Rigid-flexible composite pavement material based on modified emulsified asphalt mortar as well as mix proportion design and preparation method of rigid-flexible composite pavement material

Abstract

The invention discloses a rigid-flexible composite pavement material based on modified emulsified asphalt mortar as well as a mix proportion design and a preparation method of the rigid-flexible composite pavement material. According to the method, the pavement performance of the material is directly used as an index, the mix proportion design and the gradation design of the modified emulsified asphalt mortar are sequentially carried out, then a relation curve of the stability of the target rigid-flexible composite pavement material mixture and the addition amount of the modified emulsified asphalt is constructed through a Marshall test, and the optimal use amount of the target rigid-flexible composite pavement material mixture is determined. It is further ensured that the obtained material meets the performance requirement of a target material through a pavement performance test; according to the rigid-flexible composite pavement material designed based on the method, by optimizing the mixing ratio of all the raw materials, the adhesion state and the forming process of cement, emulsified asphalt and a material collecting piece are effectively improved, and therefore the high-temperature performance and the low-temperature performance of the material are improved at the same time; heating is not needed in the whole preparation process of the material, grouting is not needed in the actual laying process, and the technical problems that the early strength of the pavement is low and the passage is slow due to the fluidity of the grouting material are fundamentally solved.

Description

Technical Field

[0001] The present invention relates to a rigid-flexible composite pavement material, in particular to a rigid-flexible composite pavement material based on modified emulsified asphalt mortar and a mix ratio design and preparation method thereof, belonging to the technical field of pavement materials. Background Art

[0002] When exposed to high temperatures, asphalt pavement loses viscosity, weakening its bond with aggregate and interfacial strength. This in turn leads to a decrease in pavement strength and deformation resistance, which can ultimately cause problems such as rutting. At low temperatures, asphalt loses both ductility and viscosity, exhibiting significant brittleness. Under vehicle loads, this can lead to pavement cracking and other problems. While traditional cement pavements offer superior temperature sensitivity, strength, and service life compared to asphalt concrete pavements, they suffer from limitations in construction technology, resulting in joints and poor ride quality. Furthermore, construction is complex, maintenance is difficult, and reopening to traffic is slow.

[0003] To overcome the shortcomings of cement and asphalt pavements, rigid-flexible composite pavements were first used on the jet-propelled aircraft runway at Cognac Airport in France as a heat-resistant pavement. This method, known as the "Salviacim" method, was patented and applied for the "cement slurry open-graded asphalt concrete construction method." Rigid-flexible composite pavements are most widely used in Japan, where they were then known as rigid-flexible composite pavements. Several construction companies, including Obayashi Road Co., Ltd., Kajima Road Co., Ltd., and Nippon Paving Co., Ltd., have conducted extensive research on rigid-flexible composite pavements and established company standards for their promotion and application.

[0004] Despite extensive research on rigid-flexible composite pavements, there are still many problems: the high requirements for the flow properties of the grouting material result in low early strength and an inability to quickly open traffic; the inability to detect the grouting rate in real time, so when the grouting rate does not meet the standard, the road performance of the rigid-flexible composite pavement material will be reduced; the addition of cement increases the brittleness of the grouted rigid-flexible composite pavement material, resulting in poor low-temperature crack resistance; the parent asphalt mixture in the rigid-flexible composite pavement material uses matrix asphalt, which requires high-temperature heating during the preparation process, consumes a lot of energy and has a greater impact on the environment. Summary of the Invention

[0005] To address the challenges of the existing technology, the first objective of the present invention is to provide a rigid-flexible composite pavement material based on modified emulsified asphalt mortar. This pavement material, leveraging the synergistic effect between the modified emulsified asphalt mortar and aggregate, significantly enhances its road performance while maintaining excellent mechanical properties. By optimizing the mix ratio of the various raw materials, the material effectively improves the adhesion between cement, emulsified asphalt, and aggregate, as well as the molding process, thereby enhancing both high- and low-temperature performance.

