Modified asphalt composition, modified asphalt and emulsified asphalt

Abstract

The invention provides a modified asphalt composition, modified asphalt and emulsified asphalt, and the modified asphalt composition comprises silicate, hydrochloric acid, a silane coupling agent, raw rubber, asphalt and a polymer modifier. The silicic acid gel composite raw rubber modified asphalt can be prepared, the high / low temperature resistance of an asphalt product is improved, and the working temperature range of the asphalt product is expanded.

Description

Technical Field

[0001] The present invention relates to the field of asphalt, and in particular to a modified asphalt composition, modified asphalt and emulsified asphalt. Background Art

[0002] Asphalt is the primary pavement material currently used in road construction. Modern road traffic is characterized by high traffic volumes, high speeds, and heavy loads, leading to ever-increasing demands on pavement quality. Conventional asphalt materials generally suffer from high penetration, low ductility, and a low softening point within the project scope. These shortcomings manifest as poor compressive crack resistance, poor plasticity, high temperature sensitivity, and a narrow operating temperature range, making them difficult to meet the pavement quality requirements of modern road traffic.

[0003] Modified asphalt refers to asphalt or asphalt mixtures that have been modified by adding modifiers such as rubber, resin, high molecular polymer, natural asphalt, ground rubber powder or other materials to improve the performance of asphalt. The use of modified asphalt can significantly improve the performance of asphalt pavement, reduce early road damage, and lower operating costs. It can also extend road maintenance cycles and pavement service life, and reduce the economic losses caused by frequent road reconstruction.

[0004] However, the existing modified asphalt will experience mechanical property degradation during mass production as the waiting time increases. In addition, during actual road spray construction applications, the existing modified emulsified asphalt will demulsify due to water evaporation. In winter or extremely cold conditions, the demulsified asphalt phase will become hard and brittle when exposed to the environment, and cracks will appear under the influence of repeated rutting and external forces. Summary of the Invention

[0005] The present invention provides a modified asphalt composition. By introducing silicate, hydrochloric acid, a silane coupling agent and raw rubber, the modified asphalt composition can be used to prepare silicate gel composite raw rubber modified asphalt, thereby improving the high / low temperature resistance of the asphalt product and expanding the operating temperature range of the asphalt product.

[0006] The present invention also provides a modified asphalt. Since the modified asphalt is prepared from the modified asphalt composition, the emulsified asphalt prepared therefrom has good high-temperature stability and low-temperature crack resistance and creep resistance.

[0007] The present invention also provides an emulsified asphalt. Since the emulsified asphalt is prepared from the modified asphalt, it has good high-temperature stability and low-temperature crack resistance and creep resistance.

[0008] In a first aspect, the present invention provides a modified asphalt composition comprising: a silicate, hydrochloric acid, a silane coupling agent, raw rubber, asphalt, and a polymer modifier.

[0009] According to some embodiments of the present application, the modified asphalt composition comprises, in terms of mass fraction:

[0010] Silicate 2-14 parts, hydrochloric acid 8-50 parts, silane coupling agent 0.5-6 parts, raw rubber 30-200 parts, asphalt 400-450 parts, polymer modifier 10-20 parts; wherein the mass concentration of the hydrochloric acid is 35%-40wt%.

[0011] According to some embodiments of the present application, the polymer modifier comprises a thermoplastic high molecular polymer;

[0012] Preferably, the thermoplastic high molecular polymer comprises at least one of styrene-butadiene rubber (SBS), styrene-ethylene-butylene-styrene block copolymer (SEBS), styrene-isoprene-styrene block copolymer (SIS), styrene-butadiene rubber (SBR), natural rubber (NR), rubber powder (CR), ethylene-vinyl acetate copolymer (EVA).

[0013] According to some embodiments of the present application, the raw rubber comprises at least one of silicone rubber raw rubber, fluororubber raw rubber, and ternary ethylene-propylene recycled rubber.

[0014] According to some embodiments of the present application, the asphalt comprises at least one of petroleum asphalt, coal tar pitch, and natural asphalt.

