EFFECT OF ACCELERATED MOISTURE DAMAGE ON CREEP COMPLIANCE CHARACTERISTICS OF ASPHALT CONCRETE MIXTURES

Abstract

Major pavement deterioration can be attributed to the presence of water on the pavement surface. Within this framework, this research is focused on studying the impact of accelerated moisture conditioning on pavement deterioration. This study is based on laboratory evaluation of creep characteristics and mechanical properties of asphalt concrete mixtures. This evaluation can aid in assessing the long-term stripping susceptibility and permanent deformation potential of asphalt concrete mixtures. Cement dust was incorporated in the mixture as mineral filler and compared with traditional lime stone filler. Accelerated moisture damage program was established to evaluate the mixture resistance to moisture damage. Marshall specimens were immersed in a water bath under vacuum of 510 mm of mercury (Hg) for different moisture conditioning periods of 0, 1, 2 and 7 days. A power law model was used to characterize the creep compliance behavior of the studied mixtures. Creep testing results have revealed that the creep compliance power law parameters have a strong relationship with mixture type and moisture conditioning period. The creep resistance of the studied mixtures, as indicated by the creep compliance parameters, decreases as the moisture conditioning period increases. Results also revealed an enhancement in the creep resistance, Marshall stability, indirect tensile strength and compressive strength for mixtures containing cement dust as compared to mixtures with traditional lime stone filler.