Performance Evaluation of Hot Mix Asphalt Modified with RHA

Nowadays, by increasing of the load and volume of traffic passing through asphalt pavements, increase in the durability and resistance of these types of mixtures have become more of interest to researchers. Using appropriate filler is of the factors affecting the quality of asphalt production. Although low amounts of fillers are used for preparing asphalt mixtures, their significant influence has become specified and wide researches have been performed on this subject. As the fine part, filler has an effective role on the mechanical and behavioral properties of asphalt mixture and influences the interlock of materials, intensively. Some results indicate that most of biomass ashes are of various elements that are useful for asphalt. Rice husk ash, which is considered as a biomass ash, is one of the waste products obtained from furnaces at power plants, which is obtained due to the burning of rice husk. Currently, rice husk ash is widely used due to its beneficial properties in the concrete production industry. In this research, rice husk ash was used as a replacement for a part of filler (rock powder) in hot mix asphalt. First, Marshall Samples were prepared to determine the optimum bitumen content based on grading No. 4 and 5 in the percentages of 0, 25, 50, 75 and 100 of rice husk ash, as the replacement of the rock powder. Then, new samples with optimum bitumen content were obtained and prepared according to the previous gradation. Finally, the effect of using rice husk ash on rutting phenomena, moisture sensitivity and resilient modulus of hot mix asphalt was investigated. The results showed that using this additive by an optimum extent improves the asphalt performance, significantly.