CN-122011791-A - High-mixing-amount rubber powder composite gram-refined No. 90 modified asphalt and preparation process thereof

CN122011791ACN 122011791 ACN122011791 ACN 122011791ACN-122011791-A

Abstract

The invention relates to the technical field of road engineering materials, and discloses a high-mixing-amount rubber powder composite gram-refining No. 90 modified asphalt and a preparation process thereof, wherein the modified asphalt is prepared by compounding gram-refining No. 90 matrix asphalt, 10% -20% rubber powder, SBS, a viscosity reducing agent, nano calcium carbonate, a coupling agent and sand forest resin, and the preparation process comprises the steps of fast heating of the matrix asphalt, staged multistage mixing, high-shear grinding and fine dispersion of a colloid mill. The invention realizes the high-value utilization of waste resources, obviously improves the road performance and construction convenience of the modified asphalt, solves the problems of high-doping-amount rubber powder segregation and overhigh viscosity, and has excellent softening point, ductility, elastic recovery rate and low construction viscosity.

Inventors

LI JIE
Numeti. Ablimiti
Phreti ainival
TAO ZHENHUA
GUAN JINGANG
SHI JIANJIANG
LI HONGKANG
WANG XUEYING
ZHANG GUOBIN
SHAO MINGXING

Assignees

新疆交投建设管理有限责任公司
新疆长和文博石化有限公司
新疆那巴高速公路发展有限责任公司

Dates

Publication Date: 20260512
Application Date: 20260211

Claims (10)

