is beneficial to enhancing the early strength of asphalt mixtures. When the coarse aggregate is basalt and steel slag, and the weight ratio of basalt to steel slag is (0.5-1):(1.5-2.3), the early strength is better.

[0032] Preferably, the filler is limestone powder and cement, and the mass ratio of limestone powder to cement is (3-5):(1-3).

[0033] By adopting the above technical solutions, cement can adjust the gradation of limestone powder, improve the workability of asphalt mixtures, extend the mixing time, and accelerate the curing and molding of the mixture, thereby improving early strength.

[0034] Secondly, this application provides a method for preparing low-temperature paving asphalt mixture, employing the following technical solution:

[0035] A method for preparing low-temperature paving asphalt mixture includes the following steps:

[0036] Mix the coarse and fine aggregates evenly, then add water and mix evenly. Next, add emulsified asphalt and mix evenly. Finally, add filler, rubber powder, basalt fiber and viscosity reducer, and mix evenly to obtain asphalt mixture.

[0037] In summary, this application has the following beneficial effects:

[0038] The asphalt mixture prepared using the formula and preparation method of this application can be laid at low temperatures, has a long mixing time, can cure quickly, and has high early strength. Detailed Implementation

[0039] The present application will be further described in detail below with reference to the embodiments. It should be noted that: unless otherwise specified in the following embodiments, the conditions are carried out according to conventional conditions or the conditions recommended by the manufacturer; unless otherwise specified, the raw materials used in the following embodiments can be obtained from commercially available sources.

[0040] The technical specifications of SBS modified asphalt are shown in Table 1 below.

[0041] Table 1

[0042] Testing items Penetration / dm Softening point / °C Ductility (5℃) / cm The example used in this embodiment 73 65.5 50 Technical Requirements 50-80 ＞60 ＞30

[0043] The aggregate gradation is shown in Table 2 below.

[0044] Table 2

[0045] Sieve aperture size (mm) 30 20 9.5 4.75 2.36 1.18 0.6 0.3 0.15 0.075 Pass rate of gradation 1 (%) 100 95 68.8 48.2 28.4 18.6 11.6 5.5 1.3 0.2 Grade 2 pass rate (%) 100 95 68.2 35 20 12.9 8.0 3.8 1.0 0.2

[0046] Preparation Example

[0047] Example 1 of Emulsified Asphalt Preparation

[0048] The preparation of emulsified asphalt is as follows:

[0049] Heat 6 kg of distilled water to 70°C, dissolve 0.1 kg of polyvinyl alcohol in the hot water, and after it is completely dissolved, lower the temperature of the aqueous solution to 60°C, add 2 kg of emulsifier, stir well, and then add hydrochloric acid to obtain a soap solution with a pH of 2.

[0050] While stirring, 14 kg of hot SBS modified asphalt at 80°C was slowly added to the soap solution and stirred evenly to obtain emulsified asphalt 1.

[0051] Example 2 of emulsified asphalt preparation

[0052] The preparation of emulsified asphalt is as follows:

[0053] Heat 9 kg of distilled water to 80°C, dissolve 0.3 kg of polyvinyl alcohol in the hot water, and after it is completely dissolved, lower the temperature of the aqueous solution to 65°C, add 6 kg of emulsifier, stir well, and then add hydrochloric acid to obtain a soap solution with a pH of 3.

[0054] While stirring, 10 kg of hot SBS modified asphalt at 100℃ was slowly added to the soap solution and stirred evenly to obtain emulsified asphalt 2.

[0055] Example 3 of emulsified asphalt preparation

[0056] The preparation of emulsified asphalt is as follows:

[0057] Heat 8 kg of distilled water to 75°C, dissolve 0.2 kg of polyvinyl alcohol in the hot water, and after it is completely dissolved, lower the temperature of the aqueous solution to 60°C, add 4 kg of emulsifier, stir well, and then add hydrochloric acid to obtain a soap solution with a pH of 2.

[0058] While stirring, 12 kg of hot SBS modified asphalt at 85°C was slowly added to the soap solution and stirred evenly to obtain emulsified asphalt 3.

