No. 50 asphalt and preparation method thereof

Abstract

The invention belongs to the technical field of road asphalt, and particularly relates to 50 # asphalt and a preparation method thereof, the 50 # asphalt comprises, by weight, 100 parts of 70 # matrix asphalt, 2-25 parts of hard deoiled asphalt, 0.5-0.7 part of a polymer modifier and 0.5-1 part of a phase change material. A blending micro-modification mode is adopted, the situation that product benefits are affected by too many intermediate transition products caused by brand switching during production of small-batch 50 # asphalt through a direct fraction method is avoided, compared with 50 # asphalt through an existing direct fraction method and a blending method, the method has good construction workability, the construction temperature of the method is close to that of common 70 # asphalt, and the construction mode does not need to be changed; good high and low temperature performance is considered, the index surplus is sufficient, and the probability of quality risk in the later use process is greatly reduced; and the material has good anti-aging performance, the property is basically not changed after the material is stored for 10 days at high temperature, and the index also meets the JTG F40 index requirement of the Ministry of Communications.

Description

Technical Field

[0001] The invention belongs to the technical field of road asphalt, and specifically relates to No. 50 asphalt and a preparation method thereof. Background Art

[0002] With the development of the economy, traffic volume and traffic load have increased rapidly. At the same time, the frequency of extreme climate has also increased significantly, making rutting the main type of disease in domestic asphalt pavements. Studies have shown that under the action of load, the middle and lower layers of asphalt pavements are prone to deformation. Therefore, improving the rutting resistance of the middle and lower layers has become one of the key technologies to solve the rutting problem. Using high modulus asphalt or hard asphalt instead of traditional No. 70 asphalt in the middle and lower layers of asphalt pavements can effectively improve the rutting resistance of asphalt pavements. Compared with high modulus asphalt, hard asphalt is more cost-effective for projects with limited budgets. As a type of hard asphalt, No. 50 asphalt is an effective way to solve the rutting problem of asphalt pavements.

[0003] However, the current No. 50 asphalt has certain problems in both production and performance. From a production perspective, there are two production methods for No. 50 asphalt: straight distillation and blending. Straight distillation method: (1) It is generally suitable for large-scale production of No. 50 asphalt. For small-batch order requirements, the straight distillation method is used, which has the problem of too many intermediate transition products when switching grades, and the product economic benefit accounting is not ideal; (2) It cannot take into account its three major indicators, or there is a small surplus of indicators, which will cause quality problems; (3) Compared with No. 70 asphalt, it has excellent high-temperature performance and good temperature sensitivity, but its low-temperature performance will be slightly worse; (4) In order to coordinate the indicators of No. 50 asphalt, the control accuracy of the straight distillation process is required to be improved; (5) There are also certain requirements for crude oil. Only suitable crude oil can produce No. 50 asphalt that meets the requirements of JTG F40; (6) Some of the No. 50 asphalt produced by the straight distillation method have the problem of rapid indicator decay. Although the blending method for producing No. 50 asphalt overcomes the disadvantage (1) of the straight distillation method and makes production more convenient, it also has certain hidden dangers: (1) The blending method often uses soft and hard components to blend. The hard component is generally de-oiled asphalt, and the soft component is generally residual oil, wax oil, aromatic oil, ordinary No. 70 asphalt, No. 90 asphalt, etc. The blending process often only focuses on the asphalt indicators, while ignoring the component structure of the blending raw materials and the No. 50 asphalt after blending. The four components of No. 50 asphalt will appear unreasonable, and there will be problems such as poor adhesion to the aggregate and looseness. Secondly, the problems (2), (3), and (6) of the straight distillation method also exist in the blending method.

[0004] Application No. CN 201410289693.0 relates to a No. 50 asphalt and its production method. The patent uses the residual oil produced by the crude oil of Marui: Boskan = 7:3 as the hard component and the four-line wax oil as the soft component. The soft components are mixed in a blending ratio of 8-12% to prepare No. 50 asphalt. The patent feedback overcomes the problem of the existing No. 50 asphalt's unqualified low-temperature ductility. The ductility at 10°C before and after aging reaches 17cm and 6cm, meeting the No. 50 asphalt standard requirements of the Ministry of Transportation JTG F40. However, the technical solution does not reflect its anti-aging performance, construction and workability indicators, and the ductility before and after aging is limited.

[0005] Application No. CN 201911012026.7 relates to a No. 50 asphalt and its preparation method and application. The patent selects Caesarje crude oil, Geno crude oil, and Plutone crude oil as mixed crude oils, oil slurry as distillation regulators, and mild oxidants as raw materials. No. 50 asphalt is obtained through normal and vacuum distillation and deep distillation. However, the No. 50 asphalt has large fluctuations in low-temperature elongation, and the elongation is sometimes greater than 15 cm and sometimes less than 15 cm, which does not meet the Ministry of Transport's JTG F4050 asphalt standard requirements. In addition, its indicators only reflect the three major indicators before aging, and there is no description of indicators after aging, so its true performance cannot be judged.

