It is well recognized that mineral fillers play an important role in the properties of mastics and hot-mix asphalt (HMA) mixtures. Better understanding of the effects of fillers on the properties of mastics and HMA mixtures is crucial to good mix design and high performance of HMA mixtures. This paper presents a laboratory investigation into the effects of crushed boulders dust compared to reference (control) filler(limestone dust)on some properties of asphalt HMA mixtures.. The effects of

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... r on the characteristics of HMA mixtures were also investigated. The properties of HMA mixtures evaluated include optimum asphalt cement (AC) content, MarshallStability and flow, the indirect tensile strength (I.T.S) to evaluate the temperature susceptibility, Index of Retained strength to measure the moisture damage resistance. The research concluded that the use of crushed boulders dust as mineral filler with same texture of crushed aggregates(same source) into asphaltic mixtures an economic objective positive effect administratively(Full control and maneuvering of the production and quality control) in addition to improving the performance of the HMA like (marshall stiffness value more than 160%, less temperature susceptible to low temperature cracking,and increase the resistanceof moisture damage more than 135% ) in comparison to reference (conventional)lime stone dust. This tendency of the mix nature used in the Erbil-Perda highway project is observed in the pavement and in spite of the truck axles loading exceeding levels specified in the specifications under the temperature exceeded 65 C o for two Consecutive seasons and then the depth of accumulative rutting remained within the limits allowed on the right truck lane.