Low temperature thermal cracking, rutting, moisture damage and fatigue cracking are popular damages
that appear in the asphalt mixture. These problems occur mainly because of the growth in the number
of heavy load vehicles, design and construction errors and environmental condition that reduce the quality, performance and the service life of the pavement. Several previous studies showed that using additives
like fibers to modify asphalt mixtures could enhance the efficiency and boost the quality and service life of
the pavement. This paper presents a review of the role of lignin and glass fiber as a modifier in bituminous
mixes. To evaluate some main mixture properties, some tests such as the low temperature bending, indirect tensile strength, the wheel loading tracking, Hamburg wheel tracking, Marshall immersion, freezingthaw splitting, third-point bending fatigue and indirect tensile fatigue are applied to analyze rutting, low
temperature cracking resistance, moisture damage resistance and fatigue resistance of asphalt mixture
modified with lignin or glass fiber. Results denoted that the quality of asphalt mixture enhanced significantly by adding lignin fiber or glass fiber. Previous researches demonstrated an obvious improvement
in low temperature performance in the pavement when adding 0.2–0.4% lignin fiber of asphalt mixtures,
with a limited improvement of high temperature performance. On the contrary, the asphalt mixtures
modified with 0.2–0.6% glass fiber of asphalt mixtures significantly improved the resistance of high temperature. So it is hard to improve all the performances of the mixture by using only a single admixture at
the same time. Thus, a new way of modifying asphalt mixture that is called double-mixture technology or
composite modification, which is able to enhance the overall properties of asphalt mixture.