The research, development, and promotion of modified asphalt with waste rubber powder are flourishing, unstoppable, and the era of widespread replacement of SBS-modified asphalt with waste rubber powder is about to arrive. Compared to SBS-modified asphalt, roads made with waste rubber powder-modified asphalt boast excellent anti-skid performance, wear resistance, high safety coefficients, low traffic noise, and lower economic investment.
Therefore, vigorously promoting the application of modified asphalt with recycled rubber powder is of great significance, and the research on the formula of this modified asphalt is of paramount importance.
The appropriate dosage of waste rubber powder primarily considers the following factors: a) the pavement usage of rubber powder-modified asphalt. b) Processing, transportation, and laying performance. c) Processing costs.
Through continuous experimentation and production practice, it has been found that:
When the powder addition is 10%, the softening point of the modified asphalt is only 51℃, and the elongation at 5℃ is 7.80, indicating a significant improvement to the base asphalt.
At 15% of the powder addition, the softening point of the modified asphalt with the powder reaches 53°C, and the elongation at 5°C is 9.00. The improvement effect on the base asphalt is enhanced, but it does not meet the quality and technical standards.
At a 20% addition of the rubber powder, the modified asphalt exhibits a softening point of 61.5°C and a elongation at 5°C of 10.05, which essentially meets the technical specifications for rubber-modified asphalt. However, without the addition of an activator and a penetrant, the viscosity is too high, reaching 11.8 at 180°C, making it difficult to process. To rectify this, an activator and penetrant below one part per thousand must be added.
When the amount of rubber powder reaches 25% to 30%, although its softening point, elongation, and penetration are improved, its viscosity is too high. Even with the addition of activators or penetrants, normal production and processing are not possible, thus the product cannot be sprayed or spread.
