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The present article investigates in laboratory conditions the effect of cyclic freezing and thawing (CFT) on characteristics of the neat bitumen and bitumens modified with different polymers, as well as stone mastic asphalt concretes prepared with the use of the neat and the modified bitumens. Maximal and minimal temperature in cycles of freezing and thawing (FT) is accepted equal to +20 • C and −18 ± 2 • C respectively. Characteristics of low temperature resistance of bitumens (stiffness S and m-value) have been determined on bending beam rheometer at the temperatures of −24 • C, −30 • C, and −36 • C. Strength at direct tension of the stone mastic asphalt concretes has been evaluated in the device TRAVIS (Infratest Ltd., Brackenheim, Germany) at the temperatures of 0 • C, −10 • C, −20 • C, and −30 • C. Resistance of stone mastic asphalt concretes to rutting has been determined on a Hamburg wheel tracking machine. The characteristics of the bitumens have been determined in the initial condition and after 25 and 50 cycles of FT, and the characteristics of stone mastic asphalt concretes, in the initial condition and after 50 cycles of FT. The results obtained experimentally have shown that CFT impacts essentially on the investigated characteristics of bitumens and stone mastic asphalt concretes. Modification with polymers improves the mechanical characteristics of the bitumens and decreases the effect of CFT. It is also found out that when selecting a bitumen for specific climatic conditions it is necessary to take into account both the number of cycles of FT and the characteristic low temperature.

The paper represents the research results for the process of crude oil-contaminated soil neutralization with the use of a neutralizer obtained on the basis ofhumic substances. Using physical methods (gas and liquid chromatography, fluorimetry, atomic absorption spectrometry, IR spectrometry), the element and group compositionswere determined for the crude oil-contaminated soil, neutralizer, and neutralized soil. Optimal parameters were determined for the process of the crude oil-contaminated soil neutralization under laboratory conditions:weight ratios of the crude oil-contaminated soil, neutralizer and water, and the temperature and neutralization process duration. The technological scheme was developed for the neutralization of the crude oil-contaminated soil in field conditions. It was found that low-boiling point hydrocarbon fractions (C12–C17) disappear completely at neutralization, the content of high-boiling point hydrocarbon fractions (C20–C23) is essentially increased, and the content of oil components and metals, including the toxic ones, is decreased. The engineering characteristics for nine mixtures of the stabilized soil, containing the neutralized soil, were evaluated under laboratory conditions and the conditions were determined for their use in road construction (with regard to road category, characteristic pavement layer, minimal air temperature). An experimental road section was constructed with the use of the stabilized soil with neutralized soil (40%).

Physical and chemical indicators of bitumen quality of grade BND 70/100 with the added carbon nanopowder 2% by weight have been studied by laboratory test methods and analysis. High reaction ability of nanopowder particles and concentration of excess surface and internal energy in them have been determined, which provide the increase of low-temperature resistance, aggregate strength, and improvement of rheological properties of nanostructured bitumen. Essential structure variation has been proved: the increase of asphaltenes and oils content for 9% and 7.2% respectively due to the decrease of resins for 16.2% by weight. Methods have been discussed for preparing a liquid nanocarbon mix, adding of the mix into bitumen and homogenization of the bitumen. Some economic indicators have been represented which influence essentially the reduction for the cost value of the nanostructure bitumen.