Performance Assessment of Cold Asphalt Concrete Mixtures Containing Recycled Paving Materials

The disposal of the milled asphalt mixtures has a negative impact on the environment. The reuse of recycled paving materials in road pavement may improve the mechanical properties of asphalt concrete mixtures. These properties are mostly related to major pavement distresses. Therefore, the aim of this research is to investigate the possibility of reusing the recycled paving materials in cold asphalt concrete mixtures. Also, it aims to determine the critical response parameters such as vertical stress on the top of base layer and tensile strain at the bottom of asphalt layer in a flexible pavement. The cold asphalt mixtures were prepared with different percentages of recycled aggregates. They were 0%, 25%, 50%, 75% and 100%. The laboratory testing program for asphalt mixtures included standard Marshall test, loss of stability test, wheel tracking test and triaxial shear test. BISAR software was used to determine the stress and strain values. The results indicated that the recycled aggregate can be used to reduce the asphalt content of paving mixtures. Moreover, the mixtures with recycled aggregate of 75% and 100% achieved the better performance of the cold asphalt concrete mixtures.