Rock asphalt powder, modified asphalt, foamed asphalt, mixture and preparation method

Abstract

The invention provides rock asphalt powder, modified asphalt, foamed asphalt, a mixture and a preparation method. Specifically, the rock asphalt powder comprises rock asphalt powder and a film layer located on the surface of the rock asphalt powder; and the film layer comprises polyoxyethylene and glycerol. The softening agent is added on the surface of the rock asphalt powder, so that the surface characteristics of the rock asphalt are improved, the surface energy of the rock asphalt is reduced, the flexibility is improved, the rock asphalt is easy to foam, the low-temperature crack resistance of a natural rock asphalt mixture is improved, the application range of the rock asphalt is expanded, and the site construction temperature is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of road engineering, and in particular to rock asphalt powder, modified asphalt, foamed asphalt, a mixture and a preparation method thereof. Background Art

[0002] Rock asphalt is an asphalt-like substance produced by the combined effects of heat, pressure, oxidation, catalysts, bacteria, etc. after hundreds of millions of years of deposition and change of petroleum. Rock asphalt has a large molecular weight and is not flexible enough under low temperature conditions. It also makes its processing and modification process difficult, limiting the promotion and application of rock asphalt. Summary of the invention

[0003] In view of this, the purpose of the present disclosure is to provide a rock asphalt powder, modified asphalt, foamed asphalt, mixture and preparation method.

[0004] Based on the above purpose, the present disclosure provides a rock asphalt powder, including a rock asphalt powder body and a film layer located on the surface of the rock asphalt powder body; the film layer includes polyoxyethylene and glycerol.

[0005] In some embodiments, the size of the rock asphalt powder is ≤0.6 mm.

[0006] In some embodiments, the film layer is obtained by soaking; the mass content of the polyoxyethylene in the soaking solution is 0.8% to 1.2%.

[0007] In some embodiments, the mass content of the glycerol in the soaking solution is 1% to 2%.

[0008] Based on the same inventive concept, the present disclosure also provides a rock asphalt modified asphalt, including any of the rock asphalt powders described above; wherein the rock asphalt modified asphalt also includes base asphalt and a modifier.

[0009] In some embodiments, the modifier includes at least one of styrene-butadiene-styrene block copolymer and butylene terephthalate.

[0010] In some embodiments, based on the mass of the base asphalt, the content of the styrene-butadiene-styrene block copolymer is 4% to 6%, the content of the butylene terephthalate is 2% to 4%, and the content of the rock asphalt powder is 4% to 8%.

[0011] Based on the same inventive concept, the present disclosure also provides a rock asphalt foamed asphalt, including any of the aforementioned rock asphalt modified asphalts; wherein the rock asphalt foamed asphalt is obtained by foaming in the presence of a foaming aid and water.

[0012] In some embodiments, the foaming aid includes at least one of an aromatic diazonium salt and a silane coupling agent.

[0013] In some embodiments, based on 100% by mass of the rock asphalt modified asphalt, the content of the aromatic diazonium salt is 1.0% to 2.0%.

[0014] In some embodiments, the content of the silane coupling agent is 0.8% to 1.2%.

[0015] Based on the same inventive concept, the present disclosure also provides a rock asphalt mixture, including any of the aforementioned rock asphalt foamed asphalt; wherein the rock asphalt mixture also includes graded aggregate and mineral powder.

[0016] Based on the same inventive concept, the present disclosure also provides a method for preparing rock asphalt powder, the preparation method comprising:

[0017] Grinding the rock asphalt to obtain rock asphalt powder;

[0018] The rock asphalt powder is soaked in a soaking solution and dried to obtain the rock asphalt powder; wherein the soaking solution includes polyoxyethylene and glycerol.

[0019] Based on the same inventive concept, the present disclosure also provides a method for preparing rock asphalt foamed asphalt, the preparation method comprising:

[0020] Grinding the rock asphalt to obtain rock asphalt powder;

[0021] The rock asphalt powder is soaked in a soaking solution and then dried; wherein the soaking solution comprises polyoxyethylene and glycerol;

[0022] The base asphalt, the modifier and the rock asphalt powder are mixed during the grinding process to obtain the rock asphalt modified asphalt;

[0023] The rock asphalt modified asphalt is subjected to a foaming treatment to obtain the rock asphalt foamed asphalt; wherein the foaming treatment is carried out in the presence of a foaming aid.