[0059] Example 4 of emulsified asphalt preparation

[0060] The preparation of emulsified asphalt is as follows:

[0061] Heat 8 kg of distilled water to 75°C, dissolve 0.2 kg of polyvinyl alcohol in the hot water, and after it is completely dissolved, lower the temperature of the aqueous solution to 60°C, add 4 kg of emulsifier, stir well, and then add hydrochloric acid to obtain a soap solution with a pH of 2.

[0062] Under an environment where the stirring speed of the soap solution is 3400 r / min, 12 kg of hot SBS modified asphalt at 85℃ is slowly added to the soap solution. During the slow addition of the hot SBS modified asphalt, the stirring speed is gradually increased to 6000 r / min. After the SBS modified asphalt is completely added, it is stirred for another 30 minutes. The SBS modified asphalt forms uniform and fine particles that are stably and evenly dispersed in the soap solution, resulting in fine and uniform brown emulsified asphalt 4.

[0063] Example 5 of emulsified asphalt preparation

[0064] The preparation of emulsified asphalt is as follows:

[0065] Heat 8 kg of distilled water to 75°C, dissolve 0.1 kg of polyvinyl alcohol in the hot water, and after it is completely dissolved, lower the temperature of the aqueous solution to 60°C, add 4 kg of emulsifier and 0.1 kg of calcium chloride, stir well, and then add hydrochloric acid to obtain a soap solution with a pH of 2.

[0066] Under conditions where the stirring speed of the soap solution is 3400 r / min, 12 kg of hot SBS modified asphalt at 85℃ is slowly added to the soap solution. During the slow addition of the hot SBS modified asphalt, the stirring speed is gradually increased to 6000 r / min. After the SBS modified asphalt is completely added, it is stirred for another 30 minutes. The SBS modified asphalt forms uniform and fine particles that are stably and evenly dispersed in the soap solution, resulting in fine and uniform brown emulsified asphalt 5.

[0067] Example 6 of emulsified asphalt preparation

[0068] The preparation of emulsified asphalt is as follows:

[0069] Heat 8 kg of distilled water to 75°C, dissolve 0.13 kg of polyvinyl alcohol in the hot water. After complete dissolution, lower the temperature of the aqueous solution to 60°C, add 4 kg of emulsifier and 0.07 kg of calcium chloride, stir well, and then add hydrochloric acid to obtain a soap solution with a pH of 2.

[0070] Under conditions where the stirring speed of the soap solution is 3400 r / min, 12 kg of hot SBS modified asphalt at 85℃ is slowly added to the soap solution. During the slow addition of the hot SBS modified asphalt, the stirring speed is gradually increased to 6000 r / min. After the SBS modified asphalt is completely added, it is stirred for another 30 minutes. The SBS modified asphalt forms uniform and fine particles that are stably and evenly dispersed in the soap solution, resulting in fine and uniform brown emulsified asphalt 6.

[0071] Example

[0072] Example 1

[0073] A method for preparing a low-temperature paving asphalt mixture includes the following steps:

[0074] Mix 200 kg of aggregate according to gradation 1 evenly, then add 10 kg of water and stir evenly; then add 10 kg of emulsified asphalt 1 and stir evenly; finally add 8 kg of filler, 1 kg of rubber powder, 1 kg of basalt fiber and 0.5 kg of viscosity reducer, and stir evenly to obtain asphalt mixture.

[0075] In this embodiment 1, the aggregate includes coarse aggregate and fine aggregate, and the coarse aggregate is basalt;

[0076] The filler is limestone powder;

[0077] The viscosity reducer is EV-DAT viscosity reducer.

[0078] Example 2

[0079] A method for preparing a low-temperature paving asphalt mixture includes the following steps:

[0080] Mix 250 kg of aggregate according to gradation 1 evenly, then add 12 kg of water and stir evenly; then add 13 kg of emulsified asphalt 1 and stir evenly; finally add 5 kg of filler, 3 kg of rubber powder, 2 kg of basalt fiber and 0.7 kg of viscosity reducer, and stir evenly to obtain asphalt mixture.

