The viability of using an air meter (type b) for determining themaximum theoretical specific gravity (mtsg) of asphalt mixtures wasevaluated. The air meter normally has been used for determining thepercentage of air in fresh portland cement concrete. A series of experiments were performed using this new method (herein called the "pressure method") and the current standard (rice) method. The primaryexperiment involved determining mtsg by two methods on 10 asphalt mixtures with varying asphalt contents. There was good correlation and no significant difference in the performance or precision between the two methods. There was little difference in obtaining the optimum asphalt content by the two methods. The results of the additionalexperiments with aggregates from three different sources indicated no difference in precision between methods or operators. Suggestionswere made for modifying and improving the air meter for pressure method testing, to add versatility in the options for determining the mtsg of asphalt mixtures (and other materials of a porous or water-absorbent nature). This paper appears in transportation research record no. 1269, Asphalt mix materials and mixtures 1990.
Abstract