High-temperature instant stable dry-process high-viscoelasticity asphalt modifier and preparation method thereof

Abstract

The invention discloses a high-temperature instant stable dry-process high-viscoelastic asphalt modifier and a preparation method thereof, and belongs to the technical field of road engineering materials. The high-temperature instant stable dry-process high-viscoelastic asphalt modifier comprises the following components in percentage by mass: 20%-32% of matrix asphalt, 18%-20% of SBS (Styrene Butadiene Styrene), 12%-15% of a solubilizer, 35%-40% of a compound tackifier, 1.5%-2.5% of a heat conducting agent and 1.5%-2.5% of a coupling agent. The high-temperature instant stable dry-process high-viscoelastic asphalt modifier provided by the invention can be stably stored in a normal-temperature state, and does not generate a bonding phenomenon; and under the condition of high temperature, the modified asphalt can be quickly dissolved, effectively wraps the hot aggregate, is well compatible with the matrix asphalt, and has no other technical difficulties. The high-temperature instant stable dry-process high-viscosity and high-elasticity asphalt modifier provided by the invention can be directly put into commodity SBS modified asphalt to prepare high-viscosity and high-elasticity modified asphalt.

Description

Technical Field

[0001] The invention belongs to the technical field of road engineering materials, and specifically relates to a high-temperature fast-dissolving stable dry-process high-viscosity elastic asphalt modifier and a preparation method thereof. Background Art

[0002] High-viscosity and high-elasticity modified asphalt refers to asphalt with a dynamic viscosity of more than 20,000 Pa·s at 60°C and an elastic recovery of more than 85% at 25°C. It has excellent adhesion, elastic recovery and anti-aging properties, and can improve road performance. The traditional wet process to produce this asphalt is to produce finished modified asphalt in the factory and then transport it to the mixing plant for mixing the mixture. This method allows the modifier to be evenly dispersed and fully swelled into the base asphalt, but the poor thermal storage stability makes it easy to segregate; and the production method is not flexible, and mass production does not match the needs of small-scale high-precision engineering. Multiple unfavorable factors lead to increased costs.

[0003] To solve the above problems, researchers proposed a dry preparation process, which directly puts the dry modifier into the mixing pot where the hot aggregate is evenly mixed, and then adds the base asphalt for mixing. The modification of the binder is completed while the mixture is mixed. On the one hand, this production process does not need to consider the thermal storage stability of the highly viscous and highly elastic modified asphalt, which can improve the overall stability of the mixture system; on the other hand, it saves transportation costs and is flexibly applicable to production of various scales, eliminating the phenomenon of waste of raw materials.

[0004] At present, there is a lot of research on dry-process modifiers, and the types of modifiers are also diversified, but they still face three major challenges. First, due to the lack of swelling and development processes, the modification effect of the dry process is often inferior to that of the traditional wet process. Secondly, dry-process modifiers are expensive, and it is difficult to meet the technical requirements of high-viscosity and high-elasticity asphalt at low dosages. Finally, in order to enhance the viscosity, a large amount of high-molecular polymers are added to the dry-process modifier, which makes it easy to stick together and clump at room temperature, making it difficult to store; it is difficult to dissolve quickly at high temperatures, which affects the rapid and uniform dispersion of the modifier in the asphalt.

[0005] In view of this, there is an urgent need for a high-temperature, fast-dissolving, stable, dry-process, high-viscosity and elastic asphalt modifier. Summary of the invention

[0006] The purpose of the present invention is to provide a high-temperature, fast-dissolving, stable, dry-process, high-viscosity and high-elastic asphalt modifier and a preparation method thereof. The modifier can be stably stored at room temperature without adhesion; under high temperature conditions, it can dissolve quickly, effectively wrap hot aggregates and be well compatible with matrix asphalt, without other technical difficulties. In addition, the dry-process high-viscosity and high-elastic modifier provided by the present invention can also achieve the preparation of high-viscosity and high-elastic modified asphalt with low dosage, and surpass ordinary high-viscosity and high-elastic asphalt.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] One of the technical solutions of the present invention is to provide a high-temperature, fast-dissolving, stable, dry-process, high-viscosity elastic asphalt modifier, which comprises, by mass percentage, 20% to 32% of base asphalt, 18% to 20% of styrene-butadiene-styrene block copolymer (SBS), 12% to 15% of solubilizer, 35% to 40% of compound viscosity enhancer, 1.5% to 2.5% of thermal conductor and 1.5% to 2.5% of coupling agent.

