Geopolymer-modified bio-asphalt mixture and method of making same

Abstract

The application provides a geopolymer modified bio-asphalt mixture, raw materials of which include the following components in terms of mass ratio: bio-asphalt 5-10%, geopolymer modifying material 2-5%, aggregate 80-90%, and filler 3-5%; and the application also provides a preparation method of the geopolymer modified bio-asphalt mixture, which is used for preparing the geopolymer modified bio-asphalt mixture; and the geopolymer modified bio-asphalt mixture and the preparation method thereof solve the problems of low softening point, small viscosity, poor adhesion, and insufficient high-temperature stability when applied in road engineering of bio-asphalt through the geopolymer modifying material and the preparation method.

Description

Technical Field

[0001] This invention relates to the technical field of road engineering, and in particular to a geopolymer-modified bio-asphalt mixture and its preparation method. Background Technology

[0002] With the rapid development of my country's economy, highway construction has maintained high-speed growth for many years, and road paving and maintenance have also seen rapid development for a considerable period. At the same time, the consumption of asphalt has been continuously increasing. As a byproduct of petroleum, asphalt is a non-renewable resource, and its price continues to rise as petroleum resources become increasingly depleted. Consequently, the construction cost of highways in my country has been rising, which has already had a negative impact on my country's economic development.

[0003] To address the dwindling oil resources and rising crude oil costs, developed countries, particularly in Europe and America, have begun researching biomass resources as alternatives to petroleum asphalt. Currently, the primary method for utilizing biomass resources both domestically and internationally involves the pyrolysis of organic matter such as plant straw and animal manure. The lighter components of the reaction products are typically used as biodiesel, while the heavier components, being more difficult to convert, are used as bioasphalt. However, recent research has revealed that bioasphalt suffers from low softening points, low viscosity, and poor adhesion, resulting in insufficient high-temperature stability when used as road asphalt.

[0004] In view of this, the inventors have specifically designed a geopolymer-modified bio-asphalt mixture and its preparation method, which leads to this invention. Summary of the Invention

[0005] To address the insufficient high-temperature stability of bio-asphalt, this invention provides a geopolymer-modified bio-asphalt mixture and its preparation method, thereby solving the problem of insufficient high-temperature stability of bio-asphalt in road engineering applications. The specific technical solution of this invention is as follows: A geopolymer-modified bio-asphalt mixture, comprising the following components by mass ratio: Bio-asphalt 5-10%; geopolymer modified material 2-5%; the geopolymer modified material includes mineral components and activating components, wherein the mineral components are 70-80% and the activating components are 20-30%; the mineral components are one or a mixture of two or more of metakaolin, slag powder, circulating fluidized bed ash, and waste incineration ash; the geoactivating components are one or a mixture of two or three of hydrated lime, sodium hydroxide, and potassium hydroxide; aggregate 80-90%; filler 3-5%.

[0006] Furthermore, the bio-asphalt is obtained by high-pressure pyrolysis of one or a mixture of two or three of wheat straw, rice straw, and corn straw.

[0007] Furthermore, the bio-asphalt is obtained by vacuum distillation separation of a pyrolytic biomass mixture.

[0008] Furthermore, the metakaolin is ground to a specific surface area of ​​500-700 m². 2 / kg; the slag powder is of grade S95~S105; the circulating fluidized bed ash powder is ground to a specific surface area of ​​500~700m². 2 / kg; the waste incineration ash powder is ground to a specific surface area of ​​500~700m² 2 / kg.

[0009] Furthermore, the effective calcium oxide and magnesium oxide content in the slaked lime is 80-99%; the sodium hydroxide and potassium hydroxide are industrial grade.

[0010] Furthermore, the aggregate is divided into coarse aggregate and fine aggregate, wherein the coarse aggregate is dried, continuously graded limestone with a particle size of 2.26~19mm; and the fine aggregate is one or a mixture of two of river sand and manufactured sand.

[0011] Furthermore, the filler is natural limestone powder, wherein particles with a diameter of 0.15 mm or less account for 90-100%.

