Pavement asphalt mixture applied to high-cold regions and preparation method of pavement asphalt mixture

Abstract

The invention relates to the technical field of asphalt mixtures, and particularly discloses a pavement asphalt mixture applied to an alpine region and a preparation method of the pavement asphalt mixture. According to the invention, the rubber powder modified asphalt is selected, the type of the coarse aggregate is limited to be steel slag, and the diatomite and the polyester fiber are also added as additives. Under the synergistic effect of the rubber powder modified asphalt, the steel slag and the additive, the asphalt mixture disclosed by the invention can overcome cracking stress generated under a low-temperature condition, so that low-temperature damage is effectively resisted, the low-temperature crack resistance of the asphalt mixture is improved, and the application requirements of a pavement structure in an alpine region can be fully met.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of asphalt mixture, in particular to a road asphalt mixture applied in high-cold regions and a preparation method thereof. BACKGROUND

[0002] In recent years, the focus of highway construction in China has shifted from the plain areas to the northwest region with more complex climate conditions. In the northwest region, asphalt pavement is still the most important pavement form due to its many advantages. However, the northwest region is characterized by high altitude, cold climate, strong ultraviolet radiation, large diurnal temperature difference, and short effective construction period, which leads to more diseases of asphalt pavement in the northwest region than in the plain region, which puts higher requirements on pavement construction technology.

[0003] Warm-mix asphalt technology has the advantages of energy saving, emission reduction, and green environmental protection. This technology can reduce the production temperature of asphalt mixture by 20-30℃ compared with conventional asphalt mixture, and the road performance is equivalent to that of hot-mixed asphalt mixture, which can effectively reduce energy consumption, greatly reduce environmental pollution, and fully meet the requirements of green environmental protection. In related technology, a warm-mixed asphalt mixture uses road petroleum asphalt as asphalt, limestone aggregate as coarse aggregate, river sand as fine aggregate, and the oil-stone ratio is 5.2%. The warm-mixing agent content is 3% of the total weight of the asphalt mixture. In the high-cold region, the warm-mixing technology can increase the construction time of the construction unit by about 2 months per year.

[0004] According to the related technology in the above, the inventors believe that although the warm-mixing technology can extend the construction season, the pavement paved with warm-mixed asphalt mixture is prone to low-temperature cracking in winter in the harsh environment of the northwest region, and therefore cannot fully meet the application requirements in high-cold regions. SUMMARY

[0005] In related technology, the pavement paved with warm-mixed asphalt mixture is prone to low-temperature cracking in winter, and cannot fully meet the application requirements in high-cold regions. In order to improve this defect, the present application provides a road asphalt mixture applied in high-cold regions and a preparation method thereof.

[0006] In a first aspect, the present application provides a road asphalt mixture applied in high-cold regions, which adopts the following technical solution: A road asphalt mixture applied in high-cold regions, comprising the following components in parts by weight: 5-7 parts of rubber powder modified asphalt, 25-28 parts of fine aggregate, 50-53 parts of coarse aggregate, 10-12 parts of filler, 2.6-2.8 parts of warm-mixing agent, and 2.6-3.2 parts of additive; the coarse aggregate is steel slag, the additive comprises diatomite and polyester fiber, and the weight ratio of diatomite to polyester fiber is (2.9-3.3):1.

[0007] By adopting the technical scheme, the application selects the rubber powder modified asphalt, limits the type of the coarse aggregate to be steel slag, and adds diatomite and polyester fiber as additives. In the rubber powder modified asphalt, the rubber powder particles increase the cohesion of the asphalt, and under the oil-stone ratio condition of the application, the thickness of the asphalt film in the asphalt mixture can be effectively increased, and the rubber powder particles can consume part of the bending damage energy when bending damage occurs, thereby effectively improving the stress dispersion and absorption capacity of the asphalt mixture. The steel slag has porous characteristics, and by absorbing free asphalt, the steel slag can increase the proportion of structural asphalt in the mixture, thereby increasing the overall strength of the mixture. The alkaline components on the surface of the steel slag have strong adhesion with the asphalt, which can reduce the peeling between the aggregate and the asphalt. The above characteristics of the steel slag and the stress dispersion and absorption capacity of the rubber powder modified asphalt can produce a synergistic effect, which helps to fully resist the cracking stress under low temperature conditions. The polyester fiber can form an interwoven network structure in the rubber powder modified asphalt, which hinders the cracking deformation of the asphalt mixture, and the diatomite and the rubber powder particles can be attached to the surface of the polyester fiber, thereby enhancing the bonding strength between the polyester fiber and the asphalt, so that the polyester fiber can fully improve the low-temperature crack resistance of the asphalt mixture. Under the synergistic effect of the rubber powder modified asphalt, the steel slag and the additives, the asphalt mixture of the application can overcome the cracking stress under low temperature conditions, thereby effectively resisting low-temperature damage and improving the low-temperature crack resistance of the asphalt mixture, which helps to fully meet the application requirements of the pavement structure in the high-cold region.