[0081] In this embodiment 2, the aggregate includes coarse aggregate and fine aggregate, and the coarse aggregate is basalt;

[0082] The filler is limestone powder;

[0083] The viscosity reducer is EV-DAT viscosity reducer.

[0084] Example 3

[0085] A method for preparing a low-temperature paving asphalt mixture includes the following steps:

[0086] Mix 300 kg of aggregate according to gradation 1 evenly, then add 15 kg of water and stir evenly; then add 15 kg of emulsified asphalt 1 and stir evenly; finally add 3 kg of filler, 5 kg of rubber powder, 1 kg of basalt fiber and 1 kg of viscosity reducer, and stir evenly to obtain asphalt mixture.

[0087] In this embodiment 3, the aggregates include coarse aggregates and fine aggregates, with the coarse aggregates being basalt;

[0088] The filler is limestone powder;

[0089] The viscosity reducer is EV-DAT viscosity reducer.

[0090] Example 4

[0091] A method for preparing a low-temperature paving asphalt mixture includes the following steps:

[0092] Mix 250 kg of aggregate according to gradation 1 evenly, then add 12 kg of water and stir evenly; then add 13 kg of emulsified asphalt 1 and stir evenly; finally add 5 kg of filler, 3 kg of rubber powder, 2 kg of basalt fiber and 0.7 kg of viscosity reducer, and stir evenly to obtain asphalt mixture.

[0093] In this embodiment 4, the aggregate includes coarse aggregate and fine aggregate. The coarse aggregate is basalt and steel slag, and the weight ratio of basalt and steel slag is 1:1.

[0094] The filler is limestone powder;

[0095] The viscosity reducer is EV-DAT viscosity reducer.

[0096] Example 5

[0097] A method for preparing a low-temperature paving asphalt mixture includes the following steps:

[0098] Mix 250 kg of aggregate according to gradation 1 evenly, then add 12 kg of water and stir evenly; then add 13 kg of emulsified asphalt 1 and stir evenly; finally add 5 kg of filler, 3 kg of rubber powder, 2 kg of basalt fiber and 0.7 kg of viscosity reducer, and stir evenly to obtain asphalt mixture.

[0099] In this embodiment 5, the aggregate includes coarse aggregate and fine aggregate. The coarse aggregate is basalt and steel slag, and the weight ratio of basalt to steel slag is 1:2.

[0100] The filler is limestone powder;

[0101] The viscosity reducer is EV-DAT viscosity reducer.

[0102] Example 6

[0103] A method for preparing a low-temperature paving asphalt mixture includes the following steps:

[0104] Mix 250 kg of aggregate according to gradation 1 evenly, then add 12 kg of water and stir evenly; then add 13 kg of emulsified asphalt 1 and stir evenly; finally add 5 kg of filler, 3 kg of rubber powder, 2 kg of basalt fiber and 0.7 kg of viscosity reducer, and stir evenly to obtain asphalt mixture.

[0105] In this embodiment 6, the aggregate includes coarse aggregate and fine aggregate. The coarse aggregate is basalt and steel slag, and the weight ratio of basalt to steel slag is 1:3.

[0106] The filler is limestone powder;

[0107] The viscosity reducer is EV-DAT viscosity reducer.

[0108] Example 7

[0109] A method for preparing a low-temperature paving asphalt mixture includes the following steps:

[0110] Mix 250 kg of aggregate according to gradation 1 evenly, then add 12 kg of water and stir evenly; then add 13 kg of emulsified asphalt 1 and stir evenly; finally add 5 kg of filler, 3 kg of rubber powder, 2 kg of basalt fiber and 0.7 kg of viscosity reducer, and stir evenly to obtain asphalt mixture.

[0111] In this embodiment 7, the aggregate includes coarse aggregate and fine aggregate. The coarse aggregate is basalt and steel slag, and the weight ratio of basalt to steel slag is 1:2.

[0112] The filler is limestone powder and cement, and the weight ratio of limestone powder to cement is 1:1.