[0006] The second purpose of the present invention is to provide a method for designing the mix ratio of rigid-flexible composite pavement materials based on modified emulsified asphalt mortar. This method directly uses the road performance of the material as an indicator to sequentially design the mix ratio and gradation of the modified emulsified asphalt mortar. A Marshall test is then used to construct a curve showing the relationship between the stability of the target rigid-flexible composite pavement material mixture and the amount of modified emulsified asphalt added, determining its optimal dosage. Further road performance tests are conducted to ensure that the resulting material meets the performance requirements of the target material. This method uses actual road performance as the criterion for the design method, allowing for the rapid and accurate selection of a mix ratio that meets the requirements, significantly reducing initial investment and time costs.

[0007] The third object of the present invention is to provide a method for preparing a rigid-flexible composite pavement material based on modified emulsified asphalt mortar. This preparation method, based on the characteristics of the modified emulsified asphalt mortar in the pavement material, is obtained by mixing and stirring the modified emulsified asphalt mortar with coarse aggregate, fine aggregate, and mineral powder at room temperature and then curing. No heating is required throughout the preparation process, significantly reducing preparation costs. The grouting process is omitted during the actual paving process, greatly simplifying the construction process and fundamentally resolving the technical problems of low early pavement strength and slow access caused by the fluidity of the grouting material.

[0008] In order to achieve the above technical objectives, the present invention provides a method for designing a mix ratio of a rigid-flexible composite pavement material based on modified emulsified asphalt mortar, comprising:

[0009] Step S1: determining various performance parameters of the target rigid-flexible composite pavement material, screening the required raw materials, and obtaining their basic physical and chemical parameters;

[0010] Step S2: Designing the mix ratio of the modified emulsified asphalt mortar based on the basic physicochemical parameters in step S1, and obtaining the optimal mix ratio;

[0011] Step S3: Based on the basic physicochemical parameters in step S1, the aggregate gradation is designed, and the modified emulsified asphalt mortar in step S2 is used as a variable factor to determine the optimal amount of each raw material of the target rigid-flexible composite pavement material;

[0012] Step S4: Perform a road performance test based on the optimal dosage obtained in step S3. When the test results meet the various performance parameters of the target rigid-flexible composite pavement material, output the results. If not, return to step S3 to re-determine the optimal dosage of each raw material of the target rigid-flexible composite pavement material.

[0013] As a preferred solution, the performance parameters of the target rigid-flexible composite pavement material include: dynamic stability, freeze-thaw splitting tensile strength ratio, maximum bending-tensile strain, maximum shear stress and maximum tensile stress.

[0014] As a preferred solution, the raw materials of the target rigid-flexible composite pavement material include: stone chips, cement, emulsified asphalt, sand, mineral powder, expansion agent, early strength agent, water reducing agent and styrene acrylic emulsion.

[0015] As a preferred solution, the emulsified asphalt is cationic emulsified asphalt, and its evaporation residue is ≥58%.

[0016] As a preferred solution, the process of obtaining the optimal mix ratio is: mix the raw materials including cement, emulsified asphalt, sand and water evenly, and obtain mortar specimens according to the "Test Code for Cement and Cement Concrete for Highway Engineering" (JTGE30-2020); use the mortar specimens as independent variables, and the compressive strength, flexural strength, fracture energy and compression-flexure ratio as dependent variables, respectively, and obtain the optimal mortar ratio including water-cement ratio, sand-cement ratio and blue-cement ratio through orthogonal experiments.

[0017] As a preferred solution, the orthogonal experiment process is: using the orthogonal experiment design method to observe the influence of different factors on the mechanics of modified emulsified asphalt mortar, and then calculating the range and variance of each factor to screen out the optimal mortar ratio including water-cement ratio, sand-cement ratio and blue-cement ratio.

[0018] As a preferred solution, the aggregate gradation design process is as follows: the raw materials of the target rigid-flexible composite pavement material are dried in a drying oven at 100-120°C to constant weight, and then the stone chips and other raw materials are graded. More preferably, the gradation method is AC-16.

[0019] As a preferred solution, the process for determining the optimal amount of each raw material of the target rigid-flexible composite pavement material is as follows: using the modified emulsified asphalt mortar in step S2 as a variable factor, after the aggregate is mixed and processed into a Marshall specimen, a Marshall test is performed, and a relationship curve between the stability of the mixture and the amount of modified emulsified asphalt mortar added to the mixture is established, and the content of modified emulsified asphalt mortar in the mixture corresponding to the peak of the curve is determined as the optimal amount of the rigid-flexible composite pavement material.