[0008] Preferably, the filler comprises modified zirconium tungstate, which is prepared by the following method: (1) adding zirconium tungstate powder into sodium hydroxide solution, filtering and drying after standing and soaking, to obtain pretreated zirconium tungstate, for standby use; (2) adding the pretreated zirconium tungstate into sodium silicate solution, stirring, filtering, adding the wet filter cake into stearic acid anhydrous ethanol solution, filtering after reaction at room temperature, and drying the filter cake, to obtain modified zirconium tungstate.

[0009] By adopting the technical scheme, the application first pretreats the zirconium tungstate powder with sodium hydroxide solution to make the surface of the zirconium tungstate powder rougher, and then further treats it with stearic acid to obtain modified zirconium tungstate coated with stearic acid. The modified zirconium tungstate can improve the bending tensile strength and bending tensile strain of the asphalt mixture, thereby improving the low-temperature crack resistance of the asphalt mixture.

[0010] Preferably, the rubber powder modified asphalt is prepared by the following method: (1) mixing waste rubber powder and waste engine oil, and obtaining pretreated rubber powder after sealed standing; mixing the pretreated rubber powder, plasticizer, cuprous chloride and polyalkylphenol disulfide, and obtaining activated rubber powder after shearing processing, and cooling for standby; (2) heating base asphalt, then adding activated rubber powder into the base asphalt, shearing processing the mixture, and baking the product to remove bubbles, to obtain rubber powder modified asphalt.

[0011] By adopting the above technical scheme, the waste rubber powder is pretreated by using waste engine oil, so that the waste rubber powder is swollen, and then the waste rubber powder is desulfurized by shearing processing in the assistance of plasticizer, cuprous chloride and polyalkylphenol disulfide, to obtain activated rubber powder. The swelling effect of waste engine oil and the plasticizing effect of plasticizer enable cuprous chloride and polyalkylphenol disulfide to contact with waste rubber powder more fully, promote the desulfurization activation of waste rubber powder, and improve the compatibility of rubber powder particles with base asphalt. After desulfurization activation, the original cross-linking bond in the rubber powder particles is destroyed, new active groups are generated on the surface of the rubber powder, and activated rubber powder is obtained. By blending activated rubber powder with base asphalt, rubber powder modified asphalt can be obtained.

[0012] Preferably, the weight ratio of the waste rubber powder to the waste engine oil is 1:(0.32-0.37).

[0013] By adopting the above technical scheme, the weight ratio of the waste rubber powder to the waste engine oil is preferred, which helps to fully realize the activation modification of the waste rubber powder.

[0014] Preferably, in step (1) of preparing the rubber powder modified asphalt, a desulfurization aid is mixed with the pretreated rubber powder, plasticizer, cuprous chloride and polyalkylphenol disulfide, and the desulfurization aid includes tetramethyl decyne glycol.

[0015] By adopting the above technical scheme, tetramethyl decyne glycol has good surface activity, improves the compatibility between rubber powder and asphalt, promotes the uniform dispersion of rubber powder particles, effectively improves the stress dispersion and absorption capacity of asphalt mixture, and optimizes the low-temperature anti-cracking performance of asphalt mixture.

[0016] Preferably, the desulfurization aid further includes sec-butyl alcohol.

[0017] By adopting the above technical scheme, sec-butyl alcohol can cooperate with tetramethyl decyne glycol to improve the compatibility between rubber powder and asphalt, promote the uniform dispersion of rubber powder particles, and optimize the low-temperature anti-cracking performance of asphalt mixture.

[0018] Preferably, the weight ratio of tetramethyl decyne glycol to sec-butyl alcohol is 1:(0.15-0.18).

