Department of Civil Engineering, Shahrood Branch, Islamic Azad University, Shahrood, Iran.
Nowadays, in addition to materials and components of asphalt mixtures that are bitumen, aggregates and mineral fillers, other materials known as additives or modifiers are also used. These compounds include wide range of organic, inorganic, industrial, and natural materials used in order to reduce deficiencies, to improve the physical properties and to modify some mechanical properties of bitumen and asphalt mixtures. In the present study, the effect of the oxide shell of hot rolled steel with different percentages of bitumen 70- 60 was investigated by tests of penetration, softening point, kinematic viscosity, and elasticity property. RTFO was performed to determine the viscosity and penetration degree after aging modeling. According to the percentages of additives used in the test (3%, 4% and 5%), results indicate that use of oxide shell increases viscosity, reduces the penetration degree, reduces gum plasticity of bitumen, increases softening point, and improves aging properties in bitumen samples prepared by one of wastes produced by steel factories.