Effect of Composition Peculiarities of Shungite From Various Deposits on Structure Formation of Polymer Modified Bitumen Binder

Abstract

For reduction the amount of expensive polymers and improving the technological, physico-mechanical, thermophysical and other properties of road materials fillers are introduced into polymer modified bitumen binders (PBB). Therefore, in recent years the interest in natural materials that are similar in composition and have comparable characteristics to synthetic products has been increased. In relation to graphene structures used to modify bitumen and polymers, shungite is seems to be a good alternative, the rock that is essentially a composite material from mixture of shungite carbon and mineral phases. When shungite powder using as PBB modifier the distinctive features of the shungite composition should have a positive effect on the structuring of a bitumen matrix in the presence of a polymer. Since the most important structural component of the rock is carbon, the purpose of this work is to study the effect of shungite carbon from rocks of various deposits on the structure formation of the polymer modified bitumen binder. A set of studies (differential scanning calorimetry, Raman spectroscopy, energy dispersive spectroscopy based on a scanning electron microscope) has established that carbon from samples from seven deposits of Karelia is characterized by varying degree of ordering of graphite-like (sp2-carbon) structures depending on the sampling location. An increase in the amount of carbon in the composition of shungite powder and a decrease in the degree of ordering of its structure determine higher values of the specific surface area and a greater effect from modification when adding fillers into the polymer modified bitumen binder. Samples from the Zazhoginsky deposit are the most active fillers with a high modifying effect, which maximally improve the cohesive strength of the composite organic binder and structure the system by the best way. The powders from rocks from other deposits also have the positive effect relative to the base PBB, but with less efficiency. All this indicates the prospects of the proposed modification.