[0006] Application No. CN 201811474299.9 relates to a No. 50A grade road petroleum asphalt and its preparation method. The patent prepares No. 50 asphalt from vacuum residue oil, anti-rutting agent and aromatic oil. The No. 50 asphalt prepared by the patent has a poor elongation index before and after aging, and there is a quality risk problem of elongation. Summary of the invention

[0007] The purpose of the present invention is to provide a No. 50 asphalt and a preparation method to solve the problems existing in the above-mentioned background technology.

[0008] To achieve the above objectives, this application is implemented through the following technical solutions:

[0009] A No. 50 asphalt is composed by weight of 100 parts of No. 70 base asphalt, 2-25 parts of hard deoiled asphalt, 0.5-0.7 parts of a polymer modifier and 0.5-1 parts of a phase change material.

[0010] Furthermore, the No. 70 base asphalt comes from a constant pressure reduction device, and is required to have a softening point of ≮47°C, a needle penetration of 65-75dmm, a flash point of ≮260°C, and its raw materials must contain a Boskan crude oil, and the Boskan blending ratio is 30-40%, its saturated content is 15-25%, the aromatic content is 40-45%, the colloid is 21-28%, and the asphaltene is 9-13%.

[0011] Furthermore, the hard de-oiled asphalt comes from a solvent deasphalting device, and is required to have a softening point of ≮58°C, a needle penetration of ≯30dmm, saturated content of 3-8%, aromatic content of 30-35%, resin content of 15-22%, and asphaltenes of 35-45%.

[0012] Furthermore, the phase change material is polyethylene wax, model PE-6000, which is polyethylene wax with a molecular weight of about 6000.

[0013] Furthermore, the polymer modifier is a linear or star-shaped SBS modifier with a molecular weight of 100,000-300,000 and a block ratio of 3:7, or an SBR modifier.

[0014] The method for preparing No. 50 asphalt described in any one of the above items comprises the following steps:

[0015] S1. Add hard deoiled asphalt and polymer modifier to No. 70 base asphalt, heat to 160-175°C, and shear at a shear rate of 4000r / min for 0.3h using a shearing machine;

[0016] S2. Transfer the mixture after shearing in step S1 to a constant temperature heating jacket, add phase change material, stir at a constant temperature of 160-175° C. and a speed of 400 r / min for 1.0 h, and then cool naturally to room temperature.

[0017] The beneficial effects of the present invention are:

[0018] 1. The present invention adopts a blending and slightly modified method to avoid the problem of excessive intermediate transition products and unsatisfactory product economic benefit accounting caused by brand switching during the production of small batches of No. 50 asphalt using the straight distillation method, thereby improving production flexibility and economic benefits.

[0019] 2. Compared with the straight-run and blended No. 50 asphalts in conventional patents, the present invention has good construction and workability, and its construction temperature is similar to that of ordinary No. 70 asphalt, and there is no need to change the construction method.

[0020] 3. The patent of this invention takes into account good high and low temperature performance, and the index has sufficient redundancy, which greatly reduces the probability of quality risks in the later use process.

[0021] 4. The patent of this invention has good anti-aging performance. After being stored at high temperature for 10 days, the properties are basically unchanged, and the indicators also meet the requirements of JTG F40 of the Ministry of Transport. DETAILED DESCRIPTION

[0022] The technical solution of the present invention is described in detail below through examples. The following examples are merely exemplary and can only be used to explain and illustrate the technical solution of the present invention, but cannot be construed as limiting the technical solution of the present invention.

[0023] Embodiment 1:

[0024] Asphalt No. 70 (penetration 68dmm, softening point 47.5℃, saturated fraction 17%, aromatic fraction 43%, colloid 25%, asphaltene 12%, flash point 270℃), is obtained by cutting the crude oil of Marui, Blue Light and Boskan by actual boiling point, of which the proportion of Boskan is 35%, 100 parts of this raw material; 0.7 parts of polymer modifier 791SBS; 2 parts of hard deoiled asphalt (penetration 0dmm, softening point 115℃, saturated fraction 4%, aromatic fraction 30%, colloid 22%, asphaltene 41%); phase change material: 0.5 parts of polyethylene wax. Preparation method: Add hard deoiled asphalt and SBS modifier to the base asphalt, heat to 165℃, use a shearing machine, shear at a shear rate of 4000r / min for 0.3h, transfer to a constant temperature heating jacket after shearing, add phase change material, keep constant temperature at 165℃, and stir at a speed of 400r / min for 1.0h.

