SYMPOSIA PAPER Published: 01 January 1995

Properties of Microwave Recycled Asphalt Cement Binders


Recycling asphalt concrete pavements are currently limited to about 40 to 60 percent of recyclable asphalt pavement (RAP) in the mixture, with the remaining material composed of new asphalt and aggregates. The use of microwaves for heating allows the possibility of recycling with 100 percent RAP material. The effect of microwaves on asphalt cement binders was evaluated using conventional viscosity and penetration tests. The binders were also evaluated using Gel Permeation Chromatography (GPC), Fourier-Transform Infrared Spectroscopy (FTIR), and Dynamic Shear Rheometer (DSR). Viscosity and penetration testing provided opposing results with each showing slight increases in value after microwaving of the binder. A noticeable change in the molecular size distribution was observed with the GPC with the addition of a recycling agent. An increase in G* occurred at high temperatures or low frequencies after microwaving. This increase was more pronounced on severely oxidized or hardened asphalts. The increase in G* did not correlate well with measured viscosity and penetration values. The steady-state viscosity values obtained followed the same general trend as the results from conventional viscosity testing.

Author Information

Shoenberger, JE
U.S. Army Engineer Waterways Experiment Station, Vicksburg, MS
Rollings, RS
U.S. Army Engineer Waterways Experiment Station, Vicksburg, MS
Graham, RT
U.S. Army Engineer Waterways Experiment Station, Vicksburg, MS
Price: $25.00
Contact Sales
Reprints and Permissions
Reprints and copyright permissions can be requested through the
Copyright Clearance Center
Developed by Committee: D04
Pages: 199–213
DOI: 10.1520/STP18196S
ISBN-EB: 978-0-8031-5303-5
ISBN-13: 978-0-8031-1988-8