[0015] According to some embodiments of the present application, the modified asphalt composition further comprises an asphalt compatible extender, and the mass ratio of the asphalt compatible extender to asphalt is 400-450:15-25.

[0016] In a second aspect, the present application provides a modified asphalt prepared from the modified asphalt composition of the first aspect.

[0017] According to some embodiments of the present application, the modified asphalt is prepared by a method comprising the following steps:

[0018] S1, adding hydrochloric acid to a dispersion system containing silicate and silane coupling agent, and mixing to obtain a silicic acid gel;

[0019] S2, mixing the fluid of raw rubber and the silicic acid gel to obtain a silicic acid gel composite raw rubber modifier;

[0020] S3, mixing asphalt, polymer modifier, and the silicic acid gel composite raw rubber modifier to obtain the modified asphalt.

[0021] According to some embodiments of the present application, step S3 specifically comprises the following process:

[0022] The bitumen and the bitumen compatible extender are mixed once at 150-160 DEG C, the polymer modifier and the silica gel composite green rubber modifier are added, the temperature is raised to 180-185 DEG C, the mixing is carried out twice, the temperature is reduced to 170-175 DEG C, and the modified bitumen is obtained.

[0023] In a third aspect, the present application provides an emulsified bitumen prepared by emulsifying the modified bitumen of the second aspect.

[0024] The modified bitumen composition provided by the present application can be used to prepare the modified bitumen with good high-temperature stability and low-temperature crack resistance and creep resistance.

[0025] The emulsified bitumen provided by the present application has a wide working temperature range, good high-temperature stability, low-temperature crack resistance and creep resistance. DETAILED DESCRIPTION

[0026] The present application will be further described in detail below. The following specific embodiments are only used to describe the principles and characteristics of the present application, and the examples are used to explain the present application, but not to limit the scope of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of the present application.

[0027] To solve the technical problems of the existing modified bitumen, such as high-temperature mechanical property decay and low-temperature hardening and embrittlement, the present application adopts the following technical solutions:

[0028] In a first aspect, the present application provides a modified bitumen composition, comprising: a silicate, hydrochloric acid, a silane coupling agent, green rubber, bitumen and a polymer modifier.

[0029] The bitumen composition of the present application can be used to prepare the modified bitumen with good high-temperature stability and low-temperature crack resistance and creep resistance, because the silicate and hydrochloric acid in the combination can form a silica gel, and the silane coupling agent (R n SiX 4-nThe -Si group in the silane coupling agent is similar in polarity to the -Si atom in the silicic acid gel, and the silicic acid gel particles can tightly coat the surface of the silane coupling agent by physical adsorption, and can also form -Si-O-Si- bonds by chemical reaction to tightly connect the coupling agent to the surface of the silicic acid gel particles. The -R in the silane coupling agent is a non-hydrolytic organic functional group that can be combined with raw rubber, thereby realizing the complexing of the silicic acid gel-raw rubber macromolecule and forming a silicic acid gel composite raw rubber modifier. The modifier is dispersed in the asphalt and can effectively delay the thermal aging of the polymer modifier under high temperature conditions, inhibit the volatilization and loss of the light components of the asphalt, and effectively eliminate the mechanical property degradation problem that occurs when the modified asphalt is produced in batches. In the actual road spraying construction application process, the introduction of the silicic acid gel composite raw rubber modifier causes the asphalt to be dispersed in the silicic acid gel-raw rubber phase to form physical crosslinking points, effectively compensating for the brittleness and hardness of the asphalt phase at low temperatures, relieving the freezing of the molecular chain of the polymer modifier, and improving the low-temperature crack resistance and anti-cree performance of the material. The service life of the material in a low-temperature environment is enhanced.

[0030] In an embodiment, the modified asphalt composition comprises, by mass fraction:

[0031] 2-14 parts of silicate, 8-50 parts of hydrochloric acid, 0.5-6 parts of silane coupling agent, 30-200 parts of raw rubber, 400-450 parts of asphalt, and 10-20 parts of polymer modifier; wherein the mass concentration of the hydrochloric acid is 35%-40wt%.

