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The paper presents the results of the study of the effect of a Fischer-Tropsch (F-T) synthetic wax on the resistance to permanent deformation of the AC 11S asphalt concrete. The synthetic wax was dosed at 1.5%, 2.5% and 3.5% by weight of bitumen 35/50. The compaction temperatures were 115°C, 130°C and 145°C. The criteria adopted for measuring the resistance to permanent deformation included the following parameters: stiffness modulus at 2, 10 and 20°C, permanent deformation (RTS), fatigue life determined using the indirect tensile fatigue test (ITFT) and resistance to rutting (WTSAIR, PRDAIR). The test results confirmed the positive influence of F-T synthetic wax on enhancing the permanent deformation resistance of asphalt concrete placed at lower compaction temperatures compared to that of standard asphalt concrete compacted at 140°C.

The technology of recycling with foamed bitumen is a new technology of road rehabilitation. Due to the climatic conditions in the Central European countries road pavement structure should be water and frost resistant. This problem is especially important for pavements rehabilitation with the cold recycling technology because of their specific production conditions. Determining the physical and mechanical properties as well as water and frost resis- tance depending on the binder and filler contents is an essential element before its introduction to road building. The tests were performed on mineral recycled base mixes with foamed bitumen, in which the material from the existing layers was used. The content of bitumen binder amounted to 2.0 %, 2.5 %, 3.0 % and 3.5 %, while of cement 1.0 %, 1.5 %, 2.0 %, 2.5 %. The results obtained were subjected to the optimization process, which allowed to state that with the application of 2.5 % foamed bitumen and 2.0 % of cement the base has the required physical and mechanical properties as well as water and frost resistance according to the applied criteria.