[0009] The traditional dry preparation lacks swelling and development process, and the modification effect is not as good as the wet process. Therefore, in the present invention, asphalt is added to the raw materials, and SBS and the compounded viscosity enhancer absorb the light components of asphalt to swell during mixing to form a two-phase structure, which is sheared and dispersed by mechanical force to achieve pre-swelling.

[0010] Preferably, the base asphalt includes No. 70 base asphalt, No. 90 base asphalt or No. 110 base asphalt; and / or, the styrene-butadiene-styrene block copolymer includes one or more of SBS791H, SBS791E, SBS792, SBS1201 and SBS4303; and / or, the solubilizing agent includes one or more of furfural extracted oil, rubber oil, aromatic oil, pine tar and vegetable oil.

[0011] Preferably, the compound tackifier is a mixture of a resin tackifier and a PE tackifier, wherein the resin tackifier is one or more of C5 petroleum resin, C9 petroleum resin, terpene resin and epoxy resin; the PE tackifier is one or more of high-density polyethylene (HDPE), low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE) and ultra-high molecular weight polyethylene (UHMWPE).

[0012] The PE component in the composite tackifier of the present invention can greatly improve the viscosity of the modified asphalt and optimize its properties. The dynamic viscosity of the high-viscosity and high-elastic modified asphalt with a 5% dry modifier dosage can reach more than 320,000 Pa·s at 60°C. The crystal hardening characteristics of the resinous tackifier component can keep the dry modifier stable at room temperature, prevent adhesion and agglomeration, ensure storage and facilitate transportation, and can also be compatible with the asphalt component to improve the viscosity characteristics of the modified asphalt.

[0013] More preferably, the mass ratio of the resin-based tackifier to the PE-based tackifier is 2:1 to 3:2.

[0014] Preferably, the thermal conductor includes one or more of nano copper particles, nano aluminum particles, carbonyl iron powder, silicon dioxide and graphene; and / or, the coupling agent includes one or more of a chromium complex coupling agent, a silane coupling agent, a titanate coupling agent and a zirconium coupling agent.

[0015] The thermal conductor of the present invention is a high thermal conductivity powder material, which interacts with the coupling agent, that is, the thermal conductor quickly absorbs heat at high temperature and promotes the activation of high molecular polymer, thereby increasing molecular fluidity and making the modifier quickly dissolve at high temperature.

[0016] Technical solution 2 of the present invention: A method for preparing the above-mentioned high-temperature fast-dissolving stable dry-process high-viscosity elastic asphalt modifier comprises the following steps:

[0017] A solubilizer, styrene-butadiene-styrene block copolymer, a compound tackifier, a thermal conductor and a coupling agent are sequentially added to the melted base asphalt, and then the raw materials are mixed and sheared to fully dissolve them. The mixed materials are then developed and cooled, and granulated after cooling to obtain the high-temperature, fast-dissolving, stable, dry-process high-viscosity elastic asphalt modifier.

[0018] Preferably, the styrene-butadiene-styrene block copolymer is added in 2 to 4 times.

[0019] Preferably, the banburying shearing temperature is 175-185° C., the shearing rate is 7000-9000 r / min, and the banburying shearing time is 1.5-2.5 h.

[0020] Preferably, the growth temperature is 170-180°C and the growth time is 1-2 hours.

[0021] The third technical solution of the present invention is to provide an application of the above-mentioned high-temperature fast-soluble stable dry-process high-viscosity and high-elastic asphalt modifier in the preparation of high-viscosity and high-elastic modified asphalt.

[0022] Preferably, the dosage of the high-temperature fast-soluble stable dry-process high-viscoelastic asphalt modifier is 5% of the asphalt mass.

[0023] The beneficial technical effects of the present invention are as follows:

[0024] The present invention adopts pre-swelling technology to prepare a high-temperature fast-dissolving stable dry-process high-viscosity elastic asphalt modifier. The asphalt, SBS and the compound tackifier swell with each other, and then form fine particles through internal mixing and shearing, which facilitates the high-temperature fast-dissolving stable dry-process high-viscosity elastic asphalt modifier to swell quickly and efficiently in the asphalt.

