Development of a Modified Rotavapor Apparatus and Method for Short-Term Aging of Modified Asphalts

Abstract

An alternative laboratory asphalt aging process that could be used to simulate the aging effects of hot mixing on modified asphalts was developed and evaluated. The rotavapor apparatus, which has been used for recovery of asphalt from solution, was modified to work as an aging device for asphalts and modified asphalts. The rotavapor apparatus was modified such that the vacuum connection was replaced by an air pump with a controlled air flow. To reduce the variation of aging condition due to variation of the temperatures in the oil bath of the rotavapor apparatus, an insulated covering for the oil bath was constructed and used in this aging process. Evaluation results indicate that the aging severity of the modified rotavapor aging process is affected by variables such as process temperature, duration, and sample weight. All these factors could be adjusted to achieve the desirable level of asphalt aging. Because of the flexibility in controlling these variables in the modified rotavapor process, it appears that this method could be used to simulate the aging effects of hot mix plant process effectively.