Cold-mixed permeable asphalt and method for preparing the same

Abstract

The application relates to the field of asphalt materials, and particularly discloses a cold-mixed water-permeable asphalt and a preparation method thereof. The cold-mixed water-permeable asphalt comprises the following raw materials in parts by weight: 20-30 parts of single-component polyurethane, 10-20 parts of asphalt, 50-60 parts of aggregate, 1-3 parts of porous ceramic microbeads, 1-3 parts of alkali activator, 3-5 parts of reinforcing fiber and 3-5 parts of 4A molecular sieve; the aggregate comprises the following raw materials in parts by weight: 13-16 parts of coarse aggregate with a particle size of 12-19 mm, 20-30 parts of coarse aggregate with a particle size of 8-11 mm, 10-13 parts of fine aggregate with a particle size of 1-4.5 mm and 1-3 parts of mineral powder. The cold-mixed water-permeable asphalt has good water-permeable performance and reduces the deformation phenomenon under the synergistic action of various components.

Description

Technical Field

[0001] This application relates to the field of asphalt materials, and more specifically, to a cold-mix permeable asphalt and a method for preparing the same. Background Technology

[0002] In recent decades, asphalt pavement has seen a continuous increase in its use on highways due to its advantages such as convenient maintenance, safe and comfortable driving, low noise, and less dust. Although paved asphalt pavement has many advantages, traditional hot-mix asphalt pavement is prone to producing exhaust fumes, dust, and other harmful substances that affect health during the paving process, and it also leads to energy consumption. Therefore, a new type of material—cold-mix asphalt mixture—is now being used.

[0003] However, existing cold-mix asphalt mixtures often use dense-graded asphalt composites, which have the advantages of low porosity and good durability. However, due to the continuous gradation, the drainage effect of asphalt pavement is low. In rainy weather, water cannot drain out in time and forms a water film on the pavement surface, which can easily cause vehicles to slip and cause traffic accidents, while also shortening the service life of asphalt mixtures. Summary of the Invention

[0004] To improve the permeability of cold-mixed asphalt mixtures, this application provides a cold-mixed permeable asphalt and its preparation method.

[0005] Firstly, this application provides a cold-mix permeable asphalt, employing the following technical solution:

[0006] A cold-mix permeable asphalt comprises the following raw materials in parts by weight: 20-30 parts of single-component polyurethane, 10-20 parts of asphalt, 50-60 parts of aggregate, 1-3 parts of porous ceramic microspheres, 1-3 parts of alkali activator, 3-5 parts of reinforcing fiber, and 3-5 parts of 4A molecular sieve; wherein the aggregate comprises the following raw materials in parts by weight: 13-16 parts of coarse aggregate with a particle size of 12-19mm, 20-30 parts of coarse aggregate with a particle size of 8-11mm, 10-13 parts of fine aggregate with a particle size of 1-4.5mm, and 1-3 parts of mineral powder.

[0007] By adopting the above technical solutions, the use of coarse and fine aggregates of different particle sizes maintains good strength in asphalt mixtures. Simultaneously, controlling the amount of coarse and fine aggregates of different particle sizes in a suitable ratio maintains a certain level of porosity in the asphalt mixture, improving its permeability. The use of porous ceramic microspheres and 4A molecular sieves provides support in the asphalt mixture, reducing pore blockage due to deformation and improving the rutting resistance of asphalt pavements. Furthermore, the stable pore structure of porous ceramic microspheres and 4A molecular sieves increases the porosity of cold-mix asphalt mixtures, thereby enhancing their permeability.

[0008] Preferably, the diameter of the 4A molecular sieve is 2-5 mm, and the particle size of the porous ceramic microspheres is 1-5 mm.

[0009] By adopting the above technical solution, controlling the size of porous ceramic microspheres and 4A molecular sieves within a suitable range can improve the dispersibility of porous ceramic microspheres and 4A molecular sieves in asphalt mixtures. At the same time, controlling the pore size of porous ceramic microspheres and 4A molecular sieves can maintain good water permeability and promote better water permeability of asphalt mixtures.

[0010] Preferably, the alkaline activator is one of sodium hydroxide, potassium hydroxide, and silicate.