[0024] From the above description, it can be seen that the embodiments of the present disclosure provide a rock asphalt powder, modified asphalt, foamed asphalt, mixture and preparation method. By adding a softener to the surface of the rock asphalt powder, the surface properties of the rock asphalt are improved, the surface energy of the rock asphalt is reduced, and the flexibility is increased to make it easy to foam, which helps to improve the low-temperature crack resistance of the asphalt mixture, expand the application range of the rock asphalt, and reduce the on-site construction temperature. DETAILED DESCRIPTION

[0025] In order to make the objectives, technical solutions and advantages of the present disclosure more clearly understood, the present disclosure is further described in detail below in conjunction with specific embodiments.

[0026] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present disclosure should have the common meanings understood by persons having ordinary skills in the field to which the present disclosure belongs.

[0027] The term "comprising" or "including (comprising)" may be open, semi-closed and closed. In other words, the term also includes "consisting essentially of..." or "consisting of..."

[0028] The numerical range represented by the term "a value A to a value B" means a range including the endpoints A and B.

[0029] The terms "substantially", "substantially" or "essentially" mean that the error is less than 5%, or less than 3% or less than 1% compared to the relevant perfect standard or theoretical standard.

[0030] The term "may" includes both the meanings of performing a certain process and not performing a certain process.

[0031] The term "optional" or "optionally" means that the subsequently described event or circumstance may or may not occur, and that the description includes instances where the event occurs and instances where it does not.

[0032] The terms "some specific / preferred embodiments", "other specific / preferred embodiments", "embodiments", etc., mean that the specific elements (e.g., features, structures, properties and / or characteristics) described in connection with the embodiment are included in at least one embodiment described herein, and may or may not be present in other embodiments. In addition, it should be understood that the elements may be combined in various embodiments in any suitable manner.

[0033] The terms "normal temperature", "room temperature", etc., may mean 10 to 40°C.

[0034] Unless otherwise specified, "multiple" in "multiple", "multiple", "multiple", etc. means a value of 2 or more. Unless otherwise specified, "%" means mass percentage.

[0035] In the related art, solid rock asphalt is generally directly put into the mixing pot together with aggregates. Due to the characteristics of rock asphalt, it is not fully dissolved in the mixing pot, which has an adverse effect on the performance of the road surface.

[0036] In view of this, the embodiments of the present disclosure provide a rock asphalt powder, modified asphalt, foamed asphalt, a mixture and a preparation method, by adding a film layer on the surface of the rock asphalt powder, improving the surface properties of the rock asphalt, reducing the surface energy of the rock asphalt, and increasing the flexibility to make it easy to foam, thereby preparing foamed asphalt, which helps to improve the low-temperature crack resistance of the asphalt mixture, expand the application range of the rock asphalt, and reduce the on-site construction temperature.

[0037] In some embodiments, the rock asphalt powder includes a rock asphalt powder body and a film layer located on the surface of the rock asphalt powder body; the film layer includes polyoxyethylene and glycerol.

[0038] Here, the rock asphalt is made into powder, and a film layer composed of at least one of polyoxyethylene and glycerol is formed on the surface of the powder, which can improve the surface properties of the rock asphalt, reduce the surface energy of the rock asphalt, increase its flexibility to facilitate foaming, change the current situation in related technologies that rock asphalt is difficult to use for the preparation of foamed asphalt, and provide more ways to utilize rock asphalt.

[0039] Furthermore, the size of the rock asphalt powder is ≤0.6 mm, such as 0.6 mm, 0.55 mm, 0.50 mm, 0.42 mm, 0.47 mm, 0.35 mm, 0.3 mm, etc. It should be noted that the rock asphalt powder can be obtained by grinding rock asphalt, and the specific grinding conditions are not limited in this disclosure.

[0040] In some embodiments, the membrane layer is obtained by surface treating the rock asphalt powder, such as soaking treatment. It should be noted that the soaking solution includes polyoxyethylene and glycerol.

