The Importance of Cellulosic Fibers in Stone Mastic Asphalt (SMA)

 

Cellulosic fibers are one of the essential components used in the production of Stone Mastic Asphalt (SMA). Along with bitumen, fine aggregates, and mineral fillers, these fibers form the "mastic" portion of the asphalt mix. This mastic layer fills the voids between coarse aggregates, allowing the stones to interlock. This stone-on-stone contact is what gives SMA its exceptional durability and resistance, making it one of the most robust asphalt paving systems in the industry.

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Due to the high bitumen content in SMA, issues such as bitumen drainage, bleeding, or segregation may occur. Cellulosic fibers play a crucial role in stabilizing the bitumen, preventing runoff and ensuring the homogeneity of the mix. This not only enhances the mechanical stability of the asphalt but also extends its lifespan under heavy traffic conditions.