[0019] By adopting the technical scheme, the weight ratio of tetramethyl decynediol and sec-butanol is preferred, which helps to improve the low-temperature crack resistance of the asphalt mixture.

[0020] As preferred, in the step (2) of preparing the rubber powder modified asphalt, the recycled polyethylene is added into the base asphalt together with the activated rubber powder.

[0021] By adopting the technical scheme, the recycled polyethylene is preferred as the modified material of the rubber powder, the warm-mixing system of the application has less damage to the recycled polyethylene, and the recycled polyethylene can form a network structure together with the rubber powder particles, which is interwoven with the network structure formed by the polyester fibers, thereby hindering the movement of the asphalt macromolecular chain, and thus improving the low-temperature crack resistance of the asphalt mixture.

[0022] As preferred, the weight ratio of the recycled polyethylene to the activated rubber powder is (0.28-0.31):1.

[0023] By adopting the technical scheme, the weight ratio of the recycled polyethylene to the activated rubber powder is preferred, which helps to improve the low-temperature crack resistance of the asphalt mixture.

[0024] In the second aspect, the application provides a preparation method of a pavement asphalt mixture applied in an alpine region, which adopts the following technical scheme.

[0025] The preparation method of the pavement asphalt mixture applied in the alpine region comprises the following steps: (1) mixing fine aggregate, coarse aggregate and filler to obtain dry mixing material for standby use; preheating rubber powder modified asphalt for standby use; (2) adding a warm-mixing agent and an additive into the rubber powder modified asphalt, stirring and heating, then adding the dry mixing material, and continuously stirring to obtain the pavement asphalt mixture applied in the alpine region.

[0026] By adopting the technical scheme, the dry mixing material is prepared in advance, the rubber powder modified asphalt is preheated, then the warm-mixing agent, the additive and the dry mixing material are added in sequence, and the pavement asphalt mixture applied in the alpine region is obtained after stirring and processing.

[0027] In summary, the application has the following beneficial effects: 1. Under the synergistic effect of the rubber powder modified asphalt, the steel slag and the additive, the asphalt mixture of the application can overcome the cracking stress generated under low-temperature conditions, thereby effectively resisting low-temperature damage and improving the low-temperature crack resistance of the asphalt mixture, which helps to fully meet the application requirements of the pavement structure in the alpine region.

[0028] 2. In the filler of the application, the modified zirconium tungstate can further improve the flexural tensile strength and flexural tensile strain of the asphalt mixture, and improve the low-temperature crack resistance of the asphalt mixture.

[0029] 3、The application adds tetramethyl decyne glycol and sec-butyl alcohol in the preparation step of the activated rubber powder, which can synergistically play a good surface activity effect, improve the compatibility between the rubber powder and the asphalt, promote the uniform dispersion of the rubber powder particles, effectively improve the stress dispersion and absorption capacity of the asphalt mixture, and optimize the low-temperature anti-cracking performance of the asphalt mixture. DETAILED DESCRIPTION

[0030] The application will be further described in detail below in combination with examples, preparation examples and comparative examples. The raw materials involved in the application can be obtained by market purchase.

[0031] Preparation example of modified zirconium tungstate The following preparation example 1 is taken as an example for illustration.

[0032] Preparation example 1 In this preparation example, the modified zirconium tungstate is prepared according to the following method: (1) The zirconium tungstate powder (200 mesh) dried at 100℃ for 4h is added into a 1 mol / L sodium hydroxide solution according to a solid-liquid ratio of 1:5, and after standing and soaking for 2h, filtration and drying are performed to obtain pretreated zirconium tungstate, which is ready for use; (2) The pretreated zirconium tungstate is added into a 0.1 mol / L sodium silicate solution according to a weight ratio of 1:5, and after magnetic stirring for 30min, filtration is performed, the wet filter cake is added into a stearic acid anhydrous ethanol solution (stearic acid mass fraction of 1.5%), and after reaction at room temperature for 10min, filtration is performed, and the filter cake is dried to obtain the modified zirconium tungstate.

[0033] Preparation example of rubber powder modified asphalt The following preparation example 2 is taken as an example for illustration.

[0034] Preparation example 2 In this preparation example, the mesh number of the waste rubber powder is 40 mesh, the rubber hydrocarbon content of the waste rubber powder is 51.4%, the carbon black content is 32.6%, the acetone extract content is 10.1%, and the balance is ash; the 60℃ viscosity of the waste engine oil is 37.8cSt, the flash point is 230℃, and the 15℃ density is 0.788g / cm 3 ; the amount of the plasticizer is 10% of the weight of the waste rubber powder; the amount of cuprous chloride and the amount of polyalkylphenol disulfide are both 0.3% of the weight of the waste rubber powder.