[0011] Preferably, the reinforcing fiber is at least one of polyester fiber, lignin fiber and polypropylene fiber, and the length of the reinforcing fiber is 3-8 mm.

[0012] By adopting the above technical solution, using polyester fiber, lignin fiber and polypropylene fiber as reinforcing fibers, which have good flexibility and dispersibility, a three-dimensional network structure can be formed in asphalt mixtures, enhancing the support and durability of asphalt mixtures, reducing the phenomenon of pore blockage caused by external extrusion and deformation of asphalt mixtures, and enhancing the rutting resistance and strength of asphalt mixtures, as well as improving the permeability and dynamic stability of asphalt mixtures.

[0013] Preferably, the polyester fiber is a hollow polyester fiber, and the hollow polyester fiber has a three-dimensional 15D dimension.

[0014] By adopting the above technical solution and using hollow polyester fibers with a cavity structure, the polyester fibers can have a lower thermal conductivity, thereby reducing the thermal conductivity of the asphalt mixture, improving its permeability, and enhancing its stability. Simultaneously, the hollow polyester fibers possess high tensile strength and flexibility, thus improving the crack resistance of the asphalt mixture.

[0015] Preferably, the single-component polyurethane comprises the following raw materials in parts by weight: 20-30 parts of polyether polyol, 20-30 parts of isocyanate, 0.3-0.5 parts of catalyst, and 30-40 parts of solvent.

[0016] Preferably, the single-component polyurethane raw material further includes the following components in parts by weight: 5-8 parts methyl methacrylate, 0.3-0.5 parts crosslinking agent, 0.1-0.3 parts initiator, and 1-3 parts rutile titanium dioxide.

[0017] By adopting the above technical solution, a cross-linked network structure can be formed in the asphalt mixture through cross-linking of methyl methacrylate, cross-linking agent, and polyurethane. This enhances the hardness and adhesion of the asphalt mixture, reduces cracking and peeling, and thus improves its bonding strength and durability. Adding an appropriate amount of rutile titanium dioxide, which refracts visible and infrared light, can cool the surface of the asphalt pavement, reduce excessive heat absorption, and improve the asphalt mixture's anti-aging properties and rutting resistance.

[0018] Secondly, this application provides a method for preparing cold-mixed permeable asphalt, employing the following technical solution:

[0019] A method for preparing cold-mixed permeable asphalt includes the following specific steps:

[0020] Mix single-component polyurethane and asphalt, then add aggregates, porous ceramic microspheres, reinforcing fibers, and 4A molecular sieves and mix evenly. Finally, add alkali activator and mix evenly to obtain cold-mix permeable asphalt.

[0021] By adopting the above technical solutions, the asphalt mixture can have better permeability and deformation resistance through the synergistic effect of various components.

[0022] Preferably, the polyether polyol, isocyanate, and solvent are mixed in advance, a catalyst is added dropwise, the temperature is raised to 70-90°C for reaction, and then methyl methacrylate, initiator, crosslinking agent, and rutile titanium dioxide are added and mixed for reaction to obtain a polyurethane composite.

[0023] The polyurethane composite and asphalt are mixed, then aggregates, porous ceramic microspheres, reinforcing fibers and 4A molecular sieves are added and mixed evenly. Finally, alkali activator is added and mixed evenly to obtain cold-mix permeable asphalt.

[0024] In summary, this application has the following beneficial effects:

[0025] 1. Because this application uses coarse and fine aggregates with different particle sizes and different dosage ratios, it can maintain the asphalt mixture with both high strength and porosity. At the same time, porous ceramic microspheres and 4A molecular sieves are used to provide support, reduce the deformation and pore blockage of the asphalt mixture, and thus improve the permeability and porosity of the asphalt mixture.

[0026] 2. In this application, methyl methacrylate, a crosslinking agent, and polyurethane are preferably crosslinked to form a crosslinked network structure in the asphalt mixture, enhancing the adhesion of the asphalt mixture and promoting its firm adhesion to the road surface. Simultaneously, the addition of rutile titanium dioxide has a cooling effect on the asphalt mixture, reducing aging caused by excessively high asphalt pavement temperatures and improving the permeability and rutting resistance of the asphalt mixture. Detailed Implementation

[0027] The present application will be further described in detail below with reference to the embodiments.

