Copper slag polymer composite modified asphalt based on microwave heating and preparation method thereof

Abstract

The application provides a copper slag polymer composite modified asphalt based on microwave heating and a preparation method thereof. A base asphalt is heated to a molten flowable state, an oil phase, copper slag and an active diluent are added and stirred uniformly, then a styrene block copolymer is added under low rotation speed, followed by continuous shearing by increasing the shearing speed, full development and ensuring that the modified asphalt is radiated by a microwave emission device while shearing and developing, so as to obtain the copper slag polymer composite modified asphalt based on microwave heating. The oxides such as SiO2, CaO, MgO and Al2O3 in the copper slag and the synergistic microwave absorption effect of magnetite are used to absorb electromagnetic waves and convert them into heat energy, so that the external heating temperature in the shearing and molding process is reduced, the microwave radiation makes the modified asphalt heated more uniformly in the shearing process and the development process, the risk of asphalt aging caused by the non-uniform heating in the conventional high-temperature heating mode is avoided, and the durability and application performance of the modified asphalt are significantly improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of modified asphalt preparation, and particularly relates to a copper slag polymer composite modified asphalt based on microwave heating and a preparation method thereof. BACKGROUND

[0002] Since entering the 21st century, the heavy dependence of human beings on industry has caused a large amount of carbon emissions and pollution and a lack of environmentally friendly infrastructure construction methods, resulting in increasingly prominent environmental problems. In recent years, China has accelerated the pace of building a traffic power, among which the construction scale of asphalt pavement has gradually expanded, and most of the highways built in China are asphalt pavements. However, due to improper use and maintenance, a part of the asphalt pavement has serious cracking, peeling and rutting and other diseases, which greatly shortens the actual service life of the asphalt pavement and increases the pavement maintenance cost year by year. Therefore, it is imminent to improve and improve the road performance of the asphalt pavement and reduce the pavement maintenance cost, and the performance of the asphalt material is one of the most critical factors. It has been proved that the use of polymer modified asphalt can greatly improve the performance of the pavement, and the use of modified asphalt instead of traditional ordinary asphalt in road construction is the future development trend. In the face of the increasing consumption of polymer modified asphalt, low-carbon green production process and high-performance modified asphalt are effective ways to alleviate the environmental pollution problems in the production and use of modified asphalt.

[0003] SBS (styrene-butadiene-styrene) as a block copolymer is polymerized from styrene and butadiene two monomers, and is the most widely used and best high molecular modifier in the current international. SBS modified asphalt not only has good low-temperature ductility, but also has excellent durability and high-temperature deformation resistance, and has been widely used in the field of road construction. At present, a very high shear temperature (usually 180-200 DEG C) is needed in the preparation process of SBS modified asphalt to make the polymer uniformly dispersed in the asphalt, so that the modified asphalt meets the compatibility requirements and better reflects the advantages of polymer modification; if the shear temperature is low, the uniformity of polymer dispersion will be affected, which will adversely affect the performance of the asphalt. However, the use of too high shear temperature in the preparation process of SBS modified asphalt not only increases the emission of greenhouse gases and volatile organic gases VOCs, consumes a lot of fuel, has poor economic benefits and other problems, but also easily causes uneven heating of the asphalt inside and local overheating, increasing the risk of asphalt aging.

[0004] Therefore, it is an urgent technical problem to provide a new preparation method of modified asphalt, which can ensure uniform heating of the asphalt during shearing, reduce the risk of aging, improve the pavement application performance of the modified asphalt and reduce the pavement maintenance cost. SUMMARY

[0005] One of the purposes of the present application is to provide a preparation method of modified asphalt which ensures that the asphalt is heated more uniformly during shearing and reduces the risk of aging.

[0006] The second purpose of the present application is to provide a modified asphalt which has good pavement performance and durability and reduces pavement maintenance costs.

[0007] The technical solution adopted by the present application to achieve one of the purposes is to provide a preparation method of copper slag polymer composite modified asphalt based on microwave heating, comprising the following steps:

[0008] S1, preheat the base asphalt to fully remove moisture and be in a molten flow state, add an oil phase, mix uniformly, and obtain a first mixture;

[0009] S2, add copper slag and active diluent to the first mixture, mix uniformly, and obtain a second mixture;

[0010] S3, heat the second mixture to 130-150°C, add a styrene block copolymer under stirring conditions, and obtain a third mixture;

[0011] S4, perform high-speed shearing on the third mixture for a certain time, and then reduce the shearing speed for development; during the high-speed shearing and development, microwave is used for radiation, and a copper slag polymer composite modified asphalt based on microwave heating is obtained.

