Method for manufacturing waste rubber powder composite modified asphalt and measuring force ductility

Abstract

The invention discloses a method for manufacturing waste rubber powder composite modified asphalt and measuring force ductility in the technical field of modified asphalt. The method comprises the following steps: heating asphalt in a drying oven to a flowing state; adding the SBS modifier and the rubber powder prepared from the waste tires into the asphalt according to a specified mixing amount, and carrying out secondary heating; the asphalt is put into a shearing machine to be sheared; the sheared asphalt is transferred into an electric heating sleeve to be stirred; and placing the stirred asphalt in a heat preservation box to develop and swell, so as to complete the preparation of the waste rubber powder composite modified asphalt. The asphalt material with good low-temperature crack resistance is prepared by proportioning the rubber powder prepared from the waste tires and the SBS, is suitable for serving in high-cold and high-altitude areas, and can effectively avoid the problems of cracking, cracking, loosening and the like.

Description

Technical Field

[0001] The invention relates to a method for preparing composite modified asphalt of waste rubber powder and measuring force and ductility, belonging to the technical field of modified asphalt. Background Art

[0002] Asphalt is a dark brown complex mixture of hydrocarbons of different molecular weights and their non-metallic derivatives. It is a kind of high-viscosity organic liquid, mostly in the form of liquid or semi-solid petroleum. It has a black surface and is soluble in carbon disulfide and carbon tetrachloride. Asphalt is a waterproof, moisture-proof and anti-corrosive organic gelling material, mainly used in industries such as coatings, plastics, rubber, and road paving. It can be mainly divided into three types: coal tar asphalt, petroleum asphalt, and natural asphalt: among them, coal tar asphalt is a by-product of coking, petroleum asphalt is the residue after crude oil distillation, and natural asphalt is stored underground, some of which form mineral layers or accumulate on the surface of the earth's crust.

[0003] In high-altitude and cold areas, the temperature is low for a long time, the temperature difference between day and night is large, and it is exposed to strong ultraviolet rays for a long time during the day. Under such significant plateau climate conditions, the asphalt pavement does not have good low-temperature crack resistance, and problems such as cracking, cracks, and looseness will occur. Summary of the invention

[0004] The purpose of the present invention is to overcome the deficiencies in the prior art and to provide a method for producing and measuring the force ductility of waste rubber powder composite modified asphalt. By using this scheme, an asphalt material with good low-temperature crack resistance can be prepared, which is suitable for service in high-cold and high-altitude areas.

[0005] To achieve the above object, the present invention is implemented by adopting the following technical solutions:

[0006] In a first aspect, the present invention provides a method for preparing waste rubber powder composite modified asphalt, comprising:

[0007] The asphalt is heated in an oven until it becomes fluid;

[0008] Adding SBS modifier and rubber powder prepared from waste tires into asphalt according to specified dosage and performing secondary heating;

[0009] Put the asphalt into the shearing machine for shearing;

[0010] Transfer the sheared asphalt into the electric heating jacket for stirring;

[0011] The asphalt after mixing is placed in an insulated box for swelling, and the production of waste rubber powder composite modified asphalt is completed.

[0012] Furthermore, the asphalt adopts No. 90 base asphalt, and the temperature heated in the oven is 185°C.

[0013] Furthermore, the content of the SBS modifier is 1.5%, and the content of the rubber powder includes 19.2%, 24.9% and 29.1%.

[0014] Furthermore, the temperature of the secondary heating of the asphalt is 190°C.

[0015] Furthermore, the shear rate of the asphalt in the shearing machine is 5000 r / min, and the shearing time is 2 hours.

[0016] Furthermore, the asphalt is stirred in the electric heating jacket for 30 minutes.

[0017] Furthermore, the temperature at which the asphalt develops and swells in the insulated box is 170° C., and the time is 1 hour.