[0035] In this preparation example, the rubber powder modified asphalt is prepared according to the following method: (1) The waste rubber powder is mixed with waste engine oil at a weight ratio of 1:0.3, and after being sealed and standing for 48 h, pretreated rubber powder is obtained; the pretreated rubber powder, plasticizer, cuprous chloride and polyalkylphenol disulfide (activator 420) are mixed, and shearing processing is carried out at 1200 r / min for 10 min, with the temperature controlled at 90±5℃, and after the end of the processing, activated rubber powder is obtained and cooled for standby; (2) The base asphalt is heated, and after reaching 180℃, activated rubber powder equivalent to 15% of the base asphalt by weight is added into the base asphalt, and shearing processing is carried out on the mixture at 180℃ and 3000 r / min, and after 60 min, the product is baked to remove bubbles, and after baking for 1 h, rubber powder modified asphalt is obtained.

[0036] Preparation Example 3 The difference between the present preparation example and Preparation Example 2 is that the weight ratio of waste rubber powder and waste engine oil is 1:0.32.

[0037] Preparation Example 4 The difference between the present preparation example and Preparation Example 2 is that the weight ratio of waste rubber powder and waste engine oil is 1:0.35.

[0038] Preparation Example 5 The difference between the present preparation example and Preparation Example 2 is that the weight ratio of waste rubber powder and waste engine oil is 1:0.37.

[0039] Preparation Example 6 The difference between the present preparation example and Preparation Example 5 is that in step (1) of preparing rubber powder modified asphalt, a desulfurization aid is mixed with the pretreated rubber powder, plasticizer, cuprous chloride and polyalkylphenol disulfide, and the desulfurization aid is tetramethyl decyne glycol, and the weight ratio of tetramethyl decyne glycol to polyalkylphenol disulfide is 4:1.

[0040] Preparation Example 7 The difference between the present preparation example and Preparation Example 6 is that the desulfurization aid further includes sec-butyl alcohol, and the weight ratio of tetramethyl decyne glycol to sec-butyl alcohol is 1:0.1.

[0041] Preparation Example 8 The difference between the present preparation example and Preparation Example 7 is that the weight ratio of tetramethyl decyne glycol to sec-butyl alcohol is 1:0.15.

[0042] Preparation Example 9 The difference between the present preparation example and Preparation Example 7 is that the weight ratio of tetramethyl decyne glycol to sec-butyl alcohol is 1:0.16.

[0043] Preparation Example 10 The difference between the present preparation example and Preparation Example 7 is that the weight ratio of tetramethyl decyne glycol to sec-butyl alcohol is 1:0.18.

[0044] Preparation Example 11 The difference between the present preparation example and Preparation Example 10 is that, in the step (2) of preparing the crumb rubber modified asphalt, the recycled polyethylene and the activated crumb rubber are added into the base asphalt together, and the weight ratio of the recycled polyethylene and the activated crumb rubber is 0.2:1.

[0045] Preparation Example 12 The difference between the present preparation example and Preparation Example 11 is that, the weight ratio of the recycled polyethylene and the activated crumb rubber is 0.28:1.

[0046] Preparation Example 13 The difference between the present preparation example and Preparation Example 11 is that, the weight ratio of the recycled polyethylene and the activated crumb rubber is 0.29:1.

[0047] Preparation Example 14 The difference between the present preparation example and Preparation Example 11 is that, the weight ratio of the recycled polyethylene and the activated crumb rubber is 0.31:1. Example

[0048] Examples 1-3 The following is described by taking Example 1 as an example.

[0049] Example 1 In the present example, the crumb rubber modified asphalt is prepared according to the method of Preparation Example 2, the coarse aggregate is steel slag, the fine aggregate is river sand with fineness modulus of 2.7, the coarse aggregate and the fine aggregate meet the continuous grading requirements of AC-13; the filler is selected as limestone powder with average particle size of 3.25 mm, the warm mix agent is selected as Evotherm 3g warm mix agent, and the additive is mixed by diatomite and polyester fiber according to the weight ratio of 2.9:1 (referred to as additive ratio in Table 1).