[0113] The viscosity reducer is EV-DAT viscosity reducer.

[0114] Example 8

[0115] A method for preparing a low-temperature paving asphalt mixture includes the following steps:

[0116] Mix 250 kg of aggregate according to gradation 1 evenly, then add 12 kg of water and stir evenly; then add 13 kg of emulsified asphalt 1 and stir evenly; finally add 5 kg of filler, 3 kg of rubber powder, 2 kg of basalt fiber and 0.7 kg of viscosity reducer, and stir evenly to obtain asphalt mixture.

[0117] In this embodiment 8, the aggregate includes coarse aggregate and fine aggregate. The coarse aggregate is basalt and steel slag, and the weight ratio of basalt to steel slag is 1:2.

[0118] The filler is limestone powder and cement, and the weight ratio of limestone powder to cement is 5:3.

[0119] The viscosity reducer is EV-DAT viscosity reducer.

[0120] Example 9

[0121] A method for preparing a low-temperature paving asphalt mixture includes the following steps:

[0122] Mix 250 kg of aggregate according to gradation 1 evenly, then add 12 kg of water and stir evenly; then add 13 kg of emulsified asphalt 1 and stir evenly; finally add 5 kg of filler, 3 kg of rubber powder, 2 kg of basalt fiber and 0.7 kg of viscosity reducer, and stir evenly to obtain asphalt mixture.

[0123] In this embodiment 9, the aggregate includes coarse aggregate and fine aggregate. The coarse aggregate is basalt and steel slag, and the weight ratio of basalt to steel slag is 1:2.

[0124] The filler is limestone powder and cement, and the weight ratio of limestone powder to cement is 3:1.

[0125] The viscosity reducer is EV-DAT viscosity reducer.

[0126] Example 10

[0127] A method for preparing a low-temperature paving asphalt mixture includes the following steps:

[0128] Mix 250 kg of aggregate according to gradation 1 evenly, then add 12 kg of water and stir evenly; then add 13 kg of emulsified asphalt 1 and stir evenly; finally add 5 kg of filler, 3 kg of rubber powder, 2 kg of basalt fiber and 0.7 kg of viscosity reducer, and stir evenly to obtain asphalt mixture.

[0129] In this embodiment 10, the aggregate includes coarse aggregate and fine aggregate. The coarse aggregate is basalt and steel slag, and the weight ratio of basalt to steel slag is 1:2.

[0130] The filler is limestone powder and cement, and the weight ratio of limestone powder to cement is 3:1.

[0131] The viscosity reducer is an LRD-oil-based viscosity reducer.

[0132] Example 11

[0133] A method for preparing a low-temperature paving asphalt mixture includes the following steps:

[0134] Mix 250 kg of aggregate according to gradation 1 evenly, then add 12 kg of water and stir evenly; then add 13 kg of emulsified asphalt 1 and stir evenly; finally add 5 kg of filler, 3 kg of rubber powder, 2 kg of basalt fiber and 0.7 kg of viscosity reducer, and stir evenly to obtain asphalt mixture.

[0135] In this embodiment 10, the aggregate includes coarse aggregate and fine aggregate. The coarse aggregate is basalt and steel slag, and the weight ratio of basalt to steel slag is 1:2.

[0136] The filler is limestone powder and cement, and the weight ratio of limestone powder to cement is 3:1.

[0137] The viscosity reducer is sodium laurylamide.

[0138] Examples 12-16

[0139] The only difference between Examples 12-16 and Example 9 is the choice of emulsified asphalt, as shown in Table 3 below.

[0140] Table 3

[0141]

[0142]

[0143] Example 17

[0144] The only difference between Example 17 and Example 16 is that in Example 17, the aggregates are mixed evenly according to gradation 1, while the rest are the same as in Example 16.

[0145] Comparative Example

[0146] Comparative Example 1

[0147] The only difference between Comparative Example 1 and Example 16 is that in Comparative Example 1, USP low-temperature road asphalt was used instead of emulsified asphalt 6, while all other aspects remained the same as in Example 16.

