While there have been a several studies observing asphalt binder microstructure using the Scanning Electron Microscope (SEM) and Environmental Scanning Electron Microscope (ESEM), these have been few and far between. Thus, a procedure for the induction and identification of the microstructure has yet to be established. A suitable heat-sampling asphalt binder sample preparation method was determined for the test and a stainless steel sample holder developed. The magnification and ESEM settings conducive to observing the microstructure were determined through a number of observations. Both straight run binder (PG 58-28) and an air blown oxidized binder were analysed; their structures being compared for their relative size, abundance and other characteristics, showing a clear evolution in the fibril microstructure. It was confirmed that the fibril microstructure corresponded to actual characteristics in the asphalt binder. The results of this test will be used as the basis for a more comprehensive study on the ability of the ESEM to observe various asphalt binders, predict their rheological properties and performance-related parameters.