[0020] As a preferred solution, the process of the road performance test is: according to the optimal dosage obtained in step S3, the raw materials of the target rigid-flexible composite pavement material are evenly mixed and then cured and formed in accordance with the "Test Code for Cement and Cement Concrete for Highway Engineering" (JTGE30-2020), and rutting tests, low-temperature beam tests, water stability, interlayer adhesion and anti-skid tests are carried out respectively.

[0021] As a preferred solution, the curing and molding process is: laying the mixture in a mold, placing it in a standard environment for 20 to 40 hours after molding for demolding, and then placing the demolded specimen in a curing room with a temperature of 20 to 25°C and a humidity ≥90%, and curing for 3 to 28 days.

[0022] The present invention also provides a rigid-flexible composite pavement material based on modified emulsified asphalt mortar, comprising the following components: modified emulsified asphalt, coarse aggregate, fine aggregate and mineral powder, wherein the mixing ratio between the components is determined by the method described in any one of claims 1 to 6.

[0023] As a preferred solution, the modified emulsified asphalt includes the following components in parts by mass: 100-120 parts of ordinary Portland cement, 80-100 parts of emulsified asphalt, 20-25 parts of sand, 1-2 parts of expansion agent, 1-2 parts of water reducer, 1-2 parts of early strength agent, 5-10 parts of styrene-acrylic emulsion and 10-15 parts of water.

[0024] As a preferred solution, the coarse aggregate is basalt short fibers with a length of 4.75-19 mm; the fine aggregate is graded sand with a particle size of 0.075-4.75 mm.

[0025] The present invention also provides a method for preparing a rigid-flexible composite pavement material based on modified emulsified asphalt mortar, the process of which is: adding standard graded sand and cement to a mixing pot in sequence, stirring at a low speed to evenly mix the dry materials, then adding a water reducer to water to fully dissolve it, adding it to the dry materials and fully mixing them, then adding emulsified asphalt for step-by-step stirring, followed by adding styrene-acrylic emulsion and an early strength agent to obtain modified emulsified asphalt mortar; mixing the modified emulsified asphalt mortar with coarse aggregate, fine aggregate and mineral powder, stirring, and then curing to obtain the material.

[0026] As a preferred solution, the rotation speed of the low-speed stirring is 100-150 r / min.

[0027] As a preferred solution, the step stirring conditions are: stirring at 250-300 r / min for 1-3 min, and then stirring at 100-150 r / min for 5-8 min.

[0028] As a preferred solution, the process of mixing the modified emulsified asphalt mortar with coarse aggregate, fine aggregate and mineral powder is: stirring at 100-150 r / min for 3-5 minutes, and then stirring at 400-600 r / min for 1-3 minutes.

[0029] Compared with the prior art, the beneficial technical effects of the technical solution of the present invention are:

[0030] 1) The mix design method provided by the present invention directly uses the road performance of the material as an indicator, and sequentially performs mix design and gradation design of the modified emulsified asphalt mortar. A Marshall test is then used to construct a relationship curve between the stability of the target rigid-flexible composite pavement material mixture and the amount of modified emulsified asphalt added, to determine its optimal amount. Further, a road performance test is performed to ensure that the resulting material meets the performance requirements of the target material. This method uses actual road performance as the judgment standard for the design method, and can quickly and realistically select a mix ratio scheme that meets the requirements, significantly reducing the risk of various pavement diseases occurring during the test road paving stage and effectively improving project efficiency.

[0031] 2) The rigid-flexible composite pavement material provided by the present invention is based on the synergistic effect between modified emulsified asphalt mortar and aggregate. While ensuring the material has excellent mechanical properties, it also significantly improves its road performance. By optimizing the mixing ratio between the various raw materials, this material effectively improves the adhesion state and molding process of cement, emulsified asphalt and aggregate, thereby simultaneously improving the high-temperature and low-temperature performance of the material.

