CN-122011792-A - Warm-mix rubber powder composite modified asphalt for road and preparation method thereof

Abstract

The invention relates to the technical field of functional asphalt pavement materials, in particular to warm mix rubber powder composite modified asphalt for roads and a preparation method thereof, wherein the method comprises the steps of heating unaged asphalt cement to enable the unaged asphalt cement to reach a flowing state; the method comprises the steps of mixing rubber powder with raw asphalt in asphalt cement in a preliminary stirring manner, shearing the rubber powder and the asphalt cement, stirring and mixing the rubber powder with asphalt cement asphalt again to obtain hot rubber powder modified asphalt, adding a wax-based warm mix additive into the hot rubber powder modified asphalt, and stirring uniformly to obtain warm mix rubber powder composite modified asphalt. Compared with the prior art, the invention has the advantages of improving the dispersibility and compatibility of the rubber powder in asphalt, improving the storage stability and uniformity of asphalt, and the like.

Inventors

• LI HUI
• ZHANG HAOPENG
• WANG LIYANG
• Han Yuzhao
• PAN JIE

Assignees

• 同济大学

Dates

Publication Date

20260512

Application Date

20260302

Claims (10)

1. 1. The preparation method of the warm mix rubber powder composite modified asphalt for the road is characterized by comprising the following steps: s1, heating an unaged asphalt cement to enable the unaged asphalt cement to reach a flowing state; S2, primarily stirring and mixing the rubber powder and the raw asphalt in the asphalt cement; S3, carrying out shearing treatment on the rubber powder and the asphalt cement; S4, stirring and mixing the rubber powder and asphalt cement asphalt again to obtain hot rubber powder modified asphalt; S5, adding the wax-based warm mix additive into the hot rubber powder modified asphalt, and uniformly stirring to obtain the warm mix rubber powder composite modified asphalt.
2. 2. The method for preparing the warm mix rubber powder composite modified asphalt for the road according to claim 1, wherein the wax-based warm mix additive is linear saturated alkane, and comprises octadecane, twenty-four alkane, forty alkane and salubide.
3. 3. The method for preparing the warm mix rubber powder composite modified asphalt for the road according to claim 2, wherein the wax-based warm mix additive is short-chain linear saturated alkane.
4. 4. The method for preparing the warm mix rubber powder composite modified asphalt for the road according to claim 1, wherein the rubber powder comprises activated rubber powder and unactivated rubber powder.
5. 5. The method for preparing the warm mix rubber powder composite modified asphalt for the road according to claim 1, wherein in the step S1, the heating temperature is 160 ℃, and the heating time is 1 hour.
6. 6. The method for preparing the warm-mix rubber powder composite modified asphalt for the road according to claim 1, wherein in the step S2, the stirring mode is a mechanical mode, the stirring temperature is 185 ℃, the stirring speed is 500 rpm, and the stirring time is 30min.
7. 7. The method for preparing the warm mix rubber powder composite modified asphalt for the road according to claim 1, wherein in the step S3, the shearing temperature is 185 ℃, the stirring speed is 4500 rpm, and the stirring time is 60min.
8. 8. The method for preparing the warm-mix rubber powder composite modified asphalt for the road according to claim 1, wherein in the step S4, the stirring mode is a mechanical mode, the stirring temperature is 160 ℃, the stirring speed is 500 rpm, and the stirring time is 5min.
9. 9. The method for preparing the warm mix rubber powder composite modified asphalt for roads according to claim 1, wherein in S5, the wax-based warm mix additive and the hot rubber powder modified asphalt are mixed by manual stirring, the stirring temperature is 160 ℃, and the stirring time is about 2min.
10. 10. A warm mix rubber powder composite modified asphalt for roads, which is characterized by comprising an unaged asphalt cement, rubber powder and a wax-based warm mix additive, and is prepared by the method of any one of claims 1-9.

Description

Warm-mix rubber powder composite modified asphalt for road and preparation method thereof Technical Field The invention relates to the technical field of functional asphalt pavement materials, in particular to warm mix rubber powder composite modified asphalt for roads and a preparation method thereof. Background Compared with polymer modified asphalt (Polymer modified asphalt, PMA), the traditional asphalt binder has the defects in rut resistance, water resistance, heat crack resistance, fuel resistance, loosening resistance and ageing durability, and is difficult to meet the increasing traffic demands. Meanwhile, the treatment of junked tires also brings serious environmental and resource challenges. The rubber particles (CR) generated by the waste tires are added into the asphalt, so that not only can the rheological property and the mechanical property be improved, but also an effective strategy can be provided for recycling the tires on a large scale. Thus, rubber particle modified asphalt (Crumb rubber modified bitumen, CRMB) is considered a sustainable material with both environmental remediation and advanced pavement engineering. However, the large-scale application of the high-temperature stirring agent is still limited, and the high-temperature stirring agent not only comprises the problems of storage stability, processing uniformity, long-term performance consistency and the like, but also comprises the environmental defects of higher stirring temperature, higher energy consumption, additional gas emission and the like. In recent years, the use of rubber and warm mix additives (Warm mix additives, WMA) in warm mix rubber powder modified asphalt (Warm rubberized bitumen, WRB) to improve the toughness of road infrastructure has received more attention, which can further enhance the environmental performance of rubber powder modified asphalt. The method is characterized in that the warm mixing technology can reduce the construction temperature of the asphalt pavement by 20-30 ℃, so that the carbon emission in the construction process of the asphalt pavement is reduced by more than 30%, and the working condition of the asphalt pavement is improved. Meanwhile, the previous research results show that the combination of the rubber powder and the wax-based warm mix additive can produce positive synergistic effect on the rheological property of asphalt. Therefore, the warm mix rubber powder modified asphalt can promote the development of environment-friendly asphalt pavement. At present, the rubber powder modified asphalt has the problem of insufficient stability in the high-temperature storage and transportation process. Because of limited compatibility between the rubber powder and the matrix asphalt, uneven swelling, agglomeration or sedimentation of rubber powder particles easily occurs, so that the system is subjected to phase separation under the standing condition, and the system is characterized by increased softening point difference and uneven performance distribution. The insufficient storage stability restricts centralized production and large-scale application of the rubber powder modified asphalt, and also brings adverse effects to engineering quality control. Through retrieval, chinese patent application publication No. CN117272580A discloses a polar enhanced regenerated rubber-plastic asphalt modifier based on shear sulfur decomposition-surface oxidation and a preparation method thereof, adopts the action of double-screw anisotropic shear extrusion, and adds the modifier into hydrogen peroxide solution for soaking treatment to improve the compatibility, stability and road performance of modified asphalt. The Chinese patent application publication No. CN116254006A proposes a high-mixing amount rubber powder-rock asphalt composite modified asphalt with high thermal decomposition and high mixing amount and its preparation process, and the modified asphalt has excellent storage stability and durability. Chinese patent application publication No. CN114685846a discloses a supercritical decrosslinking pretreatment rubber powder and rubber powder modified asphalt and a preparation method thereof, the rubber powder, a decrosslinking agent and dry ice are mixed uniformly and then placed in a sealed high-pressure reaction kettle, and the carbon dioxide in the high-pressure reaction kettle is heated and pressurized by electrifying to reach a supercritical state, thereby improving the storage stability, construction workability and environmental friendliness of the rubber powder modified asphalt. However, the prior patent applications require expensive test equipment and specialized and toxic chemicals. Therefore, the universality and engineering popularization of the conventional rubber powder compatibility improvement scheme are limited. On the basis of not influencing the effect of improving the compatibility of rubber powder, the use cost is reduced, the environment is friendly, and the technical p