[0025] The high-temperature fast-dissolving stable dry-process high-viscosity elastic asphalt modifier prepared by the present invention has a uniform granular appearance, is non-sticky, has a single particle mass of ≤0.3g, a melt index of ≥4.0g / 10min, an ash content of ≤5%, and dry-mixing dispersibility that can meet the technical requirement of no particle residue.

[0026] The high-temperature, fast-dissolving, stable, dry-process high-viscosity and high-elastic asphalt modifier provided by the present invention can be directly added to commercial SBS modified asphalt to prepare high-viscosity and high-elastic modified asphalt. During the preparation process, only 5% of the dry-process modifier needs to be added, and the preparation can be completed by mechanical stirring for 3min to 5min. The obtained high-viscosity and high-elastic modified asphalt has excellent viscoelastic properties, with a dynamic viscosity of ≥320,000 Pa·s at 60°C and an elastic recovery rate of ≥95%; it has good physical properties, with a needle penetration of 40dmm to 50dmm, a softening point of ≥85°C, and an elongation of ≥30cm. DETAILED DESCRIPTION

[0027] Now, various exemplary embodiments of the present invention are described in detail, and this detailed description should not be considered as a limitation of the present invention, but should be understood as a more detailed description of certain aspects, characteristics and embodiments of the present invention. It should be understood that the terms described in the present invention are only for describing specific embodiments and are not used to limit the present invention.

[0028] In addition, for the numerical range in the present invention, it is understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. The intermediate value in any stated value or stated range, and each smaller range between any other stated value or intermediate value in the range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0029] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the invention pertains. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of the present invention.

[0030] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0031] Unless otherwise specified, the room temperature in the embodiments of the present invention refers to a temperature of 20±10°C.

[0032] Example 1

[0033] Preparation of high temperature fast dissolving stable dry process high viscosity elastic asphalt modifier:

[0034] (1) Prepare the raw materials according to the mass percentage of base asphalt 27%, SBS 18%, solubilizer 12%, compound tackifier 38%, thermal conductor 2.5% and coupling agent 2.5%;

[0035] (2) The base asphalt is heated to completely melt, and then the solubilizer, SBS (added in equal amounts in three times), compound tackifier, thermal conductor, and coupling agent are added to the asphalt in sequence, and the mixture is placed in an internal mixer for internal mixing and shearing. The mixing temperature is 180°C, the shear rate is 8000 r / min, and the internal mixing and shearing is performed for 2 hours to fully dissolve the raw materials;

[0036] (3) The obtained mixture was placed in an oven at 170° C. for 1 h, and then the developed mixture was allowed to cool at room temperature for 6 h;

[0037] (4) The cooled and shaped mixture is put into a granulator to prepare a dry-process modifier. The extrusion aperture is set to 3 mm and the extrusion temperature is set to room temperature to obtain a high-temperature, fast-dissolving, stable dry-process high-viscosity elastic asphalt modifier.

[0038] In this embodiment, the base asphalt is No. 70 base asphalt (needle penetration 76.4 dmm at 25°C, elongation 135 cm at 15°C, softening point 45.7°C); the SBS is SBS792; the solubilizer is pine tar oil; the compounded viscosity enhancer is C9 petroleum resin and LDPE compounded in a mass ratio of 3:1; the thermal conductor is carbonyl iron powder (average particle size is 3 μm); and the coupling agent is LD-139 zirconium coupling agent.

[0039] Referring to T / CHTS20003-2018 "Technical Guide for Highway Dry SBS Modified Asphalt Pavement", the appearance, single particle mass, melt index, ash content and dry mixing dispersibility of the high temperature instant stable dry high-viscoelastic asphalt modifier prepared in this example were tested respectively. The test results are shown in Table 1.

[0040] Table 1 Performance results of high temperature instant stable dry process high viscosity elastic asphalt modifier

[0041]

[0042] The results in Table 1 show that the high-temperature fast-dissolving stable dry-process high-viscosity elastic asphalt modifiers all meet the specification T / CHTS20003-2018. The dry-process modifier has a uniform granular appearance, a single particle mass ≤0.3g, a melt index ≥2.0g / 10min, an ash content ≤5%, and dry-mix dispersibility can meet the technical requirements of no particle residue.