[0025] Embodiment 2:

[0026] No. 70 asphalt (penetration 68dmm, softening point 47.5℃, saturated fraction 17%, aromatic fraction 43%, gum 25%, asphaltene 12%, flash point 270℃) is obtained by cutting the actual boiling point of Marui, Blue Light and Boskan crude oil, among which the proportion of Boskan is 35%, 100 parts of this raw material; 0.5 parts of polymer modifier 4303SBS; 0.2 parts of SBR modifier; 15 parts of hard deoiled asphalt (penetration 18dmm, softening point 59℃, saturated fraction 7%, aromatic fraction 33%, gum 18%, asphaltene 38%); phase change material: 1.0 parts of polyethylene wax. Preparation method: Add hard deoiled asphalt, SBS modifier and SBR modifier to the base asphalt, heat to 165°C, use a shearing machine to shear at a shear rate of 4000r / min for 0.3h, after shearing, transfer to a constant temperature heating jacket, add phase change material, keep a constant temperature of 165°C, and stir at a speed of 400r / min for 1.0h.

[0027] Comparative Example 1:

[0028] The 50-grade asphalt was obtained by straight distillation using mixed crude oil from Ma Rui and Lan Guang, and the cutting temperature was 440°C. Storage stability test: stored at 150°C, and key indicators were regularly sampled and analyzed.

[0029] Table 1 Test results of different embodiments

[0030]

[0031] Table 1

[0032]

[0033] As shown in Table 1, the 60°C dynamic viscosity of the No. 50 asphalt prepared by this patent is higher than that of the comparative example, indicating that it has excellent high-temperature performance and stronger bond strength with aggregates, but its 135°C viscosity is lower than that of the No. 50 asphalt, and is similar to that of the No. 70 asphalt (the viscosity of the No. 70 asphalt at 135°C: 0.39pa·s), indicating that its construction and workability are better than those of the comparative example. After replacing No. 70 with No. 50 asphalt, there is no need to increase the construction temperature. Secondly, under the premise of ensuring the softening point index, its 10°C elongation before and after aging is better, and the surplus is larger, it has better high and low temperature performance, and is not prone to quality risks. Compared with the comparative example, the penetration index is also better, indicating that its temperature sensitivity is better.

[0034] Table 2 Comparison of storage stability between Example 1 and comparative example

[0035]

[0036] Table 2

[0037]

[0038] As shown in Table 2, the No. 50 asphalt prepared by this patent has a good component structure, and its four components are basically consistent with the straight distillation method, and the high-temperature storage stability is good. After being stored at 150°C for 10 days, the three major indicators before aging are qualified and abundant, and it has good anti-aging performance. Compared with the comparative example, after 6 days of storage, the elongation reduction rate of the comparative example is 13%, and the elongation of Example 1 is increased by 6.7%.

[0039] The embodiments of the present invention are merely examples for clearly explaining the present invention, and are not intended to limit the implementation methods of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all implementation methods here, and these obvious changes or modifications derived from the spirit of the present invention are still within the scope of protection of the present invention.

Claims

1. A No. 50 asphalt, characterized in that: It consists of 100 parts of No. 70 base asphalt, 2-25 parts of hard deoiled asphalt, 0.5-0.7 parts of polymer modifier and 0.5-1 parts of phase change material by weight.

2. The No. 50 asphalt according to claim 1, characterized in that: The No. 70 base asphalt comes from a constant pressure reduction device, and is required to have a softening point of ≮47°C, a needle penetration of 65-75dmm, a flash point of ≮260°C, and its raw materials must contain a Boskan crude oil, and the Boskan blending ratio is 30-40%, its saturated content is 15-25%, the aromatic content is required to be 40-45%, the colloid is 21-28%, and the asphaltene is 9-13%.

3. The No. 50 asphalt according to claim 1, characterized in that: The hard de-oiled asphalt comes from a solvent deasphalting device, and is required to have a softening point of ≮58°C, a needle penetration of ≯30dmm, saturated content of 3-8%, aromatic content of 30-35%, colloid content of 15-22%, and asphaltenes of 35-45%.

4. The No. 50 asphalt according to claim 1, characterized in that: The phase change material is polyethylene wax, model PE-6000, which is polyethylene wax with a molecular weight of 6000.

5. The No. 50 asphalt according to claim 1, characterized in that: The modifier is a linear or star-shaped SBS modifier with a molecular weight of 100,000-300,000 and a block ratio of 3:7, or an SBR modifier.

6. A method for preparing No. 50 asphalt as described in any one of claims 1 to 5, characterized in that: The following steps are involved: S1. Add hard deoiled asphalt and polymer modifier to No. 70 base asphalt, heat to 160-175°C, and shear at a shear rate of 4000r / min for 0.3h using a shearing machine; S2. Transfer the mixture after shearing in step S1 to a constant temperature heating jacket, add phase change material, stir at a constant temperature of 160-175° C. and a speed of 400 r / min for 1.0 h, and then cool naturally to room temperature.

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