THE EFFECTS OF USING FOAMED BITUMEN AND BITUMEN EMULSION IN THE COLD RECYCLING TECHNOLOGY

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 rehabilitated with the cold recycling technology. The aim of the research project was to determine the impact of foamed bitumen and bitumen emulsion content on the physical and mechanical properties of the base course with the cold recycling technology and to determine its water and frost resistance. The bitumen binder was added to the recycled material in the amount of 2.0% to 3.5 % with changes every 0,5%, and hydraulic binder (cement) of 1.0%. The test showed that the application of foamed bitumen in the base course materials results in an improvement its mechanical properties (Marshall stability and stiffness, static creep modulus and indirect tensile strength) in comparison to bitumen emulsion. The measurements of water and frost resistance (according to AASHTO 1283) and the resistance to low temperature cracking (according to PANK 4303) have showed that the use of foamed bitumen results in higher resistance to these climatic factors than in case of the application of the bitumen emulsion as a binder in the cold base course mixes.