LOW TEMPERATURE MEASUREMENT OF ASPHALTS FOR VISCOSITY AND DUCTILITY

The main purpose of this research was to search for a method of characterizing asphalt viscosity at temperatures of 77 F and below. A cone-plate viscometer was found to be useful for measureing viscosities down to about 23 F and up to 140 F. This, combined with measurement procedure for glass transition temperature of asphalts (which was developed by Tons and Funazaki in 1972-73 studies), provides a proceudre for showing asphalt viscosity between 140 F and temperatures below 0 F (at the glass transition point). Once such viscosity curves are available, they can be correlated with field performance and specified limits for different grades of asphalts can be established. The work also involved preliminary viscosity-penetration studies at 77 F for establishing criteria for changing to viscosity grading of asphalts in Michigan.