[0032] 3) The preparation method provided by the present invention is based on the characteristics of the modified emulsified asphalt mortar in the pavement material. The modified emulsified asphalt mortar is mixed with coarse aggregate, fine aggregate and mineral powder under room temperature conditions and then cured. No heating is required during the entire preparation process, which greatly reduces the preparation cost. In addition, the grouting process is omitted in the actual paving process, which greatly simplifies the construction process and fundamentally solves the technical problems of low early strength of the pavement and slow access due to the fluidity of the grouting material. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a stability change curve at different emulsified asphalt contents in Example 1 of the present invention;

[0034] Figure 2 Schematic diagram of a Marshall test piece formed in Example 1 of the present invention;

[0035] Figure 3 Schematic diagram of a rutting plate specimen formed in Example 1 of the present invention;

[0036] Figure 4 This is a schematic diagram of a beam bending test in Example 1 of the present invention;

[0037] Figure 5 This is a schematic diagram of a direct shear test in Example 1 of the present invention;

[0038] Figure 6 Schematic diagram of the drawing test in Example 1 of the present invention. DETAILED DESCRIPTION

[0039] The following will be combined with the tables in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] Example 1

[0041] This embodiment provides a method for designing a mix ratio of rigid-flexible composite pavement materials based on modified emulsified asphalt mortar, specifically:

[0042] Step S1: determining various performance parameters of the target rigid-flexible composite pavement material, screening the required raw materials, and obtaining their basic physical and chemical parameters;

[0043] The performance parameters of the target rigid-flexible composite pavement material include: dynamic stability, freeze-thaw splitting tensile strength ratio, maximum bending tensile strain, maximum shear stress and maximum tensile stress;

[0044] The raw materials of the target rigid-flexible composite pavement material include: stone chips, cement, emulsified asphalt, sand, mineral powder, expansion agent, early strength agent, water reducing agent and styrene acrylic emulsion;

[0045] Step S2: Based on the basic physicochemical parameters in step S1, the modified emulsified asphalt mortar mix ratio is designed, and the optimal mix ratio is obtained, wherein the water-cement ratio, sand-cement ratio, and blue-cement ratio are 0.4, 0.2, and 0.8, respectively, the content of the water reducer and the early strength agent is 1%, and the content of the styrene acrylic emulsion is 6%.

[0046] The prepared modified emulsified asphalt mortar is composed of cement, emulsified asphalt, sand, water, expansion agent, early strength agent, water reducer and other materials. The orthogonal experimental design method is used to observe the influence of different factors on the mechanics of the modified emulsified asphalt mortar, so as to select the optimal combination. The water-cement ratio, sand-cement ratio and blue-cement ratio (i.e. the ratio of emulsified asphalt to cement) are considered in the study. L9 (3 3) orthogonal table. The evaluation indicators are 7d flexural strength, 7d compressive strength and compression-flexural ratio. Combined with multiple tests, when the water-cement ratio is too low, the fluidity is poor and stirring is difficult. When the water-cement ratio is high, the modified emulsified asphalt mortar takes a long time to set. The selected water-cement ratios are 0.35, 0.4, and 0.45. Fine sand serves as the mortar skeleton. Adding fine sand can improve the strength of the modified emulsified asphalt mortar, but the amount of addition should not be too much. The selected sand-cement ratios are 0.2, 0.25, and 0.3. If the blue-ash ratio is too low, the mortar is too rigid and has low toughness. Taking into account the toughness requirements, the blue-ash ratios are selected to be 0.6, 0.7, and 0.8. The effect of admixtures on cement mortar is not considered for the time being. The dosages of water reducer, expansive agent, and early strength agent are fixed at 1%, 1%, and 1%, respectively. The orthogonal test factor levels for the modified emulsified asphalt mortar mix ratio are shown in Table 1, and the specific orthogonal test results are shown in Table 2. Range and variance analysis are shown in Table 3-4.

