Stone Matrix Asphalt (SMA) may include fibers as part of the mix.

• A. Sometimes
• B. True
• C. False
• D. Not characteristic

Answer: (B)

In Stone Matrix Asphalt, the mix is designed with a dense stone skeleton and a high asphalt binder content to resist deformation. To keep that high binder content from draining out during handling, transport, and placement, fibers are sometimes added as a stabilizing aid. These fibers—often cellulose or mineral fibers—help trap the binder within the aggregate, improving mix stability, resistance to drain-down, and overall durability. Because this fiber addition is a common practice in SMA designs but not mandatory for every SMA job, the statement is true.