CN118530602A - High-viscosity high-elasticity anti-aging modified asphalt and preparation method thereof - Google Patents

Abstract

The present invention relates to the technical field of modified asphalt, and in particular to a high-viscosity, high-elastic, anti-aging modified asphalt and a preparation method thereof. The present invention provides a high-viscosity, high-elastic, anti-aging modified asphalt, which comprises 100 parts of base asphalt, 7 to 13 parts of high-viscosity and high-elastic agent, and 3 to 8 parts of anti-aging agent, in terms of mass fractions; wherein the high-viscosity and high-elastic agent comprises: 5 to 7 parts of thermoplastic styrene-butadiene rubber, 1 to 3 parts of polyurethane, and 1 to 3 parts of lignin fiber. The modified asphalt provided by the present invention has both high viscosity and high elasticity, and anti-fatigue and anti-aging properties, and is also suitable for harsh environments such as high or low temperatures, greatly extending the service life of asphalt pavement. Moreover, the preparation method of the high-viscosity, high-elastic, anti-aging modified asphalt provided by the present invention is simple, greatly saves construction time and construction costs, and improves construction efficiency.

Description

A high-viscosity, high-elastic, anti-aging modified asphalt and preparation method thereof

Technical Field

The present invention relates to the technical field of modified asphalt, and in particular to a high-viscosity, high-elastic, anti-aging modified asphalt and a preparation method thereof.

Background Art

Asphalt pavement has good bearing capacity, adhesion and elastic plasticity, fast construction and repair speed, good anti-skid performance and visual effect, and is mostly used as pavement material for high-grade highways. However, with the increasing traffic volume, higher requirements have been placed on the performance of high-grade highways, especially the road surface should not only meet the requirements of structural strength, but also take into account driving safety and reduce the impact on the surrounding environment. For example, when it rains, the road surface of the highway is slippery and prone to water accumulation, which increases the probability of traffic accidents; for another example, the increase in the number of vehicles in the city has led to increasingly serious road traffic noise, which seriously affects the living environment of the people.

In order to solve the problems of water accumulation, slippage and noise pollution on the road, some studies have designed the surface structure of the road into an open-graded large-pore structure. The structural porosity of the road surface with this structure is mostly 15% to 25%, which can achieve rapid drainage and noise reduction. In addition, the surface of this road surface is rough and the structural depth is large, which increases the friction between the car tires and the road surface, thereby achieving an anti-skid effect and improving driving safety. However, the larger porosity also makes the asphalt have a larger contact area with the external environment, and it is easily damaged by ultraviolet rays, oxygen and water erosion, which leads to road surface diseases, such as loose road surface, cracks and rutting, which seriously affect the safety and comfort of driving. Therefore, it is necessary to use asphalt with high viscosity, good elasticity and anti-aging to improve the bonding degree between aggregates and ensure that the road surface has a longer service life. This is important for preventing the asphalt from peeling off and the aggregate from loosening.

At present, there are many types of modifiers that can be used to improve the viscoelasticity of matrix asphalt, mainly including thermoplastic elastomers, rubbers, resins, fibers, nanomaterials and other types. Among them, the production cost of thermoplastic elastomer modifiers is high and the low-temperature performance is poor, which may limit the use of asphalt in low-temperature environments; the production cost of rubber modifiers is high, and it may cause the color of the road surface to turn black, affecting the visual effect when the light is insufficient; the elastic modulus of resin modifiers is low, it is difficult to achieve the elastic modulus required by the road surface, and it will increase the hardness of the road surface and reduce the comfort of the road surface; the construction of fiber modifiers is difficult, and special construction technology is required, resulting in high construction costs; the production cost of nanomaterials is also high, and special construction technology and equipment are required, and the construction is difficult. In summary, the existing high-viscosity and high-elasticity modifiers are either high in cost or difficult to construct, and rarely have anti-aging properties, which cannot meet the needs of actual production.

Summary of the invention

In view of the above technical problems, the present invention provides a high-viscosity, high-elasticity, anti-aging modified asphalt and a preparation method thereof. The modified asphalt provided by the present invention has both high viscosity and high elasticity, anti-fatigue and anti-aging properties, and is also suitable for harsh environments such as high or low temperatures, greatly extending the service life of asphalt pavement.