[0012] The general idea of the present application is as follows: the present application provides a preparation method which uses microwave technology to assist heating, fully radiates the modified asphalt in the high-speed shearing and development stage, makes the asphalt heat more uniformly during preparation, fully develops the asphalt, and thus improves the road application performance and aging resistance of the asphalt. The method adds a certain proportion of copper slag to the modified asphalt raw material, and the metal oxides and magnetite contained in the copper slag are used as wave-absorbing materials. In a microwave environment, the originally bound electric charges in the dielectric of the wave-absorbing material move at high speed with high-frequency electromagnetic waves, thereby generating a large amount of internal energy to make the temperature of the wave-absorbing material increase step by step from the inside to the outside. Compared with other heating technologies, microwave heating is convenient to control, the internal and external temperature difference is small, and the internal heating of the asphalt material is more uniform. The present application uses microwave radiation in cooperation with an external heating source to ensure the overall uniformity of the heating of the asphalt material during preparation, slow down the aging of the asphalt during preparation, and improve the durability of the asphalt material.

[0013] Further, in step S1, the base asphalt is selected from a mixture of one or more of No. 160, No. 130, No. 110, No. 90, No. 70, No. 50, or No. 30 petroleum asphalt.

[0014] Further, in step S1, the oil phase is selected from a combination of one or more of soybean oil, naphthenic oil, chlorinated paraffin, furfural extract oil. The addition of the oil phase can soften and dissolve the styrene block copolymer elastomer. Preferably, the oil phase is selected from soybean oil. The long carbon chain (C17) in the structural formula of soybean oil gives it excellent flexibility, which gives soybean oil excellent swelling aid effect, making it easier to penetrate into the interior of the styrene block copolymer. At the same time, soybean oil also has good compatibility with asphalt, and can act as a component in asphalt, reducing the viscosity of asphalt, promoting the swelling and dispersion of the polymer elastomer in the base asphalt, improving the interaction between the two phases, thereby further reducing the shear temperature.

[0015] Further, in step S2, the copper slag contains the following components: SiO2 30% to 40%, CaO 5% to 10%, MgO 1% to 5%, Al2O3 2% to 4%, and magnetite 2% to 5%. The copper slag contains high contents of SiO2, CaO, MgO, Al2O3, and a high content of magnetite. These components are uniformly dispersed in the third mixture containing base asphalt and styrene block copolymer, and under the radiation of the microwave emission device, the synergistic microwave absorption effect of the above components absorbs electromagnetic waves, significantly improves the microwave heating effect, thereby generating a large amount of internal energy, and the temperature will diffuse from the inside to the outside of the asphalt system in a stepwise manner, thereby reducing the external heating temperature required for the formation of the polymer modified asphalt, saving energy consumption, assisting the asphalt industry in energy saving and emission reduction, and conforming to the green production concept; at the same time, high-speed shearing and development are carried out under the cooperation of internal and external heat sources, the modified asphalt is uniformly heated inside and outside, and the problem of severe aging of asphalt materials during preparation can be avoided, and the durability of the modified asphalt is significantly improved.

[0016] Further, the copper slag has a mesh size of 100 to 1250 mesh.

[0017] Further, in step S2, the active diluent is selected from a combination of one or more of 1,4-butanediol diglycidyl ether, glycidyl methacrylate, and bisphenol A type epoxy resin.

[0018] Further, in step S3, the styrene block copolymer is selected from a mixture of SBS and SEBS. In the mixture, the tri-block structure of SBS can be broken into SB-dual block structure under photo-oxidation or thermal oxidation environment, and the end position of the SB-block forms hydroxyl and carboxyl groups. The active diluent has a double epoxy group which can catalyze the reaction with the hydroxyl and carboxyl groups formed on the SB-block, repair the molecular structure of part of SBS, and further enhance the durability of the modified asphalt. Using SEBS to replace part of SBS can improve the stability of the modified asphalt under photo-oxidation conditions while maintaining the excellent low-temperature performance and rheological performance of the SBS polymer modified asphalt, improve the anti-aging performance, and further improve the durability of the modified asphalt. Preferably, the mass ratio of SBS to SEBS is (1-3): 1.

