Laboratory investigation of moisture damage in rubberised asphalt mixtures containing reclaimed asphalt pavement

In many parts of the world, highway officials are utilising crumb rubber and reclaimed asphalt pavement (RAP) in order to save money, protect the environment, and improve the life of asphalt pavement. However, due to the use of these materials, the effects of moisture damage should be investigated for rubberised asphalt concrete (RAC) mixtures containing RAP. The objective of this research involved investigating the moisture susceptibility of RAC containing RAP. The testing conducted included the determination of binder viscosity, toughness and indirect tensile strength (ITS) analysis. Several mixtures containing different crumb rubber types, two different RAP sources and various percentages of rubber and RAP were evaluated. The results indicated that, in general, the additional of RAP was beneficial in improving the ITS values and reducing the moisture susceptibility of the mixture although the addition of crumb rubber had a slightly negative effect.