[0047]

[0048]

[0049]

[0050] The order of importance of factors affecting the flexural strength of modified emulsified asphalt mortar is blue-lime ratio (C), water-lime ratio (A), and sand-lime ratio (B), and the optimal factor level combination is A1B2C1. The order of importance of factors affecting the compressive strength of modified emulsified asphalt mortar is blue-lime ratio (C), sand-lime ratio (B), and water-lime ratio (A), and the optimal factor level combination is A1B2C1. The order of importance of factors affecting the compression-flexural ratio of modified emulsified asphalt mortar is blue-lime ratio (C), sand-lime ratio (B), and water-lime ratio (A), and the optimal factor level combination is A1B1C3. The order of importance of factors affecting the fracture energy of modified emulsified asphalt mortar is blue-lime ratio (C), water-lime ratio (B), and sand-lime ratio (A), that is, the optimal factor level combination is A2B1C3.

[0051]

[0052] Note: Indicates significant difference, P value < 0.05; Indicates extremely significant difference, P value < 0.01.

[0053] In summary, it can be seen that the blue-ash ratio has the most significant impact on the compressive strength and flexural strength. First, considering the reasonable range of emulsified asphalt, the best combination with small compressive flexural ratio, good toughness and good mechanical strength is A2B1C3. The water-cement ratio, sand-cement ratio and blue-ash ratio are 0.4, 0.2 and 0.8 respectively. The performance is shown in Table 5.

[0054]

[0055] Add 20 parts of standard sand and 100 parts of cement to a mixing pot, starting the mixer at low speed (approximately 140 rpm) to mix the dry materials evenly. Add 1 part of water reducer to 10 parts of water and stir thoroughly to dissolve it completely. Then add the aqueous solution to the dry materials and stir thoroughly. After the mixture is left for 1 minute under intermittent stirring conditions, add 80 parts of emulsified asphalt and start the mixer at high speed (approximately 280 rpm). After stirring for 2 minutes, start stirring at low speed and continue stirring for 4 minutes, then stir at low speed for another 1 minute. Add 6 parts of styrene-acrylic emulsion and 1 part of early strength agent and stir for 5 minutes to obtain the modified emulsified asphalt mortar.

[0056] Step S3: Based on the basic physical and chemical parameters in step S1, the aggregate gradation is designed. The modified emulsified asphalt mortar in step S2 is used as a variable factor to determine the optimal amount of each raw material for the target rigid-flexible composite pavement material. This example uses the AC-16 gradation, as shown in Table 6 below:

[0057]

[0058] The modified emulsified asphalt mortar in step S2 is used as a variable factor and processed into a Marshall specimen after the aggregate is mixed. A Marshall test is carried out, and a relationship curve between the stability of the mixture and the amount of modified emulsified asphalt mortar added to the mixture is established. The content of modified emulsified asphalt mortar in the mixture corresponding to the peak of the curve is determined as the optimal amount of the rigid-flexible composite pavement material. The emulsified asphalt content (the percentage of emulsified asphalt in the total mass) is 5%, 5.5%, 6%, 6.5% and 7%, respectively. The water-cement ratio, sand-cement ratio and blue-cement ratio obtained in step S2 of the optimal ratio of modified emulsified asphalt mortar are added (0.4, 0.2, 0.8) respectively. The amount of emulsified asphalt is fixed, and the mass of cement and sand is calculated to make a Marshall specimen. In summary, the emulsified asphalt content of 6% is selected as its optimal mix ratio, and the content of cement, sand and other materials is determined at the same time.

[0059] Add 2 parts of standard sand and 10 parts of cement to a mixing pot, 100 grams each. Start the mixer at low speed (approximately 140 rpm) to mix the dry materials evenly. Add 0.1 parts of water reducer to 1 part of water and stir thoroughly to dissolve it completely. Then add the aqueous solution to the dry materials and stir thoroughly. After leaving the mixture for 1 minute under intermittent stirring conditions, add 8 parts of emulsified asphalt and start the mixer at high speed (approximately 280 rpm). After stirring for 2 minutes, start the mixer at low speed and continue stirring for 4 minutes, then stir at low speed for another 1 minute. Add 0.6 parts of styrene-acrylic emulsion and 0.1 parts of accelerator and stir for 5 minutes to obtain the modified emulsified asphalt mortar. Then add 133 parts of coarse and fine aggregates (73 parts of coarse aggregates larger than 4.75 mm, 53 parts of fine aggregates smaller than 4.75 mm, and 7 parts of mineral powder), mix at 100 r / min for 3 minutes, and then stir at 500 r / min for 1 minute. When the CA mortar completely wraps the aggregates and the whole thing appears light brown, the materials in the mixer are evenly mixed.