[0019] Further, in step S4, the speed of high-speed shearing is 5000-6500 r / min, and the time of high-speed shearing is 1-1.5 h; in the development, the shearing speed is 500-1000 r / min, and the development time is 20-40 min.

[0020] Further, in step S4, in the microwave radiation, the frequency of the microwave is 2.45 GHz, and the power of the microwave is 100 W-30 kW. In the present application, the power of the microwave radiation in step S4 is determined according to the total weight and scale of the modified asphalt to be prepared. In the present application, when the modified asphalt is prepared in a small scale in the laboratory, the power of the microwave radiation is controlled to be between 300 W and 1000 W; considering the large-scale application and promotion in engineering, a high-power microwave radiation source with a power of 10 kW-30 kW can be used.

[0021] Preferably, in step S4, in the high-speed shearing, the power of the microwave radiation is 300-1000 W, and the time of the microwave radiation is 0.5-1.5 h; in the development, the power of the microwave radiation is 300-1000 W, and the time of the microwave radiation is 20 min-40 min. In the high-speed shearing and development process, the microwave radiation can be continuously or intermittently performed for a certain time, or the radiation can be continuously performed during the entire high-speed shearing and development process. More preferably, the microwave is continuously radiated during the entire high-speed shearing and development process.

[0022] In the present application, it is found that, in the high-speed shearing and development stage of the modified asphalt preparation process, the running speed and dispersion state of the copper residue in the modified asphalt are different due to different shearing speeds. The faster the shearing speed, the faster the movement speed of the copper residue in the asphalt, and the greater the dispersion range, and the lower the concentration rate. Therefore, in order to generate stable heat energy by using the microwave absorption effect, a higher microwave radiation power is required. Similarly, in the development process, the shearing speed is low, the movement speed of the copper residue is also low, and the dispersion is relatively concentrated, which is more conducive to microwave absorption. Therefore, in order to avoid high temperature, the microwave radiation power needs to be correspondingly reduced.

[0023] In some preferable embodiments, during the entire high-speed shearing and development process, microwave is used for continuous radiation, wherein the microwave radiation power in the high-speed shearing stage is set to 300-800 W, and the microwave radiation power in the development process is set to 100-500 W (the microwave radiation power is controlled to be lower than the radiation power in the high-speed shearing stage by 200-300 W). Under the above conditions, the microwave radiation and the external heating source cooperate with each other to keep the temperature of the modified asphalt in a relatively stable range in the high-speed shearing stage and the development stage, promote the uniform heating and sufficient development of the asphalt inside, and improve the durability of the product.

[0024] Further, in step S4, the microwave radiation device is arranged at a position 0.5-0.8 m above the modified asphalt to realize sufficient radiation during the shearing and development process of the modified asphalt.

[0025] The technical scheme for realizing the second purpose of the present application is to provide a copper residue polymer composite modified asphalt based on microwave heating, which is prepared by the preparation method according to the first purpose of the present application.

[0026] Preferably, the raw materials of the copper residue polymer composite modified asphalt include, in terms of weight fractions, 200-300 parts of base asphalt, 6-15 parts of oil phase, 12-30 parts of copper residue, 4-12 parts of active diluent, and 10-18 parts of styrene block copolymer.

[0027] More preferably, the amount of the copper residue is 6wt.%-10wt.% of the mass of the base asphalt.

[0028] The copper residue polymer composite modified asphalt based on microwave heating prepared by the application has a penetration of 37-42mm at 5℃ with 1 / 10mm as a unit, a softening point of 77-84℃, a ductility of 49-57cm at 5℃, a difference value of 0.5-2.0℃ of the softening point after segregation, a rotary viscosity of 1.80-2.70Pa·s at 135℃, an increment of the softening point of 10-16℃ before and after heat oxygen aging at 163℃ for 5h in a rotary film oven, a ductility retention rate of 59-66%, and a penetration ratio of 51-60% before and after aging. 2 The application also provides a UV aging box with a UV wavelength of 365nm, an intensity of 15mW / cm

