Significance of RAP Content and Foamed Binder Content on Mechanistic Characteristics of Recycled Foamed Bituminous Mixes

To reduce the energy consumption and CO2 emissions during asphalt production, several environmentally friendly technologies have been developed during the last years. One of these technologies is the cold recycling by using foamed bitumen. Foaming the bitumen reduces the binder viscosity temporarily and increases the volume as well. Homogenous foams are produced by injection of cold water into hot bitumen. The paper presents the results of laboratory testing of the physical and mechanical parameters of the recycled mixes using the foamed bitumen and resistance to the action of water. The aim of the tests was to evaluate the properties of the mixes in terms of the RAP Content and Foam Binder Content. To evaluate the significance of impact of both factors i.e., Foam Binder Content and RAP Content on the distribution of the analyzed parameters, two-way Analysis of Variance (ANOVA) was performed. ANOVA Analysis results suggest that the RAP in cold mixes is not completely acting as black rock implying that some portion of the residual aged binder is possibly rejuvenated or softened by adding new binders.