%0 Journal Article
%T Tribological Evaluation for an In
%A Biswajit K. Bairgi
%A Rafiqul A. Tarefder
%A Umme A. Mannan
%J Transportation Research Record
%@ 2169-4052
%D 2673
%R 10.1177/0361198119835510
%X Asphalt binder acts as a lubricant between two aggregates during mixing and compaction. The frictional behavior of asphalt binder as a lubricant in an asphalt-aggregate system plays an important role in mixing and compaction (workability) of warm-mix asphalt (WMA). This study evaluates the frictional behavior of foamed WMA through tribological characterization using a ball-on-three-plates apparatus assembled inside a dynamic shear rheometer (DSR). The tribological test was conducted on six foamed asphalts with varying foaming water contents (FWCs) and on a controlled unfoamed asphalt binder at four different temperatures: 25ˇăC, 60ˇăC, 100ˇăC, and 135ˇăC. These binders were also characterized for rheological and chemical properties. Test results show that the foaming process alters the frictional resistance of the foamed asphalts; specifically, the foaming process reduces the coefficient of friction in elastohydrodynamic and hydrodynamic lubrication regimes. Reduced frictional resistance helps in the formation of a better coating during mixing and improves the sliding ability between aggregates during compaction at reduced temperature
%U https://journals.sagepub.com/doi/full/10.1177/0361198119835510