1. The high-mixing-amount rubber powder composite gram-refined No. 90 modified asphalt is characterized by comprising the following components in percentage by mass: 70% -85% of gram-refined 90 # matrix asphalt; 10% -20% of rubber powder; 1.5% -3% of a styrene-butadiene-styrene block copolymer; 3% -5% of viscosity reducer; 1.5% -2.5% of nano calcium carbonate filling material; 0.5% -1.5% of coupling agent; 1.5% -2.5% of sarin resin; the total mass of each component is 100 percent.
2. The high-blend rubber powder composite g-refined 90 # modified asphalt according to claim 1, which is characterized in that: The penetration of the gram-refined 90 # matrix asphalt is 80-100, the softening point is 43-50 ℃, and the ductility is more than or equal to 100cm; The mass percentage content ranges of the saturated fraction, the aromatic fraction, the resin fraction and the asphaltene of the gram-refined 90-grade matrix asphalt are respectively 5% -10% of the saturated fraction, 40% -50% of the aromatic fraction, 30% -40% of the resin fraction and 10% -15% of the asphaltene; The rubber powder is obtained by mechanically crushing waste tires through multistage crushing and screening processes, the D90 value of the particle size distribution is less than 425 microns, the D50 value is between 150 and 250 microns, the bulk density of the rubber powder is 0.4 to 0.6g/cm 3 , and the water content is less than 0.5%.
3. The high-blend rubber powder composite g-refined 90 # modified asphalt according to claim 1, which is characterized in that: the styrene-butadiene-styrene block copolymer has a radial or linear structure, the styrene content is 25% -35%, the melt index is 1-5g/10min, and the Mooney viscosity is 40-60; The viscosity reducer is mainly composed of rubber oil or aromatic hydrocarbon oil, has a flash point of more than or equal to 200 ℃, kinematic viscosity of 10-50mm 2 /s, density of 0.9-1.0g/cm 3 and aniline point of 10-50 ℃, is rich in aromatic hydrocarbon components, and has good compatibility with high-content colloid and asphaltene in the asphalt No. 90.
4. The high-blend rubber powder composite g-refined 90 # modified asphalt according to claim 1, which is characterized in that: The nano calcium carbonate filling material has an average particle size of 20-80 nanometers and a specific surface area of 15-30m 2 /g, the surface of the nano calcium carbonate filling material is coated and modified by fatty acid or a silane coupling agent, and the main component of the silane coupling agent is an organosilane coupling agent or a titanate coupling agent with inorganic-philic groups and organic-philic groups, preferably gamma-aminopropyl triethoxysilane or isopropyl titanate.
5. The high-blend rubber powder composite g-refined 90 # modified asphalt according to claim 1, which is characterized in that: The main component of the sarin resin is an ethylene- (methyl) zinc salt, sodium salt or lithium salt plasma bond polymer, the melt index is 0.5-5g/10min, the density is 0.92-0.96g/cm 3 , the glass transition temperature is between-10 ℃ and 5 ℃, and the sarin resin forms a physical network with ionic crosslinking points.
6. The preparation process of the high-mixing-amount rubber powder composite gram-refined No. 90 modified asphalt is applied to the high-mixing-amount rubber powder composite gram-refined No. 90 modified asphalt in any one of claims 1 to 5, and is characterized by comprising the following steps: Step one, preprocessing matrix asphalt and quickly heating; step two, mixing and strategic adding in the first stage; step three, mixing in the second stage and adding the rest components; Step four, mixing and homogenizing in the third stage; Step five, high shear grinding; Step six, fine dispersion and stability enhancement of a colloid mill; And step seven, development and storage.
7. The preparation process according to claim 6, characterized in that: Heating the gram-refined No. 90 matrix asphalt to 160-170 ℃, premixing by mechanical stirring, and then rapidly raising the temperature of the asphalt to 195-205 ℃ by a tubular rapid heater, wherein the heating rate of the tubular rapid heater is controlled to 5-10 ℃ per second, and maintaining the temperature range; The second step comprises the steps of introducing the heated gram-refined 90-grade matrix asphalt into a primary mixer, adding the viscosity reducer, part of rubber powder and all coupling agents into the primary mixer according to a preset proportion under a continuous stirring state, wherein the primary mixer adopts an anchor type or paddle type stirrer, the stirring rotating speed is controlled to be 100-300 revolutions per minute, and the stirring time is 15-30 minutes.
8. The manufacturing process according to claim 7, characterized in that: Transferring the mixture obtained in the step II to a secondary spiral stirring mixer, adding the rest rubber powder, all SBS, all nano-grade calcium carbonate filling materials and all sand forest resin under the stirring condition, wherein the secondary spiral stirring mixer adopts a double-spiral or multi-spiral structure, the stirring rotating speed is controlled at 200-400 r/min, the mixing temperature is maintained at 190-200 ℃, and the stirring time is 30-60 min; the fourth step comprises the steps of introducing the mixture obtained in the third step into a three-stage spiral stirring mixer, wherein the stirring speed is 300-500 revolutions per minute, the mixing temperature is 185-195 ℃, and the stirring time is 20-40 minutes.
9. The manufacturing process according to claim 8, characterized in that: Continuously pumping the mixture obtained in the step four to rotor-stator type high-shear grinding equipment for shearing treatment, wherein the linear speed of a rotor is 20-35 m/s, the gap between a stator and the rotor is controlled to be 0.1-0.5 mm, the mixture needs to be subjected to single or multiple-cycle shearing grinding until the D90 value of the particle size distribution of rubber powder particles in asphalt is less than 100 microns, and the temperature in the shearing grinding process is controlled to be 180-190 ℃; The step six comprises the step of continuously pumping the mixture obtained in the step five to a colloid mill for fine dispersion treatment, wherein the linear speed of a rotor of the colloid mill is 25-40 m/s, the grinding gap is controlled to be 0.05-0.2 mm, and the temperature of the colloid mill in the treatment stage is controlled to be 175-185 ℃.
10. The manufacturing process according to claim 9, characterized in that: Pouring the composite modified asphalt obtained in the step six into an anti-sedimentation rubber asphalt development tank with a low-shear stirring device, and continuously stirring and developing at a low speed at 170-180 ℃ for 2.5 to 3.5 hours; The penetration of the high-doping-amount rubber powder composite gram-refined 90 # modified asphalt prepared by the preparation process is 60-80, the softening point is more than or equal to 65 ℃, the ductility is more than or equal to 20cm, the elastic recovery rate is more than or equal to 80%, the segregation is less than or equal to 2.5 ℃, the Brookfield rotational viscosity is less than or equal to 3000 mPas, and the Brookfield rotational viscosity is less than or equal to 1000 mPas.