[0012] A method for preparing geopolymer-modified bioasphalt mixture, used to prepare geopolymer-modified bioasphalt mixture, is implemented according to the following steps: First, the bio-asphalt is sheared for 20-30 minutes at 165°C and a stirring rate of 4000 rpm to ensure that it has sufficient fluidity. Second, mix the filler and geopolymer material evenly and heat to 165℃. Add it to the bioasphalt in three portions according to a certain mass percentage, and shear at 400 rpm for 10-20 minutes and then at 4000 rpm for 30-40 minutes to obtain the geopolymer-modified bioasphalt mortar. Third, the geopolymer-modified bioasphalt mortar is heated to 180°C and mixed evenly with the aggregate at a certain mass percentage to obtain the geopolymer-modified bioasphalt mixture.

[0013] The geopolymer-modified bioasphalt mixture and its preparation method of the present invention solve the problems of low softening point, low viscosity, poor adhesion, and insufficient high-temperature stability of bioasphalt when applied in road engineering by combining geopolymer-modified materials with preparation methods. Detailed Implementation

[0014] To make the technical problems, technical solutions, and beneficial effects of this invention clearer and more understandable, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention. Example 1

[0015] A geopolymer-modified bioasphalt mixture comprises the following components by mass percentage: 5% bioasphalt, 2% geopolymer modifier, 90% aggregate, and 3% filler.

[0016] The components of the geopolymer material, by mass percentage, are: 30% metakaolin and 40% slag powder in the mineral components, and 15% hydrated lime and 15% sodium hydroxide in the activating components.

[0017] The method for preparing geopolymer-modified bio-asphalt mixture is specifically implemented according to the following steps: The bio-asphalt was sheared for 20 minutes at 165°C and a stirring rate of 4000 rpm. The filler and geopolymer materials were mixed evenly and heated to 165°C. The mixture was added to the bio-asphalt in three portions at a specific mass percentage, and sheared at 400 rpm for 10 minutes followed by shearing at 4000 rpm for 30 minutes to obtain the geopolymer-modified bio-asphalt slurry. The geopolymer-modified bio-asphalt slurry was heated to 180°C and mixed evenly with the aggregate at a specific mass percentage to obtain the geopolymer-modified bio-asphalt mixture. Example 2

[0018] A geopolymer-modified bioasphalt mixture comprises the following components by mass percentage: 10% bioasphalt, 5% geopolymer modifier, 80% aggregate, and 5% filler.

[0019] The components of the geopolymer material, by mass percentage, are as follows: 70% in the mineral component (incineration ash), 15% in the activating component (sodium hydroxide), and 15% in the activating component (potassium hydroxide).

[0020] The method for preparing the geopolymer-modified bioasphalt mixture is specifically implemented according to the following steps: Bioasphalt is sheared for 23 minutes at 165°C and a stirring rate of 4000 rpm. The filler and geopolymer material are mixed evenly and heated to 165°C. The filler is added to the bioasphalt in three portions at a certain mass percentage, and the mixture is sheared at 400 rpm for 15 minutes and then at 4000 rpm for 40 minutes to obtain the geopolymer-modified bioasphalt slurry. The geopolymer-modified bioasphalt slurry is heated to 180°C and mixed evenly with the aggregate at a certain mass percentage to obtain the geopolymer-modified bioasphalt mixture. Example 3

[0021] A geopolymer-modified bio-asphalt mixture comprises the following components by mass percentage: 8% bio-asphalt, 3% geopolymer modifier, 85% aggregate, and 4% filler.

[0022] The components of the geopolymer material, by mass percentage, are as follows: mineral components: 20% slag powder, 20% circulating fluidized bed fly ash, and 30% waste incineration ash; activating components: 30% hydrated lime.

[0023] The preparation method of the geopolymer-modified bioasphalt mixture is specifically implemented according to the following steps: Bioasphalt is sheared for 30 minutes at 165°C and a stirring rate of 4000 rpm. The filler and geopolymer material are mixed evenly and heated to 165°C. The filler is added to the bioasphalt in three portions at a certain mass percentage, and sheared at 400 rpm for 20 minutes and then at 4000 rpm for 36 minutes to obtain the geopolymer-modified bioasphalt slurry. The geopolymer-modified bioasphalt slurry is heated to 180°C and mixed evenly with the aggregate at a certain mass percentage to obtain the geopolymer-modified bioasphalt mixture. Example 4

[0024] The bio-asphalt mixture comprises the following components by mass percentage: 5% bio-asphalt, 90% aggregate, and 5% filler.