[0043] The high temperature instant stable dry process high viscosity elastic asphalt modifier prepared in this embodiment was added to the commercial SBS modified asphalt in a molten state and manually stirred for 5 minutes, and the amount was 5% of the mass of the commercial SBS modified asphalt to obtain high viscosity and high elastic modified asphalt. Referring to JTG 5142-2019 "Technical Specifications for Highway Asphalt Pavement Maintenance", the 60°C dynamic viscosity, 25°C elastic recovery rate, 5°C elongation, 25°C penetration and softening point of the high viscosity and high elastic modified asphalt prepared in this embodiment were tested respectively, and the test results are shown in Table 2.

[0044] Table 2 Performance results of high viscosity and high elasticity modified asphalt

[0045]

[0046] The results in Table 2 show that the high-viscosity and high-elasticity modified asphalts all meet the specifications of GB / T 30516-2014, with dynamic viscosity greater than 20,000 Pa·s and elastic recovery rate at 25°C greater than 95%; and the viscosity is greater than 320,000 Pa·s, showing excellent viscoelastic properties.

[0047] Example 2

[0048] Preparation of high temperature fast dissolving stable dry process high viscosity elastic asphalt modifier:

[0049] (1) Prepare the raw materials according to the mass percentage of base asphalt 20%, SBS 20%, solubilizer 15%, compound tackifier 40%, thermal conductor 2.5% and coupling agent 2.5%;

[0050] (2) The base asphalt is heated to completely melt, and then the solubilizer, SBS (added in equal amounts in three times), compound tackifier, thermal conductor, and coupling agent are added to the asphalt in sequence, and the mixture is placed in an internal mixer for internal mixing and shearing. The mixing temperature is 175°C, the shear rate is 8000 r / min, and the internal mixing and shearing is performed for 1.5 hours to fully dissolve the raw materials;

[0051] (3) The obtained mixture was placed in an oven at 170°C for 1.5 hours, and then the developed mixture was allowed to stand at room temperature for 5 hours;

[0052] (4) The cooled and shaped mixture is put into a granulator to prepare a dry-process modifier. The extrusion aperture is set to 3 mm and the extrusion temperature is set to room temperature to obtain a high-temperature, fast-dissolving, stable dry-process high-viscosity elastic asphalt modifier.

[0053] In this embodiment, the base asphalt is No. 90 base asphalt (needle penetration at 25°C is 91.3dmm, elongation at 15°C is ≥150cm, and softening point is 44°C); the SBS is SBS791H; the solubilizer is aromatic oil; the compounded viscosity enhancer is a compound of terpene resin and LLDPE in a mass ratio of 3:2; the thermal conductor is carbonyl iron powder (average particle size is 3μm); and the coupling agent is LD-139 zirconium coupling agent.

[0054] Referring to T / CHTS20003-2018 "Technical Guide for Highway Dry SBS Modified Asphalt Pavement", the appearance, single particle mass, melt index, ash content and dry mixing dispersibility of the high temperature instant stable dry high-viscoelastic asphalt modifier prepared in this example were tested respectively. The test results are shown in Table 3.

[0055] Table 3 Performance results of high temperature instant stable dry process high viscosity elastic asphalt modifier

[0056]

[0057] The results in Table 3 show that the high-temperature fast-dissolving stable dry-process high-viscosity elastic asphalt modifiers all meet the specification T / CHTS20003-2018. The dry-process modifier has a uniform granular appearance, a single particle mass ≤0.3g, a melt index ≥2.0g / 10min, an ash content ≤5%, and dry-mix dispersibility can meet the technical requirements of no particle residue.

[0058] The high temperature instant stable dry process high viscosity elastic asphalt modifier prepared in this embodiment was added to the commercial SBS modified asphalt in a molten state and manually stirred for 5 minutes, and the amount was 5% of the mass of the commercial SBS modified asphalt to obtain high viscosity and high elastic modified asphalt. Referring to JTG 5142-2019 "Technical Specifications for Highway Asphalt Pavement Maintenance", the 60°C dynamic viscosity, 25°C elastic recovery rate, 5°C elongation, 25°C penetration and softening point of the high viscosity and high elastic modified asphalt prepared in this embodiment were tested respectively, and the test results are shown in Table 4.