[0060] Step S4: Perform a road performance test based on the optimal dosage obtained in step S3. When the test results meet the various performance parameters of the target rigid-flexible composite pavement material, output the results. If not, return to step S3 to re-determine the optimal dosage of each raw material of the target rigid-flexible composite pavement material.

[0061] The high-temperature performance, water stability, and low-temperature performance tests conducted in this institute followed the rutting test, immersion Marshall test, freeze-thaw splitting test, and beam bending test specified in JTGE20-2011 "Test Procedures for Asphalt and Asphalt Mixtures for Highway Engineering" T0719-2011. The anti-skid performance was tested in accordance with the "Field Test Procedures for Highway Roadbed and Pavement" (JTG E60-2008), using the manual sand spreading method and a pendulum instrument to measure the pavement swing value. The interlayer adhesion test was conducted using a pull-out test and a direct shear test.

[0062] Rigid-flexible composite material test: The control group AC-16 adopts the ratio in Table 6, with an oil-stone ratio of 4.7%. The high-temperature performance test data of AC-16 and Example 1 are shown in Table 7 below.

[0063]

[0064] As can be seen from Table 7 above, the dynamic stability of Example 1 is about 10 times that of AC-16 asphalt mixture and is far greater than the specification requirements, indicating that the high-temperature performance of the rigid-flexible composite material under this ratio is excellent.

[0065] The water stability test data are shown in Table 8 below:

[0066]

[0067] It can be seen from Table 8 that the residual stability and freeze-thaw splitting strength ratio of Example 1 are stronger than those of AC-16 asphalt mixture, indicating that the rigid-flexible composite material with this ratio has excellent water stability.

[0068] The low temperature performance test data is shown in Table 9 below:

[0069]

[0070] It can be seen from Table 9 that the maximum flexural strain of Example 1 is stronger than that of AC-16 asphalt mixture, indicating that the low-temperature performance of the rigid-flexible composite material under this ratio is excellent.

[0071] Example 1 uses pit treatment, and the interlayer adhesion test data obtained are shown in Table 10 below:

[0072]

[0073] It can be seen from Table 10 that the bonding performance of the rigid-flexible composite pavement material after pitting treatment is better than that of the asphalt mixture, indicating that its bonding performance is excellent.

[0074] The anti-slip test data are shown in Table 11 below:

[0075]

[0076] As can be seen from Table 11 above, the swing value and structural depth of Example 1 are slightly lower than those of AC-16 asphalt mixture, but far higher than the specification requirements, indicating that the rigid-flexible composite material with this ratio has excellent anti-skid performance.

Claims

1. A method for designing the mix ratio of rigid-flexible composite pavement materials based on modified emulsified asphalt mortar, characterized in that: include: Step S1: determining various performance parameters of the target rigid-flexible composite pavement material, screening the required raw materials, and obtaining their basic physical and chemical parameters; Step S2: Designing the mix ratio of the modified emulsified asphalt mortar based on the basic physicochemical parameters in step S1, and obtaining the optimal mix ratio; Step S3: Based on the basic physicochemical parameters in step S1, the aggregate gradation is designed, and the modified emulsified asphalt mortar in step S2 is used as a variable factor to determine the optimal amount of each raw material of the target rigid-flexible composite pavement material; Step S4: Perform a road performance test based on the optimal dosage obtained in step S3. When the test results meet the various performance parameters of the target rigid-flexible composite pavement material, output the results. If not, return to step S3 to re-determine the optimal dosage of each raw material of the target rigid-flexible composite pavement material.

2. The method for designing a mix ratio of a rigid-flexible composite pavement material based on modified emulsified asphalt mortar according to claim 1, characterized in that: The performance parameters of the target rigid-flexible composite pavement material include: dynamic stability, freeze-thaw splitting tensile strength ratio, maximum bending tensile strain, maximum shear stress and maximum tensile stress; The raw materials of the target rigid-flexible composite pavement material include: stone chips, cement, emulsified asphalt, sand, mineral powder, expansion agent, early strength agent, water reducing agent and styrene-acrylic emulsion.