[0018] In a second aspect, the present invention provides a method for measuring the force and ductility of waste rubber powder composite modified asphalt, wherein glycerin and talcum powder are used in a ratio of 2 to 1 to prepare an isolation agent and stirred until uniform, the isolation agent is evenly brushed on the test mold except for the arc, and then asphalt with different rubber powder dosages made by the waste rubber powder composite modified asphalt making method is poured into the test mold. After the asphalt is formed, it is classified and marked according to different rubber powder dosages. The test mold is cooled for at least 30 minutes, the heating plate temperature is set to 260°C and then a heated scraper is used to scrape off excess asphalt on the test mold from the middle to both sides and cool to room temperature, and then the asphalt specimens are placed in water for further cooling. After cooling for 30 minutes, they are placed in a force and ductility measuring instrument, the experimental conditions are set, and data recording begins.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] 1. The present invention uses rubber powder prepared from waste tires and SBS to make a proportion, and adds them to the base asphalt through heating, shearing, stirring and swelling to prepare an asphalt material with good low-temperature crack resistance, which is suitable for service in high-cold and high-altitude areas and can effectively avoid the problems of cracking, cracks, looseness, etc.;

[0021] Second, the rubber powder prepared by recycling waste tire solid waste is essentially waste recycling, which realizes the resource utilization of waste materials and is a key focus of the research field of transportation infrastructure under the background of low-carbon and environmental protection;

[0022] 3. The SBS content in the common SBS modified asphalt in the prior art is about 6%. The SBS content in the waste rubber powder composite modified asphalt production method of this scheme is 1.5%, which saves the paving cost to a certain extent. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0024] Figure 1 A schematic flow chart of a method for producing composite modified asphalt from waste rubber powder provided in Example 1 of the present invention. DETAILED DESCRIPTION

[0025] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments. It should be noted that the embodiments and features in the embodiments of the present invention can be combined with each other without conflict.

[0026] The following detailed description is an exemplary description, which is intended to provide further detailed description of the present invention. Unless otherwise specified, all technical terms used in the present invention have the same meaning as those generally understood by those skilled in the art to which the present invention belongs. The terms used in the present invention are only for describing specific embodiments, and are not intended to limit the exemplary embodiments according to the present invention.

[0027] Embodiment 1:

[0028] A method for preparing waste rubber powder composite modified asphalt, firstly, based on the principle of compound modification design, the performance of different types of rubber powder, modifier, stabilizer and asphalt materials are evaluated, and the compatibility of the formula under the orthogonal design combination is evaluated. The principle of compound modification design requires a comprehensive and systematic evaluation of various modified materials. As important components of modified asphalt, the performance of modifiers and stabilizers directly affects the overall performance of modified asphalt. Therefore, in the process of compound modification design, different types of modifiers and stabilizers must be evaluated to ensure that the modified asphalt achieves the best performance. The rubber powder finally obtained here is the rubber powder prepared from waste tires, the modifier is SBS, and the asphalt is No. 90 and No. 110 base asphalt. The low-temperature performance is evaluated by force ductility test, and the evaluation standard is the ductility of modified asphalt. The evaluation of compatibility is carried out through a series of experiments, which will test various performance indicators of asphalt materials under different formula combinations, such as low-temperature crack resistance, ductility, stability, etc. The purpose of evaluating the compatibility of the formula under the orthogonal design combination is to ensure that the selected formula can show stable performance in practical applications. Compatibility evaluation and performance evaluation complement each other. Performance evaluation mainly focuses on the various performance indicators of asphalt materials, while compatibility evaluation pays more attention to the interaction and compatibility between different materials.

[0029] Secondly, based on the principle of swelling and development of rubber powder, different processing technologies are designed, focusing on processing temperature and swelling development time, and determining the appropriate processing technology. The processing technology mainly refers to the different steps and conditions taken when preparing modified asphalt, including heating temperature, shear rate, stirring time, swelling development time, etc. The processing objects are mainly base asphalt and rubber powder prepared from waste tires. The purpose of processing is to obtain a modified asphalt material with good low-temperature crack resistance. According to the principle of swelling and development of rubber powder, when designing the processing technology, it is necessary to focus on processing temperature and swelling development time. The processing temperature will affect the fluidity of asphalt, the swelling of rubber powder, and the aging of asphalt. The appropriate processing temperature can ensure that the base asphalt and rubber powder can be fully mixed; while the swelling development time will affect the swelling development process, performance optimization, etc. The appropriate swelling development time can allow the rubber powder to fully swell in the asphalt. By designing experiments, it is judged that the processing temperature and swelling time will have an impact on asphalt, so as to determine the appropriate processing technology.