[0041] Exemplarily, the mass content of polyoxyethylene in the soaking solution is 0.8% to 1.2%, for example, 0.8% to 1.1%, 0.8% to 1.0%, 0.8% to 0.9%, 0.9% to 1.2%, 0.9% to 1.0%, 1.0% to 1.2%, 0.95% to 1.05%, 0.8%, 1.2%, 0.9%, 1.1%, 0.95%, 1.0%, 1.1%, 1.02%.

[0042] Exemplarily, the mass content of glycerol in the soaking solution is 1% to 2%, for example, 1.1% to 1.9%, 1.2% to 1.5%, 1.5% to 2.0%, 1.2% to 1.8%, 1.3% to 1.7%, 1.4% to 1.7%, 1.4% to 1.6%, 1.5%, 1.2%, 1.9%, 1.1%, 1.75%, 2.0%, 1.6%, 1.42%.

[0043] Furthermore, the present disclosure also provides a method for preparing rock asphalt powder. Exemplarily, the preparation method comprises:

[0044] Grinding the rock asphalt to obtain rock asphalt powder; the grinding process may be mechanical grinding, for example, using a grinder to grind into 40 mesh powder;

[0045] The rock asphalt powder is soaked in a soaking solution and dried to obtain the rock asphalt powder; wherein the soaking solution includes polyoxyethylene and glycerol.

[0046] In some embodiments, the soaking treatment time may be 5 to 8 hours, for example, 5 hours, 6 hours, 7 hours or 8 hours.

[0047] In some embodiments, the drying condition may be 110° C. for 6 hours. It should be noted that the drying temperature and drying time are only exemplary, and other combinations of drying temperatures (e.g., 120° C.) and drying times (e.g., 5 hours) are sufficient to dry the rock asphalt powder to a constant weight, and the present disclosure does not limit this.

[0048] In some embodiments, the solvent of the soaking solution may be water. It should be noted that the contents of polyoxyethylene and glycerol in the soaking solution are as described above and will not be repeated herein.

[0049] It should be noted that the soaking solution only needs to be able to immerse the rock asphalt powder, and the present disclosure does not limit the amount of the soaking solution.

[0050] The present disclosure further provides a rock asphalt modified asphalt using the rock asphalt powder on the basis of the rock asphalt powder. Specifically, the rock asphalt modified asphalt includes a base asphalt, a modifier, and the rock asphalt powder provided by any of the above embodiments. The rock asphalt powder changes the material defects of the rock asphalt itself, and is used together with the modifier to modify the asphalt, and can be fully integrated with the base asphalt, providing a new material source for the preparation of foamed asphalt, which helps to improve the low-temperature crack resistance of the asphalt mixture.

[0051] The present disclosure does not specifically limit the base asphalt, and it can be some commonly used asphalt source materials in the art, such as road petroleum asphalt, etc. Generally speaking, road petroleum asphalt includes one or a combination of two or more of 70# to 200# road petroleum asphalt, etc.

[0052] In some embodiments, the modifier includes at least one of styrene-butadiene-styrene block copolymer (SBS for short) and butylene terephthalate.

[0053] Illustratively, based on the mass of the base asphalt, the content of the styrene-butadiene-styrene block copolymer is 4% to 6%, for example, 4% to 5%, 4.5% to 5.5%, 4%, 6%, 5%, etc.

[0054] Illustratively, based on the mass of the base asphalt, the content of butylene terephthalate is 2% to 4%, for example, 2.0% to 3.5%, 2.5% to 4.0%, 2.5% to 3.5%, 2%, 2%, 3.5%, etc.

[0055] Exemplarily, based on the mass of base asphalt, the content of rock asphalt powder is 4% to 8%, for example, 4.% to 7%, 4.5% to 7.5%, 5.5% to 8%, 5% to 7%, 4%, 5%, 5.5%, 6%, 6.5%, 8%, etc.

[0056] For example, the mass of the base asphalt is 100 g, the added amount of styrene-butadiene-styrene block copolymer is 5 g, the added amount of butylene terephthalate is 3 g, and the added amount of rock asphalt powder is 6 g.

[0057] It should be noted that after the base asphalt, modifier and rock asphalt powder are mixed in proportion, the rock asphalt modified asphalt is prepared by high-speed shear stirring.

