Despite the high cost of paving the roads in Iran, according to experts, the useful life of asphalt is expected to be only 3 to 5 years. Due to the abundance of palm trees, the objective of this study is to determine the resistance of palm fiber-reinforced asphalt mixtures as an additive and asphalt modifier. In this study, four types of mixtures were prepared. The first mix was prepared as a control and non-fibrous mixture, and the second type were mixed with 0.1% and the third type with 0.3% and the fourth type with 0.5% weight of asphalt mixture of palm fiber. Six samples were prepared for each mixture, three samples were dried and three others were tested after partial saturation and moisture treatment with a melting and freezing cycle (24 samples). The Semi-Circular Bend Test (SCB), Marshall Stability of bituminous mixture, flow tests, indirect tensile strength, resilient modulus and moisture damage were assessed. The results of indirect tensile strength test showed that the use of palm fiber in dry condition at all percentages of 0.3, 0.4 and 0.5% improves the resistance. In saturated state, for fibers added up to 0.3% results were positive, but for more fibers, the results were negative. For moisture sensitivity parameter of the asphalt mixtures of the addition of fiber up to 0.3%, the least moisture damage was observed. The results of the resilient modulus of the mixtures showed that using 0.3% fiber had better result than other percentages and control sample.