[0025] The method for preparing the bio-asphalt mixture is specifically implemented according to the following steps: The bio-asphalt is sheared for 20 minutes at 165°C and a stirring rate of 4000 rpm. The filler is mixed evenly and heated to 165°C. It is added to the bio-asphalt in three portions at a certain mass percentage, and sheared at 400 rpm for 10 minutes followed by shearing at 4000 rpm for 30 minutes to obtain the bio-asphalt slurry. The bio-asphalt slurry is heated to 180°C and mixed evenly with the aggregate at a certain mass percentage to obtain the bio-asphalt mixture.

[0026] Performance tests were conducted on the bio-asphalt latex and bio-asphalt mixtures prepared in the above embodiments and comparative embodiments. The specific methods followed the test methods specified in JTG E20-2011 "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering". The test results are shown in Table 1. Table 1 Performance Comparison of the Example and the Comparative Example

[0027] The results showed that, compared with the comparative examples, the penetration of the asphalt mastic after modification with geopolymer materials in Examples 1-3 decreased, the softening point increased, and the ductility slightly increased. The dynamic stability of the geopolymer-modified bioasphalt mixture was improved, and the permanent deformation was reduced. This indicates that the geopolymer-modified bioasphalt provided by this invention increases the viscosity of the asphalt mastic and improves the rutting resistance of the asphalt mixture. In short, the high-temperature performance of the geopolymer-modified bioasphalt mixture is significantly improved, while also showing a slight improvement in low-temperature performance.

[0028] The present invention has been described above with reference to the embodiments. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any non-substantial improvements made using the inventive concept and technical solution of the present invention, or the direct application of the inventive concept and technical solution of the present invention to other occasions without modification, are all within the protection scope of the present invention.

Claims

1. A method for preparing a geopolymer-modified bio-asphalt mixture, characterized in that, The raw materials for this polymer-modified bio-asphalt mixture include the following components by mass ratio: Bio-asphalt 5-10%; geopolymer modified material 2-5%; the geopolymer modified material includes a mineral component and an activating component, wherein the mineral component is 70-80% and the activating component is 20-30%; the mineral component is at least one of metakaolin, slag powder, circulating fluidized bed ash, and waste incineration ash; the activating component is at least one of hydrated lime, sodium hydroxide, and potassium hydroxide; aggregate 80-90%; filler 3-5%; the metakaolin is ground to a specific surface area of ​​500-700 m². 2 / kg; the slag powder is of grade S95~S105; the circulating fluidized bed ash powder is ground to a specific surface area of ​​500~700m². 2 / kg; the waste incineration ash powder is ground to a specific surface area of ​​500~700m² 2 / kg; the effective calcium oxide and magnesium oxide content in the slaked lime is 80~99%; the sodium hydroxide and potassium hydroxide are industrial grade; The preparation method is implemented according to the following steps: First, the bio-asphalt is sheared for 20-30 minutes at 165°C and a stirring rate of 4000 rpm to ensure that it has sufficient fluidity. Second, mix the filler and geopolymer modified material evenly, heat to 165°C, and add it to the bioasphalt in three batches according to a certain mass percentage. Shear at 400 rpm for 10-20 minutes and then shear at 4000 rpm for 30-40 minutes to obtain the geopolymer modified bioasphalt mortar. Third, the geopolymer-modified bioasphalt mortar is heated to 180°C and mixed evenly with the aggregate at a certain mass percentage to obtain the geopolymer-modified bioasphalt mixture.

2. The method for preparing a geopolymer-modified bio-asphalt mixture according to claim 1, characterized in that, The bio-asphalt is obtained by high-pressure pyrolysis of one or a mixture of two or three of wheat straw, rice straw, and corn straw.

3. The method for preparing a geopolymer-modified bio-asphalt mixture according to claim 1, characterized in that, The bio-asphalt is obtained by vacuum distillation of a pyrolytic biomass mixture.

4. The method for preparing a geopolymer-modified bio-asphalt mixture according to claim 1, characterized in that, The aggregate is divided into coarse aggregate and fine aggregate. The coarse aggregate is dried, continuously graded limestone with a particle size of 2.26~19mm. The fine aggregate is one or a mixture of two of river sand and manufactured sand.

5. The method for preparing a geopolymer-modified bio-asphalt mixture according to claim 1, characterized in that, The filler is natural limestone powder, of which particles with a diameter of 0.15 mm or less account for 90-100%.

6. A geopolymer-modified bio-asphalt mixture, characterized in that, It is prepared by the method for preparing a geopolymer-modified bio-asphalt mixture according to any one of claims 1-5.

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