Abstract
Asphalt binder represents a visco-elastic material that consist of four types of chemical fractions named saturates, aromatics, resins, and asphaltene, differ in their polarity and molecular weight, and then their effect on the properties of asphalt binder. The high solar absorption of asphalt binder due to its black color, making asphalt pavements suffer from various types of distresses like: rutting, fatigue, raveling, etc. The high increment in traffic loads and volumes nowadays leads to sever increment in these distresses. Therefore, the concept of improving asphalt pavements, as well as, reducing the environmental problems and maintaining the natural resources, in addition to saving costs, have stimulated researchers to use the sustainable materials in the improvement process of asphalt binder. Nevertheless, there are limited researches deals with these modifiers. This study aims to study the effect of Reed Fly Ash (RFA) that is represents a type of by-product materials on the physical properties of asphalt binder. Neat bitumen was blend with three dosages of RFA: 6%, 12% and 18% by weight of bitumen. The effect of this modifier on the properties of bitumen was characterized in terms of penetration, softening point, ductility, penetration index, viscosity and aging. The results of these properties indicate that the use of RFA as a modifier for asphalt binder help in decrease both penetration and ductility, increase softening point, viscosity and bitumen sensitivity, as well as, help in enhance the resistance of bitumen to aging, and the influence of RFA on these properties increase as RFA increase. The results encourage the concept of enhancing the asphalt binder by fly ash products.