[0029] Compared with the prior art, the application has the following beneficial effects:

[0030] (1) The application provides a preparation method of copper residue polymer composite modified asphalt based on microwave heating, which introduces copper residue containing metal oxide and magnetite as a wave-absorbing material in the preparation process of modified asphalt, and the wave-absorbing effect is generated in the subsequent high-speed shearing and development process with microwave radiation, so that the conventional heating mode is matched with the microwave radiation heating, sufficient heat is provided for the preparation process of modified asphalt, the internal heating of asphalt is uniform, the temperature of the external heat source heating plate is reduced, the aging of asphalt in the preparation process is slowed down, the durability of asphalt material is improved, the energy saving and emission reduction of the asphalt industry are assisted, and the green production concept is met.

[0031] (2) The copper residue polymer composite modified asphalt based on microwave heating prepared by the application is produced at a lower temperature (130-150℃) by replacing direct high-temperature heating with the matched mode of microwave radiation and external heating source, and the prepared modified asphalt also has good viscosity, excellent plasticity, temperature sensitivity and heat storage stability. Short-term aging and long-term aging simulation experiments show that the increment of the softening point of the copper residue polymer composite modified asphalt based on microwave heating is obviously reduced, the smaller the increment of the softening point, the stronger the heat oxygen aging resistance and the UV blocking effect, and the ductility retention rate and the penetration ratio after aging are also effectively improved.

[0032] (3) The copper slag polymer composite modified asphalt prepared based on microwave heating contains a certain proportion of copper slag, which can be used for road paving and also used as a wave-absorbing material to improve the efficiency of microwave maintenance of roads, and under the premise that the road performance meets the specification requirements, large-scale use of copper slag not only utilizes the waste resources, but also protects the environment, reduces the cost of road paving and maintenance, and can also cooperate with the microwave maintenance vehicle to speed up the maintenance efficiency, and has a wide popularization and application prospect. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 A flowchart of a preparation method of a copper slag polymer composite modified asphalt based on microwave heating provided by the embodiments of the present application is shown. DETAILED DESCRIPTION

[0034] The technical solutions of the present application will be described clearly and completely in combination with the embodiments, obviously, the described embodiments are only part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor belong to the scope of protection of the present application.

[0035] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0036] The present application will be further described in combination with specific embodiments, but not as a limitation of the present application.

[0037] The types and amounts (weight parts / g) of the main raw materials involved in the embodiments and comparative examples of the present application are shown in Table 1 below, and the main parameters involved in the preparation method of each embodiment are shown in Table 2 below.

[0038] Table 1

[0039]

[0040] In the above table, 70# road petroleum asphalt is used as the base asphalt in each embodiment, in actual application, one or a mixture of several of 160, 130, 110, 90, 50 or 30# petroleum asphalt can be used to replace it, and similar effects can also be obtained; in the copper slag, the main components account for 30-40% of SiO2, 5-10% of CaO, 1-5% of MgO, 2-4% of Al2O3, and 2-5% of magnetite, the components of the copper slag used in each embodiment are the same; the mesh number of the copper slag is 200 mesh; in the styrene block copolymer, the ratio of SBS and SEBS is mass ratio.

[0041] Table 2

[0042]

[0043] The above embodiments are carried out in the laboratory, using WSPS-2450-300-CCFB small power solid-state microwave source as the microwave emission device (microwave frequency 2.45 GHz), and the microwave radiation device is arranged at a position 0.5-0.8 m above the modified asphalt to achieve sufficient radiation for the preparation process of the modified asphalt. If it is extended to actual engineering application for mass production of modified asphalt, a large power (10 kW-30 kW) solid-state microwave power source such as WSPS-2450-30K-CEWA can be used.

