Microscopic action and rheological properties of reinforced modified asphalt with varying fiber content

Traditional asphalt pavement is prone to rutting, looseness, and other issues during usage resulting in overall poor durability. The service life of asphalt pavement may be improved, however, by targeted modifications. The modification mechanism and strengthening effect of polyester fiber and straw fiber on asphalt were investigated in this study in an effort to optimize the anti-aging and anti-fatigue performance of asphalt pavement. Molecular dynamics simulation, basic performance testing, dynamic shear rheological testing, and bending beam rheological testing were conducted on fiber-modified asphalt to observe the interaction modes between the asphalt components and its applicable conditions. Fiber appears to have some compatibility with asphalt, which can improve its performance; straw fiber’s ability to modify asphalt at high temperatures is less effective than that of polyester fiber, but it is stronger at low temperatures. Under high-temperature conditions, the optimal dosages of polyester fiber and straw fiber are 3.00 % and 3.00 %, respectively, while at low temperatures, they are 2.00 % and 3.00 %.