Physical properties of different fibers (mineral,
cellulose, or carbon fiber) and their stabilizing and reinforcing
effects on asphalt mortar performance were studied.
Scanning electron microscopy was used to study the
effect of fiber’s microstructure on asphalt mortar’s performance.
Laboratory tests of mesh-basket draindown and
oven heating were designed and performed to evaluate the
fibers’ asphalt absorption and thermostability. A cone
penetration test was used to study the flow resistance of
fiber-modified asphalt mortar. Results showed that fiber
can form a three-dimensional network structure in asphalt,
and this network can be retained at high temperature. This
network of fibers favors the formation of a thick coating of
mastic without asphalt draining down. Cellulose fiber
possessed a greater effect on asphalt absorption and stabilization
than did the other fibers (mineral and carbon
fiber). A dynamic shear rheometer was used to evaluate
their rheological properties and rut resistance. Results
indicated that fiber can effectively improve the rut and flow
resistance of asphalt mortar. However, the bending beam
rheometer results demonstrated that the addition of fiber
had negative effects on the creep stiffness and creep rate of
asphalt mortar.