In order to solve the above technical problems, the present invention adopts the following technical solutions:

The present invention provides a high-viscosity, high-elasticity, anti-aging modified asphalt, which comprises 100 parts of base asphalt, 7-13 parts of high-viscosity and high-elasticity agent and 3-8 parts of anti-aging agent in terms of weight; wherein the high-viscosity and high-elasticity agent comprises: 5-7 parts of thermoplastic styrene-butadiene rubber, 1-3 parts of polyurethane and 1-3 parts of lignin fiber.

The high-viscosity, high-elasticity, and anti-aging modified asphalt provided by the present invention uses a specific ratio of thermoplastic styrene-butadiene rubber, polyurethane, and lignocellulose as high-viscosity and high-elastic agents to modify the base asphalt; wherein, thermoplastic styrene-butadiene rubber has good wear resistance, heat resistance, and aging resistance, and using it to modify asphalt can greatly improve the high temperature resistance and aging resistance of asphalt; polyurethane has the functions of enhancing viscosity and adhesion, improving flexibility, durability, and improving low temperature performance in asphalt; lignin fiber, as a natural material, is low in cost, and is used as a filler in asphalt to enhance the mechanical properties of modified asphalt, and can also improve the deformation resistance and crack resistance of asphalt mixture, so that it can better adapt to changes in traffic load and ambient temperature. The high-viscosity, high-elasticity, and anti-aging modified asphalt prepared by the present invention using a high-viscosity, high-elasticity agent and an anti-aging agent simultaneously has excellent viscoelastic properties, fatigue resistance, and high and low temperature resistance, while also having good anti-aging performance, solving the problem that traditional modified asphalt is difficult to have high viscoelastic properties and anti-aging performance at the same time.

Preferably, in terms of weight percentage, the above-mentioned high-viscosity, high-elasticity, anti-aging modified asphalt includes 100 parts of base asphalt, 10 parts of high-viscosity and high-elasticity agent and 5.5 parts of anti-aging agent; wherein the high-viscosity and high-elasticity agent includes: 6 parts of thermoplastic styrene-butadiene rubber, 2 parts of polyurethane and 2 parts of lignin fiber.

In combination with the first aspect, the anti-aging agent includes, by weight: 1 to 3 parts of nickel-containing compounds, 1 to 3 parts of amine compounds, 0.5 to 1 part of carbon black, and 0.5 to 1 part of hindered amine.

Among them, nickel-containing compounds can prevent and delay the aging of base asphalt, amine compounds can weaken the oxidative effect of oxygen in the air on base asphalt, light shielding agent carbon black and light stabilizer hindered amine work together to improve the ability of base asphalt to resist ultraviolet rays. The anti-aging agent composed of the above four ingredients can greatly enhance the anti-aging ability of base asphalt and extend the service life of asphalt pavement.

Preferably, the anti-aging agent comprises, by weight: 2 parts of nickel-containing compounds, 2 parts of amine compounds, 0.7 parts of carbon black, and 0.8 parts of hindered amines. This ratio of anti-aging agent can make the obtained modified asphalt have excellent comprehensive properties.

In actual construction applications, the above-mentioned high-viscosity, high-elasticity, anti-aging modified asphalt can also be used in combination with the designed amount of aggregate.

The second aspect of the present invention provides a method for preparing the above-mentioned high-viscosity, high-elasticity, anti-aging modified asphalt, the steps comprising: heating the base asphalt to a fluid state, adding the high-viscosity and high-elasticity agent under heating conditions and mixing evenly; then adding the anti-aging agent, mixing evenly according to a specific stirring procedure to obtain the high-viscosity, high-elasticity, anti-aging modified asphalt.

The preparation method of the high-viscosity, high-elasticity, anti-aging modified asphalt provided by the present invention only requires directly adding the high-viscosity, high-elasticity agent and the anti-aging agent to the base asphalt in sequence, and the operation steps are simple, saving construction time and construction costs.

In combination with the second aspect, the heating temperature when the base asphalt is heated to a fluid state is 165°C±5°C; the heating temperature in the heating conditions is 170°C±5°C. This temperature range can ensure that the high-viscosity and high-elasticity agent, anti-aging agent and base asphalt are fully mixed, thereby ensuring that the obtained modified asphalt has high viscosity and elasticity, high strength and good anti-aging ability.