[0058] The present disclosure does not particularly limit the conditions for high-speed shearing. Specifically, the high-speed shearing machine can be used for shearing at 160 to 180° C. for 30 to 60 minutes, and the shearing rate can be 4000 to 5000 r / min.

[0059] In addition to the above-mentioned rock asphalt modified asphalt, the present disclosure also provides a rock asphalt foamed asphalt. Exemplarily, the rock asphalt foamed asphalt is obtained by foaming the rock asphalt modified asphalt in the presence of a foaming aid using a solution.

[0060] The rock asphalt foamed asphalt disclosed in the present invention can not only utilize the rock asphalt, but also effectively combine the foaming aid and the rock asphalt powder, thereby improving the wetting ability and bonding force of the foamed asphalt, and enhancing the aggregate adhesion and anti-stripping effect of the foamed asphalt.

[0061] In some embodiments, the foaming aid includes at least one of an aromatic diazonium salt and a silane coupling agent.

[0062] It should be noted that the aromatic diazonium salt may be polyvinyl pyrrolidone, hydroxybenzoic acid diazonium salt, salicylic acid diazonium salt, etc., which is not limited in the present disclosure.

[0063] It should be noted that the present disclosure does not specifically limit the specific composition of the silane coupling agent, and it can be a silane coupling agent commonly used in the art. Specifically, the silane coupling agent can be one or a combination of two or more of vinyl trimethoxy silane, vinyl triethoxy silane, vinyl-tri (2-methoxyethoxy) silane, etc.

[0064] The use of aromatic diazonium salts and silane coupling agents can improve the foaming effect of foamed asphalt, improve the low-temperature flexibility of rock asphalt, and improve the adhesion between foamed asphalt and aggregates.

[0065] In some embodiments, based on 100% by mass of rock asphalt modified asphalt, the content of the aromatic diazonium salt is 1.0% to 2.0%, such as 1.0%, 1.2%, 1.5%, 1.8%, 2.0%, etc. In some embodiments, the content of the silane coupling agent is 0.8% to 1.2%, such as 0.8%, 1.0%, 1.1%, 1.2%, etc.

[0066] Next, the present disclosure also provides a method for preparing rock asphalt foamed asphalt. Specifically, the preparation method comprises:

[0067] When the rock asphalt modified asphalt enters the asphalt foaming pipe, water containing a foaming aid is sprayed into it to prepare foamed asphalt.

[0068] For the specific method of foaming, it can be carried out in accordance with the contents recorded in the "Technical Specifications for Highway Asphalt Pavement Regeneration" (JTG / T5521-2019).

[0069] It should be noted that the proportion of the foaming agent added during the foaming treatment is as described above and will not be repeated here.

[0070] Optionally, based on 100% of the total mass of the rock asphalt modified asphalt, the amount of water added is generally 0.5-2%, for example, 0.5%, 0.8%, 1%, 1.2%, 1.5%, 2%, etc.

[0071] Optionally, the temperature of the foaming treatment may be 160-180°C, for example, 160°C, 170°C, 180°C.

[0072] It should be noted that by adopting such foaming temperature and solvent addition amount, foamed asphalt with better expansion rate and half-life can be obtained.

[0073] Here, the expansion rate is the ratio of the maximum volume of asphalt foaming to the original volume. The half-life is the time (s) it takes for the foamed asphalt to decay from the maximum volume to half of its volume.

[0074] Furthermore, the embodiments of the present disclosure also provide a rock asphalt mixture, comprising any of the rock asphalt foamed asphalt described above.

[0075] In some embodiments, the rock asphalt mixture includes graded aggregate and mineral powder in addition to rock asphalt foamed asphalt. Specifically, taking the total mass of the graded aggregate and the mineral powder as 100%, the gradation range of the graded aggregate is: the mass percentage of aggregate with a particle size of 11 to 16 mm is 40 to 45%; the mass percentage of aggregate with a particle size of 6 to 11 mm is 25 to 30%; the mass percentage of aggregate with a particle size of 3 to 6 mm is 2 to 8%; the mass percentage of aggregate with a particle size of 0 to 3 mm is 18 to 23%; the mass percentage of the mineral powder is 2 to 7%.