[0028] Preparation example of one-component polyurethane

[0029] Preparation Example 1

[0030] The single-component polyurethane comprises the following raw materials in parts by weight: 25 kg of polyether polyol, 25 kg of isocyanate, 0.4 kg of catalyst, and 35 kg of solvent. The isocyanate is toluene diisocyanate TDI-80, the polyether polyol is polyether diol N210, the catalyst is T12, and the solvent is dichloromethane.

[0031] The preparation method of one-component polyurethane includes the following specific steps:

[0032] Polyether polyol and solvent were mixed in advance, then isocyanate was added and the mixture was heated to 50°C and stirred evenly. Then, catalyst was added dropwise and the reaction was carried out at 80°C for 1 hour. After cooling, a one-component polyurethane was obtained.

[0033] Preparation Example 2

[0034] The difference between Preparation Example 2 and Preparation Example 1 is that the amount of polyether polyol used in the single-component polyurethane raw material is 20 kg, the amount of isocyanate used is 20 kg, the amount of catalyst used is 0.3 kg, and the amount of solvent used is 30 kg.

[0035] Preparation Example 3

[0036] The difference between Preparation Example 3 and Preparation Example 1 is that the amount of polyether polyol used in the single-component polyurethane raw material is 30 kg, the amount of isocyanate used is 30 kg, the amount of catalyst used is 0.5 kg, and the amount of solvent used is 40 kg.

[0037] Preparation Example 4

[0038] The difference between Preparation Example 4 and Preparation Example 1 is that the single-component polyurethane raw material also includes 7 kg of methyl methacrylate, 0.4 kg of crosslinking agent, and 0.2 kg of initiator. The crosslinking agent is N,N-methylenebisacrylamide, and the initiator is potassium persulfate.

[0039] The preparation method of one-component polyurethane includes the following specific steps:

[0040] Polyether polyol and solvent were mixed beforehand, and then isocyanate was added and the mixture was heated to 50°C and stirred evenly. Then, catalyst was added dropwise and the mixture was reacted at 80°C for 1 hour. Crosslinking agent and methyl methacrylate were added under heat preservation and the mixture was reacted for 1 hour. Then, initiator was added dropwise and the mixture was kept at heat preservation for 1 hour. After cooling, polyurethane composite was obtained.

[0041] Preparation Example 5

[0042] The difference between Preparation Example 5 and Preparation Example 4 is that the single-component polyurethane raw material also includes 2 kg of rutile titanium dioxide.

[0043] The preparation method of one-component polyurethane includes the following specific steps:

[0044] Polyether polyol and solvent were mixed in advance, then isocyanate was added and the mixture was heated to 50°C and stirred evenly. Then, catalyst was added dropwise and the reaction was carried out at 80°C for 1 hour. Crosslinking agent and methyl methacrylate were added under heat preservation and the mixture was reacted for 1 hour. Then, initiator was added dropwise and the reaction was carried out under heat preservation for another 1 hour. Finally, rutile titanium dioxide was added and the mixture was cooled to obtain polyurethane composite.

[0045] Preparation Example 6

[0046] The difference between Preparation Example 6 and Preparation Example 5 is that the amount of methyl methacrylate used in the single-component polyurethane raw material is 5 kg, the amount of crosslinking agent is 0.3 kg, the amount of initiator is 0.1 kg, and the amount of rutile titanium dioxide is 3 kg.

[0047] Preparation Example 7

[0048] The difference between Preparation Example 7 and Preparation Example 5 is that the amount of methyl methacrylate used in the single-component polyurethane raw material is 8 kg, the amount of crosslinking agent is 0.5 kg, the amount of initiator is 0.3 kg, and the amount of rutile titanium dioxide is 1 kg.

[0049] Example of aggregate preparation

[0050] Preparation Example 8

[0051] The aggregate comprises the following raw materials in parts by weight: 15 kg of coarse aggregate with a particle size of 12-19 mm, 25 kg of coarse aggregate with a particle size of 8-11 mm, 12 kg of fine aggregate with a particle size of 1-4.5 mm, and 2 kg of mineral powder. The coarse aggregate is steel slag, the fine aggregate is natural sand, and the average particle size of the mineral powder is 0.5-1 mm.