[0059] Table 4 Performance results of high viscosity and high elasticity modified asphalt

[0060]

[0061] The results in Table 4 show that the high-viscosity and high-elasticity modified asphalts all meet the specifications of GB / T 30516-2014, with dynamic viscosity greater than 20,000 Pa·s and elastic recovery rate at 25°C greater than 95%; and the viscosity is greater than 320,000 Pa·s, showing excellent viscoelastic properties.

[0062] Example 3

[0063] Preparation of high temperature fast dissolving stable dry process high viscosity elastic asphalt modifier:

[0064] (1) Prepare the raw materials according to the mass percentage of base asphalt 25%, SBS 20%, solubilizer 15%, compound tackifier 35%, thermal conductor 2.5% and coupling agent 2.5%;

[0065] (2) The base asphalt is heated to completely melt, and then the solubilizer, SBS (added in equal amounts in three times), compound tackifier, thermal conductor, and coupling agent are added to the asphalt in sequence, and the asphalt is placed in an internal mixer for internal mixing and shearing. The mixing temperature is 175°C, the shear rate is 9000 r / min, and the internal mixing and shearing is performed for 1.5 hours to fully dissolve the raw materials;

[0066] (3) the obtained mixture was placed in an oven at 170°C for 2 hours, and then the developed mixture was allowed to cool at room temperature for 4.5 hours;

[0067] (4) The cooled and shaped mixture is put into a granulator to prepare a dry-process modifier. The extrusion aperture is set to 3 mm and the extrusion temperature is set to room temperature to obtain a high-temperature, fast-dissolving, stable dry-process high-viscosity elastic asphalt modifier.

[0068] In this embodiment, the base asphalt is No. 110 base asphalt (needle penetration at 25°C is 109dmm, elongation at 15°C is ≥150cm, and softening point is 45°C); the SBS is SBS791E; the solubilizer is furfural extracted oil; the compound viscosity enhancer is C5 petroleum resin and HDPE compounded in a mass ratio of 2:1; the thermal conductor is carbonyl iron powder (average particle size is 3μm); and the coupling agent is LD-139 zirconium coupling agent.

[0069] Referring to T / CHTS20003-2018 "Technical Guide for Highway Dry SBS Modified Asphalt Pavement", the appearance, single particle mass, melt index, ash content and dry mixing dispersibility of the high temperature instant stable dry high-viscoelastic asphalt modifier prepared in this example were tested respectively. The test results are shown in Table 5.

[0070] Table 5 Performance results of high temperature instant stable dry process high viscosity elastic asphalt modifier

[0071]

[0072] The results in Table 5 show that the high-temperature, fast-dissolving, stable dry-process high-viscoelastic asphalt modifiers all meet the specification T / CHTS20003-2018. The dry-process modifier has a uniform granular appearance, a single particle mass ≤0.3g, a melt index ≥2.0g / 10min, an ash content ≤5%, and dry-mix dispersibility can meet the technical requirements of no particle residue.

[0073] The high temperature instant stable dry process high viscosity elastic asphalt modifier prepared in this embodiment was added to the commercial SBS modified asphalt in a molten state and manually stirred for 5 minutes, and the amount was 5% of the mass of the commercial SBS modified asphalt to obtain high viscosity and high elastic modified asphalt. Referring to JTG 5142-2019 "Technical Specifications for Highway Asphalt Pavement Maintenance", the 60°C dynamic viscosity, 25°C elastic recovery rate, 5°C elongation, 25°C penetration and softening point of the high viscosity and high elastic modified asphalt prepared in this embodiment were tested respectively, and the test results are shown in Table 6.

[0074] Table 6 Performance results of high viscosity and high elasticity modified asphalt

[0075]

[0076] The results in Table 6 show that the high-viscosity and high-elasticity modified asphalts all meet the specifications of GB / T 30516-2014, with dynamic viscosity greater than 20,000 Pa·s and elastic recovery rate at 25°C greater than 95%; and the viscosity is greater than 320,000 Pa·s, showing excellent viscoelastic properties.