[0030] In this embodiment, modified asphalt with an SBS content of 1.5% and a rubber powder content of 19.2%, 24.9%, and 29.1% is prepared. The preparation process is as follows: No. 90 base asphalt is heated to 185°C in an oven to allow the base asphalt to flow. The heating temperature of the base asphalt is controlled at 185°C to ensure that the asphalt can flow, facilitate subsequent processing operations, and avoid excessive temperature causing asphalt aging or performance degradation; the asphalt is poured into a small pot and weighed, and the mass required for the rubber powder is calculated. The 19.2%, 24.9%, and 29.1% mentioned here are the proportions of the rubber powder in the modified asphalt, that is, the ratio of the rubber powder mass to the total mass of the asphalt; then the rubber powder is poured into the asphalt pot and reheated to 190°C. Although the base asphalt is already in a liquid state at 185°C, heating to 190°C is to ensure that the rubber powder can fully swell and develop. The temperature of 190°C helps the rubber powder to be better dispersed and dissolved in the asphalt, thereby improving the uniformity and performance of the modified asphalt. Then put it into the shearing machine, take the shear rate of 5000r / min for shearing for 2 hours, and then transfer it to the electric heating jacket for further stirring for 30 minutes. The shearing process helps to evenly disperse the rubber powder into the asphalt to form a stable mixed system. Through long-term shearing, it can ensure sufficient contact and mixing between the rubber powder particles and the asphalt molecules. Shearing for 2 hours can significantly improve the performance of the modified asphalt. Long-term shearing helps to optimize the microstructure of the modified asphalt, making it more uniform and stable. This structural optimization can further improve the durability and service life of the asphalt. Although the sheared mixture has achieved uniform mixing of rubber powder and asphalt to a certain extent, in order to ensure a more uniform distribution of components in the entire mixture, it is necessary to continue stirring. And in order to promote swelling development, the modified asphalt that continues to be stirred in the electric heating jacket for 30 minutes will further improve its key performance indicators such as low-temperature crack resistance and ductility. Continuing stirring can further optimize the microstructure of the modified asphalt, making it more uniform and stable, thereby improving its overall performance. After stirring, wait for the modified asphalt to continue to maintain 170℃ in the insulation box for 1 hour to develop swelling. Promote the further fusion of rubber powder and asphalt, improve the performance of modified asphalt, and optimize the microstructure of modified asphalt.

[0031] Secondly, the force-ductility tester was used to conduct ductility tests on modified asphalt at different temperatures, and the test data were collected to perform fitting analysis on the force-ductility curve.

[0032] Before the force-ductility test, first prepare the isolation agent, using glycerin and talcum powder in a ratio of two to one and stir until uniform. Then brush the isolation agent evenly on the specimen mold, and do not apply it on the arc of the mold; then cast the mold quickly, wait for the asphalt specimen to be formed, and classify and mark it according to different rubber powder dosages. Cool the mold for at least 30 minutes, set the heating plate temperature to 260℃, heat the scraper, and scrape off the asphalt that exceeds the mold from the middle to both sides. Use a hot scraper to scrape off the excess asphalt and cool to room temperature. Then put the asphalt specimens into the water corresponding to the test temperature for further cooling. After cooling for 30 minutes, put them into the force-ductility instrument, set the experimental conditions and start recording data. There are three types of experimental asphalt, with rubber powder dosages of 19.2%, 24.9% and 29.1% respectively; there are three experimental temperatures, 5℃, 10℃ and 15℃ respectively; there are two tensile rates, 10mm / min and 50mm / min respectively. A total of 30 groups of experiments were conducted. After one group of asphalt was broken, it was taken out and the temperature was reset. After the water temperature reached the set temperature, another group of asphalt was put in for curing. After curing for more than 30 minutes, the above experiment was repeated.

[0033] Finally, the test data results are analyzed and the design formula and processing technology of high-ductility and crack-resistant modified asphalt materials for airport pavement are proposed.

