GAS PERMEABILITY MEASUREMENTS ON ASPHALT USING THE ELECTRODYNAMIC BALANCE. IN: AMERICAN CHEMICAL SOCIETY SYMPOSIUM ON CHEMISTRY AND CHARACTERIZATION OF ASPHALTS, AUGUST 1990, WASHINGTON, D.C.

A novel experimental method developed for the measurement of the transport properties such as the diffusion coefficient, D, solubility, S, and permeability, P, for oxygen into asphalt materials using an electrodynamic balance is described. Both unaged and aged rolling thin-film oven test (RTFOT) asphalt particle samples in the 12 to 62 micrometer size range were suspended contactless and weighted in the balance to measure D, S, and P in the temperature range 17 degrees Celsius to 66 degrees Celsius. Volatilization rate data were obtained from the particle mass measurements made prior to the start of the sorption experiments. Sorption curves obtained in this study for unweathered asphalt samples showed a non-Fickian, two-stage type sorption behavior indicating the possibility of an additional mechanism other than diffusion. Analogous behavior in sorption was observed for weathered samples.