In combination with the second aspect, the specific stirring procedure is a first low-speed stirring step - a high-speed stirring step - a second low-speed stirring step; the rotation speeds of the first low-speed stirring step and the second low-speed stirring step are 50 to 70 r/min, and the rotation speed of the high-speed stirring step is 1800 to 2200 r/min.

Preferably, the rotation speed of the first low-speed stirring step and the second low-speed stirring step is 60 r/min, and the rotation speed of the high-speed stirring step is 2000 r/min.

In combination with the second aspect, the stirring time of the first low-speed stirring step is 8 to 12 minutes, the stirring time of the high-speed stirring step is 60 to 80 minutes, and the stirring time of the second low-speed stirring step is 5 to 10 minutes.

The third aspect of the present invention provides a mixture, which includes high-viscosity, high-elasticity, and anti-aging modified asphalt prepared according to the above-mentioned preparation method of high-viscosity, high-elasticity, and anti-aging modified asphalt and aggregate.

The fourth aspect of the present invention provides a method for preparing the above-mentioned mixture, the steps comprising: mixing the high-viscosity and high-elastic agent, anti-aging agent, matrix asphalt and aggregate evenly, and stirring at 180±2°C at a stirring rate of 65-75r/min for more than 2 minutes.

In actual construction applications, the inventors have discovered through a large number of experiments that the above-mentioned high-viscosity and high-elastic agent, anti-aging agent, matrix asphalt and aggregate can be mixed in a certain mass ratio and evenly mixed under the above-mentioned conditions before construction and use. There is no need to pre-mix the high-viscosity and high-elastic agent, anti-aging agent and matrix asphalt evenly and then mix them with the aggregate, which significantly improves the construction efficiency.

The beneficial effects of the present invention are as follows: the high-viscosity, high-elastic, anti-aging modified asphalt provided by the present invention has high-viscosity, high-elasticity, good anti-fatigue and anti-aging properties, and is also suitable for harsh environments such as high or low temperatures, greatly extending the service life of asphalt pavement; moreover, the high-viscosity, high-elastic agent and anti-aging agent used in the present invention are selected from widely available and inexpensive materials as raw materials, greatly reducing the construction cost. In addition, the present invention adopts a direct-cast preparation method, and the high-viscosity, high-elastic agent, anti-aging agent, matrix asphalt and aggregate are uniformly mixed together and can be used for pavement paving, the construction method is simple, and the construction efficiency is significantly improved.

DETAILED DESCRIPTION

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 specific 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.

The relevant chemical reagents used in the embodiments of the present invention are all commercially available products.

Examples 1 to 3

Embodiments 1 to 3 of the present invention each provide a high-viscosity, high-elastic, anti-aging modified asphalt, and the specific components thereof are shown in Table 1 in terms of mass fractions.

Example 4

This embodiment provides a method for preparing the high-viscosity, high-elastic, anti-aging modified asphalt in Embodiment 1, the steps comprising:

According to the formula composition in Example 1, the container containing the base asphalt is placed in an oven and heated to 165°C. At this time, the base asphalt is in a flowing state. It is then transferred to a constant temperature oil bath at 170°C, and the high-viscosity and high-elastic agent and anti-aging agent in Example 1 are added in sequence. The mixture is first stirred at a stirring rate of 60 r/min for 10 minutes to allow the raw materials to fully dissolve. The stirring rate is then increased to 2000 r/min and stirred for 70 minutes to thoroughly mix the raw materials. Finally, the mixture is stirred at a stirring rate of 60 r/min for 8 minutes to expel the bubbles inside the asphalt, thereby obtaining a liquid high-viscosity, high-elastic, anti-aging modified asphalt.

Example 5

This embodiment provides a method for preparing the high-viscosity, high-elastic, anti-aging modified asphalt in Embodiment 2, the steps comprising:

According to the formula composition in Example 2, the container containing the base asphalt is placed in an oven and heated to 160°C. At this time, the base asphalt is in a flowing state. It is then transferred to a constant temperature oil bath at 165°C, and the high-viscosity and high-elastic agent and anti-aging agent in Example 2 are added in sequence. The mixture is first stirred at a stirring rate of 50 r/min for 8 minutes to fully dissolve the raw materials. The stirring rate is then increased to 1800 r/min and stirred for 60 minutes to thoroughly mix the raw materials. Finally, it is stirred at a stirring rate of 50 r/min for 5 minutes to expel the bubbles inside the asphalt, thereby obtaining a high-viscosity, high-elastic, anti-aging modified asphalt in liquid form.