[0052] The method for preparing aggregates includes the following raw materials in parts by weight:

[0053] Coarse aggregate with a particle size of 12-19mm, coarse aggregate with a particle size of 8-11mm, fine aggregate with a particle size of 1-4.5mm, and mineral powder are mixed and stirred evenly to obtain aggregate.

[0054] Preparation Example 9

[0055] The difference between Preparation Example 9 and Preparation Example 8 is that the amount of coarse aggregate with a particle size of 12-19 mm used in the aggregate raw materials is 13 kg, the amount of coarse aggregate with a particle size of 8-11 mm used is 30 kg, the amount of fine aggregate with a particle size of 1-4.5 mm used is 10 kg, and the amount of mineral powder used is 1 kg.

[0056] Preparation Example 10

[0057] The difference between Preparation Example 10 and Preparation Example 8 is that the amount of coarse aggregate with a particle size of 12-19 mm used in the aggregate raw materials is 16 kg, the amount of coarse aggregate with a particle size of 8-11 mm used is 20 kg, the amount of fine aggregate with a particle size of 1-4.5 mm used is 13 kg, and the amount of mineral powder used is 3 kg.

[0058] Preparation Example 11

[0059] The difference between Preparation Example 11 and Preparation Example 8 is that coarse aggregates with a particle size of 12-19 mm are not used in the aggregate raw materials.

[0060] Preparation Example 12

[0061] The difference between Preparation Example 12 and Preparation Example 8 is that fine aggregates with a particle size of 1-4.5 mm are not used in the aggregate raw materials.

[0062] Preparation Example 13

[0063] The difference between Preparation Example 13 and Preparation Example 8 is that mineral powder is not used in the aggregate raw materials.

[0064] Example

[0065] Example 1

[0066] This embodiment provides a cold-mixed permeable asphalt, comprising the following raw materials in parts by weight: 25 kg of single-component polyurethane, 15 kg of asphalt, 55 kg of aggregate, 2 kg of porous ceramic microspheres, 2 kg of alkali activator, 4 kg of reinforcing fiber, and 4 kg of 4A molecular sieve. The single-component polyurethane is derived from Preparation Example 1, and the asphalt is Xinhai 70. # The base bitumen was produced in Huanghua, Hebei Province. The aggregate was derived from Preparation Example 8. The average particle size of the porous ceramic microspheres was 1-5 mm, the average diameter of the 4A molecular sieve was 2-5 mm, the alkali activator was sodium hydroxide, and the reinforcing fiber was lignin fiber with an average length of 3-8 mm.

[0067] The preparation method of cold-mixed permeable asphalt includes the following specific steps:

[0068] Mix single-component polyurethane and asphalt, then add aggregates, porous ceramic microspheres, reinforcing fibers, and 4A molecular sieves, mix thoroughly, and finally add alkali activator and mix thoroughly to obtain cold-mix permeable asphalt.

[0069] Example 2

[0070] The difference between Example 2 and Example 1 is that the amount of single-component polyurethane used in the cold-mixed permeable asphalt raw material is 20 kg, the amount of asphalt used is 20 kg, the amount of aggregate used is 50 kg, the amount of porous ceramic microspheres used is 1 kg, the amount of alkali activator used is 1 kg, the amount of reinforcing fiber used is 3 kg, and the amount of 4A molecular sieve used is 5 kg.

[0071] Example 3

[0072] The difference between Example 3 and Example 1 is that the amount of single-component polyurethane used in the cold-mixed permeable asphalt raw material is 30 kg, the amount of asphalt is 10 kg, the amount of aggregate is 60 kg, the amount of porous ceramic microspheres is 3 kg, the amount of alkali activator is 3 kg, the amount of reinforcing fiber is 5 kg, and the amount of 4A molecular sieve is 3 kg.

[0073] Example 4

[0074] The difference between Example 4 and Example 1 is that the single-component polyurethane in the cold-mixed permeable asphalt raw material is derived from Preparation Example 2, and the aggregate is derived from Preparation Example 9.

