Use of carbon black as a modifier for petroleum bitumen

The problem of recycling worn-out tires and recycling of solid carbon-containing residue from the pyrolysis of tires is considered. The possibility of processing carbon black from the pyrolysis of tires into a high-quality concentrate, which can serve as a raw material for modifying petroleum bitumen, has been shown. The nature of the interactions occurring between the components of carbon black and the matrix of petroleum road bitumens has been studied. The chemical interaction of carbon black with the bitumen matrix through unsaturated C=C bonds has been proven. The introduction of carbon black as a modifying additive leads to a significant change in the physical, mechanical and rheological properties of the resulting bitumen binder systems. Based on spectrometric studies, an assessment is made of the structural changes occurring in the original and modified bitumen during the production of modified bitumen binders. It has been established that with such modification, diffusion of aromatic hydrocarbons occurs from the bitumen component into the modifier particles. During the modification process, six-membered cyclic aromatic compounds are formed in the bitumen part, the composition of paraffin-naphthenic hydrocarbons changes, and sulfur compounds are formed that “transfer” from the modifier particles to the bitumen. Thus, in this study, the phenomenon of mutual diffusion between bitumen and CBWT modifier was confirmed using IR spectroscopy.