Accelerated aging tests for asphalt concretes

To clarify the effect of aging on properties of asphalt concretes, a series of laboratory tests were conducted. In the study two accelerated aging processes, that is, heat aging and oxygen aging, were applied and exposure in natural conditions (oudoor) was also used for comparison purpose. After the aging processes, the asphalt concrete samples were examined to clarify the influence of aging on their properties from various viewpoints. It is indicated that though asphalt concretes are hardened by both heat aging and exposure at outdoor, the mechanism of hardening seems greatly different. Even if the heat aging method can be used to evaluate hardening of asphalt concretes in mechanical properties, it cannot be used to evaluate the changes in physical and chemical properties of asphalt. To replicate the aging of the asphalt itself similar to that by exposure at outdoor, the oxygen aging method is useful. However, the mechanical properties of asphalt concrete cannot be well simulated by this method. As a result, a combination of heat aging and oxygen aging might be adapted to simulate an actual aging. For the covering abstract see ITRD E117423.