[0044] Example 1

[0045] Step 1: 300 parts of No. 70 road petroleum asphalt were placed on a hot plate and heated to 100°C to sufficiently remove water and to a molten flow state, and 15 parts of soybean oil (5% of the mass fraction of the base asphalt) were added;

[0046] Step 2: 30 parts (10% of the mass fraction of the base asphalt) of 200-mesh copper slag and 12 parts (4% of the mass fraction of the base asphalt) of 1,4-butanediol diglycidyl ether were added and stirred uniformly;

[0047] Step 3: The heating plate was heated to 150°C, a high-speed shearing machine was used, the shearing speed was 500 r / min, and 15 parts (5% of the mass fraction of the base asphalt) of SBS / SEBS mixture (SBS:SEBS = 1:1 by mass) were slowly added at a speed of 5 g / min;

[0048] Step 4: The shearing speed was increased to 6500 r / min, after shearing for 1.5 h, the shearing speed was reduced to 500 r / min again, the temperature was maintained, and the development time was 30 min. The modified asphalt was fully radiated by the microwave emission device during the whole shearing and development process, and the microwave frequency was 2.45 GHz. The power of the high-speed shearing stage was set to 800 W, and the power of the development stage was set to 500 W. A copper slag polymer composite modified asphalt based on microwave heating was obtained.

[0049] Example 2

[0050] Step 1: 300 parts of No. 70 road petroleum asphalt were placed on a hot plate and heated to 100°C to sufficiently remove water and to a molten flow state, and 12 parts of soybean oil (4% of the mass fraction of the base asphalt) were added;

[0051] Step 2: 30 parts (10% of the mass fraction of the base asphalt) of 200-mesh copper slag and 12 parts (4% of the mass fraction of the base asphalt) of 1,4-butanediol diglycidyl ether were added and stirred uniformly;

[0052] Step 3: The heating plate is heated to 150℃, and 12 parts (4% of the mass fraction of base asphalt) of SBS / SEBS mixture (SBS:SEBS = 1:1 by mass) is slowly added at a speed of 5g / min under the rotation speed of 500r / min using a high-speed shearing machine;

[0053] Step 4: The shearing speed is increased to 6500r / min, and after shearing for 1.5h, the shearing speed is reduced to 500r / min again, the temperature is maintained unchanged for sufficient development, the development time is 30min, and the modified asphalt is fully radiated using a microwave emission device during the whole shearing and development process, the microwave frequency is 2.45GHz, wherein the power setting of the high-speed shearing stage is 500W, and the power setting of the development stage is 300W, to obtain the copper slag polymer composite modified asphalt based on microwave heating.

[0054] Example 3

[0055] Step 1: 300 parts of No. 70 road petroleum asphalt is placed on a heating plate and heated to 100℃ to fully remove moisture and reach a molten flow state, and 15 parts of naphthenic oil (5% of the mass fraction of base asphalt) is added;

[0056] Step 2: 30 parts (10% of the mass fraction of base asphalt) of 200 mesh copper slag and 10 parts (3.3% of the mass fraction of base asphalt) of 1,4-butanediol diglycidyl ether are added and stirred uniformly;

[0057] Step 3: The heating plate is heated to 150℃, and 12 parts (4% of the mass fraction of base asphalt) of SBS / SEBS mixture (SBS:SEBS = 1:1 by mass) is slowly added at a speed of 5g / min under the rotation speed of 500r / min using a high-speed shearing machine;

[0058] Step 4: The shearing speed is increased to 6500r / min, and after shearing for 1.5h, the shearing speed is reduced to 500r / min again, the temperature is maintained unchanged for sufficient development, the development time is 30min, and the modified asphalt is fully radiated using a microwave emission device during the whole shearing and development process, the microwave frequency is 2.45GHz, wherein the power setting of the high-speed shearing stage is 300W, and the power setting of the development stage is 100W, to obtain the copper slag polymer composite modified asphalt based on microwave heating.

[0059] Example 4

[0060] Step 1: 300 parts of No. 70 road petroleum asphalt is placed on a heating plate and heated to 100℃ to fully remove moisture and reach a molten flow state, and 10 parts of chlorinated paraffin (3.3% of the mass fraction of base asphalt) is added;

[0061] Step 2: 30 parts (10% of the mass fraction of base asphalt) of 200-mesh copper slag and 9 parts (3% of the mass fraction of base asphalt) of 1,4-butanediol diglycidyl ether were added and stirred uniformly;

[0062] Step 3: The heating plate was heated to 150°C, and 10 parts (3.3% of the mass fraction of base asphalt) of an SBS / SEBS mixture (SBS:SEBS = 3:1 by mass) was slowly added at a speed of 5 g / min using a high-speed shearing machine at a rotation speed of 500 r / min;

[0063] Step 4: The shearing speed was increased to 6500 r / min, and after shearing for 1.5 h, the shearing speed was again reduced to 500 r / min, the temperature was maintained unchanged for sufficient development, and the development time was 30 min; wherein, the high-speed shearing stage was subjected to microwave radiation with a power of 800 W for 50 min, and the development stage was subjected to microwave radiation with a power of 500 W for 20 min; the microwave frequency was 2.45 GHz, and the copper slag polymer composite modified asphalt based on microwave heating was obtained.