Example 6

This embodiment provides a method for preparing the high-viscosity, high-elastic, anti-aging modified asphalt in Embodiment 3, the steps comprising:

According to the formula composition in Example 3, the container containing the base asphalt is placed in an oven and heated to 170°C. At this time, the base asphalt is in a flowing state. It is then transferred to a constant temperature oil bath at 175°C, and the high-viscosity and high-elastic agent and anti-aging agent in Example 3 are added in sequence. The mixture is first stirred at a stirring rate of 70 r/min for 10 minutes to allow the raw materials to fully dissolve. The stirring rate is then increased to 2200 r/min and stirred for 80 minutes to allow the raw materials to be thoroughly mixed. Finally, the mixture is stirred at a stirring rate of 70 r/min for 10 minutes to expel the bubbles inside the asphalt, thereby obtaining a high-viscosity, high-elastic, anti-aging modified asphalt in liquid form.

Comparative Example 1

This comparative example provides a modified asphalt, and its specific components, calculated by weight, are shown in Table 1. The difference between it and the components in Example 1 is that only high-viscosity and high-elasticity agent-modified asphalt is used, and it is prepared according to the method in Example 4.

Comparative Example 2

This comparative example provides a modified asphalt, and its specific components, calculated by weight, are shown in Table 1. The difference between the components in Example 1 and those in Example 1 is that only the anti-aging agent is used to modify the asphalt, and the preparation is carried out according to the method in Example 4.

Comparative Example 3

This comparative example provides a modified asphalt, whose specific components are shown in Table 1 in terms of mass fractions. The difference between it and the components in Example 1 is that the high-viscosity and high-elastic agent does not contain wood cellulose, and it is prepared according to the method in Example 4.

Comparative Example 4

This comparative example provides a modified asphalt, whose specific components, measured by weight, are shown in Table 1. The difference between the components in Example 1 and those in Example 1 is that the anti-aging agent does not contain carbon black, and the asphalt is prepared according to the method in Example 4.

Table 1 Mass fractions of each raw material in Examples 1 to 3 and Comparative Examples 1 to 4

Test example

In order to examine the various properties of the high-viscosity, high-elasticity and anti-aging modified asphalt of the present invention, basic performance tests and short-term aging and long-term aging experiments were carried out on the modified asphalts prepared in Examples 4 to 6 and Comparative Examples 1 to 4, respectively. The specific test results are shown in Tables 2 to 5.

Table 2 Basic properties of modified asphalt obtained from different examples and comparative examples

Table 3 Various properties of modified asphalt obtained from different embodiments and comparative examples (short-term aging)

It can be seen from the data in Table 3 that after short-term aging, the anti-fatigue performance, high temperature performance and low temperature performance of the modified asphalt obtained in Examples 4 to 6 are different, but the difference is very small, and the performance can be considered consistent. It shows that the modified asphalt provided by the present invention has high viscosity and high elasticity, anti-fatigue performance and high and low temperature resistance at the same time. Compared with Example 4, the anti-fatigue performance and low temperature performance of the modified asphalt obtained in Example 1 are reduced, indicating that the anti-aging agent plays an important role in improving the anti-fatigue performance and low temperature performance of the modified asphalt; the anti-fatigue performance, high temperature performance and low temperature performance of the modified asphalt obtained in Example 2 are reduced, indicating that the high viscosity and high elastic agent plays an important role in improving the anti-fatigue performance, high temperature performance and low temperature performance of the modified asphalt; the high temperature performance and low temperature performance of the modified asphalt obtained in Example 3 are both reduced, indicating that the addition of wood cellulose can improve the high temperature performance and low temperature performance of the modified asphalt; the high temperature performance of the modified asphalt obtained in Example 4 is reduced, indicating whether the addition of carbon black has a greater impact on improving the high temperature performance of the modified asphalt.

Table 4 Various properties of modified asphalt obtained from different embodiments and comparative examples (long-term aging)

It can be seen from the data in Table 4 that after long-term aging, the performance gap between Examples 4 to 6 is still small, and it can be considered that the performance is consistent. Compared with Example 4, Comparative Example 1 shows that the anti-aging agent plays an important role in improving the fatigue resistance and low-temperature performance of the modified asphalt; Comparative Example 2 shows that the high-viscosity and high-elastic agent plays an important role in improving the fatigue resistance, high-temperature performance and low-temperature performance of the modified asphalt; Comparative Example 3 shows that the addition of wood cellulose can also improve the fatigue resistance of the long-term aged modified asphalt; Comparative Example 4 shows that the addition of carbon black can improve the high-temperature performance of the long-term aged modified asphalt.

