Published in 1998
This laboratory study compared several methods of selecting the optimum asphalt content of surface mixes. Six surface mixes were tested using the 50-blow Marshall design, the 75-blow Marshall design, two brands of SHRP gyratory compactors, and the U.S. Army Corps of Engineers' gyratory testing machine (GTM) with the oil-filled and the air-filled rollers. The Georgia loaded wheel tester (GLWT) was also used in an attempt to define the maximum allowable asphalt content. The GTM with the air-filled roller and the 75-blow Marshall design produced the largest differences in optimum asphalt content. The two SHRP gyratory compactors gave comparable contents. The lack of rutting with the GLWT at a high asphalt content prevented determining the maximum allowable asphalt content and fulfilling the primary purpose of the study. However, other findings were of interest.
Last updated: December 15, 2023