Investigation on the influence of air voids and active filler on the mechanical response of bitumen stabilized material

Cold in-place recycling technology for reclaimed material in pavement rehabilitation holds promise as a solution to resource scarcity. This paper reports results of a systematic experimental investigation of the material produced by this technique and in particular the role of cement and air void content. The internal structure is characterized using computed tomography and environmental scanning electron microscopy. A tension and tension-compression test is carried out to characterize the response of the material at 15 and 45°C. From microscopy, it is seen that the addition of cement did not result in formation of hydration compounds, but instead aids in densifying the material substantially. From the mechanical experiments, it is seen that the response of the material is clearly viscoelastic at the temperatures at which it is tested. The experimental data are used to find relevant linear viscoelastic parameters, and a methodology to compute these parameters directly is presented.