[0064] Example 5

[0065] Step 1: 300 parts of 70# road petroleum asphalt were placed on a heating plate, heated to 100°C, and sufficiently removed of water and brought to a molten flow state, and 12 parts of furfural extract oil (4% of the mass fraction of base asphalt) was added;

[0066] Step 2: 30 parts (10% of the mass fraction of base asphalt) of 200-mesh copper slag and 12 parts (4% of the mass fraction of base asphalt) of 1,4-butanediol diglycidyl ether were added and stirred uniformly;

[0067] Step 3: The heating plate was heated to 150°C, and 15 parts (5% of the mass fraction of base asphalt) of an SBS / SEBS mixture (SBS:SEBS = 1:1 by mass) was slowly added at a speed of 5 g / min using a high-speed shearing machine at a rotation speed of 500 r / min;

[0068] Step 4: The shearing speed was increased to 6500 r / min, and after shearing for 1.5 h, the shearing speed was again reduced to 500 r / min, the temperature was maintained unchanged for sufficient development, and the development time was 30 min; wherein, the high-speed shearing stage was subjected to microwave radiation with a power of 800 W for 20 min, and the development stage was subjected to microwave radiation with a power of 500 W for 10 min; the microwave frequency was 2.45 GHz, and the copper slag polymer composite modified asphalt based on microwave heating was obtained.

[0069] Example 6

[0070] The difference between this embodiment and embodiment 1 is that the amount of copper residue added in step 2 is adjusted to 24 parts (8% of the mass fraction of base asphalt), and the other conditions and steps remain unchanged, to obtain copper residue polymer composite modified asphalt based on microwave heating.

[0071] Example 7

[0072] The difference between this embodiment and embodiment 1 is that the amount of copper residue added in step 2 is adjusted to 18 parts (6% of the mass fraction of base asphalt), and the other conditions and steps remain unchanged, to obtain copper residue polymer composite modified asphalt based on microwave heating.

[0073] Example 8

[0074] Step 1: 300 parts of 70# road petroleum asphalt are placed on a heating plate and heated to 100°C to fully remove moisture and reach a molten flow state, and 15 parts of soybean oil (5% of the mass fraction of base asphalt) are added;

[0075] Step 2: 30 parts (10% of the mass fraction of base asphalt) of 200 mesh copper residue and 12 parts (4% of the mass fraction of base asphalt) of glycidyl methacrylate are added and stirred uniformly;

[0076] Step 3: The heating plate is heated to 140°C, a high-speed shearing machine is used, the shearing speed is 500 r / min, and 15 parts (5% of the mass fraction of base asphalt) of SBS / SEBS mixture (SBS:SEBS = 1:1 by mass) is slowly added at a speed of 5 g / min;

[0077] Step 4: The shearing speed is increased to 5000 r / min, after shearing for 1.5 h, the shearing speed is reduced to 1000 r / min again, the temperature is maintained, and the development time is 30 min. The modified asphalt is fully radiated by a microwave emission device during the entire shearing and development process, and the microwave frequency is 2.45 GHz. The power of the high-speed shearing stage is set to 800 W, and the power of the development stage is set to 500 W. Thus, the copper residue polymer composite modified asphalt based on microwave heating is obtained.