[0034] Through experimental data, at 5°C, it was found that the asphalt with a rubber powder content of 29.1% had the largest force-ductility value and the largest maximum fracture energy, indicating that the asphalt with a rubber powder content of 29.1% had the strongest ability to resist stretching and performed best in the force-ductility test.

[0035] In this embodiment, rubber powder prepared from waste tires and SBS are used to prepare an asphalt material with good low-temperature crack resistance. By comparing asphalts with different processing technologies, the appropriate processing technology is determined, and then the force-ductility test under different environmental conditions is simulated to test the low-temperature crack resistance of asphalt. Finally, according to the data analysis of the laboratory, the asphalt material suitable for service in high-cold and high-altitude areas is obtained.

[0036] The resource utilization of rubber powder prepared by recycling solid waste from waste tires is a key focus topic in the field of transportation infrastructure research under the background of low-carbon environmental protection. Rubber powder has excellent low-temperature crack resistance and flexibility due to molecular cross-linking, and is an asphalt modifier with excellent performance. Asphalt materials show significant brittle characteristics under low temperature conditions. Through the coordinated design of compatibility, a new high-ductility crack-resistant modified asphalt material is effectively prepared. The rubber powder prepared from waste tires in this embodiment is essentially the recycling of waste. The SBS content in the common SBS modified asphalt on the market is about 6%. In this experiment, the SBS content was 1.5%, which saved the paving cost to a certain extent.

[0037] It is known from common technical knowledge that the present invention can be implemented by other embodiments that do not deviate from its spirit or essential features. Therefore, the above disclosed embodiments are only illustrative in all respects and are not exclusive. All changes within the scope of the present invention or within the scope equivalent to the present invention are included in the present invention.

[0038] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for producing composite modified asphalt from waste rubber powder, characterized in that: include: The asphalt is heated in an oven until it becomes fluid; Adding SBS modifier and rubber powder prepared from waste tires into asphalt according to specified dosage and performing secondary heating; Put the asphalt into the shearing machine for shearing; Transfer the sheared asphalt into the electric heating jacket for stirring; The asphalt after mixing is placed in an insulated box for swelling, and the production of waste rubber powder composite modified asphalt is completed.

2. The method for preparing composite modified asphalt from waste rubber powder according to claim 1, characterized in that: The asphalt adopts No. 90 base asphalt, and the temperature heated in the oven is 185°C.

3. The method for preparing composite modified asphalt from waste rubber powder according to claim 1, characterized in that: The content of the SBS modifier is 1.5%, and the content of the rubber powder includes 19.2%, 24.9% and 29.1%.

4. The method for producing composite modified asphalt from waste rubber powder according to claim 1, characterized in that: The temperature of the secondary heating of the asphalt is 190°C.

5. The method for producing composite modified asphalt from waste rubber powder according to claim 1, characterized in that: The shear rate of the asphalt in the shearing machine is 5000 r / min, and the shearing time is 2 hours.

6. The method for producing composite modified asphalt from waste rubber powder according to claim 1, characterized in that: The asphalt was stirred in the electric heating jacket for 30 minutes.

7. The method for producing composite modified asphalt from waste rubber powder according to claim 1, characterized in that: The asphalt is swollen in the insulated box at a temperature of 170° C. for 1 hour.

8. A method for measuring force and ductility of waste rubber powder composite modified asphalt, characterized in that: Glycerin and talcum powder are used to prepare the isolation agent in a ratio of 2 to 1 and stirred until uniform. The isolation agent is evenly brushed on the test mold except the arc, and then asphalt with different rubber powder dosages made by the method for making waste rubber powder composite modified asphalt as claimed in claim 1 is poured into the test mold. After the asphalt is formed, it is classified and marked according to different rubber powder dosages. The test mold is cooled for at least 30 minutes. The heating plate temperature is set to 260°C and then a heated scraper is used to scrape off excess asphalt on the test mold from the middle to both sides and cool to room temperature. Subsequently, the asphalt specimens are placed in water for further cooling. After cooling for 30 minutes, they are placed in a force ductility meter, the experimental conditions are set, and data recording begins.

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