Description

High-mixing-amount rubber powder composite gram-refined No. 90 modified asphalt and preparation process thereof Technical Field The invention belongs to the technical field of road engineering materials, and particularly relates to high-mixing-amount rubber powder composite gram-refined No. 90 modified asphalt and a preparation process thereof. Background The resource utilization of waste becomes an important way for realizing sustainable development. Especially in the field of traffic infrastructure construction, asphalt which is one of core materials has the important functions of improving the road service level, prolonging the service life and reducing the carbon emission in the whole life cycle by optimizing the performance and doping environment-friendly materials. The waste tires are typical and large-scale refractory polymer wastes, and the unordered stacking of the waste tires not only occupies a large amount of land resources, but also forms a long-term threat to the ecological environment. Traditional disposal methods of junked tires, such as landfill or incineration, all bring serious environmental problems, and effective recycling of resources cannot be realized. In order to solve the disposal problem of the junked tires and improve the performance of the asphalt pavement, a series of technical paths have been developed in the industry, wherein the junked tires are processed into rubber powder, and the rubber powder is most commonly applied to asphalt concrete as a modifier. Specifically, the method generally comprises the steps of mechanically crushing, desulfurizing, finely granulating and the like on the junked tires so as to obtain rubber powder with uniform particle size and enhanced surface activity. Subsequently, the rubber powder subjected to the complex pretreatment is mixed into matrix asphalt, and the modified asphalt with excellent elasticity, ductility and high-temperature stability is formed through physical blending or certain chemical crosslinking. The modified asphalt can effectively improve the fatigue cracking resistance, rutting deformation resistance and noise reduction of the pavement, thereby remarkably improving the service performance and durability of the pavement. In the past, the technical route has obvious technical progress and application effect in the aspects of simultaneously solving the problem of waste treatment and improving the performance of road materials for a long period of time, and lays a solid foundation for the development of asphalt modification technology. The design principle is that the rubber particles and the asphalt matrix can form a relatively stable dispersion system through fine treatment, and the brittleness and plasticity deficiency of the asphalt are compensated by using the elasticity and toughness of the rubber, so that the cooperative optimization of the performance is realized. However, with the increasing traffic load and the increasingly stringent requirements on the performance of road materials, the above prior art solutions gradually expose the inherent limitations and deep contradictions in practical applications. The preparation process of the existing junked tire rubber powder is at the root, and in order to ensure that the rubber powder can be well dispersed in asphalt and perform a modification function, huge equipment cost is often required, high energy is consumed, and the production efficiency is low. For example, links such as desulfurization regeneration and fine granulation are beneficial to improving the activity of rubber powder and the compatibility of the rubber powder with asphalt, but the complex process flow leads to significant increase of production cost, so that the final rubber powder cost is far higher than that of raw rubber powder which is not subjected to deep processing, the economic benefit of recycling of waste tires is seriously weakened, and the possibility of realizing high-mixing-amount application in asphalt is further limited. The trade-off between the economic cost and the technical effect constitutes the first deep contradiction faced by the high-value utilization of the current junked tires. More critical and challenging, the inherent bottlenecks of prior art systems are increasingly pronounced when attempting to apply these modified gums or conventional polymer modifiers (e.g., SBS) to specific types of base asphalt, such as g-90 asphalt, which has a high gum content. The gram asphalt No. 90 shows extremely remarkable viscosity increase phenomenon rapidly after the conventional modifier is introduced due to the unique chemical components and rheological characteristics. Such abnormal viscosity surge is not a simple controllable change, but a nearly uncontrolled system response, resulting in modified asphalt becoming abnormally viscous, difficult to pump, mix and pave, severely restricting subsequent construction operations, and even making the modification process technically infeasib