EFFECT OF MODIFICATORS ON THE PROPERTIES OF BITUMEN AND ASPHALT CONCRETE

The work is devoted to the search for new effective modifying additives that allow to purposefully regulate the technological properties of bitumen and the physicomechanical parameters of asphalt concrete based on combinations of modifiers and bitumen, which are at the same time a structure-forming agent of multicomponent asphalt concrete. It is proposed to use a block-copolymer of styrene and butadiene - SBS and a copolymer of ethylene-vinyl acetate - EVA as high-molecular modifying additives in road bitumen. The influence of modifiers Europrene SOL T 6302 based on styrene-butadiene and ethylene vinyl acetate thermoplastic brand LG EVA EA 28400 based on ethylene vinyl acetate on the main parameters of polymer-bitumen binder and performance characteristics of asphalt concrete has been studied. As the content of the modifier in the bitumen increases, the immersion depth of the needle increases and the softening temperature rises to 58 degrees C, the brittleness temperature decreases to -32-35 degrees C, and the range of operating temperatures of the road surface expands significantly. Research shows that SBS copolymer is thermoplastic elastomer and it gives comparatively better results than EVA. As a result of the study of adhesion properties, it was found that the addition of polyethylene polyamine containing 1.5% MasterLife PVA 100 significantly improves the compatibility and adhesion of bitumen to mineral materials. However, an increase in the content of MasterLife PVA 100 above 2% leads to a structural change and deteriorates the quality of asphalt concrete pavements. Studies have shown that the use of a polymer modifier improves many properties of asphalt concrete. So, in particular, the heat and frost resistance, wear resistance of asphalt concrete in the aggregate improves, affecting the increase in their operational life. According to the results of the study, the optimal ratios of polymer-bitumen binders (bitumen 95.5% + SBS 4%+ + MasterLife PVA 100 1.5%) in the composition of the asphalt concrete pavement, ensuring their high operational properties, have been revealed.