Viscoelastic characterisation of asphalt-aggregate mixes in diametral compression

An approach is offered for extracting linear viscoelastic (VE) properties of asphalt-aggregate mixes in diametral compression. The modelling treats the material both as VE (solid) and viscoplastic (VP), while the suggested scheme aims at inferring 'pure' VE properties by removing the interlaced VP effects. The characterisation calls for exposing the specimen to several load-unload-rest cycles, and then matching the measurements in the time-domain with an appropriate forward solver - controlled by a non-linear optimisation algorithm. A case study is presented to demonstrate the required testing protocol and subsequent analysis. Overall, the approach is deemed viable, capable of identifying the material's VE properties over a very broad time interval even when operating under a single temperature level.