[0050] The present example provides a pavement asphalt mixture applied in high-cold regions, which comprises the following components: 5 kg of crumb rubber modified asphalt, 25 kg of fine aggregate, 50 kg of coarse aggregate, 10 kg of filler, 2.6 kg of warm mix agent, and 2.6 kg of additive.

[0051] The present example provides a preparation method of a pavement asphalt mixture applied in high-cold regions, which comprises the following steps: (1) mixing the fine aggregate, the coarse aggregate and the filler to obtain dry mixing material, for standby use; preheating the crumb rubber modified asphalt at 120℃, for standby use; (2) adding the warm mix agent and the additive into the crumb rubber modified asphalt, continuing to stir at a speed of 1500 r / min for 30 min and heating to 140℃, then adding the dry mixing material, and after 1 h of stirring, obtaining the pavement asphalt mixture applied in high-cold regions.

[0052] As shown in Table 1, the main difference between Examples 1-3 is that the raw material ratio of the asphalt mixture is different.

[0053] Table 1 Raw material ratio of asphalt mixture Example 4 The difference between this example and Example 3 is that the filler also includes modified zirconium tungstate, which is prepared according to the method of Preparation Example 1, and the weight of the modified zirconium tungstate is 20% of the total weight of the filler.

[0054] Examples 4-16 As shown in Table 2, the difference between Examples 4-16 is that the preparation examples of the rubber powder modified asphalt are different.

[0055] Table 2 Preparation examples of rubber powder modified asphalt Sample Preparation Example Example 4 Preparation Example 2 Example 5 Preparation Example 3 Example 6 Preparation Example 4 Example 7 Preparation Example 5 Example 8 Preparation Example 6 Example 9 Preparation Example 7 Example 10 Preparation Example 8 Example 11 Preparation Example 9 Example 12 Preparation Example 10 Example 13 Preparation Example 11 Example 14 Preparation Example 12 Example 15 Preparation Example 13 Example 16 Preparation Example 14 Comparative Example Comparative Example 1 This comparative example provides a warm mix asphalt mixture, the oil-stone ratio is 5.2%, the asphalt used is 90# road petroleum asphalt, the coarse aggregate is limestone aggregate, the fine aggregate is river sand, and the coarse aggregate and the fine aggregate meet the continuous gradation requirements of AC-13; the filler is selected to be limestone powder with an average particle size of 3.25 mm; the warm mix agent is selected to be Evotherm 3g warm mix agent, and the warm mix agent content is 3.46% of the total weight of the asphalt mixture.

[0056] Comparative Example 2 The difference between this comparative example and Example 1 is that the diatomite in the additive is removed.

[0057] Comparative Example 3 The difference between this comparative example and Example 1 is that the polyester fiber in the additive is removed.

[0058] Comparative Example 4 The difference between this comparative example and Example 1 is that the coarse aggregate is limestone aggregate.

[0059] Comparative Example 5 The difference between this comparative example and Example 1 is that the rubber powder modified asphalt is replaced by 90# road petroleum asphalt.

[0060] Performance detection test method The low-temperature anti-cracking performance of the asphalt mixture is detected by the small beam bending test recorded in the “JTG E20-2011 Highway Engineering Asphalt and Asphalt Mixture Test Procedures”, and the ratio between the failure strain of each example and comparative example and the failure strain of Comparative Example 1 is calculated, which is recorded as the relative failure strain, and the results are shown in Table 3.

