Effect of Nanostructured Shungite on the Rheological Properties of Bitumen

Improving the physico-mechanical characteristics of bitumen is a constant and pressing problem in road construction. The issue is solved by modifying bitumen with various additives, one of which is a nanostructured modifier. This paper examines the effect of adding a natural mineral, shungite, to bitumen from the Koksu deposit (Kazakhstan) after grinding under different conditions. The mechanochemical activation of shungite made it possible to obtain samples with an average particle diameter of up to 3 μm. Using scanning electron microscopy, nanostructured particles with sizes of up to 100 nm were discovered in their structure. The effect of nanostructured shungite on the rheological characteristics of bitumen—elasticity and loss moduli, and loss tangent at high and low temperatures—was studied. The transition temperatures of bitumen from the viscoelastic to the liquid state were established, and their shift to the region of elevated temperatures when modified with ground shungite are shown. The presence of organic and inorganic components in the composition of shungite—carbon, silica, and metal oxides—has a beneficial effect on the rheological properties of bitumen by forming bonds with resinous asphaltene components of bitumen. The use of bitumen modified with nanostructured shungite makes it possible to replace the polymer modifier with a natural mineral to improve the quality of the road surface.