[0076] Optionally, based on 100% of the total mass of the graded aggregate and the mineral powder, the content of the rock asphalt foamed asphalt is 4-7%, for example, 4%, 5%, 5.5%, 6%, 7%, etc. When the content of the rock asphalt foamed asphalt is 4-7%, the prepared rock asphalt mixture has excellent low temperature performance.

[0077] It should be noted that the graded aggregate of the rock asphalt mixture disclosed in the present invention is preferably graded aggregate SMA-13, but graded aggregate AC and the like which are often used in road engineering are also applicable.

[0078] The present invention forms rock asphalt foamed asphalt by mechanically foaming equipment with rock asphalt modified asphalt, foaming aid and solvent, thereby increasing the specific surface area of ​​rock asphalt and reducing the hardness of rock asphalt, so that it can be mixed with coarse and fine aggregates, mineral powder, etc. at a lower temperature in a mixing plant, and at the same time improves the low-temperature crack resistance of rock asphalt. Under the premise of ensuring road performance, the production temperature is reduced and the emission of toxic gases is greatly reduced.

[0079] Example

[0080] The embodiments of the present disclosure will be described in detail below in conjunction with the examples, but those skilled in the art will appreciate that the following examples are only used to illustrate the present invention and should not be considered to limit the scope of the present invention. Where specific conditions are not specified in the examples, they are carried out under conventional conditions or conditions recommended by the manufacturer. Where the manufacturers of the reagents or instruments used are not specified, they are all conventional products that can be obtained commercially.

[0081] Example 1

[0082] The rock asphalt was ground into 40-mesh powder using a grinder, and surface treated by immersing it in a solution containing 1% polyoxyethylene and 1.5% glycerol for 6 hours, and then dried in an oven at 110° C. to constant weight to obtain rock asphalt powder.

[0083] Based on the mass of the base asphalt of 100%, the amount of rock asphalt powder added is 6%, the amount of SBS modifier added is 5%, and the amount of butylene terephthalate added is 3%. The base asphalt is heated to 180°C, and the rock asphalt powder, SBS modifier and butylene terephthalate are added, ground and mixed to obtain a mixed precursor; then the rock asphalt modified asphalt is prepared by high-speed shear stirring, and finally fully swelled, and the swelling reaction time is 50 minutes. Among them, the high-speed shear stirring method is to use a high-speed shearing machine to shear for 50 minutes at 175°C, and the shear rate is 4500r / min.

[0084] Taking the total mass of the rock asphalt modified asphalt as 100%, the amount of water is 1%, the content of polyvinyl pyrrolidone is 1.5%, and the content of silane coupling agent is 1%. The foaming temperature is 170°C and the time of uniform stirring is 1h. The rock asphalt modified asphalt is foamed with water using the asphalt foaming test method listed in the "Technical Specifications for Highway Asphalt Pavement Regeneration" (JTG / T 5521-2019) to obtain rock asphalt foamed asphalt. It should be noted that polyvinyl pyrrolidone and silane coupling agent can be added to the foaming water tank first.

[0085] SMA-13 ​​rock asphalt mixture was prepared, and the content of rock asphalt foamed asphalt was 5.0% based on the total mass of the rock asphalt mixture. The graded aggregate and mineral powder were dried and mixed with the rock asphalt foamed asphalt. The mixing and discharging temperature was 160°C.

[0086] Table 1 Graded aggregate and mineral powder dosage

[0087] Material Specifications 0~3mm 3~6mm 6~11mm 11~16mm Mineral powder Proportion(%) 21 5 27 43 4

[0088] According to (JTG E20-2011) T0701 and T0736, asphalt mixture specimens were mixed and molded and then various performance tests were carried out.

[0089] Example 2

[0090] The difference between this embodiment and embodiment 1 is that the samples were immersed in a solution containing 1.2% polyoxyethylene and 2% glycerol.

[0091] Example 3

[0092] The difference between this embodiment and embodiment 1 is that the samples were immersed in a solution containing 0.8% polyoxyethylene and 1.0% glycerol.

[0093] Example 4

[0094] The difference between this embodiment and embodiment 1 is that the amount of SBS modifier used is 4%, the amount of butylene terephthalate used is 2%, and the amount of rock asphalt powder added is 4%.

