The performance and the fundamental weaknesses of asphalt mix under environmental
temperature and water effects have made researchers try to modify the asphalt mix properties by
using the proper additives. For this reason, this paper aims to improve the anti-cracking performance
and water stability of asphalt pavement by adding a novel composite of diatomite and lignin fiber
in asphalt mixes. Four types of asphalt mixes, including control asphalt mix (CAM), diatomite
modified asphalt mix (DMAM), lignin fiber modified asphalt mix (LFMAM), and diatomite-lignin
fiber composite modified asphalt mix (DLFMAM) were prepared in the laboratory. Low-temperature
bending test, Marshall Immersion test, and freeze-thaw splitting test were employed to evaluate
the performance of the asphalt mixes. Results reveal that the use of the lignin fiber in reinforced
asphalt mixes combined with diatomite led to an enhancement in the asphalt pavement performance
more than the other three types of mixes. Diatomite has an important influence on the water damage
resistance of asphalt mix more than lignin fiber. On the other hand, diatomite has a small effect on the
anti-cracking performance; meanwhile, lignin fiber showed a significant improvement in the cracking
resistance of asphalt mixes. DLFMAM has the best traveling performances among all asphalt mixes.
Thus, this work provides a good reference for the design of composite asphalt mixes.