[0078] Example 9

[0079] Step 1: 300 parts of 70# road petroleum asphalt are placed on a heating plate and heated to 100°C to fully remove moisture and reach a molten flow state, and 15 parts of soybean oil (5% of the mass fraction of base asphalt) are added;

[0080] Step 2: 30 parts (10% of the mass fraction of base asphalt) of 200 mesh copper residue and 12 parts (4% of the mass fraction of base asphalt) of bisphenol A type epoxy resin are added and stirred uniformly;

[0081] Step 3: The heating plate is heated to 130℃, a high-speed shearing machine is used, 15 parts (5% of the mass fraction of the base asphalt) of the SBS / SEBS mixture (SBS:SEBS = 1:1 by mass) is slowly added at a speed of 5g / min under a rotation speed of 500r / min;

[0082] Step 4: The shearing speed is increased to 6000r / min, after shearing for 1.5h, the shearing speed is reduced to 800r / min again, the temperature is maintained unchanged for sufficient development, the development time is 30min, and the modified asphalt is fully radiated by using the microwave emission device during the whole shearing and development process, the microwave frequency is 2.45GHz, wherein the power of the high-speed shearing stage is set to 800W, and the power of the development stage is set to 500W, thereby obtaining the copper slag polymer composite modified asphalt based on microwave heating.

[0083] Comparative Example 1

[0084] The difference between the present comparative example and Example 1 is that the modified asphalt is not radiated by using the microwave emission device during the shearing and development process of Step 4, and the other steps and parameters are unchanged, thereby obtaining the ordinary copper slag polymer composite modified asphalt.

[0085] Comparative Example 2

[0086] Step 1: 300 parts of No. 70 road petroleum asphalt is placed on a heating plate and heated to 100℃, so as to fully remove water and reach a molten and flowable state, and 15 parts of soybean oil (5% of the mass fraction of the base asphalt) is added;

[0087] Step 2: 12 parts (4% of the mass fraction of the base asphalt) of 1,4-butanediol diglycidyl ether is added and stirred uniformly by hand;

[0088] Step 3: The heating plate is heated to 150℃, a high-speed shearing machine is used, 15 parts (5% of the mass fraction of the base asphalt) of the SBS / SEBS mixture (SBS:SEBS = 1:1 by mass) is slowly added at a speed of 5g / min under a rotation speed of 500r / min;

[0089] Step 4: The shearing speed is increased to 6000r / min, after shearing for 1.5h, the shearing speed is reduced to 500r / min again, the temperature is maintained unchanged for sufficient development, the development time is 30min, thereby obtaining the polymer composite modified asphalt.

[0090] Comparative Example 3

[0091] Step 1: 300 parts of No. 70 road petroleum asphalt is placed on a heating plate and heated to 100℃, so as to fully remove water and reach a molten and flowable state;

[0092] Step 2: heating plate is heated to 180℃, using a high-speed shearing machine, 15 parts (5% of the mass fraction of base asphalt) SBS polymer elastomer is slowly added at a speed of 5g / min at a rotating speed of 500r / min;

[0093] Step 3: the shearing speed is increased to 6000r / min, after shearing for 1.5h, the shearing speed is reduced to 500r / min again, the temperature is maintained to develop sufficiently, and the development time is 30min, and ordinary SBS modified asphalt is obtained.

[0094] Performance test

[0095] The modified asphalts prepared in each of the above examples and the comparative examples are tested according to the standard GB / T 4509 2010 Determination of penetration of bitumen, the standard GB / T 4507 2014 Determination of softening point of bitumen (ring and ball method), the standard GB / T 4508 2010 Determination of ductility of bitumen, the SH / T 0740 2003 Test method for segregation of polymer modified bitumen, and the SH / T 0654 1998 Determination of rotational viscosity of petroleum bitumen, and the test results are shown in Table 3:

[0096] Table 3

[0097]

[0098] As can be seen from the table, even under the condition of lower external heating temperature (130-150℃), the modified asphalt prepared by the method of the present application still has good viscosity, excellent plasticity, temperature sensitivity and heat storage stability, which shows that the method of the present application for preparing modified asphalt by microwave radiation assisted heating can reduce the external heating temperature while still meeting the performance requirements of the prepared composite modified asphalt.

[0099] By comparing the test results of examples 1-9 with the test results of comparative examples 1 and 2, it can be seen that in the present application, the interaction between the copper slag in the modified asphalt raw material and the microwave radiation is a necessary prerequisite for ensuring that the modified asphalt is heated uniformly at a lower external heating temperature and meets the performance requirements.