[0095] Example 5

[0096] The difference between this embodiment and embodiment 1 is that the amount of SBS modifier used is 6%, the amount of butylene terephthalate used is 4%, and the amount of rock asphalt powder added is 8%.

[0097] Example 6

[0098] The difference between this embodiment and embodiment 1 is that the amount of polyvinyl pyrrolidone used is 1%, and the amount of silane coupling agent used is 0.8%.

[0099] Example 7

[0100] The difference between this embodiment and embodiment 1 is that the amount of polyvinyl pyrrolidone used is 2%, and the amount of silane coupling agent used is 1.2%.

[0101] Comparative Example 1

[0102] The difference between this comparative example and Example 1 is that the steps of soaking and drying polyoxyethylene and glycerol are omitted, and rock asphalt modified asphalt is directly prepared from rock asphalt powder. The mixing and discharging temperature is 180°C.

[0103] Comparative Example 2

[0104] The difference between this comparative example and Example 1 is that the SBS modifier and butylene terephthalate are omitted.

[0105] Comparative Example 3

[0106] The difference between this comparative example and Example 1 is that polyvinyl pyrrolidone and silane coupling agent are omitted.

[0107] Comparative Example 4

[0108] The difference between this comparative example and Example 1 is that the amount of SBS modifier used is 8%, and the amount of butylene terephthalate used is 6%.

[0109] Comparative Example 5

[0110] The difference between this comparative example and Example 1 is that the amount of SBS modifier used is 3%, and the amount of butylene terephthalate used is 1%.

[0111] Comparative Example 6

[0112] The difference between this comparative example and Example 1 is that there is no polyoxyethylene.

[0113] Comparative Example 7

[0114] The difference between this comparative example and Example 1 is that there is no glycerol.

[0115] Comparative Example 8

[0116] The difference between this comparative example and Example 1 is that the amount of polyvinyl pyrrolidone used is 0.5%, and the amount of silane coupling agent used is 0.5%.

[0117] Comparative Example 9

[0118] The difference between this comparative example and Example 1 is that the modified rock asphalt is directly used to prepare the mixture without foaming. The mixing and discharging temperature is 190°C.

[0119] Performance Testing

[0120] (1) Surface performance test of rock asphalt modified asphalt

[0121] The contact angle was used to test the surface energy. The specific method was based on GB / T 30693-2014.

[0122] (2) Separation of rock asphalt modified asphalt

[0123] The segregation of rock asphalt modified asphalt was tested using method T0661 in the Test Procedure for Asphalt and Asphalt Mixtures for Highway Engineering (JTG E20-2011).

[0124] (3) Expansion rate and half-life are used as two-phase evaluation indicators for evaluating rubber foamed asphalt.

[0125] The expansion rate and half-life are tested using the method of "Technical Specifications for Highway Asphalt Pavement Regeneration" (JTG / T 5521-2019).

[0126] (4) Rutting test (high temperature performance), low temperature bending failure strain (low temperature performance), freeze-thaw splitting test (anti-water damage performance) The rutting test (high temperature performance), low temperature bending failure strain (low temperature performance), and freeze-thaw splitting test (anti-water damage performance) were tested using T0729 in the "Test Procedure for Asphalt and Asphalt Mixtures in Highway Engineering" (JTG E20-2011).

[0127] The test results of the above tests are shown in Table 2.

[0128] Table 2

[0129]

[0130] As can be seen from Table 2, by comparing Example 1, Example 2, Example 3, Comparative Example 1, Comparative Example 6 and Comparative Example 7, it can be seen that the addition of polyoxyethylene and glycerol can significantly improve the foaming performance of rock asphalt modified asphalt, especially in Comparative Example 1, which lacks polyoxyethylene and glycerol, and the performance of the foamed asphalt is poor, resulting in the mixture being unable to adopt the discharge temperature of the foamed asphalt, resulting in increased construction temperature, increased carbon emissions and more serious asphalt smoke pollution and other adverse effects.

[0131] Comparison of Example 1, Example 6, Example 7 and Comparative Example 3, Comparative Example 8 shows that increasing the amount of polyvinyl pyrrolidone and silane coupling agent is helpful for foaming and improving the low temperature performance and water damage resistance of the mixture. However, when the amount of polyvinyl pyrrolidone exceeds 2% and the amount of silane coupling agent exceeds 1.2%, the performance improvement is limited and the cost increases.