[0077] Example 4

[0078] Preparation of high temperature fast dissolving stable dry process high viscosity elastic asphalt modifier:

[0079] (1) Prepare the raw materials according to the mass percentage of base asphalt 22%, SBS 20%, solubilizer 15%, compound tackifier 40%, thermal conductor 1.5% and coupling agent 1.5%;

[0080] (2) Heat the base asphalt to completely melt it, then add the solubilizer, SBS (added in 2 to 4 times), compound tackifier, thermal conductor, and coupling agent to the asphalt in sequence, and put it into an internal mixer for internal mixing and shearing. The mixing temperature is 180°C, the shear rate is 7000 r / min, and the internal mixing and shearing is 1.5 hours to make the raw materials fully miscible;

[0081] (3) the obtained mixture was placed in an oven at 170°C for 2 hours, and then the developed mixture was allowed to cool at room temperature for 4.5 hours;

[0082] (4) The cooled and shaped mixture is put into a granulator to prepare a dry-process modifier. The extrusion aperture is set to 3 mm and the extrusion temperature is set to room temperature to obtain a high-temperature, fast-dissolving, stable dry-process high-viscosity elastic asphalt modifier.

[0083] In this embodiment, the base asphalt is No. 70 base asphalt (needle penetration 71.2 dmm at 25°C, elongation 123 cm at 15°C, softening point 46°C); the SBS is SBS791E; the solubilizer is pine tar; the compound viscosity enhancer is C9 petroleum resin and LDPE compounded in a mass ratio of 3:1; the thermal conductor is nano-silicon dioxide; and the coupling agent is KH-560 silane coupling agent.

[0084] Referring to T / CHTS20003-2018 "Technical Guidelines for Highway Dry SBS Modified Asphalt Pavement", the appearance, single particle mass, melt index, ash content and dry mixing dispersibility of the high temperature instant stable dry high-viscoelastic asphalt modifier prepared in this example were tested respectively. The test results are shown in Table 7.

[0085] Table 7 Performance results of high temperature fast dissolving stable dry process high viscosity elastic asphalt modifier

[0086]

[0087] The results in Table 7 show that the high-temperature fast-dissolving stable dry-process high-viscosity elastic asphalt modifiers all meet the specification T / CHTS20003-2018. The dry-process modifier has a uniform granular appearance, a single particle mass ≤0.3g, a melt index ≥2.0g / 10min, an ash content ≤5%, and dry-mix dispersibility can meet the technical requirements of no particle residue.

[0088] The high temperature instant stable dry process high viscosity elastic asphalt modifier prepared in this embodiment was added to the commercial SBS modified asphalt in a molten state and manually stirred for 5 minutes, and the amount was 5% of the mass of the commercial SBS modified asphalt to obtain high viscosity and high elastic modified asphalt. Referring to JTG 5142-2019 "Technical Specifications for Highway Asphalt Pavement Maintenance", the 60°C dynamic viscosity, 25°C elastic recovery rate, 5°C elongation, 25°C penetration and softening point of the high viscosity and high elastic modified asphalt prepared in this embodiment were tested respectively, and the test results are shown in Table 8.

[0089] Table 8 Performance results of high viscosity and high elasticity modified asphalt

[0090]

[0091] The results in Table 8 show that the high-viscosity and high-elasticity modified asphalts all meet the specifications of GB / T 30516-2014, with dynamic viscosity greater than 20000 Pa·s and elastic recovery rate at 25°C greater than 95%; and the viscosity is greater than 320000 Pa·s, with excellent viscoelastic properties.

[0092] Example 5

[0093] Preparation of high temperature fast dissolving stable dry process high viscosity elastic asphalt modifier:

[0094] (1) Prepare the raw materials according to the mass percentage of base asphalt 21%, SBS 20%, solubilizer 15%, compound tackifier 40%, thermal conductor 2% and coupling agent 2%;

[0095] (2) The base asphalt is heated to completely melt, and then the solubilizer, SBS (added in equal amounts in three times), compound tackifier, thermal conductor, and coupling agent are added to the asphalt in sequence, and the mixture is placed in an internal mixer for internal mixing and shearing. The mixing temperature is 180°C, the shear rate is 8000 r / min, and the internal mixing and shearing is performed for 1.5 hours to fully dissolve the raw materials;

[0096] (3) The obtained mixture was placed in an oven at 170°C for 2 hours, and then the developed mixture was allowed to cool at room temperature for 6 hours;

[0097] (4) The cooled and shaped mixture is put into a granulator to prepare a dry-process modifier. The extrusion aperture is set to 3 mm and the extrusion temperature is set to room temperature to obtain a high-temperature, fast-dissolving, stable dry-process high-viscosity elastic asphalt modifier.