3. The method for designing a mix ratio of a rigid-flexible composite pavement material based on modified emulsified asphalt mortar according to claim 1, characterized in that: The process of obtaining the optimal mix ratio is as follows: the raw materials including cement, emulsified asphalt, sand and water are mixed evenly, and mortar specimens are obtained according to the "Test Code for Cement and Cement Concrete for Highway Engineering" (JTGE30-2020); the mortar specimens are used as independent variables, and the compressive strength, flexural strength, fracture energy and compression-flexural ratio are used as dependent variables, respectively, and the optimal mortar ratio including water-cement ratio, sand-cement ratio and blue-cement ratio is obtained through orthogonal experiments.

4. The method for designing a mix ratio of a rigid-flexible composite pavement material based on modified emulsified asphalt mortar according to claim 1, characterized in that: The aggregate gradation design process is as follows: the raw materials of the target rigid-flexible composite pavement material are dried in a drying oven at 100-120° C. to constant weight, and then the stone chips and other raw materials are graded.

5. The method for designing a mix ratio of a rigid-flexible composite pavement material based on modified emulsified asphalt mortar according to claim 1, characterized in that: The process for determining the optimal amount of each raw material for the target rigid-flexible composite pavement material is as follows: using the modified emulsified asphalt mortar in step S2 as a variable factor, after the aggregate is mixed and processed into a Marshall specimen, a Marshall test is performed, and a relationship curve between the stability of the mixture and the amount of modified emulsified asphalt mortar added to the mixture is established, and the content of modified emulsified asphalt mortar in the mixture corresponding to the peak of the curve is determined as the optimal amount of the rigid-flexible composite pavement material.

6. The method for designing a mix ratio of a rigid-flexible composite pavement material based on modified emulsified asphalt mortar according to claim 1, characterized in that: The process of the road performance test is as follows: according to the optimal dosage obtained in step S3, the raw materials of the target rigid-flexible composite pavement material are evenly mixed, and then cured and formed in accordance with the "Test Code for Cement and Cement Concrete for Highway Engineering" (JTGE30-2020), and rutting tests, low-temperature beam tests, water stability, interlayer adhesion and anti-skid tests are carried out respectively.

7. A rigid-flexible composite pavement material based on modified emulsified asphalt mortar, characterized by: The invention comprises the following components: modified emulsified asphalt, coarse aggregate, fine aggregate and mineral powder, wherein the mixing ratio of the components is determined by the method described in any one of claims 1 to 6.

8. The rigid-flexible composite pavement material based on modified emulsified asphalt mortar according to claim 7, characterized in that: The modified emulsified asphalt includes the following components in parts by mass: 100-120 parts of ordinary Portland cement, 80-100 parts of emulsified asphalt, 20-25 parts of sand, 1-2 parts of expansion agent, 1-2 parts of water reducer, 1-2 parts of early strength agent, 5-10 parts of styrene-acrylic emulsion and 10-15 parts of water; the coarse aggregate is basalt short fiber with a length of 4.75-19 mm; the fine aggregate is graded sand with a particle size of 0.075-4.75 mm.

9. The method for preparing a rigid-flexible composite pavement material based on modified emulsified asphalt mortar according to claim 7 or 8, characterized in that: Add standard graded sand and cement to the mixing pot in sequence, stir at low speed to mix the dry materials evenly, then add the water reducer into the water to fully dissolve it, add it to the dry materials and mix them thoroughly, then add the emulsified asphalt and stir in steps, then add the styrene acrylic emulsion and early strength agent to obtain the modified emulsified asphalt mortar; mix the modified emulsified asphalt mortar with the coarse aggregate, fine aggregate and mineral powder, stir, and then cure to obtain the mortar.

10. The method for preparing a rigid-flexible composite pavement material based on modified emulsified asphalt mortar according to claim 9, characterized in that: The rotation speed of the low-speed stirring is 100~150r / min; the conditions of the step stirring are: stirring at 250~300r / min for 1~3min, and then stirring at 100~150r / min for 5~8min; the process of mixing and stirring the modified emulsified asphalt mortar with coarse aggregate, fine aggregate and mineral powder is: stirring at 100~150r / min for 3~5min, and then stirring at 400~600r / min for 1~3min.

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