[0032] The content of the silicate, hydrochloric acid, silane coupling agent, and raw rubber determines the amount of the silicic acid gel composite raw rubber modifier introduced. As described above, the composition components in the above-mentioned proportion range can be used to prepare a suitable amount of the silicic acid gel composite raw rubber modifier, which is dispersed in the mixed system of the polymer modifier and the asphalt, and can further improve the high-temperature stability, low-temperature crack resistance, and anti-cree performance of the asphalt product.

[0033] It can be understood that the hydrochloric acid is an aqueous solution of HCl, and the mass concentration refers to the mass proportion of HCl in the solution.

[0034] In an embodiment, the polymer modifier comprises a thermoplastic high-molecular polymer.

[0035] In an embodiment, the thermoplastic high-molecular polymer comprises at least one of styrene-butadiene rubber (SBS), styrene-ethylene-butylene-styrene block copolymer (SEBS), styrene-isoprene-styrene block copolymer (SIS), styrene-butadiene rubber (SBR), natural rubber (NR), rubber powder (CR), and ethylene-vinyl acetate copolymer (EVA).

[0036] Among them, the introduction of different polymer modifiers can improve the different properties of modified asphalt, and the skilled person can select different polymer modifiers according to the actual application scene. For example, SBS has excellent elasticity and flexibility, which can further improve the ductility and crack resistance of modified asphalt, which makes the modified asphalt not easy to crack under low temperature conditions, and maintains stable elasticity and crack resistance under high temperature conditions; SEBS is a hydrogenated SBS, which has excellent thermal stability and anti-aging performance. It can improve the elasticity and durability of modified asphalt, improve the crack resistance and fatigue resistance, and at the same time show better stability under high temperature and low temperature conditions; SIS has good elasticity and adhesion, which can improve the flexibility and crack resistance of modified asphalt. It shows excellent performance under low temperature conditions, but may not be as good as SBS in terms of high temperature stability; SBR can improve the elasticity and crack resistance of modified asphalt, and improve the low temperature flexibility and fatigue resistance. It also has a positive effect on improving the durability and water damage resistance of modified asphalt; NR can enhance the elasticity and fatigue resistance of modified asphalt, and improve the low temperature. Due to its natural source, NR also has certain environmental advantages; CR can improve the elasticity and fatigue resistance of modified asphalt, and at the same time improve the crack resistance and durability.

[0037] In a specific embodiment, the raw rubber includes at least one of silicone rubber raw rubber, fluororubber raw rubber, and ternary ethylene-propylene recycled rubber.

[0038] Among them, the specific type of raw rubber can be selected according to different application scenarios, for example, silicone rubber raw rubber not only has excellent high temperature and low temperature resistance, can maintain elasticity in the temperature range of-100℃ to 350℃, is particularly suitable for high temperature and low temperature environments, and has strong ozone resistance and weathering resistance, is suitable for long-term exposure environments, and is not easy to age and crack. Fluororubber raw rubber can resist extreme high temperatures, oil and solvents, and is suitable for high temperature, high pressure and chemical corrosion environments. Ternary ethylene-propylene recycled rubber is also stable in performance under long-term outdoor exposure, is not easy to age and crack, and is relatively inexpensive, easy to process, and suitable for large-scale production. In a specific embodiment, the asphalt includes at least one of petroleum asphalt, coal tar pitch, and natural asphalt.