[0098] In this embodiment, the base asphalt is No. 90 base asphalt (needle penetration at 25°C is 94.5dmm, elongation at 15°C is ≥150cm, and softening point is 47.9°C); the SBS is SBS791E; the solubilizer is pine tar; the compound viscosity enhancer is C9 petroleum resin and LDPE compounded in a mass ratio of 3:1; the thermal conductor is nano copper particles; and the coupling agent is LD-139 zirconium coupling agent.

[0099] Referring to T / CHTS20003-2018 "Technical Guide for Highway Dry SBS Modified Asphalt Pavement", the appearance, single particle mass, melt index, ash content and dry mixing dispersibility of the high temperature instant stable dry high-viscoelastic asphalt modifier prepared in this example were tested respectively. The test results are shown in Table 9.

[0100] Table 9 Performance results of high temperature instant stable dry process high viscosity elastic asphalt modifier

[0101]

[0102] The results in Table 9 show that the high-temperature, fast-dissolving, stable dry-process high-viscosity elastic asphalt modifiers all meet the specification T / CHTS20003-2018. The dry-process modifier has a uniform granular appearance, a single particle mass ≤0.3g, a melt index ≥2.0g / 10min, an ash content ≤5%, and dry-mix dispersibility can meet the technical requirements of no particle residue.

[0103] The high temperature instant stable dry process high viscosity elastic asphalt modifier prepared in this embodiment was added to the commercial SBS modified asphalt in a molten state and manually stirred for 5 minutes, and the amount was 5% of the mass of the commercial SBS modified asphalt to obtain high viscosity and high elastic modified asphalt. Referring to JTG 5142-2019 "Technical Specifications for Highway Asphalt Pavement Maintenance", the 60°C dynamic viscosity, 25°C elastic recovery rate, 5°C elongation, 25°C penetration and softening point of the high viscosity and high elastic modified asphalt prepared in this embodiment were tested respectively, and the test results are shown in Table 10.

[0104] Table 10 Performance results of high viscosity and high elasticity modified asphalt

[0105]

[0106] The results in Table 10 show that the high-viscosity and high-elasticity modified asphalts all meet the specifications of GB / T 30516-2014, with dynamic viscosity greater than 20,000 Pa·s and elastic recovery rate at 25°C greater than 95%; and the viscosity is greater than 320,000 Pa·s, with excellent viscoelastic properties.

[0107] Comparative Example 1

[0108] Preparation of dry asphalt modifier:

[0109] The formulation and preparation are the same as those in Example 1, except that the thermal conductor and coupling agent are replaced with LDPE of equal mass.

[0110] Referring to T / CHTS20003-2018 "Technical Guidelines for Highway Dry SBS Modified Asphalt Pavement", the appearance, single particle mass, melt index, ash content and dry mixing dispersibility of the dry asphalt modifier prepared in this comparative example were tested respectively. The test results are shown in Table 11.

[0111] Table 11 Comparative Example 1 Dry Asphalt Modifier Performance Test Results

[0112]

[0113]

[0114] The results in Table 11 show that without adding thermal conductor and coupling agent, the storage stability of the dry asphalt modifier is poor, its appearance cannot form particles and is prone to sticking, and its melt index is low and cannot meet the specification requirement of ≥2.0g / 10min.

[0115] Comparative Example 2

[0116] Preparation of dry asphalt modifier:

[0117] The formula and preparation are the same as those in Example 1, except that the base asphalt is replaced by a compound tackifier of equal mass (without adding base asphalt).

[0118] Referring to T / CHTS20003-2018 "Technical Guidelines for Highway Dry SBS Modified Asphalt Pavement", the appearance, single particle mass, melt index, ash content and dry mixing dispersibility of the dry asphalt modifier prepared in this comparative example were tested respectively. The test results are shown in Table 12.

[0119] Table 12 Comparative Example 2 Dry Asphalt Modifier Performance Test Results

[0120]

[0121]

[0122] The results in Table 12 show that without adding base asphalt, the performance of the prepared dry asphalt modifier can reach the same level as that of Example 1.

[0123] The dry asphalt modifier prepared in this comparative example was added to the commercial SBS modified asphalt in a molten state and manually stirred for 5 minutes, and the amount was 5% of the mass of the commercial SBS modified asphalt to obtain dry modified asphalt. Referring to JTG 5142-2019 "Technical Specifications for Highway Asphalt Pavement Maintenance", the 60°C dynamic viscosity, 25°C elastic recovery rate, 5°C elongation, 25°C penetration and softening point of the high-viscosity and high-elasticity modified asphalt prepared in this example were tested respectively, and the test results are shown in Table 13.

