1. Types and Characteristics of High-Strength Asphalt Fibers

High-strength fibers primarily include glass fiber, polyester fiber, polypropylene fiber, polyamide fiber (nylon), and newer carbon fiber and aramid fibers. These fibers all possess high tensile strength, excellent corrosion resistance, and a relatively high elastic modulus. Their common characteristic is their ability to form a continuous reinforcing network within the asphalt mixture, improving the overall performance of the pavement structure.

2. Mechanism of Fiber Function in Asphalt

The addition of high-strength fibers improves the performance of asphalt pavements primarily in the following ways:

- Enhanced crack resistance: The network formed by the fibers can limit the paths for crack propagation, thereby reducing crack initiation and propagation.

- Improved deformation resistance: Fibers dispersed within the asphalt mixture help distribute stress, mitigating the occurrence of rutting and deformation.

- Improved fatigue resistance: Fibers can distribute the repeated stresses exerted on the road, delaying the onset of fatigue cracks.

- Enhanced durability: The presence of fibers can slow the aging process, extending the service life of the pavement.

3. Fiber Dispersion and Proportion

The effectiveness of fibers is closely related to their uniformity of dispersion within the asphalt mixture. A proper mix ratio and mixing process ensures uniform fiber distribution within the pavement, which is crucial for achieving effective reinforcement. Generally, a fiber content of around 0.3% to 1% ensures a reinforcing effect without compromising the mix's workability.

4. Fiber Incorporation Methods

High-strength fibers can be added to hot-mix asphalt at the mixing plant or dispersed evenly on-site using mechanical equipment. Different incorporation methods affect fiber dispersion and final performance.

5. Key Construction Techniques

-Mixing Temperature Control: Maintain an appropriate mixing temperature (generally between 150°C and 180°C) to ensure adequate fiber dispersion.

-Mechanical Mixing: Use efficient mixing equipment to prevent fiber clumping and ensure uniform dispersion.

-Compaction: Optimize the compaction process to prevent fiber extrusion or uneven accumulation during compaction.