[0039] The modified asphalt composition of the present invention can be used to prepare modified asphalt. The application scenarios of modified asphalt are not limited to road construction, but can also be used in waterproofing projects such as roofs and basements of buildings, anti-corrosion coatings of buildings, insulation layers of cables and wires, etc. Therefore, the specific raw materials of the asphalt can be selected according to the application scenarios of the modified asphalt. For example, petroleum asphalt obtained by distillation or cracking in the process of petroleum refining can be widely used in paving roads and highways, for waterproofing roofs and underground projects, and for making asphalt concrete, asphalt coatings, etc. due to its good adhesion, waterproofness and durability. Coal tar asphalt obtained by distillation of coal tar is usually harder than petroleum asphalt and has better high temperature resistance, but its adhesion and flexibility are poor. It can be used for electrode binders, anti-corrosion coatings and anti-corrosion layers of aluminum electrolytic cells, etc. Natural asphalt has a higher viscosity, good durability and waterproofness, and can be used for road paving, waterproof membranes and waterproof coatings, etc.

[0040] Since ensuring good compatibility between the polymer modifier and the asphalt matrix is ​​key in asphalt modification, and compatibility affects the stability, durability, and workability of the modified asphalt, in some embodiments of the present invention, the modified asphalt composition further includes an asphalt compatibility extender, and the mass ratio of the asphalt compatibility extender to asphalt is 400-450:15-25.

[0041] In some embodiments, the asphalt compatibility extender can be one of asphalt compatibility extenders based on aromatic oil and cycloparaffin oil; for example, asphalt compatibility extender model JL-094.

[0042] In a second aspect, the present invention provides a modified asphalt prepared from the modified asphalt composition described in the first aspect.

[0043] The modified asphalt of the present invention can be used in various fields, such as road construction, waterproof materials, coating manufacturing, electrical insulation materials, etc.

[0044] In one embodiment, the modified asphalt is prepared by a method comprising the following steps:

[0045] S1. adding hydrochloric acid to a dispersed system comprising a silicate and a silane coupling agent, and mixing the mixture to obtain a silicate gel;

[0046] S2, mixing the raw rubber fluid and the silica gel to obtain a silica gel composite raw rubber modifier;

[0047] S3. Mixing asphalt, a polymer modifier and the silica gel composite rubber modifier to obtain the modified asphalt.

[0048] In the above preparation method, first, hydrochloric acid is added to a dispersed system containing silicate and a silane coupling agent, and the mixture is mixed so that the silicate ions in the silicate combine with the hydrogen ions of the hydrochloric acid to form silicic acid molecules, which are polymerized into colloidal particles or precipitates, thereby forming a silicic acid gel. The silane coupling agent is adsorbed on at least part of the surface of the silicic acid gel through bonding. Next, the fluid raw rubber is further mixed with the silicic acid gel, and the bridging effect of the silane coupling agent is utilized to combine the raw rubber and the silicic acid gel to form a silicic acid gel composite raw rubber modifier. Finally, the modifier is mixed with asphalt and a polymer modifier to obtain the above-mentioned modified asphalt.

[0049] In some embodiments of the present invention, in order to ensure the uniformity of the internal composition of the silicate gel, it is necessary to first dissolve the silicate solid in water, then add the silane coupling agent, continue stirring, and finally add hydrochloric acid. After a white precipitate appears, hydrochloric acid is slowly added dropwise until a white, non-flowing silicate gel appears.

[0050] In some embodiments of the present invention, the fluidity of the raw rubber can be made into a fluid state by heating the solid raw rubber.

[0051] In some embodiments of the present invention, step S3 specifically includes the following process:

[0052] At 150-160° C., asphalt and asphalt compatible retardant are mixed once, polymer modifier and silica gel composite rubber modifier are added, the temperature is raised to 180-185° C., a second mixing treatment is performed, and the temperature is lowered to 170-175° C. to obtain the modified asphalt.

[0053] In a third aspect, the present invention provides an emulsified asphalt obtained by emulsifying the modified asphalt described in the second aspect with an emulsifier.

[0054] In some embodiments of the present invention, the emulsifier includes a cationic emulsifier based on alkyl polyamines, quaternary ammonium salts, amidoamines, and ligninamines.

[0055] In some embodiments of the present invention, the emulsifier accounts for 2%-7% of the mass of the modified asphalt.

[0056] In some embodiments of the present invention, the emulsification treatment includes: dissolving 20-30 parts of emulsifier in water by mass to form a soap solution for emulsified asphalt, pouring the soap solution into a colloid mill, starting the colloid mill circulation, adding the modified asphalt, and circulating for 5-10 minutes to obtain emulsified asphalt.

