A New Test to Evaluate In Situ Raveling Susceptibility of Bituminous Mixtures

This paper describes how, among the different surface distresses dealing with bituminous mixes, raveling involving the dislodgement of aggregates from the surface induced by traffic is one of the most relevant and complex. Several laboratory tests have been proposed in order to evaluate raveling potential of bituminous mixes and to study mix improvements, but none of them can be applied for in-situ bituminous mixes. In this paper a new test for the evaluation of in-situ raveling potential is proposed. The test is based on several tire sweep cycles performed on pavement surface by means of steering maneuvers carried out with fixed heavy vehicles. The material loss induced by tire sweep test has been expressed as a function of dissipated frictional energy and of bituminous mix properties. Preliminary results derived by several field tests seem to indicate that this procedure may provide significant information in evaluating the raveling potential of surface bituminous mixes without employing especially devoted devices but by making use of conventional vehicles.