Rejuvenation of Scarified Bituminous Pavement Materials

Reclaimed Asphalt Pavement (RAP) material, obtained from scarified pavements, offers a sustainable solution for reducing the reliance on virgin aggregates in pavement construction. However, to ensure the desired physical properties, appropriate processing of RAP becomes crucial. This study focuses on analysing the effectiveness of cutback, emulsion rejuvenators and hot recycling methods, specifically targeting a higher percentage (50 and 75%) of RAP materials and the possible environmental effects caused by the rejuvenation processes. In the hot recycling method, RAP materials are heated to a temperature range of 140–150 °C to melt the aged binder before being mixed with virgin aggregates and in the pre-heated method, emulsion is heated prior to blending to remove the moisture. Percentages varying from 2 to 5% of cutback and emulsion were used for cold rejuvenation. The properties of the rejuvenated mixes were assessed using Indirect Tensile Strength (ITS) and wheel tracker test, supplemented by Fourier-transform infrared spectroscopy (FT-IR spectroscopy) to evaluate the environmental impact of the rejuvenation processes. Some of the rejuvenated mixes produced through hot recycling and pre-heated emulsion exhibit notably low ITS values and some combinations did not indicate any rejuvenation possibilities. However, 50% RAP mix rejuvenated 4% emulsion demonstrates superior results in terms of ITS and rutting resistance. Cutback showed very low rejuvenation properties with decreased ITS value and increased rutting potential than emulsion rejuvenated mixes. The evolution of harmful hydrocarbons during the rejuvenation process was confirmed by FT-IR spectroscopy, necessitating further investigation to quantify the evolution of these gases.