[0057] To further understand the present invention, the following will clearly and completely describe the technical solutions of the present invention in conjunction with specific embodiments. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0058] Unless otherwise specified, all reagents involved in the embodiments of the present invention are commercially available products and can be purchased through commercial channels.

[0059] The specifications or sources of some raw materials involved in the following experiments are shown in Table 1.

[0060] Table 1:

[0061]

[0062]

[0063] Example 1

[0064] This example provides a modified asphalt composition, including: 3 parts of sodium silicate, 10 parts of concentrated hydrochloric acid (hydrochloric acid mass concentration = 38%), 1 part of silane coupling agent, 40 parts of raw rubber, 430 parts of asphalt, 15 parts of SBS, and 17 parts of asphalt compatible retardant.

[0065] This example also provides a modified asphalt and emulsified asphalt prepared from the modified asphalt composition, and the preparation method thereof comprises the following steps:

[0066] S1. Mix 3 parts of sodium silicate solid and 27 parts of distilled water, heat to 60°C, and stir at 400 rpm for 20 minutes until the sodium silicate solid particles are completely dissolved. Add 1 part of silane coupling agent, lower the temperature to 25°C, continue stirring for 30 minutes, and add 10 parts of concentrated hydrochloric acid. After reacting for a while, a white, non-flowing silica gel appears.

[0067] S2. 40 parts of raw rubber were softened at 160° C. for 30 minutes until they were completely fluid, and the silica gel prepared above was evenly mixed with the fluidized raw rubber. The mixture was stirred at 500 rpm for 20 minutes, and the reaction was stopped to obtain a silica gel composite raw rubber modifier. The modifier was placed in an oven at 160° C. for heat preservation and standby use;

[0068] S3, 430 parts of solid asphalt and 17 parts of asphalt compatibility extender were mixed uniformly at 160°C and kept at a constant temperature for 30 minutes, 15 parts of SBS and the silica gel composite raw rubber modifier prepared in S2 were added, the high-speed shear disperser was turned on and set to 4000 rpm, the temperature was raised to 180°C, shear dispersion was continued for 60 minutes, and finally the temperature was lowered to 170°C to obtain modified asphalt;

[0069] S4. Mix 20 parts of emulsifier and 500 parts of distilled water, heat to 62° C., and stir at 400 rpm for 60 minutes to obtain a soap solution for emulsified asphalt;

[0070] S5. Pour the soap solution prepared above into the colloid mill, start the circulation, slowly add the modified asphalt prepared above, and circulate it for 10 minutes to prepare emulsified asphalt.

[0071] Example 2

[0072] This example provides a modified asphalt composition including: 6 parts of sodium silicate, 20 parts of concentrated hydrochloric acid (hydrochloric acid mass concentration = 38%), 2 parts of silane coupling agent, 80 parts of raw rubber, 430 parts of asphalt, 15 parts of SBS, and 17 parts of asphalt compatible retardant.

[0073] The preparation method of the modified asphalt and emulsified asphalt provided in this example is different from that in Example 1 only in that the above-mentioned modified asphalt composition is used.

[0074] Example 3

[0075] This example provides a modified asphalt composition including: 9 parts of sodium silicate, 30 parts of concentrated hydrochloric acid (hydrochloric acid mass concentration = 38%), 3 parts of silane coupling agent, 120 parts of raw rubber, 430 parts of asphalt, 15 parts of SBS, and 17 parts of asphalt compatible retardant.

[0076] The preparation method of the modified asphalt and emulsified asphalt provided in this example is different from that in Example 1 only in that the above-mentioned modified asphalt composition is used.

[0077] Example 4

[0078] This example provides a modified asphalt composition including: 12 parts of sodium silicate, 40 parts of concentrated hydrochloric acid (hydrochloric acid mass concentration = 38%), 4 parts of silane coupling agent, 160 parts of raw rubber, 430 parts of asphalt, 15 parts of SBS, and 17 parts of asphalt compatible retardant.