[0124] Table 13 Comparative Example 2 Dry Modified Asphalt Performance Test Results

[0125]

[0126] The results in Table 13 show that the raw materials do not contain matrix asphalt, and the preparation process of the dry asphalt modifier lacks the support of the "pre-swelling" technology. Therefore, the viscosity characteristics of the dry modified asphalt prepared in Example 2 are far inferior to those of Example 1; its elongation at 5°C is 28.5cm, which does not meet the requirement of ≥30cm in the specification.

[0127] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A high-temperature, fast-dissolving, stable, dry-process, high-viscosity elastic asphalt modifier, characterized in that: Calculated by mass percentage, the components include: 20% to 32% of base asphalt, 18% to 20% of styrene-butadiene-styrene block copolymer, 12% to 15% of solubilizer, 35% to 40% of compound viscosity enhancer, 1.5% to 2.5% of thermal conductor and 1.5% to 2.5% of coupling agent.

2. The high-temperature, fast-dissolving, stable, dry-process, high-viscosity elastic asphalt modifier according to claim 1, characterized in that: The base asphalt includes No. 70 base asphalt, No. 90 base asphalt or No. 110 base asphalt; and / or the styrene-butadiene-styrene block copolymer includes one or more of SBS791H, SBS791E, SBS792, SBS1201 and SBS4303; and / or the solubilizing agent includes one or more of furfural extracted oil, rubber oil, aromatic oil, pine tar and vegetable oil.

3. The high-temperature, fast-dissolving, stable, dry-process, high-viscosity elastic asphalt modifier according to claim 1, characterized in that: The compound tackifier is a mixture of a resin tackifier and a PE tackifier, wherein the resin tackifier is one or more of C5 petroleum resin, C9 petroleum resin, terpene resin and epoxy resin; and the PE tackifier is one or more of high-density polyethylene, low-density polyethylene, linear low-density polyethylene and ultra-high molecular weight polyethylene.

4. The high-temperature, fast-dissolving, stable, dry-process, high-viscosity elastic asphalt modifier according to claim 3, characterized in that: The mass ratio of the resin-based tackifier to the PE-based tackifier is 2:1 to 3:

2.

5. The high-temperature, fast-dissolving, stable, dry-process, high-viscosity elastic asphalt modifier according to claim 1, characterized in that: The thermal conductor includes one or more of nano copper particles, nano aluminum particles, carbonyl iron powder, silicon dioxide and graphene; and / or the coupling agent includes one or more of a chromium complex coupling agent, a silane coupling agent, a titanate coupling agent and a zirconium coupling agent.

6. A method for preparing the high-temperature fast-dissolving stable dry-process high-viscosity elastic asphalt modifier according to any one of claims 1 to 5, characterized in that: The following steps are involved: A solubilizer, styrene-butadiene-styrene block copolymer, a compound tackifier, a thermal conductor and a coupling agent are sequentially added to the melted base asphalt, and then the raw materials are mixed and sheared to fully dissolve them. The mixed materials are then developed and cooled, and granulated after cooling to obtain the high-temperature, fast-dissolving, stable, dry-process high-viscosity elastic asphalt modifier.

7. The method for preparing the high-temperature, fast-dissolving, stable, dry-process, high-viscosity elastic asphalt modifier according to claim 6, characterized in that: The styrene-butadiene-styrene block copolymer is added in 2 to 4 times.

8. The method for preparing the high-temperature, fast-dissolving, stable, dry-process, high-viscosity elastic asphalt modifier according to claim 6, characterized in that: The banburying shearing has a banburying temperature of 175-185° C., a shearing rate of 7000-9000 r / min, and a banburying shearing time of 1.5-2.5 h.

9. The method for preparing the high-temperature fast-dissolving stable dry-process high-viscosity elastic asphalt modifier according to claim 6, characterized in that: The temperature of the development is 170-180° C., and the time is 1-2 hours.

10. Use of the high-temperature fast-dissolving stable dry-process high-viscosity and high-elasticity asphalt modifier according to any one of claims 1 to 5 in the preparation of high-viscosity and high-elasticity modified asphalt.

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