[0148] Comparative Example 2

[0149] The only difference between Comparative Example 2 and Example 16 is that in Comparative Example 2, SBS modified bitumen was used instead of emulsified bitumen 6, while all other aspects remained the same as in Example 16.

[0150] Performance testing

[0151] The basic properties of the asphalt mixtures prepared in Examples 1-17 and Comparative Examples 1-2 were tested according to the "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" (JTG E20-2011). The specific test results are shown in Table 4 below.

[0152] The 3-day splitting strength and 7-day splitting strength were tested at 10-15℃.

[0153] Table 4

[0154]

[0155]

[0156] Based on Examples 2, 4-6 and Table 4, it can be seen that the coarse aggregate is composed of basalt and steel slag, and the weight ratio of basalt to steel slag is (0.5-1):(1.5-2.3), which can improve the early strength of asphalt mixture.

[0157] As can be seen from Examples 16 and 17 and Table 4, the gradation of aggregates also affects the early strength of asphalt mixtures. In this application, mixing according to design gradation 1 can improve the early strength of asphalt mixtures.

[0158] As can be seen from Examples 9-11 and Table 4, the choice of viscosity reducer affects the workability of asphalt mixtures. Using EV-DAT viscosity reducer can greatly improve the workability of asphalt mixtures.

[0159] As can be seen from Examples 9, 12-16 and Comparative Examples 1-2 and Table 4, emulsified asphalt has a significant impact on the workability and early strength of asphalt mixtures. Using the emulsified asphalt of this application can improve the workability of asphalt mixtures and enhance the early strength of asphalt mixtures while achieving low-temperature paving.

[0160] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A low-temperature paving asphalt mixture, characterized in that: Including the following parts by weight of raw materials: 10-15 parts emulsified asphalt, 200-300 parts aggregate, 3-8 parts filler, 1-5 parts rubber powder, 1-2 parts basalt fiber, 0.5-1 parts viscosity reducer, and 10-15 parts water; The viscosity reducer is selected from either EV-DAT viscosity reducer or LRD-oil-based viscosity reducer. The oil-stone ratio is 4%-5%; Based on the total amount of emulsified asphalt, the emulsified asphalt comprises the following raw materials in parts by weight: 50-70 parts SBS modified bitumen, 1-3 parts emulsifier, 0.05-0.15 parts stabilizer and 30-45 parts distilled water; The stabilizer is polyvinyl alcohol and anhydrous calcium chloride, and the mass ratio of polyvinyl alcohol to anhydrous calcium chloride is (1-2):(0.5-1).

2. The low-temperature paving asphalt mixture according to claim 1, characterized in that: The emulsifier is a cationic emulsifier.

3. The low-temperature paving asphalt mixture according to claim 2, characterized in that: The emulsified asphalt also includes an acidic pH adjuster.

4. The low-temperature paving asphalt mixture according to claim 1, characterized in that: The emulsified asphalt is prepared by the following method: Heat distilled water to 70-80℃, dissolve polyvinyl alcohol in hot water, and after it is completely dissolved, lower the temperature of the aqueous solution to 60-65℃, add emulsifier and calcium chloride, stir well, and then add an acidic pH adjuster to obtain a soap solution with a pH of 2-3. While stirring, hot SBS modified asphalt at a temperature of 80-100℃ is slowly added to the soap solution and stirred evenly to obtain emulsified asphalt.

5. The low-temperature paving asphalt mixture according to claim 1, characterized in that: The aggregate includes coarse aggregate and fine aggregate, and the coarse aggregate includes at least one of basalt and steel slag.

6. The low-temperature paving asphalt mixture according to claim 1, characterized in that: The filler is limestone powder and cement, and the mass ratio of limestone powder to cement is (3-5):(1-3).

7. The method for preparing low-temperature paving asphalt mixture according to any one of claims 1-6, characterized in that: Includes the following steps: Mix the coarse and fine aggregates evenly, then add water and mix evenly; then add emulsified asphalt and mix evenly; finally add filler, rubber powder, basalt fiber and viscosity reducer, and mix evenly to obtain asphalt mixture.

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