[0079] The preparation method of the modified asphalt and emulsified asphalt provided in this example is different from that in Example 1 only in that the above-mentioned modified asphalt composition is used.

[0080] Example 5

[0081] This example provides a modified asphalt composition, including: 14 parts of sodium silicate, 50 parts of concentrated hydrochloric acid (hydrochloric acid mass concentration = 38%), 6 parts of silane coupling agent, 200 parts of raw rubber, 400 parts of asphalt, 10 parts of SBS, and 15 parts of asphalt compatible retardant.

[0082] The preparation method of the modified asphalt and emulsified asphalt provided in this example refers to Example 1.

[0083] Example 6

[0084] The example provides a modified asphalt composition, comprising: sodium silicate 2 parts, concentrated hydrochloric acid 8 parts (mass concentration of hydrochloric acid = 38%), silane coupling agent 0.5 parts, raw rubber 30 parts, asphalt 400 parts, SBS 20 parts, 25 parts of asphalt compatible extender.

[0085] The example provides a preparation method of the modified asphalt and the emulsified asphalt, and the preparation method of the modified asphalt and the emulsified asphalt is as follows:

[0086] Example 7

[0087] The example provides a modified asphalt composition, comprising: sodium silicate 18 parts, concentrated hydrochloric acid 60 parts (mass concentration of hydrochloric acid = 38%), silane coupling agent 6 parts, raw rubber 240 parts, asphalt 400 parts, SBS 20 parts, 25 parts of asphalt compatible extender.

[0088] The example provides a preparation method of the modified asphalt and the emulsified asphalt, and the preparation method of the modified asphalt and the emulsified asphalt is as follows:

[0089] Comparative Example 1

[0090] The example also provides a modified asphalt and an emulsified asphalt, and a preparation method thereof, and the preparation method comprises the following steps:

[0091] S1, 430 parts of solid asphalt, 17 parts of asphalt compatible extender are uniformly mixed at 160 DEG C, and are kept at constant temperature for 30 min, 15 parts of SBS is added, a high-speed shearing dispersion machine is started to set the rotating speed to 4000 rpm, the temperature is increased to 180 DEG C, and shearing dispersion is continued for 60 min, and finally the temperature is reduced to 170 DEG C, and the modified asphalt can be obtained.

[0092] S2, 20 parts of emulsifier and 500 parts of distilled water are mixed, heated to 62 DEG C, and stirred at 400 rpm for 60 min to obtain the emulsified asphalt soap solution.

[0093] S3, the prepared soap solution is poured into a colloid mill, the circulation is started, the prepared high-temperature modified asphalt is slowly added, and full circulation is carried out for 10 min, and the emulsified asphalt can be prepared.

[0094] Comparative Example 2

[0095] A modified asphalt composition, which is only different from the example 1 in that it does not contain raw rubber.

[0096] The example also provides a modified asphalt and an emulsified asphalt prepared from the modified asphalt composition, and a preparation method thereof, and the preparation method comprises the following steps:

[0097] S1. Mix 3 parts of sodium silicate solid and 27 parts of distilled water, heat to 60°C, and stir at 400 rpm for 20 minutes until the sodium silicate solid particles are completely dissolved. Add 1 part of silane coupling agent, lower the temperature to 25°C, continue stirring for 30 minutes, and add 10 parts of concentrated hydrochloric acid. After reacting for a while, a white, non-flowing silica gel appears.

[0098] S2. Mix 430 parts of solid asphalt and 17 parts of asphalt compatibility extender at 160°C and keep the temperature constant for 30 minutes. Then add 15 parts of SBS and the silica gel prepared in S1. Start the high-speed shear disperser and set the speed to 4000 rpm. Raise the temperature to 180°C and continue shearing and dispersing for 60 minutes. Finally, lower the temperature to 170°C to obtain modified asphalt.

