Abstract—The technique of Recycling Asphalt Pavement (RAP) for road construction is widely used so that RAP has been called the most recycled material in the world. RAP is most commonly used as an aggregate substitute in asphalt mix also it is used as granular sub-base or base aggregate and embankment or fill material. Unfortunately, the mechanical properties of RAP materials do not meet the requirements of State Organization for Roads and Bridges (SORB, 2003) in Iraq for sub-base and base aggregate materials, such as gradation, California Bearing Ratio (CBR), and other strength coefficients. The objective of this study was to investigate and examine different RAP/virgin aggregate blending techniques to improve the mechanical characteristics of local RAP materials in Iraq. A detailed laboratory testing program was conducted to achieve these objectives. It was found that the blending of up to 40% RAP materials with different local virgin sub-base materials improves the RAP mechanical characteristics to meet SCRB (2003) requirements for road sub-base materials and provides economical, environmental, and sustainable road construction technique in Iraq. A computerized design and management analysis which was carried out on life cycle costs of flexible pavement with unbounded sub-base layer of blended virgin aggregate materials with RAP showed savings of up to 39% of total pavement cost depending on design in comparison with conventional flexible pavement in Iraq. 

Index Terms—mechanical properties, RAP, blending techniques, Iraq

Cite: Saud A Sultan, Mohammed B Abduljabar, and Mariam H Abbas, "Improvement of the Mechanical Characteristics of Reclaimed Asphalt Pavement in Iraq," International Journal of Structural and Civil Engineering Research, Vol. 2, No. 4, pp. 22-29, November 2013.