Restoring and strengthening existing bridges is more economically and environmentally feasible, as cement production in new RC bridges significantly contributes to CO₂ emissions. Additionally, the production of composite carbon materials for strengthening RC structures does not require a large amount of energy, unlike the production of steel for reinforcement, which requires a significant amount of electricity and, accordingly, causes a significant amount of CO₂ emissions. This is why this article presents a comprehensive review of the damage, calculations, and strengthening of RC bridge structures. It examines the main types of damage, including mechanical impacts, material fatigue, corrosion processes, seismic actions, and thermal loads. The mechanisms of their formation, correlations with environmental factors, and operational conditions are detailed. Examples of damage from real engineering objects are provided to assess the scale of the problem. Approaches to the calculation of RC bridge structures are analyzed, particularly methods for modeling the stress–strain state, considering crack formation and material degradation. Key studies by Ukrainian and foreign researchers are highlighted, identifying areas for further methodological improvement. Special attention is given to traditional and modern strengthening methods, including the use of steel elements, composites, and carbon strips. A comparative analysis of the effectiveness of different strengthening approaches is conducted. The conclusion emphasizes the need for further development of existing diagnostic, calculation, and strengthening methods. The integration of innovative materials and technologies is particularly relevant for enhancing the durability of bridges under modern operational loads.

The information in this study is based on a thorough review of recent articles related to the production of binders for road construction and the improvement of their performance properties. The main attention is paid to the physical modification of road bitumen with polymer modifiers. The influence of the three main types of polymers (thermoplastics, elastomers, and thermoplastic elastomers) on the main physical and mechanical properties of bitumen-polymer compositions is shown. The main technological parameters and features of the physical modification of bitumen by different types of polymer modifiers have been determined.

This article deals with the results of the study on the effect of technological parameters of the Butonal NX4190 cationic polymer latex modification on the physical and mechanical properties of road bitumen and various types of hot dense asphalt concrete and crushed-mastic asphalt concrete. The modification technological parameters were the content of the modifier and the modification time. The modification temperature was constant. The optimal amount of polymer latex for modification was determined according to the criteria for improving the physical and mechanical properties of bitumen and asphalt concrete.

The expediency of involving large‐tonnage sulfur production waste from Rozdil Mining and Chemical Enterprise Sirka (Ukraine) in road surface production has been substantiated theoretically and practically. In particular, the possibility of using waste from sulfur ores flotation enrichment and sulfur filtration purification from ash and organic impurities and their mixtures in the production of modified hot mix asphalt were investigated. It was found that sulfur content changes in bitumen can influence its operational properties: at sulfur concentrations of 5 wt. %, it acts as a plasticizer and at sulfur content ≥ 20 wt. %, it behaves as a filler. There are reasons to state that it is most effective to introduce sulfur into asphalt concrete (AC) as filler aggregate directly in the preparation process of sulfur asphalt mixes in an asphalt mixer. It is shown that the strength of sulfur AC grows over time and reaches maximum values within 15 days. It has been established experimentally that the use of highly sulfur‐concentrated filler aggregates instead of traditional limestone minerals significantly improves the main operational characteristics of AC, in particular: strength at a temperature of 20°C and at a temperature of 50°C; heat resistance; bitumen content to achieve regulated residual porosity is reduced. It was demonstrated that increasing the sulfur content in filler aggregate makes it possible to reduce the bitumen content in AC. Pilot construction of road pavements was conducted, which confirmed that sulfur AC has better operational characteristics compared with regular AC.

The growing emphasis on sustainable road construction has stimulated interest in environmentally friendly bitumen modifiers. This study presents the development of biodegradable adhesion promoters synthesized via the amidation of renewable raw materials (rapeseed oil and higher fatty acids) with polyethylene polyamine. The main objective was to improve bitumen–aggregate adhesion while maintaining the essential physico-mechanical and rheological properties of the bitumen. The synthesized bio-based adhesion promoters were incorporated into penetration-grade bitumen at a dosage of 0.4 wt.%. Physico-mechanical testing confirmed that their inclusion does not significantly affect the fundamental properties of the bitumen, while substantially enhancing adhesion to both glass and mineral aggregates. Rheological analysis showed that the rapeseed oil-based adhesion promoter had minimal influence on viscoelastic behavior. In contrast, the fatty acid-based promoter increased the rutting resistance parameter (|G*|/sinδ) and decreased the phase angle (δ), indicating improved resistance to permanent deformation. FTIR spectroscopy further revealed that the fatty acid-based adhesion promoter significantly reduced the formation of carbonyl groups during short-term aging, suggesting a retardation in oxidative aging and potential rejuvenating effects. In conclusion, the proposed bio-based adhesion promoters, derived from renewable sources and fully biodegradable, represent a promising solution for enhancing bitumen performance and supporting the durability and sustainability of asphalt pavements.

This study examines the effect of cationic bio-based adhesion promoters (APs) derived from rapeseed oil (RO) on the performance of bitumen and asphalt mixtures. Several synthesized APs with varying polyamine content were evaluated and compared with commercial additives (Wetfix^® BE, Nouryon, Netherlands and Carbazole AK-M, SPETSKONTRAKT, Kyiv, Ukraine). Modification of bitumen with bio-based APs improved adhesion to glass and crushed stone while keeping penetration, softening point, and ductility within standard limits. Among the tested formulations, AP20 demonstrated the most balanced performance, achieving high adhesion values even at low dosages (0.2–0.4 wt. %). Asphalt concrete mixes prepared with AP20 exhibited enhanced water resistance and higher indirect tensile strength ratio (ITSR), indicating improved durability under moisture exposure. These findings highlight the potential of rapeseed oil-based adhesion promoters as effective and sustainable alternatives to conventional anti-stripping agents in road construction.