[0099] S3. Mix 20 parts of emulsifier and 500 parts of distilled water, heat to 62° C., and stir at 400 rpm for 60 min to obtain a soap solution for emulsified asphalt;

[0100] S4. Pour the soap solution prepared above into the colloid mill, start the circulation, slowly add the modified asphalt prepared above, and circulate it for 10 minutes to prepare emulsified asphalt.

[0101] Comparative Example 3

[0102] A modified asphalt composition, which differs from Example 1 only in that it does not contain silica gel and silane coupling agent.

[0103] This example also provides a modified asphalt and emulsified asphalt prepared from the modified asphalt composition, and the preparation method thereof comprises the following steps:

[0104] S1. Heat 40 parts of raw rubber at 160°C for 30 minutes to soften until it is completely fluid;

[0105] S2. Mix 430 parts of solid asphalt and 17 parts of asphalt compatibility extender at 160°C and keep the temperature constant for 30 minutes. Then add 15 parts of SBS and 40 parts of raw rubber. Start the high-speed shear disperser and set the speed to 4000 rpm. Raise the temperature to 180°C and continue shearing and dispersing for 60 minutes. Finally, lower the temperature to 170°C to obtain modified asphalt.

[0106] S3. Mix 20 parts of emulsifier and 500 parts of distilled water, heat to 62° C., and stir at 400 rpm for 60 min to obtain a soap solution for emulsified asphalt;

[0107] S4. Pour the soap solution prepared above into the colloid mill, start the circulation, slowly add the modified asphalt prepared above, and circulate it for 10 minutes to prepare emulsified asphalt.

[0108] Test Case

[0109] Test Example 1: Normal Temperature Test

[0110] The emulsified asphalts prepared in Examples 1-7 and Comparative Examples 1-3 were subjected to performance testing, and the specific test results are shown in Table 2 below. The performance indicators and test methods in the table are based on the industry standard "JTG E20-2011 Testing Procedures for Asphalt and Asphalt Mixtures for Highway Engineering" and the "PCR Emulsified Asphalt Finished Product Technical Internal Control Standard."

[0111] Table 2:

[0112]

[0113]

[0114] The results show that the emulsified asphalt of the examples has better storage stability than the comparative examples. Further comparison with Examples 1-7 shows that when the raw rubber content is too high, the ductility index of the emulsified asphalt evaporation residue does not meet the Class A requirements of the "PCR Emulsified Asphalt Finished Product Technical Internal Control Standard".

[0115] Test Example 2: High Temperature Test

[0116] The modified asphalts prepared in Examples 1-7 and Comparative Examples 1-3 were heated and stirred at 180°C and 500 rpm for 2 h, 4 h, 6 h, and 8 h, respectively, without performing the subsequent emulsification step. The softening point, penetration, and ductility test results of the modified asphalts at different heating times are shown in Table 3 below.

[0117] Table 3:

[0118]

[0119]

[0120] As can be seen from Table 3, the softening point, penetration and ductility of the modified asphalt of Comparative Example 1 continue to decay with the extension of heating time, and the 2h softening point decays to below 60°C, which does not meet the A-grade product indicators. This is because the increase in the high-temperature waiting time of the modified asphalt causes thermal aging of the SBS, and a large amount of volatilization and loss of the light components of the asphalt causes the modified asphalt to harden, and the softening point decreases while the ductility and penetration decrease. However, for the modified asphalt of the embodiment, as the amount of silica gel composite raw rubber modifier is increased, the anti-attenuation properties of the softening point, penetration and ductility can be significantly improved, and the 2h softening point is higher than 60°C, which meets the A-grade product indicators.