[0061] Table 3 Sample Relative strain to failure / % Sample Relative strain to failure / % Example 1 122.6 Example 12 135.9 Example 2 124.2 Example 13 136.4 Example 3 125.1 Example 14 137.8 Example 4 129.2 Example 15 138.0 Example 5 130.5 Example 16 138.1 Example 6 130.8 Comparative Example 1 100.0 Example 7 131.1 Comparative Example 2 117.6 Example 8 134.0 Comparative Example 3 112.3 Example 9 134.9 Comparative Example 4 115.0 Example 10 135.3 Comparative Example 5 109.0 Example 11 Comparative Example 6 Comparative Example 7 Comparative Example 8 Comparative Example 9 Comparative Example 10 Comparative Example 11 Comparative Example 12 Comparative Example 13 Comparative Example 14 Comparative Example 15 Comparative Example 16 Comparative Example 17 Comparative Example 18 Comparative Example 19 Comparative Example 20 Comparative Example 21 Comparative Example 22 Comparative Example 23 Comparative Example 24 Comparative Example 25 Comparative Example 26 Comparative Example 27 Comparative Example 28 Comparative Example 29 Comparative Example 30 Comparative Example 31 Comparative Example 32 Comparative Example 33 Comparative Example 34 Comparative Example 35 Comparative Example 36 Comparative Example 37 Comparative Example 38 Comparative Example 39 Comparative Example 40 Comparative Example 41 Comparative Example 135.7 / / It can be seen from Examples 1-3 and Comparative Example 1 in combination with Table 3 that the relative failure strain measured in Examples 1-3 is larger, because the steel slag aggregate and the rubber powder modified asphalt in Examples 1-3 have a synergistic effect, the proportion of structural asphalt is increased by the steel slag aggregate, and the adhesion between the aggregate and the rubber powder modified asphalt is stronger, and the rubber powder modified asphalt can absorb and disperse stress, and the mutual cooperation of the two can help to fully resist the cracking stress under low temperature conditions. At the same time, the polyester fiber forms a network structure with the assistance of diatomite and rubber powder particles, and the network structure is tightly combined with asphalt, which effectively enhances the stress bearing capacity of the asphalt mixture under the condition that the stress is weakened, limits the deformation of asphalt, and hinders low-temperature cracking. Comparative Example 1 lacks rubber powder modified asphalt, steel slag and additives, so it cannot achieve the above effects, resulting in failure of the test piece under lower strain conditions.

[0062] It can be seen from Examples 1 and Comparative Examples 2-3 in combination with Table 3 that the relative failure strain measured in Comparative Examples 2-3 is lower, because Comparative Example 2 only has polyester fiber in the additive, which cannot enhance the bonding strength between polyester fiber and asphalt through diatomite, so the network structure formed by polyester fiber cannot fully limit the deformation of asphalt; and Comparative Example 3 only has diatomite in the additive, which cannot bear stress through the network structure formed by polyester fiber, resulting in failure of the test piece under lower strain conditions.

[0063] It can be seen from Examples 1 and Comparative Example 4 in combination with Table 3 that the relative failure strain measured in Comparative Example 4 is lower, because the limestone aggregate in Comparative Example 4 has a lower adsorption performance on asphalt, and cannot increase the proportion of structural asphalt by absorbing free asphalt, so the strength performance of the mixture as a whole cannot be significantly improved, and the test piece fails under lower strain conditions.

[0064] It can be seen from Examples 1 and Comparative Example 5 in combination with Table 3 that the relative failure strain measured in Comparative Example 4 is lower, because the asphalt in Comparative Example 5 is not modified by rubber powder, and has limited ability to disperse and absorb stress, so the low-temperature crack resistance of the test piece formed by the asphalt mixture is poor, and the test piece fails under lower strain conditions.

[0065] It can be seen from Examples 3 and 4 in combination with Table 3 that the relative failure strain measured in Example 4 is larger, because the modified zirconium tungstate can improve the flexural tensile strength and flexural tensile strain of the asphalt mixture, thereby improving the low-temperature crack resistance of the asphalt mixture.

[0066] It can be seen from the combination of example 4, examples 5-7 and table 3 that the relative failure strain measured in examples 5-7 is larger, which is because the swelling of waste engine oil to waste rubber powder is more thorough in the corresponding range of examples 5-7, so that the rubber powder can fully realize desulfurization activation, thereby improving the compatibility of the rubber powder particles with the matrix asphalt, so that the rubber powder particles can be more effectively dispersed and stress-absorbed, and therefore the test piece can be destroyed under the condition of generating a larger strain.

[0067] It can be seen from the combination of example 7, examples 8-12 and table 3 that the relative failure strain measured in examples 8, examples 9, examples 10-12 increases in turn, which is because tetramethyl decyne glycol has good surface activity, improves the compatibility between rubber powder and asphalt, can promote the uniform dispersion of rubber powder particles, effectively improves the stress dispersion and absorption capacity of asphalt mixture, and optimizes the low-temperature anti-cracking performance of asphalt mixture. And sec-butanol can improve the compatibility between rubber powder and asphalt in cooperation with tetramethyl decyne glycol, so as to further optimize the low-temperature anti-cracking performance of asphalt mixture. When the weight ratio of tetramethyl decyne glycol to sec-butanol is 1:(0.15-0.18), the low-temperature anti-cracking performance of the whole asphalt mixture is better.

