The influence of water on the oxidation of asphalt cements

• The interaction between water oxygen molecules and asphalt changes the asphalt properties.
• Increases in the asphalt stiffness and viscosity are observed after immersion in distilled water for one year.
• The consistency of the binder changes and its stiffness increases in the presence of water.
• Aging and oxidation are caused by the air–asphalt or air–water–asphalt interaction and by the oxygen from the water.

Two grades of paving asphalt, AC 80-100 and AC 60-70, were studied to determine changes in their physical and chemical properties caused by exposure to water. This experimental study’s primary hypothesis is that the interaction between the water oxygen molecules and asphalt, known as oxidation, changes the asphalt properties, resulting in increased damage from mechanisms such as humidity and aging for mixtures in service. The chemical responses of both asphalts were measured, and the flow activation energy concept was used to understand the resulting changes in the physical and rheological properties after immersion in distilled water for one year.