The excellent performance of ordinary rubber asphalt has been proven in a large number of engineering practices. However, in accordance with the government’s environmental protection, energy conservation and emission reduction policies have been introduced. The traditional production methods and use effects of rubber asphalt have been exposed to obvious drawbacks and shortcomings. It has gradually been unable to meet the needs of highway asphalt pavement construction under the current environmental protection situation, and its further development has been severely restricted. The main problems are the limited sources of rubber powder in traditional rubber asphalt, poor high-temperature storage stability, high processing temperature, high energy consumption, and serious flue gas pollution [
1,
2,
3]. The main reason is due to the obvious differences in physical and chemical properties between asphalt and rubber powder, which makes the compatibility of rubber powder and base asphalt poor, resulting in high viscosity, poor fluidity, poor dispersion, and difficulty in ordinary rubber asphalt. The shortcomings include the mixing of the mixture and the difficulty of compacting the road surface. It is easy to produce stratification and segregation between the rubber powder particles and the asphalt, and the disadvantage of poor high-temperature storage stability is caused. It also makes it necessary to process and mix the ordinary rubber asphalt on site, which cannot be transported as a finished product for long distances. The industrialization process and application scope of rubber asphalt are severely limited by the above-mentioned shortcomings [
4,
5].
At present, the research of Ghazi G. Al-Khateeb [
6] shows that the complex shear modulus, rutting factor, and fatigue parameters of asphalt are improved by adding rubber powder, and the rutting resistance and fatigue resistance of the asphalt binder are improved. Zhou Tao [
7] and others studied the physical and chemical changes of modified asphalt before and after aging and its aging mechanism. Modified asphalt prepared by microwave-activated rubber powder was found. Microwave activation made the swelling reaction of rubber powder more violent. Kyu-Dong Jeong [
8] et al. studied the performance changes of rubber asphalt at different dosages and temperatures and found that the greater the amount of rubber powder, the greater the content of macromolecules in the asphalt, which is mainly due to the swelling of rubber powder due to oil absorption and swelling in the asphalt. The content of light components is reduced. I.M. Ibrahim [
9] studied the preparation of rubber asphalt after pretreatment of waste rubber powder by gamma rays and proved that the rubber asphalt prepared by pretreated rubber powder in terms of high- and low-temperature performance and anti-aging performance is significantly improved than ordinary rubber asphalt. Taha Ahmed [
10] showed that the performance level of asphalt binder can be significantly improved by adding rubber powder to the base asphalt. However, part of the excessive rubber powder content is free in the asphalt and cannot be completely integrated with the asphalt. Juan Gallego [
11] was able to reduce the compaction and storage temperature of asphalt rubber mixture by adding a warm mixing agent to asphalt rubber. Energy consumption and greenhouse gas emissions have been effectively reduced. The research of Shatanawi [
12] showed that compared with ordinary rubber asphalt, the thermal storage stability of rubber asphalt prepared by using desulfurized and activated rubber powder was significantly improved. Wang Xiaofeng [
13] uses different rubber powder types, SBS, and its content as variables. The three major indexes of modified asphalt, mechanical indexes, storage stability, and other performance characteristics and modification mechanism were analyzed. The results showed that the rubber powder content of vulcanized rubber powder-modified asphalt has strong sensitivity. Zhang Xiaoliang [
14] studied the waste tire rubber powder after being treated with Trans-Polyoctenamer Rubber (TOR). It can be effectively improved for high-temperature performance and elastic recovery ability of rubber powder-modified asphalt, and the compatibility and stability of rubber powder and asphalt were also improved. Li Bo [
15] found that the viscosity of rubber asphalt is directly affected by the characteristics of waste rubber powder. The performance of rubber asphalt can be improved by rational selection of waste rubber powder from different sources. Dong Bo [
16] found that the compatibility of stable rubber powder and asphalt was significantly enhanced, the viscosity was significantly reduced, and it had good aging resistance and thermal storage stability. Zhang Qing [
17] introduced in detail the application of micro-characterization techniques, such as thermo gravimetric analysis method and micro-morphology analysis method, in the research of rubber asphalt-modification mechanism. The micro-mechanism of rubber powder-modified asphalt has provided a reasonable reference.
At present, the stable rubber powder-modified asphalt is still an innovative application in the field of rubber asphalt, and the relationship between the reaction mechanism and the microstructure morphology of the stabilized rubber powder-modified asphalt has been seldom studied. Therefore, indicators, such as penetration, penetration index, ductility, softening point, and viscosity at 135 °C, are used in this article to determine the optimal content of desulfurization rubber powder. Specific surface area analysis, scanning electron microscopy, thermal storage stability test, and differential scanning calorimetric are used to determine the dispersion state and aggregation state of rubber powder particles in the stabilized rubber powder-modified asphalt and the viscosity temperature of the stabilized rubber powder-modified asphalt. The curve is constructed, and the swelling state and reaction mechanism of the rubber powder in the stabilized rubber powder-modified asphalt are characterized.