At present, the most commonly used cellulose fibrestabilising additive is supplied as pellets – fibre is mixed with bitumen creating a pelletized form that may be easily handled and added during mixing.
Bitumen-compounded fibre pellets offer several advantages over pure fibre pellets:
- Disperse rapidly and completely
- No dry mixing time, odourless and dust-free
- Not susceptible against humidity
- May be dosed automatically
- Produce much more homogenous mix
- A higher quality of SMA
- Increasing mixing outpu
Bitumen-coated fibre pellets are not sensitive against humidity. The bitumen functions as a range spacer and pelletizing aid during production. The pellets are added centrally into the mixer, and will disperse quickly and completely. Compared with pure fibre pellets, much shorter premixing times are required with bitumen-coated fibre pellets. This has the added advantage of reducing stress on the mixer and aggregates. This allows the batch sizes to be increased resulting in higher throughput.