They are pellets composed of cellulose, mineral and/or synthetic fibres that reinforce and thicken bitumen. These pellets are suitable to obtain high-performing asphalt pavements. Fibres are used to stabilise bitumen in porous and semi-porous asphalt concrete and in Splittmastix Asphalts (SMA). By reinforcing and thickening bitumen, these products extend the asphalt pavement service life.