Influence of mixing procedures on the performance of asphalt mixtures with high reclaimed asphalt content

摘要

Primarily environmental and secondly economic reasons guide the utilization of high amount of reclaimed asphalt (RA) in new mixtures. When RA is added in higher percentage, above 25%, the aged properties of the RA binder can cause many difficulties. Risk of lower workability and insufficient homogeneity are highly reliant on the mixing procedure. Therefore, four different mixing procedures have been evaluated in the laboratory. RA is a continuous graded bituminous mixture that can be further fractioned and for that reason, in this study, RA is separated into finer and coarser particles. The basic principle is the addition of the basic components in different sequence. Consequently the mixtures were assessed in terms of compactability and mechanical properties, i.e. water sensitivity, stiffness modulus and fatigue. This paper discusses the dependency of the compactability and the performance of bituminous mixtures with RA to the mixing procedure.