Table 5 Anti-aging performance data of modified asphalt obtained from different embodiments and comparative examples

It can be seen from the data in Table 5 that the fatigue resistance and high and low temperature resistance of the modified asphalt provided by the present invention after long-term aging are reduced by about 20.3% compared with short-term aging, while the anti-aging performance of the comparative example 1 without adding an anti-aging agent is reduced by 29.7%, which is significantly higher than that of Examples 4 to 6 with added anti-aging agents, indicating that the modified asphalt provided by the present invention has good high viscosity and high elastic properties as well as good anti-aging performance.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modification, equivalent substitution or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (10)

1. The high-viscosity high-elasticity anti-aging modified asphalt is characterized by comprising, by mass, 100 parts of matrix asphalt, 7-13 parts of high-viscosity high-elasticity agent and 3-8 parts of anti-aging agent; wherein the high viscosity high elastic agent comprises: 5-7 parts of thermoplastic styrene butadiene rubber, 1-3 parts of polyurethane and 1-3 parts of lignin fiber.

2. The high-viscosity high-elasticity anti-aging modified asphalt according to claim 1, wherein the modified asphalt comprises 100 parts by mass of matrix asphalt, 10 parts by mass of high-viscosity high-elasticity agent and 5.5 parts by mass of anti-aging agent; wherein the high viscosity high elastic agent comprises: 6 parts of thermoplastic styrene-butadiene rubber, 2 parts of polyurethane and 2 parts of lignin fiber.

3. The high-viscosity high-elasticity anti-aging modified asphalt according to claim 1 or 2, wherein the anti-aging agent comprises, in parts by mass: 1 to 3 parts of nickel-containing compound, 1 to 3 parts of amine compound, 0.5 to 1 part of carbon black and 0.5 to 1 part of hindered amine.

4. The high-viscosity high-elasticity anti-aging modified asphalt according to claim 3, wherein the anti-aging agent comprises, in parts by mass: 2 parts of nickel-containing compound, 2 parts of amine compound, 0.7 part of carbon black and 0.8 part of hindered amine.

5. A method for preparing the high-viscosity high-elasticity anti-aging modified asphalt as defined in any one of claims 1 to 4, which is characterized by comprising the following steps: heating the matrix asphalt to a flowing state, adding the high-viscosity high-elastic agent under the heating condition, and uniformly mixing; and adding the anti-aging agent, and uniformly mixing according to a specific stirring procedure to obtain the high-viscosity high-elasticity anti-aging modified asphalt.

6. The method for producing a high-viscosity high-elastic aging resistant modified asphalt according to claim 5, wherein the heating temperature at which the base asphalt is heated to a flowing state is 165 ℃ ± 5 ℃, and the heating temperature in the heating condition is 170 ℃ ± 5 ℃.

7. The method for preparing the high-viscosity high-elasticity anti-aging modified asphalt according to claim 5, wherein the specific stirring procedure is a first low-speed stirring step, a high-speed stirring step, and a second low-speed stirring step;

The rotating speed of the first low-speed stirring step and the second low-speed stirring step is 50-70 r/min, and the rotating speed of the high-speed stirring program is 1800-2200 r/min.

8. The method for producing a high-viscosity high-elastic anti-aging modified asphalt according to claim 7, wherein the stirring time in the first low-speed stirring step is 8 to 12 minutes, the stirring time in the high-speed stirring step is 60 to 80 minutes, and the stirring time in the second low-speed stirring step is 5 to 10 minutes.

9. A mixture comprising the high-viscosity high-elasticity anti-aging modified asphalt and aggregate prepared by the method for preparing the high-viscosity high-elasticity anti-aging modified asphalt according to any one of claims 5 to 8.

10. A method of preparing the mixture of claim 9, comprising the steps of: the high-viscosity high-elastic agent, the anti-aging agent, the matrix asphalt and the aggregate are uniformly mixed and stirred for more than 2 minutes at 180+/-2 ℃ at the stirring speed of 65-75 r/min.