[0100] The modified asphalt is subjected to aging treatment to analyze its durability, and the steps of asphalt aging treatment are as follows:

[0101] (1) Short-term aging: according to the T0609 2011 Thin film oven test for bitumen or the T0610 2011 Rotating thin film oven test for bitumen in the Highway Engineering Bitumen and Bitumen Mixture Test Procedures (JTG E2020-11), the asphalt sample is placed in the (rotating) thin film oven and subjected to short-term aging at 163℃ for 5h. The test results are shown in Table 4:

[0102] Table 4:

[0103]

[0104] Comparing the test results of the ordinary SBS modified asphalt prepared by high temperature of Comparative Example 3 with the copper slag polymer composite modified asphalt prepared by microwave heating of the present application, it can be seen that the decrease of the softening point increment of the copper slag polymer composite modified asphalt prepared by microwave heating is more obvious, the smaller the softening point increment is, the stronger the heat-resistant and oxygen-resistant aging performance is; the ductility retention rate is also increased by 65.7% at most. The penetration ratio after aging is also obviously increased from 54.2% to 59.8%. All the indexes are improved, which shows that the durability of the copper slag polymer composite modified asphalt prepared by microwave heating is still better even at a lower shearing temperature.

[0105] (2) Simulating long-term aging under natural conditions (ultraviolet aging): ultraviolet aging test is carried out on the above materials by using an ultraviolet aging box, in which the wavelength of ultraviolet is 365 nm, the intensity is 15 mW / cm 2 , the aging temperature is 30℃, and the aging time is 120 h. The test results are shown in Table 5:

[0106] Table 5:

[0107]

[0108] Comparing the test results of the ordinary SBS modified asphalt prepared by high temperature of Comparative Example 3 with the copper slag polymer composite modified asphalt prepared by microwave heating, it can be seen that the decrease of the softening point increment of the copper slag polymer composite modified asphalt prepared by microwave heating is more obvious, the smaller the softening point increment is, the stronger the ultraviolet blocking effect is; the ductility retention rate is also increased by 68.9% at most. The penetration ratio after aging is also obviously increased from 60.7% to 65.8%. All the indexes are improved, which shows that the durability of the copper slag polymer composite modified asphalt prepared by microwave heating is still better even at a lower shearing temperature.

[0109] The above are only the preferred embodiments of the present application, and do not limit the implementation manners and protection scope of the present application. It should be realized by those skilled in the art that any equivalent replacement and obvious changes made according to the contents of the present application should be included in the protection scope of the present application.

Claims

1. A method for preparing copper slag polymer composite modified bitumen based on microwave heating, characterized in that, Includes the following steps: S1. Preheat the base asphalt to remove moisture and make it molten and fluid. Add the oil phase and mix well to obtain the first mixture. S2. Add copper slag and reactive diluent to the first mixture, mix well, and obtain a second mixture; the main components of the copper slag account for the following mass percentages: SiO2 30%~40%, CaO 5%~10%, MgO 1%~5%, Al2O3 2%~4%, magnetite 2%~5%; the reactive diluent is selected from one or more combinations of 1,4-butanediol diglycidyl ether, glycidyl methacrylate, and bisphenol A epoxy resin; S3. The second mixture is heated to 130~150℃, and a styrene block copolymer is added under stirring to obtain a third mixture; the styrene block copolymer is a mixture of SBS and SEBS, and the mass ratio of SBS to SEBS is (1~3):1; S4. The third mixture is subjected to high-speed shearing for a certain period of time, with a shearing speed of 5000~6500 r / min, while microwave radiation is applied at a microwave frequency of 2.45 GHz and a power of 300~800 W. Then the shearing speed is reduced to 500~1000 r / min and allowed to develop, and the microwave power is adjusted to 100~500 W to obtain copper slag polymer composite modified asphalt based on microwave heating.

2. The preparation method according to claim 1, characterized in that, In step S1, the oil phase is selected from one or more of soybean oil, naphthenic oil, chlorinated paraffin, and furfural extract oil.

3. The preparation method according to claim 1, characterized in that, In step S4, the high-speed shearing time is 1~1.5h, and the development time is 20~40min.

4. A copper slag polymer composite modified bitumen based on microwave heating, characterized in that, It is prepared by the method according to any one of claims 1-3.

5. The microwave-heated copper slag polymer composite modified bitumen according to claim 4, characterized in that, The raw materials, by weight, include: 200-300 parts of base bitumen, 6-15 parts of oil phase, 12-30 parts of copper slag, 4-12 parts of reactive diluent, and 10-18 parts of styrene block copolymer.

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