Bitumen chemical modification by a thermoplastic polymer

Abstract

Oil road bitumen was modified by a copolymer of ethylene with vinyl acetate (EVA) and 3-glycidyloxypropyltrimethoxysilane (epoxysilane). These modifiers were simultaneously introduced into the BND 90/130 oil bitumen at a temperature of 165 °C. The components were mixed up during two hours with further isothermal holding at the same temperature during the required period. Epoxysilane crosslinks bitumen with EVA making it possible to obtain an immiscible bitumen polymer binder. The optimal content of EVA is 12 mph, epoxysilane -3 mph with a mixing time of 4 hours. The optimal bitumen polymer binder is characterized by the following properties: softening point of 66 °C, penetration at 25 °C = 50, penetration index of 2.15, brittleness temperature of -22 ° C. Separation is significantly reduced. NMR spectroscopy has revealed that the introduction of the binding agent to the bitumen-polymer binder does not create low-mobile structures. It allows forecasting the high binder stability during storage and transportation.