[0132] By comparing Example 1, Comparative Example 2, Comparative Example 4 and Comparative Example 5, it can be seen that the addition of SBS modifier and butylene terephthalate helps to improve the performance of the mixture (such as dynamic stability in rutting test), but if the addition amount is too large, the viscosity is too high, which affects the foaming performance and segregation performance.

[0133] It can be seen from Comparative Example 9 that unfoamed rock asphalt modified asphalt cannot adopt the discharge temperature of foamed asphalt, has high construction temperature, large carbon emissions and serious asphalt fume pollution, and its performance is also worse than that of foamed asphalt.

[0134] In summary, the technical solution disclosed in the present invention obtains rock asphalt fractions and modified asphalt suitable for preparing foamed asphalt through soaking, which increases the application scope of rock asphalt and helps to save energy and reduce emissions.

[0135] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present disclosure (including the claims) is limited to these examples. Based on the concept of the present disclosure, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of the different aspects of the embodiments of the present disclosure as described above, which are not provided in detail for the sake of simplicity.

[0136] The embodiments of the present disclosure are intended to cover all such substitutions, modifications and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the embodiments of the present disclosure should be included in the scope of protection of the present disclosure.

Claims

1. A rock asphalt powder, characterized in that: It comprises rock asphalt powder and a film layer located on the surface of the rock asphalt powder; the film layer comprises polyoxyethylene and glycerol.

2. The rock asphalt powder according to claim 1, characterized in that: The size of the rock asphalt powder is ≤0.6 mm.

3. The rock asphalt powder according to claim 1, characterized in that: The film layer is obtained by soaking treatment; the mass content of the polyoxyethylene in the soaking solution is 0.8% to 1.2%; the mass content of the glycerol in the soaking solution is 1% to 2%.

4. A rock asphalt modified asphalt, characterized in that: include: The rock asphalt powder according to any one of claims 1 to 3; wherein the rock asphalt modified asphalt further comprises base asphalt and a modifier.

5. The rock asphalt modified asphalt according to claim 4, characterized in that: The modifier comprises at least one of styrene-butadiene-styrene block copolymer and butylene terephthalate; and / or Based on 100% of the mass of the matrix asphalt, the content of the styrene-butadiene-styrene block copolymer is 4% to 6%, the content of butylene terephthalate is 2% to 4%, and the content of the rock asphalt powder is 4% to 8%.

6. A rock asphalt foamed asphalt, characterized in that: It includes the rock asphalt modified asphalt as described in any one of claims 4 to 5; wherein the rock asphalt foamed asphalt is obtained by foaming the modified asphalt in the presence of a foaming aid and water.

7. The rock asphalt foamed asphalt according to claim 6, characterized in that: The foaming aid comprises at least one of an aromatic diazonium salt and a silane coupling agent; and / or Based on 100% of the mass of the rock asphalt modified asphalt, the content of the aromatic diazonium salt is 1.0% to 2.0%; and / or The content of the silane coupling agent is 0.8% to 1.2%.

8. A rock asphalt mixture, characterized in that: It comprises the rock asphalt foamed asphalt as described in any one of claims 6 to 7; wherein the rock asphalt mixture also includes graded aggregate and mineral powder.

9. A method for preparing rock asphalt powder, characterized in that: The preparation method comprises: Grinding the rock asphalt to obtain rock asphalt powder; The rock asphalt powder is soaked in a soaking solution and dried to obtain the rock asphalt powder; wherein the soaking solution includes polyoxyethylene and glycerol.

10. A method for preparing rock asphalt foamed asphalt, characterized in that: The preparation method comprises: Grinding the rock asphalt to obtain rock asphalt powder; The rock asphalt powder is soaked in a soaking solution and then dried; wherein the soaking solution comprises polyoxyethylene and glycerol; The base asphalt, the modifier and the rock asphalt powder are mixed during the grinding process to obtain the rock asphalt modified asphalt; The rock asphalt modified asphalt is subjected to a foaming treatment to obtain the rock asphalt foamed asphalt; wherein the foaming treatment is carried out in the presence of a foaming aid.

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