The paper provides results from a research project and related trial section which was focused on assessment and mix design optimization if reclaimed asphalt is used in stone mastic asphalt mixtures in a content up to 50 %. Experimental testing focused on asphalt mixtures which were gained during paving of a trial section which was divided into several subsections. These subsections differed in used bitumen, RA content as well as in several types of additives used in the SMA mixtures. At the same time cores were taken after one year operation from the trial section and selected tests were repeated and compared to the mixtures gained during the paving. In both cases some of the test specimens were additionally aged in the laboratory as well. The performance characterization of the asphalt mixtures was focused mainly on stiffness and resistance to crack propagation. Selected results are discussed in this paper and some recommendations will be given with respect to potentials or threats related to use of reclaimed asphalt in SMA mixtures.

SMA mixture; reclaimed asphalt; performance tests; stiffness; cracking behaviour