This study investigates the effect of a complex modifying admixture on the capillary water absorption and setting times of cement stone. The experimental program included the determination of capillary water absorption intensity at both early and advanced stages of saturation, as well as the evaluation of the initial and final setting times of cementitious binder containing different dosages of the admixture. The results demonstrated that increasing the admixture content leads to a significant reduction in capillary water absorption intensity. This effect was observed both during the initial stage of testing and at longer saturation periods, indicating a decrease in capillary porosity and the formation of a denser cement stone structure. The improved microstructure is attributed to the microfilling action of silica fume and the hydrophobic effect of the organic components incorporated in the admixture. The setting time analysis showed that the application of the complex admixture has a negligible influence on the standard hardening characteristics of the cementitious binder. A slight tendency toward accelerated initial setting was observed with increasing admixture dosage, whereas the final setting time remained almost unchanged. Therefore, the use of the complex admixture contributes to reduced capillary water absorption and the development of a denser cement stone structure while maintaining acceptable technological setting parameters.

This study investigates the development and optimization of a multi-component modifying additive based on industrial waste for improving the mechanical and durability properties of concrete. The additive consists of microsilica (Ms), phosphogypsum (PhG), soapstock (Sp), and post-alcohol bard (PaB), and its performance was evaluated using a staged experimental approach. The results showed that the optimal content of microsilica is 20% of the cement mass; the optimal content of phosphogypsum is 15% of the combined mass of the cement and microsilica; the optimal content of soapstock is 10% of the total mass of the cement, microsilica, and phosphogypsum; and the optimal post-alcohol bard is 5% of the water mass. At these concentrations, the compressive strength increased by up to 28.3% compared to the reference sample. Soapstock significantly reduced water absorption (up to 36.8%) and improved freeze–thaw resistance due to the hydrophobization of the cement matrix. However, excessive soapstock content led to a reduction in strength. The addition of post-alcohol bard provided a plasticizing effect and reduced water absorption, with the optimal concentration for strength being 2.5%, while the highest freeze–thaw resistance was observed at 5%. The combined effect of the components resulted in the formation of a denser microstructure and improved durability of concrete. These findings demonstrate the effectiveness of industrial waste-based additives in enhancing concrete performance and durability, contributing to sustainable material development.

This article presents part of a model study on the abrasion resistance of an anti-icing agent impregnation composition, related to the calculation and modeling of stresses transmitted by a model wheel to a concrete road, taking into account actual indicators and scaling. The aim of the research was to assess the normal stresses arising from the impact of motor vehicles, taking into account the variability of the contact patch resulting from a decrease or increase in tire pressure. Calculations were performed for different types of vehicles, from bicycles to trucks, which were conditionally divided into categories A1-A5 (in ascending order of vehicle weight). The calculation results are presented as ranges of normal stresses on the road surface caused by the operation of motor vehicles, depending on their type and standard load capacity. The calculations were performed using the linear graph method of universal tire characteristics, taking into account normal deflection and variable potential pressure in the tire. The obtained calculation results will allow for more accurate development of calculation schemes in numerical or large-scale modeling of road situations.

This study presents the development and experimental evaluation of an impregnation composition for cement concrete pavements aimed at improving ice-phobic performance while preserving tire–pavement adhesion characteristics. The formulation is based on a combination of keratin-containing raw materials and water-soluble polymer components. Optimization showed that a polymer concentration of 2.5% reduces concrete water absorption by 49–53% compared with untreated specimens. Freezing tests conducted at temperatures of 0 to −5 °C demonstrated an additional reduction in water absorption of treated specimens by 33–40% relative to uncoated concrete and improved resistance to ice formation. The influence of the impregnation on tire–pavement interaction was assessed using a direct shear method, revealing minor changes in friction coefficients of up to ~6% for polished and less than 1% for rough surfaces, remaining within acceptable safety limits. Wear resistance was evaluated through rolling tests with model vehicle wheels, where laboratory abrasion occurred after several thousand loading cycles, while probabilistic correction accounting for trajectory variability indicated an extension of service life to the order of tens of thousands of vehicle passes. The results confirm the potential of the keratin–polymer impregnation as an effective approach for enhancing the durability and operational safety of concrete pavements in cold climates.

The paper presents calculations of load-induced normal stresses generated by various vehicle types for subsequent modeling of the abrasion resistance of impregnating compositions in cement concrete pavements. The aim of the study was to evaluate normal stresses arising from vehicular loading, taking into account variations in the tire-pavement contact area due to changes in tire pressure. The study evaluates normal stress levels under vehicular loading, accounting for variations in the tire-pavement contact area associated with changes in tire pressure. Vehicles ranging from bicycles to heavy trucks were classified into categories A1-A5 in ascending order of weight. The results are expressed as ranges, where lower bounds correspond to the lightest vehicles within each category at minimum tire pressure, and upper bounds correspond to the heaviest vehicles at maximum tire pressure. Tire pressure is shown to significantly affect the pavement stress state, increasing normal stresses by 28.6-30.3% (bicycles); 30.9-33.5% (motorcycles); 31.8-32.9% (passenger cars); 31.9-33.2% (light commercial vehicles); 31.9-33.3% (heavy vehicles). The presented calculations are of interest for modeling design scenarios in both experimental studies and numerical simulations. The obtained calculation results will enable more accurate development of design schemes in numerical or large-scale modeling of road scenarios.

The article presents the results of calculations of stresses caused by tire pressure on the road surface, which are necessary for modeling design situations on a scale. Calculations of actual stresses were performed based on the standard characteristics of tires, the permissible load capacity of motor vehicles, and the potentially variable air pressure in the tire. The latter has a particular influence on the change in the contour area of the contact patch. The calculation of model stresses for the model wheel was performed based on the law of dynamic similarity from the condition of the scale ratio of the actual contact area to the model area, taking into account the elastic properties of the model wheel rubber (determined by laboratory tests). The results of the study are presented as the minimum and maximum values of actual and model stresses by category (types according to main characteristics) of motor vehicles. According to the results, stresses were obtained from the model wheel depending on the type of motor vehicle (described in detail in the article), which range from 0.5 kg/cm² (bicycles) to 12.4 kg/cm² (trucks and buses). The proposed calculation method will allow simulating the calculated stresses from motor vehicle wheels for any model tests on a scale with a high degree of correspondence (to actual stresses).