[0068] It can be seen from the combination of example 12, examples 13-16 and table 3 that the relative failure strain measured in examples 13, examples 14-16 increases in turn, which is because the warm-mixing system of the present application has less damage to the regenerated polyethylene, and the regenerated polyethylene can form a network structure with the rubber powder particles, and this network structure and the network structure formed by the polyester fiber are interwoven with each other, which cooperatively hinders the movement of asphalt macromolecular chains, thereby improving the low-temperature anti-cracking performance of asphalt mixture. When the weight ratio of regenerated polyethylene to activated rubber powder is (0.28-0.31):1, the low-temperature anti-cracking performance of the whole asphalt mixture is better.

[0069] The above examples are only an explanation of the present application, not a limitation of the present application, and those skilled in the art can make modifications to the examples of the present application without creative contribution after reading the present specification, but as long as it is within the scope of the claims of the present application, it is protected by the patent law.

Claims

1. An asphalt mixture for road surfaces used in cold regions, characterized in that, The product comprises the following components by weight: 5-7 parts of rubber-modified asphalt, 25-28 parts of fine aggregate, 50-53 parts of coarse aggregate, 10-12 parts of filler, 2.6-2.8 parts of warm mix additive, and 2.6-3.2 parts of additives; wherein the coarse aggregate is steel slag, and the additives include diatomaceous earth and polyester fiber, wherein the weight ratio of diatomaceous earth to polyester fiber is (2.9-3.3):

1.

2. The asphalt mixture for road surfaces in cold regions according to claim 1, characterized in that, The filler comprises modified zirconium tungstate, which is prepared according to the following method: (1) Add zirconium tungstate powder to sodium hydroxide solution, let it stand and soak, then filter and dry to obtain pretreated zirconium tungstate for later use; (2) Add the pretreated zirconium tungstate to the sodium silicate solution, stir and filter. Add the wet filter cake to the anhydrous ethanol solution of stearic acid, react at room temperature and filter. Dry the filter cake to obtain modified zirconium tungstate.

3. The asphalt mixture for road surfaces in cold regions according to claim 1, characterized in that, The rubber powder modified asphalt is prepared according to the following method: (1) Mix waste rubber powder and waste engine oil, and after sealing and standing, obtain pretreated rubber powder; mix pretreated rubber powder, plasticizer, cuprous chloride and polyalkylphenol disulfide, and after shearing, obtain activated rubber powder, and cool for later use; (2) Heat the base asphalt, then add activated rubber powder to the base asphalt, shear the mixture, and then bake the product to remove bubbles to obtain rubber powder modified asphalt.

4. The asphalt mixture for road surfaces in cold regions according to claim 3, characterized in that, The weight ratio of the waste rubber powder to the waste engine oil is 1:(0.32-0.37).

5. The asphalt mixture for road surfaces in cold regions according to claim 3, characterized in that, In step (1) of preparing the rubber powder modified asphalt, the desulfurization aid is mixed with pretreated rubber powder, plasticizer, cuprous chloride and polyalkylphenol disulfide, wherein the desulfurization aid includes tetramethyldecynyl diol.

6. The asphalt mixture for road surfaces in cold regions according to claim 5, characterized in that, The desulfurization aid also includes sec-butanol.

7. The asphalt mixture for road surfaces in cold regions according to claim 6, characterized in that, The weight ratio of tetramethyldecynediol to sec-butanol is 1:(0.15-0.18).

8. The asphalt mixture for road surfaces in cold regions according to claim 3, characterized in that, In step (2) of preparing the rubber powder modified asphalt, recycled polyethylene and activated rubber powder are added together to the base asphalt.

9. The asphalt mixture for road surfaces in cold regions according to claim 8, characterized in that, The weight ratio of the recycled polyethylene to the activated rubber powder is (0.28-0.31):

1.

10. The method for preparing asphalt mixtures for use in cold regions according to any one of claims 1-9, characterized in that, Includes the following steps: (1) Mix fine aggregate, coarse aggregate and filler to obtain dry mix for later use; preheat the rubber powder modified asphalt for later use. (2) Add warm mix agent and additives to the rubber powder modified asphalt, stir and heat, then add dry mix, and continue stirring to obtain the asphalt mixture for use in cold regions.

Images