[0121] Test Example 3: Low Temperature Test

[0122] The emulsified bitumen prepared in Examples 1-7 and Comparative Examples 1-3 was dried to remove water, and the remaining evaporation residue was used to prepare ductility test pieces according to the JTG E20-2011 Highway Engineering Bitumen and Bitumen Mixture Test Procedures industry standard and the PCR Emulsified Bitumen Product Technology Internal Control Standard. Four ductility test pieces were prepared for each comparative example or example, and the four ductility test pieces were cured in the laboratory for 1.5 h, one of which was placed in a 5°C constant temperature water bath in a ductility tester for 1.5 h, and the remaining three test pieces were placed in a constant temperature chamber at -5°C, -10°C and -15°C for 1.5 h, respectively, and then removed and placed in a 5°C constant temperature water bath in a ductility tester for 1.5 h. The ductility test pieces were installed and fixed, and then elongated to 20 cm at a test rate of 50 mm / min, and then immediately stopped the test, and the time for which the test piece remained at a 20 cm ductility until it broke was recorded.

[0123] Table 4:

[0124]

[0125]

[0126] As can be seen from Table 4, for the ductility test pieces of all examples and comparative examples, low temperature treatment causes the asphalt to phase change to become hard and brittle, becoming a solid state that loses fluidity, and the SBS phase molecular chain freezes, the rigidity increases, the creep resistance decreases, and macroscopically, the ability of the ductility test piece to resist deformation at low temperature decreases, and the lower the temperature, the more obvious this phenomenon. However, overall, compared to the comparative examples, the examples effectively improve the low temperature crack resistance and creep resistance of the emulsified bitumen by introducing a silica gel composite gel modifier and increasing the amount of the modifier.

[0127] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that they can still modify the technical solutions described in the foregoing examples, or make equivalent substitutions for part or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solution to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A modified asphalt composition, characterized in that: include: Silicate, hydrochloric acid, silane coupling agent, raw rubber, asphalt, polymer modifier.

2. The modified asphalt composition according to claim 1, characterized in that The modified asphalt composition comprises, by weight: 2-14 parts of silicate, 8-50 parts of hydrochloric acid, 0.5-6 parts of silane coupling agent, 30-200 parts of raw rubber, 400-450 parts of asphalt, and 10-20 parts of polymer modifier; wherein the mass concentration of the hydrochloric acid is 35%-40wt%.

3. The modified asphalt composition according to claim 1 or 2, characterized in that The polymer modifier includes a thermoplastic high molecular polymer; Preferably, the thermoplastic polymer includes at least one of styrene-butadiene rubber, styrene-ethylene-butylene-styrene block copolymer, styrene-isoprene-styrene block copolymer, styrene-butadiene rubber, natural rubber, rubber powder, and ethylene-vinyl acetate copolymer.

4. The modified asphalt composition according to claim 1 or 2, characterized in that The raw rubber includes at least one of silicone rubber raw rubber, fluororubber raw rubber and EPDM reclaimed rubber.

5. The modified asphalt composition according to claim 1 or 2, characterized in that: The asphalt includes at least one of petroleum asphalt, coal tar asphalt, and natural asphalt.

6. The modified asphalt composition according to claim 1 or 2, characterized in that: The modified asphalt composition further comprises an asphalt compatibility extender, and the mass ratio of the asphalt compatibility extender to asphalt is 400-450:15-25.

7. A modified asphalt, characterized in that: The modified asphalt composition is prepared from any one of claims 1 to 6.

8. The modified asphalt according to claim 7, characterized in that Prepared by a method comprising the following steps: S1. adding hydrochloric acid to a dispersed system comprising a silicate and a silane coupling agent, and mixing the mixture to obtain a silicate gel; S2, mixing the raw rubber fluid and the silica gel to obtain a silica gel composite raw rubber modifier; S3. Mixing asphalt, a polymer modifier and the silica gel composite rubber modifier to obtain the modified asphalt.

9. The modified asphalt according to claim 8, characterized in that Step S3 specifically includes the following process: At 150-160° C., asphalt and asphalt compatible retardant are mixed once, polymer modifier and silica gel composite rubber modifier are added, the temperature is raised to 180-185° C., a second mixing treatment is performed, and the temperature is lowered to 170-175° C. to obtain the modified asphalt.

10. An emulsified asphalt, characterized in that: The modified asphalt is obtained by emulsifying the modified asphalt according to any one of claims 8 to 9 with an emulsifier.

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