[0075] Example 5

[0076] The difference between Example 5 and Example 1 is that the single-component polyurethane in the cold-mixed permeable asphalt raw material is derived from Preparation Example 3, and the aggregate is derived from Preparation Example 10.

[0077] Example 6

[0078] The difference between Example 6 and Example 1 is that the reinforcing fiber in the cold-mix permeable asphalt raw material is polypropylene fiber. The average molecular weight of the polypropylene fiber is 180,000.

[0079] Example 7

[0080] The difference between Example 7 and Example 1 is that the reinforcing fiber in the cold-mix permeable asphalt raw material is polyester fiber. The polyester fiber is polyethylene terephthalate fiber with a molecular weight of 18,000.

[0081] Example 8

[0082] The difference between Example 8 and Example 7 is that the polyester fiber in the cold-mixed permeable asphalt raw material is a three-dimensional 15D hollow polyester fiber.

[0083] Example 9

[0084] The difference between Example 9 and Example 8 is that the single-component polyurethane in the cold-mixed permeable asphalt raw material is derived from Preparation Example 4.

[0085] Example 10

[0086] The difference between Example 10 and Example 8 is that the single-component polyurethane in the cold-mixed permeable asphalt raw material is derived from Preparation Example 5.

[0087] Example 11

[0088] The difference between Example 11 and Example 8 is that the single-component polyurethane in the cold-mixed permeable asphalt raw material is derived from Preparation Example 6.

[0089] Example 12

[0090] The difference between Example 12 and Example 8 is that the single-component polyurethane in the cold-mixed permeable asphalt raw material is derived from Preparation Example 7.

[0091] Comparative Example

[0092] Comparative Example 1

[0093] The difference between Comparative Example 1 and Example 1 is that the aggregate in the cold-mixed permeable asphalt raw material is derived from Preparation Example 11.

[0094] Comparative Example 2

[0095] The difference between Comparative Example 2 and Example 1 is that the aggregate in the cold-mixed permeable asphalt raw material is derived from Preparation Example 12.

[0096] Comparative Example 3

[0097] The difference between Comparative Example 3 and Example 1 is that the aggregate in the cold-mixed permeable asphalt raw material is derived from Preparation Example 13.

[0098] Comparative Example 4

[0099] The difference between Comparative Example 4 and Example 1 is that porous ceramic microspheres and 4A molecular sieves are not used in the cold-mixed permeable asphalt raw material.

[0100] Comparative Example 5

[0101] The difference between Comparative Example 5 and Example 1 is that no reinforcing fibers are used in the cold-mixed permeable asphalt raw material.

[0102] Performance testing

[0103] The following performance tests were conducted on the cold-mixed permeable asphalt provided in Examples 1-12 and Comparative Examples 1-5 of this application. The specific test results are shown in Table 1.

[0104] Detection methods

[0105] I. Permeability coefficient and porosity

[0106] Referring to the T0730 asphalt mixture permeability test in CJJ / T-190-2012 "Technical Specification for Permeable Asphalt Pavement" and the standard for the test method of interconnected porosity of permeable asphalt mixture, the permeability coefficient and porosity of the cold-mixed permeable asphalt prepared in this application were tested.

[0107] II. Rutting Test: The dynamic stability of the cold-mixed permeable asphalt prepared in this application was tested according to the standard T0719-2000 "Rutting Test of Asphalt Mixture". The test temperature was 60℃ and the wheel pressure was 0.7MPa.

[0108] Table 1: Performance Test Results Data Table

[0109]

[0110] The performance test results show that in Examples 1-5, the usage of each component in the cold-mixed permeable asphalt raw material is different. In this application, through the synergistic effect of each component, the asphalt mixture can have better permeability and maintain better dynamic stability.

[0111] A comparison of Examples 6-7 and Example 1 shows that, despite using different types of reinforcing fibers, Examples 6, 7, and 1 exhibit better overall performance, demonstrating that Example 7 achieves a better balance between permeability and strength, while maintaining good dynamic stability. This may be because the polyester fibers used in Example 6 contain an appropriate amount of polyterephthalic acid, which shares similarities with asphalt materials. This results in an interfacial effect between the polyester fibers and the asphalt, enhancing the cross-linked network structure of the asphalt mixture and thus improving its high-temperature stability and strength, while reducing deformation. A comparison of Examples 8 and 7 shows that, with the use of three-dimensional 15D hollow polyester fibers in Example 8, the performance test results indicate that the asphalt mixture prepared in Example 8, while maintaining good dynamic stability, also exhibits significantly improved permeability, further demonstrating the promoting effect of hollow polyester fibers on the permeability of asphalt mixtures.

[0112] As shown in Examples 10-12, adding methyl methacrylate and rutile titanium dioxide to cold-mix asphalt further improves the overall performance of the asphalt, thereby reducing deformation and enhancing the adhesion of the asphalt mixture.

[0113] A comparison of Examples 1-3 and Example 1 shows that changing the ratio of coarse and fine aggregates in cold-mix asphalt raw materials has a significant impact on the permeability and porosity of asphalt, thereby reducing the permeability of asphalt pavement.

[0114] A comparison of Comparative Examples 4-5 and Example 1 shows that Comparative Example 4, which did not use porous ceramic microspheres and 4A molecular sieves, resulted in a significant decrease in the permeability of cold-mix asphalt and a reduction in dynamic stability. Example 5, which did not use reinforcing fibers, reduced the toughness of the cold-mix asphalt, making it more prone to deformation and consequently decreasing the permeability of the asphalt pavement.

[0115] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A cold-mixed permeable asphalt, characterized in that, The raw materials include the following parts by weight: 20-30 parts of single-component polyurethane, 10-20 parts of asphalt, 50-60 parts of aggregate, 1-3 parts of porous ceramic microspheres, 1-3 parts of alkali activator, 3-5 parts of reinforcing fiber, and 3-5 parts of 4A molecular sieve; the aggregate includes the following parts by weight: 13-16 parts of coarse aggregate with a particle size of 12-19mm, 20-30 parts of coarse aggregate with a particle size of 8-11mm, 10-13 parts of fine aggregate with a particle size of 1-4.5mm, and 1-3 parts of mineral powder; The single-component polyurethane comprises the following raw materials in parts by weight: 20-30 parts polyether polyol, 20-30 parts isocyanate, 0.3-0.5 parts catalyst, 30-40 parts solvent, 5-8 parts methyl methacrylate, 0.3-0.5 parts crosslinking agent, 0.1-0.3 parts initiator, and 1-3 parts rutile titanium dioxide; the crosslinking agent is N,N-methylenebisacrylamide, and the initiator is potassium persulfate. The preparation method of one-component polyurethane includes the following specific steps: Polyether polyol and solvent were mixed in advance, then isocyanate was added and the mixture was heated to 50°C and stirred evenly. Then, catalyst was added dropwise and the mixture was reacted at 80°C for 1 hour. Crosslinking agent and methyl methacrylate were added under heat preservation and the mixture was reacted for 1 hour. Then, initiator was added dropwise and the mixture was kept at heat preservation for another 1 hour. Finally, rutile titanium dioxide was added and cooled to obtain a one-component polyurethane.

2. The cold-mixed permeable asphalt according to claim 1, characterized in that, The diameter of the 4A molecular sieve is 2-5 mm, and the particle size of the porous ceramic microspheres is 1-5 mm.

3. The cold-mix permeable asphalt according to claim 1, characterized in that, The alkaline activator is one of sodium hydroxide, potassium hydroxide, or silicate.

4. The cold-mix permeable asphalt according to claim 1, characterized in that, The reinforcing fiber is at least one of polyester fiber, lignin fiber and polypropylene fiber, and the length of the reinforcing fiber is 3-8 mm.

5. The cold-mixed permeable asphalt according to claim 4, characterized in that, The polyester fiber is a hollow polyester fiber, and the hollow polyester fiber has a three-dimensional 15D dimension.

6. A method for preparing cold-mix permeable asphalt as described in any one of claims 1-5, characterized in that, The specific steps include the following: Mix single-component polyurethane and asphalt, then add aggregates, porous ceramic microspheres, reinforcing fibers, and 4A molecular sieves and mix evenly. Finally, add alkali activator and mix evenly to obtain cold-mix permeable asphalt.

Images